Post by: David Cooper on 16/07/2022 21:47:41
Post by: Eternal Student on 16/07/2022 23:36:34
The two black holes pass each other in such a way that at the point of closest approach the edges of the two discs pass through each other.The first problem is that conventional Black Hole solutions (e.g. Schwarzschild or Kerr–Newman Solutions) just won't continue to apply (they won't even hold as a rough approximation) when two black holes come into such close proximity.
As such it's not obvious that there would be two separate event horizons, or that they would pass through each other. As the Black Holes approach each other, a different solution to the Einstein Field Equations would be exhibited. I can barely guess what that might look like but our best models are going to be those used for orbiting black holes that eventually merge (e.g. the sort of thing that LIGO has observed).
To paraphrase this, a black hole is not a physical object like a big particle of matter. It is a much more intangible thing, it's just an unusual curvature in spacetime. When two black holes get close we can't assume anything like two Black Holes continues to exist. Instead you get a different thing, a new spacetime curvature appearing.
Now, if we have a photon moving perpendicular to that action (you should visualise this as moving straight upwards) such that it passes through the edge of both discs exactly at the moment when they pass through each other,...The problem is that there wouldn't be two recognisable EH discs in this region of space. There should be just one bigger joined up event horizon surrounding an unusual gravitational source (a source that was previously recognisable as two separate black holes when they were further away from each other).
Keeping everything simple: Any photon that enters the region bound by that (new, conjoined and bigger) event horizon should not be getting out again. (To the best of my knowledge - although I'm no expert in this. With things like Hawking radiation, a similar photon might appear in the region around the event horizon if the two original black holes do manage to pass each other instead of merging and become recognisable as separate black holes again travelling away from each other).
Best Wishes.
Post by: Halc on 16/07/2022 23:48:57
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Can a photon escape from inside the event horizon of two black holes?It wouldn't be an event horizon if it could, so no, by definition.
Picture a situation where two black holes are moving in opposite directions at just a fraction under the speed of light. Their event horizons are length contracted so much that they practically become discs rather than spheres.You're using special relativity concepts to describe something gravitational, which isn't the way to go about it. A stress energy tensor might describe the situation. You're picturing a Schwarzschild black hole in a non-Schwarzschild situtation. That doesn't work.
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The two black holes pass each other in such a way that at the point of closest approach the edges of the two discs pass through each other.Translation, two black holes with high relative velocity and similar Schwarzschild radius r pass at perhaps less than 2r of each other (coordinate separation?). Event horizons can't 'pass through each other'. Either there could be events between them from which light could escape or the event horizons merge, and it must become one black hole.
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Picture one moving towards you and the other moving away, and imagine them side by side as they pass each other - both should be deflected sideways by each other's pull, and the amount of that deflection will be related to how fast they're moving.Yes, a plot of their mass centers will curve. There will be a sort of coordinate distance between them at closest approach, and we assume that they're far enough aprat that they don't merge. You're at that midpoint, and by symmetry, you go nowhere. You live to see the day and tell others about it, so light has escaped from you, and thus you've never been within either event horizon.
Post by: David Cooper on 17/07/2022 00:45:20
The first problem is that conventional Black Hole solutions (e.g. Schwarzschild or Kerr–Newman Solutions) just won't continue to apply (they won't even hold as a rough approximation) when two black holes come into such close proximity.
As such it's not obvious that there would be two separate event horizons, or that they would pass through each other. As the Black Holes approach each other, a different solution to the Einstein Field Equations would be exhibited. I can barely guess what that might look like but our best models are going to be those used for orbiting black holes that eventually merge (e.g. the sort of thing that LIGO has observed).
Clearly if it's possible for the two black holes to pass each other at very high speed without merging if their event horizons touch, then they will for a moment have a shared event horizon with two singularities in it with the shape still being that of two discs. What I expect to hear though is that there is no way for them to pass each other if this happens and that they will always merge into a single black hole, so what I really need to know first is if it's possible for such a merger to be avoided in a case with ridiculously high speeds of travel.
In the case of a photon getting close to a black hole, it can escape even if it travels close to the event horizon, but a black hole cannot copy that as it is increasing the depth of the gravity well there with its own mass, leading to a radically different situation. That increase in depth should also lead to the event horizons warping out to touch each other and join up for a moment even in cases where it initially looks as if they'll miss, so it isn't sufficient just to consider cases where the singularities are clearly on a path to being be separated by the distance of the addition of their initial radii because paths leading to greater separations than that can lead to event horizons touching too, but again in every single case where they touch I expect the answer to be that the black holes have to merge.
Post by: David Cooper on 17/07/2022 01:05:56
You're using special relativity concepts to describe something gravitational, which isn't the way to go about it.
I'm not. I'm running a different model which matches the predictions of both STR and GTR for all predictions of externally observable events. (In that model, black holes are full of stuff all the way through rather than having singularites though, so they would physically collide.)
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Translation, two black holes with high relative velocity and similar Schwarzschild radius r pass at perhaps less than 2r of each other (coordinate separation?)
No - they can pass at greater than 2r from each other with the event horizons warping out towards each other to join up.
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Event horizons can't 'pass through each other'. Either there could be events between them from which light could escape or the event horizons merge, and it must become one black hole.
This is the whole point of the question. They join up, and what I want to know is whether in all such case that leads to the black holes merging completely or if the singularities can remain just far enough to avoid that. I'd be very surprised if cases up to 2r separation haven't all been checked already and found to result in merger, but I want to make sure that all cases greater than 2r separation where the event horizons meet by warping towards each other also result in total merger.
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There will be a sort of coordinate distance between them at closest approach, and we assume that they're far enough apart that they don't merge. You're at that midpoint, and by symmetry, you go nowhere. You live to see the day and tell others about it, so light has escaped from you, and thus you've never been within either event horizon.
There may be room for an argument about whether the event horizons join up for a moment or not in a case where the black holes don't merge and go their separate ways afterwards, but symmetry enabling your escape would not keep the event horizons apart in any case where you're at sufficient depth in the combined gravity wells of the two black holes for your clock to stop.
Post by: David Cooper on 17/07/2022 04:20:06
There may be room for an argument about whether the event horizons join up for a moment or not in a case where the black holes don't merge and go their separate ways afterwardsNo there isn't. An event horizon isn't a location in space. It's a null surface, and there's no way for two null surfaces to touch and then separate. For example, it's not possible for the future light cones of two spatially separated events can intersect and then later on not intersect.
In which case you're describing a case that fails to meet my conditions.
Post by: Bored chemist on 17/07/2022 09:23:12
the edges of the two discs pass through each other.I really don't think that can happen.
The notable thing about the event horizon is that anything in it gets "trapped" in that black hole.
If you have overlapping event horizons, how would anything "know" which hole to fall into?
As far as I can tell (and I simply wouldn't know where to start with the maths), the only way to address that is to say that if the event horizons meet, then the holes must merge.
That way our unfortunate particle that is inside both, only has one hole to fall into.
Post by: David Cooper on 17/07/2022 18:23:47
If you have overlapping event horizons, how would anything "know" which hole to fall into?
It wouldn't fall towards either singularity, but it would be inside the event horizon of both. The question here is whether the two singularities have to merge or if they can move further apart and decouple their event horizons. Here's the thing - I've been imagining tiny manufactured black holes which can be guided by moving masses near them while those masses can be held apart such that their locations can be controlled at all times with precision. We may be able to use these extra masses to prevent the black holes from being diverted off straight paths as they pass each other or at least reduce the bending of their paths enough to prevent their merger. If they fail to merge after their event horizons have connected up, those event horizons can disconnect and the photon can escape.
(Clearly those masses would be much bigger than the black holes and couldn't be moved fast enough to provide the necessary control, but I'm also imagining long chains of black holes in between the end masses with the two chains of black holes meeting at close to the speed of light in opposite directions such that each black hole in the central region of each chain always has an approximately equal pull on it from either side. Have all possible scenarios of this kind been checked carefully enough to be sure that event horizons touching always lead to their singularities merging?)
The reason I want to check whether this might or might not be possible is that it would potentially enable a difference between theories to be tested by experiment. The fuzzballs of string theory (which are like the black holes in LET) are full of stuff all the way through from the event horizon at one side to the event horizon at the opposite side of the black hole, whereas in GTR there is nothing physically there because the material continues to fall on down to the singularity. If you smash the edges of two black holes together, you don't normally get the chance to see if they are made of lots of stuff or consist of nothing because no evidence ever escapes to tell you, but if the black holes fail to merge, you could then access that evidence from a safe distance.
Post by: Bored chemist on 17/07/2022 18:42:50
It wouldn't fall towards either singularity, but it would be inside the event horizon of both.In which case it must remain in both because it can't leave the event horizon of either.
That means they can not separate.
And that means they must merge.
Once the EH overlap, there's no force that can possibly separate them. Your idea of "
tiny manufactured black holes which can be guided by moving masses near them while those masses can be held apart such that their locations can be controlled at all times with precision.breaks down at that point.
Post by: Eternal Student on 17/07/2022 19:18:24
Sorry, this is going several posts back....
Clearly if it's possible for the two black holes to pass each other at very high speed without merging if their event horizons touch.....I'm not sure what this sentence or group os sentences was saying. There's an "IF" in it. Are you asking if this is possible, or is the IF an accident and you are telling us it is possible and then the rest of the stuff described in the sentence does happen?
Best Wishes.
Post by: Bored chemist on 17/07/2022 19:31:12
Hi.The trouble is it's like saying "if circles are square then pi is 4".
Sorry, this is going several posts back....Clearly if it's possible for the two black holes to pass each other at very high speed without merging if their event horizons touch.....I'm not sure what this sentence or group os sentences was saying. There's an "IF" in it. Are you asking if this is possible, or is the IF an accident and you are telling us it is possible and then the rest of the stuff described in the sentence does happen?
Best Wishes.
I don't need to worry about how you define the diameter of a square, because the idea already failed at the first hurdle.
I don't really need to worry about the "If".
Post by: Eternal Student on 18/07/2022 03:19:43
I don't really need to worry about the "If".OK, I was just wondering how best to start replying. I don't want the replies to seem like outright disagreement throughout.
Let's start as far back as possible:
Picture a situation where two black holes are moving in opposite directions at just a fraction under the speed of light. Their event horizons are length contracted so much that they practically become discs rather than spheres.No, I don't even agree on this.
Firstly the black holes aren't intrinsically changed into discs. At best that's only how it will be for a distant observer that is not moving with the black hole. Moreover, the black hole becomes a "disc" only in some co-ordinate system which the distant observer KNOWS is almost completely useless in the region of space that is not local to the observer and yet they persist in assuming distances are determined by the Minkowski metric. In particular the metric is very different around the black hole.
Special relativity only gets you so far, let's do it and see: Let's have a black hole moving along the x-axis and centred on it. Let's have an observer fixed at x=0, they assign x-axis co-ordinates x1 and x2 to the two sides of the black hole at a fixed time. The observer never learnt any General relativity so they assume the black hole has a width along the x-axis of x2 - x1. We'll have another observer but this one will be moving with the black hole along the x-axis but starting as usual at x=0 when t=0. That observer assigns co-ordinates x1' and x2' to the two sides of the black hole and, exactly as you might expect from special relativity, x2' - x1' is going to be slightly bigger (slightly wider) than the other observer reported. The second observer is only using special relativity so they will assume that the width of the black hole was x2' - x1'. We're done.... the two observers have different widths and the black hole looks like a disc to one of them and a perfectly round sphere to the other.
Now let's add some general relativity: The Minkowski metric doesn't apply when you get too far away from x=0 because the space between the observer and the black hole (and also across the black hole) wasn't flat Minkowski space. So the distance between x1 and x2 on the x-axis is NOT equal to x2 - x1 when x2 and x1 are far away from the observer and close to the black hole.
So, just to be clear, the two observers have a different value of (x2 - x1 ) and one observer has a smaller value but neither of these quantities was the physical width of the black hole anyway.
IS THIS IMPORTANT? No, not on it's own. It's just one example where not using general relativity can lead us off the tracks early on. Just because a conventional solid object would show length contraction when it is moving relative to an observer (in flat Minkowski space) it doesn't follow that a black hole would show the same sort of length contraction.
Does a black hole become flattened and disc shaped when it is travelling relative to a distant observer? I honestly don't know. I know that it's not obvious. Shapes aren't what you might have thought in curved and non-Euclidean space. For example, even if a black hole is considered to be stationary relative to a distant observer, it's still not like a sphere as the distant observer would imagine one in 3-D Euclidean space. A black hole has no spatial centre, there's no place in space where I can put the point of my compass and start to draw a perfect circle around the black hole.
Best Wishes.
Post by: David Cooper on 18/07/2022 18:25:34
It wouldn't fall towards either singularity, but it would be inside the event horizon of both.In which case it must remain in both because it can't leave the event horizon of either.
That means they can not separate.
And that means they must merge.
That's an assertion which may be correct, but I just want to check that it's guaranteed to be correct.
If there's another black hole to the other side of each of the original two, that might make it less easy for the two in the middle to spiral round each other and merge. If we have two long lines of black holes running into each other (with each black hole aimed at the open spaces between black holes in the opposite line, all the event horizons would link up into one with lots of singularities within it, while each of those singularities is moving at a fraction less than the speed of light in the opposite direction to the singularities to either side of it with an equal pull on it from either side leading to it carrying on along a straight path, so can they really be halted quickly enough to stop them separating again? (It wouldn't be an equal pull to either side for the ones towards the ends of the line, but it would be very close to equal for the central ones.)
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Firstly the black holes aren't intrinsically changed into discs. At best that's only how it will be for a distant observer that is not moving with the black hole.
If you are observing these and see the black holes approaching each other at these high relative speeds which you measure as a fraction less than c in opposite directions, you will also measure the event horizons to be contracted so strongly that they are almost turned into flat discs, exactly as a spherical planet would be when observed to be moving at such a speed. For that not to happen, absolute speeds could be measured by the failure of those objects to conform to the maths of relativity.
Next, the complications of spacetime bending do not alter that picture at all: LET and GTR map to each other perfectly when it comes to their predictions about observations (until you're inside a black hole), and LET achieves this while maintaining Euclidean geometry throughout - it has the speed of light reduce in gravity wells instead of cramming extra space in there to make light travel further without slowing down, so we get a fully valid picture of events when we imagine two lines of discs passing each other with their edges momentarily touching, and there is very little impact on the space ahead of each disc as it travels along as all of that influence has been contracted down to a tiny distance too - the entire gravity well is contracted. This is not disputed in physics - it is what would be observed under LET, STR and GTR. You can certainly calculate under both LET and GTR that the black holes look spherical to observers moving at the same speed and in the same direction as them, but that does not negate the fact that they would be measured to be almost completely flat discs by our original observer. The edges of those discs would meet with practically no response to each other until the very last moment.
Post by: Bored chemist on 18/07/2022 19:48:07
That's an assertion which may be correct,It's not an assertion, it's a deduction.
Which bit do you disagree with?
Post by: Eternal Student on 18/07/2022 22:14:48
If you are observing these and see the black holes approaching each other at these high relative speeds which you measure as a fraction less than c in opposite directions, you will also measure the event horizons to be contracted so strongly that they are almost turned into flat discs, exactly as a spherical planet would be when observed to be moving at such a speed.and also,
You can certainly calculate under both LET and GTR that the black holes look spherical to observers moving at the same speed and in the same direction as them
There is a difference between how things "look" and how they are. You might be mixing the two.
I agree that a Black hole looks like a sphere to a distant observer moving with the Black Hole. However, it is not actually a sphere as you would imagine one in 3-D Euclidean space. The distant observer knows this if they apply the right metric. For example, the Schwarzschild metric for a black hole where I've set the Schwarzschild radius to 1 unit is given by:
ds2 =
+ terms involving the other co-ordinates t,θ, φAs I mentioned, the Schwarzschild radius was set to 1 unit and a distant observer might very well see the black hole as a sphere with a radius of 1 unit. For large r (a long way from the black hole) then the r co-ordinate does behave exactly like a measure of the radial distance from the centre of the black hole. In the local region around the distant observer, these co-ordinates are describing space perfectly adequately and naturally: To the distant observer (r, θ, φ) act like spherical co-ordinates describing flat space (the metric would be the ordinary Euclidean metric) with r as the radial distance from the black hole and θ, φ as the polar and azimuthal angle from the black hole.
Now, if the distant observer plots the location of the black hole event horizon on a piece of paper using these as if they were spherical co-ordinates in ordinary flat space then they do indeed produce a plot where the black hole looks like a sphere with radius 1 unit centred at r =0.
However, the physical distance from r = 1 to r=0 is not 1 unit of length (i.e. the physical distance from the Event horizon to where the observer would naively consider the centre of the sphere to be located). This is because these locations are NOT local to the distant observer and the metric has long since stopped approximating the Minkowski metric when r is small.
The path length from r=1 to r=0 (holding constant t, θ and φ) is determined (as usual) from the metric shown earlier:
= 
Since r ≤ 1 throughout that integral we are taking roots of a negative quantity. So the integrand is imaginary and hence the total path length is imaginary. Most significantly, it is certainly not +1 unit, the Schwarzschild radius.
Best Wishes.
Post by: David Cooper on 18/07/2022 22:57:16
If the two singularities move further apart by continuing in the direction they were moving in at the start, the depth of that photon in the gravity well will reduce and it can end up outside the event horizon.That's an assertion which may be correct,It's not an assertion, it's a deduction.
Which bit do you disagree with?
I've been thinking a bit more about the case with a line of black holes, and I've now found a situation where you can play with the strength of dark energy to change the size of a universe such that you can create an infinite line of black holes separated by vast distances, all moving at a tiny fraction under the speed of light, then shrink the universe down while maintaining equal distances between them, and then stop the contraction when the separation distances are just right for the edges of their event horizons to collide when the two lines pass each other. You then have all these black holes moving along parallel paths throughout the rest of the experiment as none of them are pulled more strongly to one side than the other, so they will not spiral together. All the event horizons will connect up for a moment, but then it looks as if they should separate again.
Post by: David Cooper on 18/07/2022 23:23:54
There is a difference between how things "look" and how they are. You might be mixing the two.
I agree that a Black hole looks like a sphere to a distant observer moving with the Black Hole. However, it is not actually a sphere as you would imagine one in 3-D Euclidean space.
You have to remember that the 3D Euclidean space analysis of this is always valid as it matches the predictions of GTR, so the observer moving along with the black hole will measure it as spherical. What varies depending on which model you're applying is the calculated radius that would be measured from the inside because GTR rams in extra space there. What's more important here though when visualising the action is that our observer who sees these black holes moving relative to him at a fraction less than c in opposite directions will see them flattened to very narrow discs. If we make the speeds sufficiently high, we can compress the gravity wells to very narrow discs too such that the discs can have no detectable influence on each other almost up to the moment of contact. There will be a strong effect though just before the impact as the black holes finally begin to interact, but we then reach a point where it would take a detailed simulation to show exactly what would result from it. I want to see such a simulation test this. This case may have been overlooked up to now. Something extraordinary would need to happen to prevent those singularities from continuing on on their merry way at a fraction under the speed of light and with the event horizons detaching after connecting up for a moment. A possibility like that clearly needs to be explored, so I just wanted to put the idea out there. If anyone has simulation software capable of checking it, they should be able to provide a definitive answer on the matter as it will necessarily agree with STR, GTR and LET on the outcome. Doubtless the case of interactions between just two black holes will have been tested independently by many people and shown that any contact between their event horizons leads to a merger, but how much further has this been taken to test for extreme cases like the one I've devised?
Post by: Eternal Student on 19/07/2022 00:37:45
I can't keep up with the posts and respond to the issues systematically. I'm just going to skip to some of the latest posts.
.... I've now found a situation where you can play with the strength of dark energy to change the size of a universe such that you can create an infinite line of black holes separated by vast distances, ....... You then have all these black holes moving along parallel paths throughout the rest of the experiment....
You're doing an experiment? I once mixed some baking soda with lemon juice and was amazed with the results but your experiment does sound more impressive.
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I think the next post may have answered this, you are looking for simulations...
If anyone has simulation software capable of checking it, they should be able to provide a definitive answerOK. Regrettably I don't have any such simulation software.
Best Wishes.
Post by: Halc on 19/07/2022 17:34:34
If we have two long lines of black holes running into each other (with each black hole aimed at the open spaces between black holes in the opposite line, all the event horizons would link up into one with lots of singularities within itDoesn't work. The correct answer involves coming up with a metric describing this that is a solution to Einstein's field equations, but that is beyond either of us. But some naive reasoning may still apply.
You have a series of masses, say 1 cm radius black holes (a bit more massive than Earth each).
There's some threshold of (coordinate) separation where the line is either a series of distinct masses, or is one large mass (regardless of the number of them that you put in the line). So we presume the separation is greater than that, so they're spaced over 2cm apart. Any less than that and the mass of any pair of adjacent ones is greater than their mutual Schwarzchild radius since the latter is directly proportional to mass (well, at least for the two of them in isolation). So any finite line of these masses will have a Schwarzchild radius greater than the length of the line, and thus it will just be one big black hole.
So they're further apart than 2 cm. When the oncoming 2nd line of BHs comes on, for a moment they'll be one line with half the separation between them. Same story. If that new half-separation is under 2cm, both lines become one black hole and nothing gets out. If they're still further apart than that, then none of your event horizons (assuming naively that they don't distort) will overlap.
So they pass without incident. High speed of passing doesn't help. If anything, that just adds energy and makes it more likely to be that one big BH. If slow and steady doesn't work, doing it fast isn't going to help, at least not for the line scenario.
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so can they really be halted quickly enough to stop them separating again?If they're one big black hole, then there's no meaningful coordinate 'speed of halting'. It's just there. Under the presentism that you love to push, it takes nearly infinite time for the speedy objects to come to a complete halt, assuming equal speeds/masses in opposite directions. There is probably a brief but intense pulse of gravitational waves that you'd not want to be near.
If the two singularities move further apart by continuing in the direction they were moving in at the start, the depth of that photon in the gravity well will reduce and it can end up outside the event horizon.Said photon was never inside any EH then, by definition. See my very first sentence of my first reply. You're positing this photon outrunning a null surface, which requires it to move faster than light, a self contradiction.
Post by: Bored chemist on 19/07/2022 18:34:08
it can end up outside the event horizon.No.
It can't.
Post by: David Cooper on 19/07/2022 19:10:13
You have a series of masses, say 1 cm radius black holes (a bit more massive than Earth each).
There's some threshold of (coordinate) separation where the line is either a series of distinct masses, or is one large mass (regardless of the number of them that you put in the line). So we presume the separation is greater than that, so they're spaced over 2cm apart. Any less than that and the mass of any pair of adjacent ones is greater than their mutual Schwarzchild radius since the latter is directly proportional to mass (well, at least for the two of them in isolation). So any finite line of these masses will have a Schwarzchild radius greater than the length of the line, and thus it will just be one big black hole.
Clearly we want them just far enough to remain separate, so when the ones going the opposite way move into the spaces in between they'll increase the energy density and trigger them all to extend towards each other such that the edges of the discs don't initially need to be on direct lines for collision. The high speed at which they pass each other could prevent the propagation of changes to the shapes of the gravity wells so much though that they might not reach out in time to link up. That's what makes this whole thing dependent on simulation.
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So they're further apart than 2 cm. When the oncoming 2nd line of BHs comes on, for a moment they'll be one line with half the separation between them. Same story. If that new half-separation is under 2cm, both lines become one black hole and nothing gets out.
But with a long line of separate singularities inside that long black hole which are still moving along paths that will take them further apart again and break the event horizon back into separate units with one per singularity.
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If they're one big black hole, then there's no meaningful coordinate 'speed of halting'.
It isn't a normal black hole, and it isn't a normal merger of two either. In a normal merger there are two singularities inside a single event horizon and they're moving ever closer together. In my scenario though, there are lots of singularities in there moving along paths that will not bring them together. This is something that may never have been explored.
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Said photon was never inside any EH then, by definition. See my very first sentence of my first reply. You're positing this photon outrunning a null surface, which requires it to move faster than light, a self contradiction.
Like I said, this may never have been explored and you may be in for a surprise. The photon isn't outrunning a null surface - a chunk of space that's inside an event horizon simply loses energy density and the event horizon migrates past the photon and disappears, leaving the photon outside the black holes.
[I like the list of "similar topics" underneath: Do white sheep eat more than black sheep?]
Post by: Halc on 19/07/2022 20:15:32
But with a long line of separate singularities inside that long black holeThere's no 'long black hole'. If you put the little ones close enough together, you get one black hole, and the event horizon of it is more or less spherical (assuming minimal total angular momentum). There's no such thing as a line of barely linked black holes. I spelled out why in my prior post, which perhaps you're not bothering to read. Tell me why my explanation is wrong if it is, but don't just keep repeating refuted stuff. I lay no claim to be necessarily right on this stuff.
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It isn't a normal black hole, and it isn't a normal merger of two either. In a normal merger there are two singularities inside a single event horizonNo. Per no-hair theorem, there's no external difference distinguishing one arrangement from another. Black holes have mass, charge, and angular momentum. They don't have different shapes due to internal arrangements of matter/singularities. Your entire line is in a one black hole. It cannot differ from another black hole with the same mass/momentum/charge. It cannot separate into two parts any more than a normal one.
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This is something that may never have been explored.Per above theorem, it has been explored, and proven otherwise.
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[I like the list of "similar topics" underneath: Do white sheep eat more than black sheep?]Ah, the wonders of low-AI word matching. @neilep would love the topic, and sure enough, was the first to reply.
Answer is obviously yes since there's so many more white sheep mouths to feed than the black ones.
Post by: Bored chemist on 19/07/2022 21:05:09
Post by: Eternal Student on 19/07/2022 23:44:59
The correct answer involves coming up with a metric describing this that is a solution to Einstein's field equations, but that is beyond either of us.That much I agree with. As Halc and I implied in earlier posts - you do want to be using General Relativity and considering a solution to the EFE. Assuming a set of black holes in close proximity remain as anything that would be recognisable or behave as a collection of ordinary individual black holes is a poor assumption.
I wouldn't be trying to find a valid solution for the EFE in such a situation either and I'm not sure anyone would. I had the impression that the models of what are just 2 black holes (let alone an infinite number of black holes) orbiting each other and then merging are usually just numerical solutions or approximations for the EFE in such situations and not an exact analytical solution. BUT I'm no expert and maybe someone does have an anlytical solution for such mergers. Even if such an analytical solution exists I'll bet it's idealised and applies to a very specific set of initial conditions and all we've been doing is generalising from this. (Evidence: We are still finding new things like "lopsided" mergers resulting in the final black hole being given a significant recoil velocity when the incident black holes had unequal masses and spins. https://www.space.com/black-hole-escaping-galaxy-from-collision ).
But some naive reasoning may still apply.Yes, I'll go along with this and just try and keep an eye on where that reasoning might go astray.
When the oncoming 2nd line of BHs comes on, for a moment they'll be one line with half the separation between them.Of course, we don't know that. The trouble with General Relativity is that when you move masses around they don't move to some new piece of space in a nice predictable way like Newtonian mechanics would suggest and space has been left unchanged. In General Relativity, you can't avoid completely changing the nature of space when the mass is re-distributed.
So, using a simple Newtonian view, it looks like there should be a moment when the two lines of black holes are just one line with half the separation between them but in reality the metric is completely different at that time with the masses distributed in this way - so the separation between the black holes could be.... well... anything.
High speed of passing doesn't help. If anything, that just adds energy and makes it more likely to be that one big BHI very nearly said something like that - before deciding it just wasn't all that simple. I completely agree with the sentiment, I'm just not sure that the speed of travel of a black hole is a good measure of any "energy density" that you would want to include in the stress-energy tensor. In particular, it may not describe the kinetic energy of a black hole because it isn't really describing the velocity of any part of the black hole through the space that is local to it.
@David Cooper has repeatedly asked if the speed of travel of the black holes would make a difference and somehow allow the black holes to separate again or get past each other without merging. This has never been an easy question to answer.
If the two black holes approach each other and a shared, connected event horizon forms around what was previously recognisable as the two separate sources of gravitation, then all of the people who have replied on this thread (Halc, Bored Chemist and I) are of the opinion that there is no way that event horizon is ever going to separate again and leave what is recognisable as two separate black holes moving away from each other.
We could argue this purely on the basis on what the formal definition of an "event horizon" is. Halc mentioned this right in one of his earliest replies and Bored Chemist seems to have been consistently using this formal definition of what an event horizon should be.
In astrophysics, an event horizon is a boundary beyond which events cannot affect an observer
[Definition taken from Wikipedia]
So, exactly as has been stated in earlier posts - if a photon was on the wrong side of a genuine "event horizon" then it cannot ever reach an observer who was on the other side of that event horizon.The sort of thing @David Cooper has been talking about would not have been a genuine "event horizon". By definition there cannot be any event horizons which only temporarily constrain a photon but at a later time allow it to pass through and reach an observer who was on the other side. However, we can imagine a dynamic metric existing (one which varies with co-ordinate time such as a gravitational wave solution for the EFE), so that there is a surface through spacetime where space is flowing past that surface at the speed of light for only a finite amount of co-ordinate time. To say it another way, for a short amount of co-ordinate time, time-like paths across that surface can only take objects from region I to region II but not from region II to region I. This, I think is David Cooper's notion of how a photon could be temporarily inside the "event horizon" but then re-emerge if and when the two black holes do manage to pass each other. Formally, the photon was not inside a genuine "event horizon", it was only inside a surface where time-like paths did not exist to the region of spacetime exterior to the surface for a small amount of co-ordinate time. I don't think there is any terminology that is commonly used to describe such a surface. In summary, you ( @David Cooper ) have led everyone to a certain conclusion by using the terminology "event horizon" and suggesting that the event horizons of two black holes could merge and form a combined event horizon for a while. As stated in the very earliest replies, if a photon was on the wrong side of a genuine event horizon, then there isn't any calculation or carefull consideration that needs to be done - by definition it is never getting to an observer outside that event horizon.
I was going to discuss how the speed of travel might affect the merger of two black holes but I'll do that in another post (if at all), since this one is already quite long.
Best Wishes.
Post by: Eternal Student on 20/07/2022 03:08:19
So @David Cooper has repeatedly asked if the speed of travel of a black hole can make a difference to whether the singularities will ultimately merge when the two black holes are made to pass close to each other.
There have been a few replies based on various things and everyone has basically said "no", the most important thing would seem to be how close the black holes get.
Let's qualify some of this: In the big picture I don't see why we need to worry about both black holes having high speeds of travel. We might just as well use a different co-ordinate system so that one black hole is considered to be stationary and only the other black hole is travelling. A similar argument applies to the long lines of black holes that David Cooper was considering - one of those lines can be considered as stationary.
We do expect the speed of travel of a black hole to have some effect on the process of the two black holes merging. If the incoming black hole has a high speed of travel then you'd expect the two black holes to orbit around each other for longer and at a greater distance, steadily losing energy through gravitational radiation until eventually the conventional merging process is observed. If the incoming black hole had a very high speed of travel and it doesn't pass too close to the other black hole then they might even have a hyperbolic encounter and the incoming black hole escapes to infinity and never merges with the other black hole. Additionally, if the incoming black hole had a high initial speed of travel then you'd expect the final merged black hole that is produced to have more spin (angular momentum). So there are some ways in which the speed of travel of a black hole would affect the merging process.
However, you (David Cooper) seem to be intent on considering an encounter between two black holes where they are deliberately made to get too close to each other, i.e. where one black hole was almost on a direct collision course with the other black hole.
I think the notion of a "speed of travel" for a black hole is only useful and usefully defined for a distant observer and assigning a high or low initial "speed of travel" for black holes which do actually come into close proximity with each other makes very little difference to what happens locally around those black holes.
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How fast does a black hole move?
Let's consider a large region of empty space with just one simple black hole in it. So this is going to be described with the Schwarzschild solution. Now I did say empty space but I'm going to want an observer in it, as usual we'll assume they are of such small mass that they don't affect the solution of the EFE at all.
We'll have the observer at a large distance from the black hole and without wasting too much time, we'll have them use the Schwarzschild co-ordinates to describe the space around them. So the black hole is stationary, it's not moving through space, as far the observer is concerned. The black hole retains a constant set of spatial co-ordinates at all times. The "speed of travel" of that black hole is 0 for the distant observer.
If we want to consider a black hole that is moving through space, that's easily done. We'll just have the observer convert the spherical co-ordinate system they were using (t, r, θ, φ) that was based on the Schwarzschild co-ordinates into a Cartesian system (t, x, y, z) centred around the observer and then apply a Lorentz boost to that co-ordinate system. So to paraphrase this, we don't really need to give the black hole any movement we can just have the observer move through space instead and use a new co-ordinate system in which the observer would still consider themselves to be at rest. In this co-ordinate system the black hole has a "speed of travel" through space that is not 0 as far the observer is concerned.
The "speed of travel" of a black hole is just a co-ordinate dependant thing, it depends on the co-ordinates that a distant observer was using. That's nothing special or unique to black holes, we can say the same about any object that is distant from the observer and might be moving. The objects speed depends on the co-ordinates that the observer is using. All we need to keep in mind is just that the "speed of travel" of a black hole may not be telling you as much as you might have thought. It is just telling you something about how the co-ordinates that a distant observer might assign to the black hole change with time.
Now if space is just flat Minkowski space, then when an observer changes the frame of reference they use, it does result in a distant object moving through less (or more) of what the observer considers to be static space in exactly the way you would expect. Specifically, the frame of reference can be extended to cover the region of space around that distant object and then the distant object has a certain speed through that bit of space local to it which will be exactly what you'd expect. For example, if in one frame of reference, the distant object had a velocity, v, through the space local to it, then the observer can boost to a new frame of reference with offset velocity v and then when they examine that distant object it will have 0 velocity through what the observer now considers to be the static local space around that distant object.
However, the same does not hold for Black holes and it is simply because space is certainly not flat Minkowski space when you get close to the black hole. In General relativity you can't extend an inertial frame of reference to cover all of space. However, all is not lost: At every point in spacetime you can always find a local inertial frame. So let's just start by having the distant observer try to use a co-ordinate system where we would naively think that the black hole is moving as slowly through space as possible. Let's have the black hole have 0 "speed of travel" for the distant observer - that can be done by having the distant observer describe space with the Schwarzschild co-ordinates as set out earlier in this discussion.
Now let's have a point, p, that stays on the event horizon of the black hole and let's set-up a local inertial frame there and see how fast that point must be moving through the space that is local to it.
EDITING: This post is already too long, let's not do it but instead just refer any reader to standard texts on the Schwarzschild solution and just jump straight to some diagrams like all the Pop Sci articles would do.
The Schwarzschild solution can be thought of as if space is flowing across the event horizon and towards the singularity. Here's the diagram:
(https://d2r55xnwy6nx47.cloudfront.net/uploads/2019/12/SingularityProof_Lede1300.gif)
Here's a more relevant, if less aesthetically pleasing, diagram:
(https://upload.wikimedia.org/wikipedia/commons/5/55/Andrew_Hamilton_schwarzchild_waterfall.gif)
At the event horizon, the local space is flowing across the event horizon at the speed of light, c. It will be more useful for us to consider this the other way round: The event horizon is moving through space, it has the velocity c through the space that is local to it. This is how it will be in EVERY local inertial frame you set up around the point, p, that stays on the event horizon. You can try to find another local inertial frame, for example, by applying a Lorentz boost but it won't help. If something has the speed c in one inertial frame then this is an invariant, it will have that speed in EVERY inertial frame. Just to phrase this more strongly: You cannot find a local inertial frame centred on a point on the event horizon where the event horizon is travelling at any speed other than c.
Now let's step back a moment to consider what effect the "speed of travel" that a distant observer might have assigned to a black hole can have on what happens locally around a black hole. Well.... basically....nothing.... it makes not a jot of difference as far as I can see. Any local inertial frame you set up on the event horizon will show you that the event horizon is moving through space at the speed c. The distant observer might naively try and slow that down by boosting to another frame of reference and changing the "speed of travel" of the black hole but it doesn't help. There's nothing you can do with the local inertial frame at the event horizon, you can try and boost that in the same way as the distant observer boosted their frame but it doesn't help or matter at all. There's no local inertial frame at the event horizon where it travels at any speed other than c.
Anyway, how does this apply to the merging of two black holes? I don't think the "speed of travel" that the two black holes had initially tells you anything about what is happening locally around the black holes. It certainly doesn't affect their speed or movement through space that is local to the black hole. The "speed of travel" of a black hole is just something a distant observer can measure as described much earlier in this post and it is just an artifact of a particular co-ordinate choice. When and if the two black holes come into close proximity, I don't see how the two black holes can approach each other at a speed through local space that is anything other than c. In particular, I can see no reason to think that assigning the two black holes a high "speed of travel" initially is going to affect what happens locally where and when the black holes merge.
Best Wishes.
Post by: David Cooper on 20/07/2022 18:34:45
But with a long line of separate singularities inside that long black holeThere's no 'long black hole'. If you put the little ones close enough together, you get one black hole, and the event horizon of it is more or less spherical (assuming minimal total angular momentum). There's no such thing as a line of barely linked black holes. I spelled out why in my prior post, which perhaps you're not bothering to read. Tell me why my explanation is wrong if it is, but don't just keep repeating refuted stuff. I lay no claim to be necessarily right on this stuff.
If you have a long line of black holes which suddenly link up, they cannot immediately become a single spherical black hole. The length of the line cannot reduce at the moment of contact to the right size of event horizon for a united singularity of the total mass, and the width cannot instantly burst out to that diameter either - it has to take time to adjust. If the line of black holes is infinite, they will never make that adjustment as there is an equal pull to either side on each singularity. Even if you introduce tiny differences, some of the singularities will merge, but they'll end up further away from the nearest ones that move away from them to merge, and again the event horizons must disconnect as the energy density where they had only just managed to join up has now fallen.
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QuoteIt isn't a normal black hole, and it isn't a normal merger of two either. In a normal merger there are two singularities inside a single event horizonNo. Per no-hair theorem, there's no external difference distinguishing one arrangement from another. Black holes have mass, charge, and angular momentum. They don't have different shapes due to internal arrangements of matter/singularities. Your entire line is in a one black hole. It cannot differ from another black hole with the same mass/momentum/charge. It cannot separate into two parts any more than a normal one.
There is a difference, and it is already known that there is during black hole mergers where there are two distinct singularities within the same event horizon for some time as they cannot instantly become a single one at the moment of first event horizon contact. That will also show up in the gravitational waves.
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QuoteThis is something that may never have been explored.Per above theorem, it has been explored, and proven otherwise.
If people with your level of understanding can imagine that singularities can move billions of lightyears in an instant to merge with others as soon as a chain of event horizons touch, then it seems more than possible that this has not been adequately explored.
Post by: David Cooper on 20/07/2022 19:06:17
As Halc and I implied in earlier posts - you do want to be using General Relativity and considering a solution to the EFE.
As I mentioned earlier, whatever happens here with external observations will be the same for LET as it is for GTR (ignoring any complications caused by the space inside the event horizon being full of stuff in LET, which means that if two event horizons can be made to disconnect there could be a lot of material liberated from both black holes, which is how this experiment could reveal something about what happens inside black holes if it or something like it could be done for real). This means that an LET analysis of events as these two lines of black holes approach each other is fully valid - all the action will map to the GTR analysis of the same action and provide the exact same 3D Euclidean view to the external observer. The black holes do all look flattened to discs and they do not interact until they are almost level with each other as their entire gravity wells can be flattened to behave like discs too.
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Assuming a set of black holes in close proximity remain as anything that would be recognisable or behave as a collection of ordinary individual black holes is a poor assumption.
It isn't - what I've described right up until that moment of first interaction will be precisely as I've described it when simulated under both LET and GTR.
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So, exactly as has been stated in earlier posts - if a photon was on the wrong side of a genuine "event horizon" then it cannot ever reach an observer who was on the other side of that event horizon.
When a rule is based on an assumption (e.g. there are no black swans), no amount of insisting that the rule must be right because it's a rule will alter the fact that it's just an assumption. In all the cases previously looked at, it appeared that nothing could get from inside an event horizon to outside that event horizon, but there may be cases in which that becomes false. When someone proposes such a case, it isn't defeated by asserting that it cannot happen because there's a rule against it and that the rule must be right because it's a rule. The rule is an assumption which has stood the test of time for a very long time, just as the one about there being no black swans did.
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The sort of thing @David Cooper has been talking about would not have been a genuine "event horizon".
It most certainly would be genuine. The event horizon goes where the distribution of energy density puts it. In LET, that's where the speed of light (which reduces in gravity wells under that theory instead of cramming extra space in) falls to zero (relative to the black hole). As two black holes approach each other in a normal merger, the event horizons extend out towards each other and connect up due to the increased energy density acting on that space. In GTR the event horizon is a thing of no substance beyond curvature of spacetime, but the depth of that location in the gravity will fall and will go below the altitude of an event horizon, so it qualifies as a genuine event horizon in GTR too.
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By definition there cannot be any event horizons which only temporarily constrain a photon but at a later time allow it to pass through and reach an observer who was on the other side.
Your definition is a black swan rule. Don't let rules based on assumptions block your ability to explore what actual physics does.
Post by: David Cooper on 20/07/2022 20:21:37
We might just as well use a different co-ordinate system so that one black hole is considered to be stationary and only the other black hole is travelling. A similar argument applies to the long lines of black holes that David Cooper was considering - one of those lines can be considered as stationary.
You can indeed, and that will help show the extreme interaction when the lines of black holes begin to interact, providing a slow motion view of that. The results will be identical. In the view with both lines passing each other at what appears to be a relative speed of almost 2c, the interaction might only begin during the last fraction of a second before the two lines are on a single line if we've compressed their gravity wells sufficiently. When you view it while moving along at the speed of one of those two lines though, you'll see the other line of black holes approach the other at nearly c and it would then appear to take a very long time to move through the gravity wells of the stationary line of black holes before the two lines become for a moment a single line. If we assume that the only material in the black holes is in singularities though, what will those interactions look like? How can they be brought to a halt. Maybe all that extra energy that they're carrying from their extreme speed of travel has a role in this. A massive object doesn't collapse into a black hole due to its relativistic mass from its speed of travel, but if it's all brought to a sudden halt and is already within the event horizon, that could grow the size of the black hole as all that movement energy needs to be expressed in some other way. That might be worth exploring.
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However, you (David Cooper) seem to be intent on considering an encounter between two black holes where they are deliberately made to get too close to each other, i.e. where one black hole was almost on a direct collision course with the other black hole.
The idea is to consider a case where they are on paths that will miss each other but pass close, while the pull to either side on the singularities is always equal, forcing them to stick to the paths they're on. For the black holes to merge, the singularities will need to be halted, and then they can try to merge from there within a unified event horizon without it breaking up.
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I think the notion of a "speed of travel" for a black hole is only useful and usefully defined for a distant observer and assigning a high or low initial "speed of travel" for black holes which do actually come into close proximity with each other makes very little difference to what happens locally around those black holes.
If you want to understand the action, it's useful to imagine the speeds of approach and to understand that everything that needs to be done to halt the singularities must be done within a fraction of a second when measuring from the frame of reference in which you expect the unified black hole to end up at rest, while nothing can propagate faster than the speed of light in that frame.
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Anyway, how does this apply to the merging of two black holes? I don't think the "speed of travel" that the two black holes had initially tells you anything about what is happening locally around the black holes. It certainly doesn't affect their speed or movement through space that is local to the black hole. The "speed of travel" of a black hole is just something a distant observer can measure as described much earlier in this post and it is just an artifact of a particular co-ordinate choice. When and if the two black holes come into close proximity, I don't see how the two black holes can approach each other at a speed through local space that is anything other than c. In particular, I can see no reason to think that assigning the two black holes a high "speed of travel" initially is going to affect what happens locally where and when the black holes merge.
Nevertheless, whatever happens with the interactions between the black holes, the external observer sees them travel along straight paths in opposite directions and their event horizons touch while the singularities are forced to continue along those straight paths, so if they are to remain within the same event horizon they need to be halted, and fast. If they aren't halted, the energy density half way between any pair of these singularities will fall again and lead to those locations no longer being within the event horizon, even though they were in it at the moment of closest approach. The action may be too complex for anyone to run sufficiently accurately in their head for them to be sure of the outcome until they've seen a detailed computer simulation of it, so it may not be possible to resolve without finding someone who already has software that can handle it and which doesn't override anything with no-black-swan rules, or without writing such software, which would not be an easy task, so I don't expect definitive answers in the near future.
Post by: Eternal Student on 21/07/2022 19:41:37
As I mentioned earlier, whatever happens here with external observations will be the same for LET as it is for GTR
You've mentioned LET several times. Is that Lorentz Ether Theory? https://en.wikipedia.org/wiki/Lorentz_ether_theory
As far as I can see, this remains a fringe theory, with Special Relativity being the preferred mainstream theory. In 2012 there was apparently a viable Lorentz-invariant treatment of gravity added to the theory. https://en.wikipedia.org/wiki/Lorentz_ether_theory#Lorentz-invariant_gravitational_law . However, General Relativity still seems to be the preferred mainstream theory for gravity.
This means that an LET analysis of events as these two lines of black holes approach each other is fully valid - all the action will map to the GTR analysis of the same action and provide the exact same 3D Euclidean view to the external observer.You may need to provide some references or more details for this. What you seem to have done is apply some results from special relativity only and not utilize whatever the LET version of a theory of gravity might be.
For example, you stated this:
If the line of black holes is infinite, they will never make that adjustment as there is an equal pull to either side on each singularity.The idea of a "pull" or a force being applied is a Newtonian version of gravity. Gravity is not a force under General Relativity.
There is a difference, and it is already known that there is during black hole mergers where there are two distinct singularities within the same event horizon for some time as they cannot instantly become a single one at the moment of first event horizon contact. That will also show up in the gravitational waves.The exact details may not be entirely right but the general idea is actually OK. @Halc mentioned the no-hair theorem but this actually only applies to what are recognisable as conventional stationary Black Hole solutions and not to the unusual sources of gravitation that exist just before two black holes have merged (for example when gravitational waves are present).
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.... we have a no-hair theorem:
Stationary, asymptotically flat black hole solutions to general relativity coupled to electromagnetism that are nonsingular outside the event horizon are fully characterised by the parameters of mass, electric and magnetic charge and angular momentum.
Stationary solutions are of special interest because we expect them to be the end states of gravitational collapse. The alternative might be some sort of oscillating configuration, but oscillations will ultimately be damped as energy is lost through the emission of gravitational radiation, in fact, typical evolutions will evolve quite rapidly to a stationary configuration.
[Extract taken from p. 238, Spacetime and Geometry, Sean Carroll ]
The problem is, I think, that you (@ David Cooper ) previously referred to an arrangement of one long line of singularities as being one Black Hole. You can't then blame Halc for assuming it was an ordinary Black Hole, i.e. an ordinary stationary solution of the EFE that is asymptotically flat.
This brings me to another point about definitions and the use of existing terminology:
ES said: By definition there cannot be any event horizons which only temporarily constrain a photon but at a later time allow it to pass through and reach an observer who was on the other side.It's a definition not a rule. It's also not "my" definition, the extract I quoted came from Wikipedia. That particular definition is based on something Rindler developed in about 1950.
DC replied: Your definition is a black swan rule. Don't let rules based on assumptions block your ability to explore what actual physics does.
The physics is safe - if there is some physics to explain then it can be done by describing it with another term like an "orange horizon" or something else. However, if you use the term "Event Horizon" then people will (and they did seem to) think you were describing the thing that is given by the definition much as described in that Wikipedia article. Actually there are other definitions of an "event horizon" that you could use - but if you are doing this, then you would be advised to set out the definition you are using because the definition as set out by Rindler (approx. 1950) is the mainstream definition.
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ES said: I think the notion of a "speed of travel" for a black hole is only useful and usefully defined for a distant observer and assigning a high or low initial "speed of travel" for black holes which do actually come into close proximity with each other makes very little difference to what happens locally around those black holes.
DC replied: If you want to understand the action, it's useful to imagine the speeds of approach and to understand that everything that needs to be done to halt the singularities must be done within a fraction of a second when measuring from the frame of reference in which you expect the unified black hole to end up at rest, while nothing can propagate faster than the speed of light in that frame.
I get the impression that in your analysis (which you stated is based on LET), the black holes are very much being considered as something like billiard balls moving through a fixed static space which seems to be described by the co-ordinate system in which the black holes are said to have a speed of approach.
In General Relativity something different can happen. The black holes aren't just billiard balls moving through a static space. They are something which changes the nature of space around them. As the two black holes approach each other they can be slowed down (or sped up) relative to each other because the metric of space between them was not describing flat space and futhermore it wasn't even static - it has been changing with co-ordinate time while the black holes approached. So the co-ordinate separation between them isn't describing what it used to describe. The velocity vector of an object does change as it travels through curved space so the black holes can have their velocities completely changed while they are approaching each other.
Best Wishes.
Post by: David Cooper on 22/07/2022 19:15:44
You've mentioned LET several times. Is that Lorentz Ether Theory? https://en.wikipedia.org/wiki/Lorentz_ether_theory
As far as I can see, this remains a fringe theory, with Special Relativity being the preferred mainstream theory. In 2012 there was apparently a viable Lorentz-invariant treatment of gravity added to the theory. https://en.wikipedia.org/wiki/Lorentz_ether_theory#Lorentz-invariant_gravitational_law . However, General Relativity still seems to be the preferred mainstream theory for gravity.
The two theories map to each other perfectly when it comes to predictions of the visible action from outside black holes, but they diverge when describing the action inside them. LET has the speed of light reduce in gravity wells instead of packing extra space into them, so instead of light taking longer to pass a massive body by having that light follow a lengthened path while maintaining the speed c throughout, LET simply has the light move more slowly (and with its path bent by any difference in the speed of light to either side, and this maintains Euclidean geometry while providing the same precision in its predictions as GTR. That's why it's a valid tool for exploring these things - the two theories are essentially mathematical transformations of each other (which is why some people consider them to be different interpretations of the same theory), but they diverge in what they say about what goes on in black holes because LET doesn't have singularities. When you're trying to run the action in your head, and particularly when it becomes hard to simulate GTR's non-Euclidean geometry, it can help you picture that action if you know that it can still be done validly with Euclidean geometry: whatever happens there must match up to what things will look like with GTR. Wherever one theory says the event horizon must be, the other theory must agree with that, and the same applies to all the action outside of the event horizon. It's still hard though to picture what happens on the inside.
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What you seem to have done is apply some results from special relativity only and not utilize whatever the LET version of a theory of gravity might be.
Up until the black holes start to interact, there is no need to consider gravity: we can compress their gravity wells as good as infinitely just by making the speeds of travel ever closer to c without quite reaching it. Once the two lines of black holes are almost level though, there will be severe "interactions" for the event horizons as the gravity wells are not compressed at all perpendicular to the direction of travel. If we consider all the material to be in singularities, those cannot be diverted to either side, so they should just keep going forwards unless they can be halted. (Things would be different in the full LET analysis as the material is not locked into singularities, so it could migrate to the sides. Completely different simulation software would be needed to explore that.)
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The idea of a "pull" or a force being applied is a Newtonian version of gravity. Gravity is not a force under General Relativity.
You are expected to interpret the word "pull" in that context in any way that suits the theory you want to apply. In LET it isn't a pull either, but there's no simple vocabulary available to express the idea without taking paragraphs to do so, and I won't go into the details here as this is not a discussion of rival theories.
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The problem is, I think, that you (@ David Cooper ) previously referred to an arrangement of one long line of singularities as being one Black Hole. You can't then blame Halc for assuming it was an ordinary Black Hole, i.e. an ordinary stationary solution of the EFE that is asymptotically flat.
The words used for it should not cause confusion: if you are simulating the action and see all these black holes line up in one single line with their event horizons connecting up, you then see one unified event horizon containing a long line of singularities. The term black hole becomes fuzzy in such a situation, just as it does during part of the time when two black holes are merging and have linked up without their singularities yet merged.
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It's a definition not a rule. It's also not "my" definition, the extract I quoted came from Wikipedia. That particular definition is based on something Rindler developed in about 1950.
Definitions and rules are two sides of the same coin. If the rule doesn't match the definition, one of them is wrong. That connection between them can make them reasoning traps, and it's particularly important not to let definitions get in the way of exploring the physics. Both rule and definition can be wrong too, so when a rule is questioned, that questioning should not be shut down through the authority of a definition that goes with it. There are simulations in existence which explore black hole mergers, and if that software was turned to this, the result could provide unexpected results, which is why I'd like to get the idea to the people that have that software.
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I get the impression that in your analysis (which you stated is based on LET), the black holes are very much being considered as something like billiard balls moving through a fixed static space which seems to be described by the co-ordinate system in which the black holes are said to have a speed of approach.
They've been contracted down to extremely thin discs.
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In General Relativity something different can happen.
Nothing different can happen, other than inside an event horizon.
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The black holes aren't just billiard balls moving through a static space. They are something which changes the nature of space around them.
In LET, the speed of light reduces, reaching zero at the event horizon - this leads to the exact same gravitational lensing occurring and identical visible action for the external observer.
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As the two black holes approach each other they can be slowed down (or sped up) relative to each other because the metric of space between them was not describing flat space and futhermore it wasn't even static - it has been changing with co-ordinate time while the black holes approached.
The entire gravity well can be compressed to a very thin disc too such that you only have these interactions at the very last moment as the two lines of black holes are close together - make the speeds of travel sufficiently high and that can mean no interaction until the last fraction of a second of the approach. Switch to using a different frame though and what you see there will create the exact same action, so if you choose the frame in which one line of black holes is at rest, you will then have them completely uncontracted with the other line of black holes more extremely contracted but approaching at nearly the speed of light. Again, the stationary black holes will not react to the approaching ones until the last moment, but the approaching ones will be in the gravity well of the stationary ones for a long time and will be affected by that. In GTR, that means extra space is packed in there for the singularities to travel through, so the external observer would certainly measure them as slowing down during the last moment of approach. If you could make that extra space infinite in length for the path of the singularities, you could effectively halt them, but it's hard to visualise exactly how this would play out as we're dealing with action inside an event horizon. Different simulations might produce different results and some might break, so this would be a good test of them.
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So the co-ordinate separation between them isn't describing what it used to describe. The velocity vector of an object does change as it travels through curved space so the black holes can have their velocities completely changed while they are approaching each other.
My bet is that the singularities will slow down in the last moments of approach with the event horizons connecting up, but will then speed up again and the event horizon will split up, restoring two lines of black holes. However, this is too hard to simulate in my mind at the moment and could well be wrong, so I certainly wouldn't bet any money on which way it will go. It will likely take simulations to settle it, and it may also be necessary to run the action repeatedly to test different separation distances between the black holes. So, the question is now out there. It may be some time before it can be settled.
Post by: Bored chemist on 23/07/2022 00:47:37
Given the conventional definition of "black"; no.
Post by: Halc on 23/07/2022 13:44:09
The two theories map to each other perfectly when it comes to predictions of the visible action from outside black holesLorentz Ether Theory was, to my knowledge, never generalized to a theory of gravity anytime in the 20th century. I did find one first published in the 21st century, last revised in 2012: https://arxiv.org/abs/gr-qc/0205035
It differs significantly from your assertions, primarily in the existence of black holes, which is an Einstein-only concept. They cannot exist in a preferred frame model since no coordinate system foliates all of spacetime.
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but they diverge when describing the action inside them.Only by denying said action at all. There is no 'in them' in any preferred frame model.
You see to be making up your physics. I invite to to cite sources for your claims, and not sources from science denial sites.
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and this maintains Euclidean geometry while providing the same precision in its predictions as GTR.This is the first assertion. If physical triangles (made of rigid rods say) have angles that don't add up to 180°, it is hard to argue for Euclidean geometry. From where does this claim come?
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the two theories are essentially mathematical transformations of each other (which is why some people consider them to be different interpretations of the same theory)LET is an alternate interpretation to only Special Relativity, never to GR. It never got gravity right, unless you count theories like the one I linked above, which probably should be called something like 'Schmelzer Ether Theory'. It does have singularities in what it calls 'frozen stars'. The mathematics at the event horizon (GR only term) is necessarily singular in this preferred frame.
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I won't go into the details here as this is not a discussion of rival theories.But you've done so in making these assertions. Topic has been moved accordingly.
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The term black hole becomes fuzzy in such a situation, just as it does during part of the time when two black holes are merging and have linked up without their singularities yet merged.The verb tense usage here suggests there's a meaningful coordinate time at which what you picture as a pair of physical singularities merge after crossing each other's event horizons. I never suggested any such thing.
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In LET, the speed of light reduces, reaching zero at the event horizonHow can this object move at all through space? If the speed of light reaches zero there, the speed of matter would too, preventing a black hole from moving in coordinate space. It all seems self contradictory. I don't think Schmelzer makes this assertion/deduction either. Again, a citation would be nice here since I doubt any of it comes from Schmelzer.
Post by: David Cooper on 23/07/2022 19:41:52
It differs significantly from your assertions, primarily in the existence of black holes, which is an Einstein-only concept.
It doesn't. It merely gives them a different name to better reflect their nature, just as string theory calls them fuzzballs, but they're all referring to the same objects and the followers of these other theories still refer to them as black holes in most situation because that's what the people generally call them. This is equivalent to Christians in Indonesia referring to God as Allah in conversation with people of other religions where that word is the general word for God.
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They cannot exist in a preferred frame model since no coordinate system foliates all of spacetime.
You've been told plenty of times before that in an expanding universe there's more than one kind of absolute frame: one which applies at a specific location which is at rest relative to the local space fabric and which cannot be the same one as for other parts of that fabric which are moving relative to the first; and an absolute absolute frame which may not match up to any absolute frame within the universe as every part of the space fabric could be moving relative to the absolute absolute frame. Ignoring these details leads to you making errors in your statements.
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Quotebut they diverge when describing the action inside them.Only by denying said action at all. There is no 'in them' in any preferred frame model.
You get more irrational by the year. There are objects which science has discovered and called black holes, and they have event horizons. There is an inside and an outside of an event horizon. Different theories which agree on the action on the outside of those event horizons can disagree about what happens inside them. String theory and LET agree on both. QM has a split personality at the moment with it half agreeing with those two while still clinging to GTR and messing itself up as a result, so it preserves information at the event horizon while failing to recognise that material and light stops there too.
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You see to be making up your physics. I invite to to cite sources for your claims, and not sources from science denial sites.
You're the one making thing up here by misunderstanding things and misrepresenting my position. It is a matter of fact that the predictions of LET and GTR match up perfectly for all observations and experiments - there's already been a link in this thread to the wikipedia entry on LET which spells that out. It is not disputed by serious physicists, so what's your game? You just hate being pushed into corners where you lose, so you try to hide the evidence every time by tossing it all into the "new theories" bin - you're scared of anything that questions your broken pet models because you know deep down that they're wrong and yet you've tied yourself to them too strongly to be able to back down on them. That is the norm though in physics, and it's why it's failing miserably to self-correct, with the result that it's doomed itself to the most horrific ridicule when it all comes crashing down.
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Quoteand this maintains Euclidean geometry while providing the same precision in its predictions as GTR.This is the first assertion. If physical triangles (made of rigid rods say) have angles that don't add up to 180°, it is hard to argue for Euclidean geometry. From where does this claim come?
It comes from the fact (acknowledged on that wikipedia page) that the predictions match and that LET achieves this using Euclidean geometry with the speed of light slowing instead of trying to cram extra space into gravity wells while maintaining the speed of light at c. GTR is just a mathematical abstraction of LET, and it's one that breaks spectacularly when dealing with the contents of black holes, but it also breaks spectacularly outside them by generating event-meshing failures at every turn which have to be hidden in ALL simulations of GTR by smuggling in absolute time as part of a control mechanism to hide those errors. It's academic fraud, and some day the chickens will come home to roost. You're running out of time.
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LET is an alternate interpretation to only Special Relativity, never to GR.
Let me repeat: LET accounts for gravity by having light slow down in gravity wells, and this enables it to match up as perfectly to observations and experiments as GTR, so you're simply wrong.
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QuoteI won't go into the details here as this is not a discussion of rival theories.But you've done so in making these assertions. Topic has been moved accordingly.
No; you moved it because you've been itching to move it right from the start, so you've been waiting for any thin excuse you can find (in this case a side discussion on the validity of different ways of analysing events where the view from one valid way of doing so reveals clear truths about what would happen as the two lines of black holes approach each other and where they are denied by someone who doesn't like the method, even though what it clearly reveals must match up to the predictions of their preferred method and which they would see if they were able to apply their method correctly to the same case using the same frame of reference - where they deny the action that their own preferred theory predicts and reject the other theory which makes the exact same predictions on the basis of their own error, a side-discussion of that becomes necessary and should not be used as an excuse to hide the thread). You overrode the purpose of this forum which is to discuss interesting science questions because of your own petty grudge, and you've done the same thing many times in the past with other threads because your underlying mission is to continue to defend academic fraud and prevent it from being exposed.
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QuoteThe term black hole becomes fuzzy in such a situation, just as it does during part of the time when two black holes are merging and have linked up without their singularities yet merged.The verb tense usage here suggests there's a meaningful coordinate time at which what you picture as a pair of physical singularities merge after crossing each other's event horizons. I never suggested any such thing.
You said,
"There's no 'long black hole'. If you put the little ones close enough together, you get one black hole, and the event horizon of it is more or less spherical (assuming minimal total angular momentum). There's no such thing as a line of barely linked black holes. I spelled out why in my prior post, which perhaps you're not bothering to read. Tell me why my explanation is wrong if it is, but don't just keep repeating refuted stuff. I lay no claim to be necessarily right on this stuff."
So, that had to be corrected, and it just added to your drive to hide this thread in the subforum bin dominated by mathematically illiterate ramblings where hundreds more of your errors are stored. You have to move my threads to hide your errors just as much as to defend the establishment's broken models.
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QuoteIn LET, the speed of light reduces, reaching zero at the event horizonHow can this object move at all through space? If the speed of light reaches zero there, the speed of matter would too, preventing a black hole from moving in coordinate space. It all seems self contradictory.
As I mentioned in an earlier post, the speed of light is slowed relative to the black hole - not relative to the space fabric. It's the same in string theory: matter/energy doesn't exist at a single point, but is spread out, so when we look at a particle and say, "it's there", we're only seeing the place it's centered on, but the particle is spread out through the entire visible universe. Its made out of waves which have a density distribution with most of the energy being where we see the particle, though the point at which the particle exists at any moment depends on probabilities tied to that distribution, making its location uncertain until we interact with it in some way. Those waves spreading through space serve as a medium which slows light relative to that medium. If a black hole is moving, the medium associated with it moves along with it. The medium also contracts when it moves, and if the black hole accelerates, the contraction has to adjust with that adjustment propagating at the speed of light: that's what gravitational waves are in LET. This medium also allows LET to account for frame dragging because when a massive body rotates, one side is moving one way and the other side is going the opposite way, so if you're close to one side of it you have more of this unseen medium moving past you one way than the opposite way, resulting in light taking longer to pass the body on one side than light moving in the same direction past the other side. This mechanism also applies to black holes which in LET (and string theory) are packed with stuff all the way through and lack singularities. That's another reason why LET is a superior theory to GTR because it accounts for more of the action.
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Again, a citation would be nice here since I doubt any of it comes from Schmelzer.
This last bit about the medium is from string theory and I have not seen any reference to it in anything about LET, but it must be a standard part of LET because it's so damned obvious that light has to be slowed relative to the black hole and that there must be a medium causing that slowing which is additional to the space fabric. The bit about it accounting for frame dragging is my own discovery though and I don't know if I was the first to find it. I don't bother to publish my findings though because good science just goes into a black hole and is ignored by an establishment which merely wants to defend broken models, so I put it up online in various places and wait for future recognition when AGI trawls through everything and marks everyone's work. And now you'll use the last few paragraphs as another excuse for putting this thread in new theories, but you pushed for these paragraphs to be written so you've engineered that excuse yourself. It's only been necessary to discuss this because of you. You should not be a moderator because you deliberately sabotage discussions.
Post by: Kryptid on 23/07/2022 20:40:12
you try to hide the evidence
Do you really think that's what he's doing? This forum isn't hidden.
Post by: Eternal Student on 23/07/2022 22:19:51
It is a matter of fact that the predictions of LET and GTR match up perfectly for all observations and experiments - there's already been a link in this thread to the wikipedia entry on LET which spells that out.I'll take responsibility for putting that reference in.
However, it doesn't state that LET and GTR match up perfectly. It only states ... it is not possible to distinguish between LET and SR by experiment...
Halc and I have asked for references a few times now, I think .....
You may need to provide some references or more details for this.
I invite to to cite sources for your claims, and not sources from science denial sites.This doesn't mean just telling people what you think LET is supposed to be about. It means finding a textbook, research paper or article and providing the details of that. Ideally, you'll even provide the relevant page numbers. Then the reader can go and check the source information directly themselves.
Sadly, this does take up your time but it's essential in any academic discussion. I took the time to try and find out something about LET even though you hadn't provided any references. I took the time to find the exact page numbers people might need in a book by Sean Carroll in post #29 etc. Halc took the time to find a paper on the arxiv print server and provide us the reference for that and (it seems) spent a while trying to check for similar papers about a treatment of gravity in LET.
You should not be a moderator because you deliberately sabotage discussions.I'm not a moderator and I wouldn't want to be. However, you've got to see that the moderators have some obligation to follow some rules and policies.
The "new theories" section isn't the same thing as the "dustbin", it's just where any new theory is supposed to be discussed. If Einstein had posted his first draft of STR then it probably would have started in the new theories section. The main criteria for a discussion in the other sections is that it should be discussing what is considered to be the mainstream science of today.
Your posts were using some vocabulary that has an established meaning (e.g. "event horizon" as discussed in post #29) but you were directly stating that you were setting your own definitions and rules and just using the same terms anyway. That's OK but you can't then argue that you are discussing mainstream science. What you are doing is likely to accidentally or deliberately mislead people by using common terms to describe different things.
Best Wishes.
Post by: Bored chemist on 24/07/2022 10:15:59
Post by: Halc on 24/07/2022 15:00:21
This is using Einstein's model, not a preferred frame model. To my knowledge, no preferred frame model has an event horizon at black holes since there are no events on the other side to define one. I may be wrong about this, so kindly put in the citation. Your lack of citations reduces your posts to mere assertions. LET does not make the claims you ascribe to it.QuoteOnly by denying said action [within black holes] at all. There is no 'in them' in any preferred frame model.You get more irrational by the year. There are objects which science has discovered and called black holes, and they have event horizons. There is an inside and an outside of an event horizon.
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You're the one making thing up here by misunderstanding things and misrepresenting my position.Misunderstanding your position isn't 'making things up'. You asserted valid physics in Euclidean space. You asserted action (or even space at all) within black holes in a preferred frame model like LET. I need references for those claims, else you very much indeed are making up your physics. I'd not have moved the thread just for saying what LET theory posits, but you seem to simply be attaching the LET label to your personal ideas. That puts the topic here in new theories.
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It is a matter of fact that the predictions of LET and GTR match up perfectly for all observations and experiments - there's already been a link in this thread to the wikipedia entry on LET which spells that out.Wiki spells out something entirely different. It says LET in only an interpretation of special relativity and thus matches the predictions only of SR because it had never been generalized.
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The non-existence [up until apparently 2012] of a generalization of the Lorentz ether to gravity was a major reason for the preference for the spacetime interpretation.Wiki says an entire century went by without LET having a theory of gravity. The one in 2012 is not called LET as far as I know, and it does not back your claims as far as I know, but I invite your to prove me wrong.
In particular, when does say an infalling particle actually get inside a black hole? How long does it last there? These questions are meaningful in an interpretation with absolute time.
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It is not disputed by serious physicists, so what's your game?I'm disputing your personal claims, not disputing anything on which serious physicicts have commented.
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Wiki says nothing of the sort. I'm looking at the LET page ES linked. Kindly quote the text you think says this. The article I see says LET doesn't have a theory of gravity at all, per the line I quoted above. It says nowhere that LET is a mathematical abstraction of GTR.QuoteIt comes from the fact (acknowledged on that wikipedia page) that the predictions match and that LET achieves this using Euclidean geometry with the speed of light slowing instead of trying to cram extra space into gravity wells while maintaining the speed of light at c.Quoteand this maintains Euclidean geometry while providing the same precision in its predictions as GTR.This is the first assertion. If physical triangles (made of rigid rods say) have angles that don't add up to 180°, it is hard to argue for Euclidean geometry. From where does this claim come?
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LET is an alternate interpretation to only Special Relativity, never to GR.
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Let me repeat: LET accounts for gravity by having light slow down in gravity wells, and this enables it to match up as perfectly to observations and experiments as GTR, so you're simply wrong.Perhaps so, but citation needed. It certainly doesn't say that on the wiki page, which actually says that LET doesn't account for gravity at all.
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You said,This fails to tell my why my explanation is wrong, and didn't even bother to quote the explanation itself. Your purposes seem to be evangelism and not actual science. A scientist would back his claims, and would demonstrate how erroneous explanations such as the one you didn't quote above are wrong. Instead I get raving assertions of conspiracy.Quote from: HalcThere's no 'long black hole'. If you put the little ones close enough together, you get one black hole, and the event horizon of it is more or less spherical (assuming minimal total angular momentum). There's no such thing as a line of barely linked black holes. I spelled out why in my prior post, which perhaps you're not bothering to read. Tell me why my explanation is wrong if it is, but don't just keep repeating refuted stuff. I lay no claim to be necessarily right on this stuff.So, that had to be corrected, and it just added to your drive to hide this thread in the subforum bin dominated by mathematically illiterate ramblings where hundreds more of your errors are stored. You have to move my threads to hide your errors just as much as to defend the establishment's broken models.
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Sounds then like relativity. In an absolute interpretation, speed is relative to the absolute frame an not to any other. It's a property, not a relation. Schmelzer seems to have solved this issue, but seemingly not by the premises you're asserting. I admittedly don't know any of his premises. The premises of SR are not held of course, but the Einstein Equivalence Principle is derived (not postulated as in GTR), which is impressive.QuoteHow can this object move at all through space? If the speed of light reaches zero there, the speed of matter would too, preventing a black hole from moving in coordinate space. It all seems self contradictory.As I mentioned in an earlier post, the speed of light is slowed relative to the black hole - not relative to the space fabric.
Post by: David Cooper on 25/07/2022 00:14:33
you try to hide the evidence
Do you really think that's what he's doing? This forum isn't hidden.
It's a standard way of putting things where they will hardly ever be seen by anything other than bots, so yes.
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Hi.It is a matter of fact that the predictions of LET and GTR match up perfectly for all observations and experiments - there's already been a link in this thread to the wikipedia entry on LET which spells that out.I'll take responsibility for putting that reference in.
However, it doesn't state that LET and GTR match up perfectly. It only states ... it is not possible to distinguish between LET and SR by experiment...
You're right - I didn't look it up and just went by what I thought I remembered it saying, but it does restrict that to STR.
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Halc and I have asked for references a few times now, I think .....
It isn't something that needs references, so you should not be demanding any. If your model doesn't conform to the requirements of STR, it will enable you to measure absolute speeds with ease, so GTR has to include STR as part of itself in order to fit observations. GTR also has to conform to our 3D Euclidean view of events while doing its 4D stuff, so the two things have to map to each other through transformations and must match in the 3D Euclidean view that they generate. LET describes what you get in that 3D Euclidean view, and it uses the exact same equations to describe how light slows down in a gravity well as GTR uses to describe how light doesn't slow down, but extra space is put in its path instead to slow it's passage through a gravity well. The two ways of looking at it necessarily map to each other and you don't need a reference to understand that. That is why you can be certain that what LET tells you you will see in the Euclidean view of the action will match up to what GTR tells you you will see in the Euclidean view. This should not be in dispute as it's such an obvious mathematical necessity when they are calculating that using the exact same maths. They don't even diverge inside black holes in that regard - they necessarily match each other at every turn.
That's why whenever I employ LET as a tool for viewing the action, it should not lead to a demand to justify it every time with the resulting discussion then being used as an excuse to throw the whole thread into new theories - the theory behind the tool is not what the thread's about, but Halc keeps using any mention of the tool that I use as a deliberate way of generating a way of throwing the thread into that bin. I use that tool because it fits the facts of what the universe does while providing a view of events that ordinary people can actually simulate in their head to follow the action, unlike the GTR 4D view which 99.9% of professional physicists can't simulate in their head. It is the far better tool for public understanding of science and it is useful as it reveals errors in the 4D simulations that people attempt in their head and get wrong.
When LET and STR tell you what these lines of black holes look like as they approach each other before the gravitational interaction becomes significant (due to the extreme contraction of the gravity wells - no amount of applying GTR can change that because the gravity acting on each line from the other is so weak up to that point and cannot affect the 3D Euclidean view of the action), GTR cannot disagree without diverging from what the universe is observed to do. STR only loses its ability to predict the action once the two lines of black holes are almost level with each other, so that's when you have to add GTR to predict what happens next, but you don't then throw out STR at that point as you have to continue to apply all the relevant contractions. When I simulate the action using my preferred tool of LET, I can see with ease that running the action up to this point provides no room for any significant interaction as these compressed gravity wells approach each other, but if you're trying to do the equivalent with GTR, your attempt to simulate what GTR does up to that point is much more likely to go wrong because the odds are that you aren't one of the few who can run that action correctly - the brain is not designed to visualise the 4D metric in the same way as it has evolved to see the 3D Euclidean view. I see the speed of light beginning to fall infinitesimally. You imagine the space beginning to warp, but you have huge errors in your visualisation of it.
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You should not be a moderator because you deliberately sabotage discussions.I'm not a moderator and I wouldn't want to be. However, you've got to see that the moderators have some obligation to follow some rules and policies.
When the exact same discussion has to be gone through as a pantomime due to Halc repeatedly pretending that we haven't already established the validity of the tool, you are actually seeing him using it as a wrecking mechanism to shut down discussions that he doesn't like. He does this every time
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The "new theories" section isn't the same thing as the "dustbin", it's just where any new theory is supposed to be discussed. If Einstein had posted his first draft of STR then it probably would have started in the new theories section. The main criteria for a discussion in the other sections is that it should be discussing what is considered to be the mainstream science of today.
This thread is about a question and it's theory-independent. My use of a tool to indicate that someone else is not applyint their chosen tool correctly is not the discussion. The discussion is an interesting idea that under all these theories there might be a way for a photon to escape from inside an event horizon, and that kind of question is one of general interest to people. It is nothing to do with new theories, but is about whether some possible actions may have been missed within GTR. My use of LET as a tool to show up a misuse of GTR does not turn it into something else.
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Your posts were using some vocabulary that has an established meaning (e.g. "event horizon" as discussed in post #29) but you were directly stating that you were setting your own definitions and rules and just using the same terms anyway. That's OK but you can't then argue that you are discussing mainstream science. What you are doing is likely to accidentally or deliberately mislead people by using common terms to describe different things.
That is incorrect. I was using the terms the way they are normally used, but there are places where definitions can be unsound and misleading. In a case where two event horizons have linked up but there are two singularities which then move further apart such that the event horizons decouple again, you have a region of space that dips below the gravity well level at which event horizons exist, but then rises back above that level again. If that action is possible, then the definition of the event horizon that you are using for GTR is inherently wrong and would need to be corrected to match up to the change in the understanding of the science of that happening. Definitions of things within a theory can actively contradict some things that can actually happen in that theory if they haven't been constructed perfectly. Again what we have here is an attempt to derail legitimate discussion of science by playing games with words and definitions.
Let me give you a parallel for this. It used to be thought that a sailing boat couldn't travel downwind faster than the wind, so that could have been built into the definition of a sailing boat: a sailing boat is a boat powered by the wind hitting its sails and which cannot go downwind faster than the wind. Now, if someone comes along and says, "What if it zigzags downwind and there's very little drag against the water? It might be able to go downwind faster than the wind." Someone might then object by saying, "Nonsense: by definition a sailing boat cannot go downwind faster than the wind, so you cannot be talking about a sailing boat! You must call it something else" That's the direct equivalent of what you're doing here. When they discovered that sailing boats could indeed travel downwind faster than the wind, they kept calling them sailing boats and any part of anyone's definition stating that they couldn't go downwind faster than the wind was deleted from the definitions. It will be the same with event horizons if we find cases where things can escape them due to the local depth in the gravity well reducing due to the singularities moving further apart. So, your objection has been a language game and not a scientific objection.
Post by: Kryptid on 25/07/2022 02:29:07
It's a standard way of putting things where they will hardly ever be seen by anything other than bots, so yes.
Citation please. It takes just as many clicks to get to New Theories as it does to get to any other forum here.
Post by: David Cooper on 25/07/2022 04:14:56
This is using Einstein's model, not a preferred frame model. To my knowledge, no preferred frame model has an event horizon at black holes since there are no events on the other side to define one. I may be wrong about this, so kindly put in the citation. Your lack of citations reduces your posts to mere assertions. LET does not make the claims you ascribe to it.
The event horizon is called the event horizon because it's the limit of detectable events. It can be called that regardless of which theory you're applying, and given that it's the most commonly understood name for it and there's no other commonly understood name for it at all, it's the name people use. I don't need to cite anything to call out your language games.
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Misunderstanding your position isn't 'making things up'. You asserted valid physics in Euclidean space. You asserted action (or even space at all) within black holes in a preferred frame model like LET. I need references for those claims, else you very much indeed are making up your physics.
You don't need references for any of it. Everything GTR does visibly in this scenario maps to a 3D Euclidean metric with an identical result to the LET predictions because they apply the same maths to it.
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I'd not have moved the thread just for saying what LET theory posits, but you seem to simply be attaching the LET label to your personal ideas. That puts the topic here in new theories.
I wasn't attaching LET to the discussion beyond using it as a tool to show that GTR cannot magically do anything different to the action that's measured in a 3D Euclidean metric.
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Wiki says an entire century went by without LET having a theory of gravity. The one in 2012 is not called LET as far as I know, and it does not back your claims as far as I know, but I invite your to prove me wrong.
Guess what the LET in CLET stands for. Doug Marett's site dates back before that and deals with LET and how it covers the same ground as GTR. You ought to remember this page; http://www.conspiracyoflight.com/Conspiracy.html
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In particular, when does say an infalling particle actually get inside a black hole? How long does it last there? These questions are meaningful in an interpretation with absolute time.
With LET it slows to a halt just outside the event horizon, as does light, and then because the energy density has gone up a little, the event horizon eventually migrates out past this frozen stuff.
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QuoteIt is not disputed by serious physicists, so what's your game?I'm disputing your personal claims, not disputing anything on which serious physicicts have commented.
When "personal claims" are backed by mathematics (e.g. the necessity of both theories to generate the same 3D view of the action as they're applying the same maths, there is no cause to dispute them.
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Wiki says nothing of the sort. I'm looking at the LET page ES linked. Kindly quote the text you think says this. The article I see says LET doesn't have a theory of gravity at all, per the line I quoted above. It says nowhere that LET is a mathematical abstraction of GTR.
I misremembered what it said having not looked at it for over a year or more. Again though, you shouldn't need to look anything up to be able to see that two theories applying the same maths will generate the same 3D view. GTR merely generates an additional 4D view which cannot lead to a different 3D view.
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QuoteLet me repeat: LET accounts for gravity by having light slow down in gravity wells, and this enables it to match up as perfectly to observations and experiments as GTR, so you're simply wrong.Perhaps so, but citation needed. It certainly doesn't say that on the wiki page, which actually says that LET doesn't account for gravity at all.
People who actually work on LET with this simple addition of having light slow down in gravity wells do call it LET. They just aren't easy to find and aren't known to the people who write that wikipedia page.
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This fails to tell my why my explanation is wrong,
That had already been done, so there was no need to repeat it.
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and didn't even bother to quote the explanation itself.
That was an exact quote of it.
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Your purposes seem to be evangelism and not actual science.
The purpose of this thread was to draw attention to a case that may have been overlooked. There is no evangelism in it whatsoever, and every part of the tool I use is proper science.
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A scientist would back his claims, and would demonstrate how erroneous explanations such as the one you didn't quote above are wrong. Instead I get raving assertions of conspiracy.
I do back them, and I did explain why your idea that a line of black holes doesn't suddenly have a single singularity in it the moment the event horizons connect. Those singularities cannot suddenly move faster than the speed of light to merge.
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Sounds then like relativity. In an absolute interpretation, speed is relative to the absolute frame an not to any other.
The speed of light reduces in gravity wells relative to the mass that forms the gravity well, and at no point can it go faster than c relative to the space fabric. When we're dealing with light moving next to the event horizon, it's slowed to a crawl whether going outwards or inwards, but that crawl is a speed relative to the black hole and not relative to the space fabric.
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Schmelzer seems to have solved this issue, but seemingly not by the premises you're asserting.
His solution for that would need to be the same if it fits observations.
Post by: David Cooper on 25/07/2022 04:17:37
It's a standard way of putting things where they will hardly ever be seen by anything other than bots, so yes.
Citation please. It takes just as many clicks to get to New Theories as it does to get to any other forum here.
You can get into all sorts of things with the same small number of clicks, but different things attract different amounts of readers based on the reward. There is very rarely any reward from reading things in New Theories, so the people who would be interested in the question that this thread poses will not see it. But it's your forum you're sabotaging, so that's up to you.
Post by: Kryptid on 25/07/2022 07:03:18
There is very rarely any reward from reading things in New Theories
Depends on the reason one is reading New Theories. It tends to be one of the forums I look at more often than others.
so the people who would be interested in the question that this thread poses will not see it.
A Google search of "photon escape event horizon" links directly to this thread. So anyone looking for the answer to that question can still find it easily.
But it's your forum you're sabotaging, so that's up to you.
(1) It's not my forum.
(2) I don't see how I'm sabotaging anything.
Post by: Bored chemist on 25/07/2022 08:47:57
It's a standard way of putting things where they will hardly ever be seen by anything other than bots, so yes.If that was true, we wouldn't be commenting on it.
Post by: Halc on 25/07/2022 18:34:57
It isn't something that needs references, so you should not be demanding any. If your model doesn't conform to the requirements of STR, it will enable you to measure absolute speeds with ease, so GTR has to include STR as part of itself in order to fit observations.I do see what you're saying here. If it was just an absolute interpretation of GTR, any empirical claim of GTR would also be an empirical claim of this alternate interpretation. But then it must also conform to GTR’s geometry, and your assertions deviate from that. Hence the need for references since the equations of GTR only work with GTR geometry.
Calling a hypothetical unwritten theory ‘ LET’ seems a mistake. Still, the references you indicate here are not needed when talking about this alternate nameless theory. There's the Schmelzer absolute ether theory which I will call SET for lack of a better name.
The references for which we're asking are the ones that violate GTR:
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GTR also has to conform to our 3D Euclidean view of events while doing its 4D stuffBut GTR includes the effects of gravity and thus is not confined to Euclidean 3D space like STR is. Space is not Euclidean under GTR, so if it is under the hypothetical LET theory, it no longer can use GTR mathematics, and we need a reference for the new mathematics that maintains consistent empirical measurements. You don’t give this because no such theory exists.
SET does not suggest Euclidean 3D space as its preferred frame. The frame is the harmonic coordinate condition, a coordinate condition in GTR which makes it possible to solve the Einstein field equations. This is a non-linearly expanding metric, which Euclidean space is not.
SET is not just a trivial hand-wave, saying everything GTR says is true, but there's a preferred foliation. It derives everything from completely different premises. It very much has differences. Like any absolute interpretation, the preferred frame doesn't foliate all of spacetime, so black holes, wormholes and such cannot exist. There can be no black hole event horizon at all. The big bang must be replaced by a big bounce, perhaps to solve the issue of 'something from nothing' that you get with a model with the universe being contained by time, instead of time being contained by the universe as in GTR, but I didn't actually see if SET posits universe contained by time. LET doesn't posit this, but nLET (another incomplete theory) does.
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LET describes what you get in that 3D Euclidean viewThat's the claim that needs the reference. A 3D Euclidean view with slowed physics makes different predictions, such as the angles of physical rigid triangles adding up to 180°. You're essentially making claims of a nonexistent theory. If space is Euclidean but light (and other motion) merely slows down based on the dilation equations for gravitational potential, you'd get different times for light to get from A to B through a gravity well. By positing this Euclidean assertion, you throw away all the mathematics of GTR that uses a different geometry, and yes, this completely new way of doing it very much does need a reference.
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The two ways of looking at it necessarily map to each other and you don't need a reference to understand that.I actually agree with this, but if they map to each other, then the space under gravity is necessarily non-Euclidean. SET (the only generalization of LET of which I am aware) does not agree with your assertions.
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That's why whenever I employ LET as a tool for viewing the actionIf you're matching GTR descriptions, then you’re using GTR despite calling it LET. If you're making up new rules that contradict GTR, then it needs an actual theory behind it to make the new predictions since the GTR mathematics no longer apply. That needs justification, or it is just 'making up your physics'.
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When LET and STR tell you what these lines of black holesNeither LET nor STR deal with black holes.
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... what these lines of black hole look like as they approach each other before the gravitational interaction becomes significant (due to the extreme contraction of the gravity wells - no amount of applying GTR can change that because the gravity acting on each line from the other is so weak up to that point and cannot affect the 3D Euclidean view of the action)This assertion not backed by mathematics. I tried to point this out in an earlier post, but you don't seem interested in actually working it out. This is another reason for the topic to be in new theories.
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"What [the boat] it zigzags downwind and there's very little drag against the water? It might be able to go downwind faster than the wind." Someone might then object by saying, "Nonsense: by definition a sailing boat cannot go downwind faster than the wind, so you cannot be talking about a sailing boat!This is entirely valid. Based on the definition of sailing boat you gave, the thing you describe isn’t a sailing boat. Ditto for event horizon.
We did have a thread on a sailing ‘car’ that did go directly down wind (no tacking) faster than the wind, or even directly upwind. With a similar definition, we’d have to call it something else.
Guess what the LET in CLET stands for. Doug Marett's site dates back before that and deals with LET and how it covers the same ground as GTR. You ought to remember this page; http://www.conspiracyoflight.com/Conspiracy.htmlAh, an actual reference! I was actually wondering if you would bring up this crackpot site.
I invite to to cite sources for your claims, and not sources from science denial sites.conspiracyoflight is very much a science denial site. It asserts that GTR and even STR is wrong, so if it asserts that CLET makes the same claims as Einstein’s theories (as you do), then it follows that CLET is wrong. I doubt they piggyback off GTR since it attempts to debunk Einstein at every possible turn.
It became a classroom exercise to take any random article listed on that site and find the flaw in it. It isn’t difficult. Pick one if you want a demonstration. This is actually the site you choose to back your claims?
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the necessity of both theories to generate the same 3D view of the action as they're applying the same maths, there is no cause to dispute them.But you’re asserting an alternate 3D view, so the dispute stands.
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People who actually work on LET with this simple addition of having light slow down in gravity wells do call it LET.OK. That claim come right from GTR, so they can stick on the label if they want, despite the lack of an actual theory that does it. But when the claims diverge from GTR, then it becomes something that needs backing since the backing of GTR is lost.
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I did explain why your idea that a line of black holes doesn't suddenly have a single singularity in it the moment the event horizons connect.I never asserted otherwise.
Post by: David Cooper on 25/07/2022 19:27:02
so the people who would be interested in the question that this thread poses will not see it.
A Google search of "photon escape event horizon" links directly to this thread. So anyone looking for the answer to that question can still find it easily.
Most visitors will take a look at the new theories forum and quickly determine that it's dominated by a host of broken or unintelligible junk, so they will never return to it. The also don't do google searches to look for things to read that might be interesting because that depends on them having the idea for themselves before reading the thread. What they want to do is look in from time to time to scan through the topics and see if any interesting ideas are being discussed in the forums where they are most likely to appear. That's how it's supposed to work, and I feel sorry for Chris that it's being sabotaged. Perhaps I shouldn't have turned down the invitation to be a moderator way back, but I didn't want it to look as if my ideas were endorsed in any way by Cambridge University. Anyway, we'll be able to fix that in the future with moderation by AGI which makes rational and fair decisions about all this.
Post by: David Cooper on 25/07/2022 19:28:09
It's a standard way of putting things where they will hardly ever be seen by anything other than bots, so yes.If that was true, we wouldn't be commenting on it.
If it had been put there to begin with, it would have been in the wrong place and you wouldn't have commented on it.
Post by: Bored chemist on 25/07/2022 21:05:27
If it had been put there to begin with, it would have been in the wrong place and you wouldn't have commented on it.Ok, two more errors.
It is in the right place.
I have my account set up so it tells me about any new posts; it doesn't look at which sub-forum they are in.
Since what you asked has a very obvious answer, I would have commented on it regardless- even if you had accidentally put it in biology or whatever.
You need to get over yourself.
Post by: David Cooper on 25/07/2022 21:22:48
But then it must also conform to GTR’s geometry, and your assertions deviate from that.
They don't deviate from it - that's the whole point.
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Calling a hypothetical unwritten theory ‘ LET’ seems a mistake.
It isn't - it's precisely what the people working on LET ordinarily call it.
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The references for which we're asking are the ones that violate GTR:QuoteGTR also has to conform to our 3D Euclidean view of events while doing its 4D stuffBut GTR includes the effects of gravity and thus is not confined to Euclidean 3D space like STR is. Space is not Euclidean under GTR, so if it is under the hypothetical LET theory, it no longer can use GTR mathematics, and we need a reference for the new mathematics that maintains consistent empirical measurements. You don’t give this because no such theory exists.
Everything GTR does can be mapped to a Euclidean 3D view which is the one that all our observations are based on, so you are denying the valid transformations that have to be made between the 3D and 4D views.
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SET does not suggest Euclidean 3D space as its preferred frame. The frame is the harmonic coordinate condition, a coordinate condition in GTR which makes it possible to solve the Einstein field equations. This is a non-linearly expanding metric, which Euclidean space is not.
LET does not try to make Euclidean 3D space a preferred frame, as I've pointed out before by distinguishing between different types of "absolute frame". At some point you ought to take in the difference between them and stop conflating them.
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SET is not just a trivial hand-wave, saying everything GTR says is true, but there's a preferred foliation. It derives everything from completely different premises. It very much has differences. Like any absolute interpretation, the preferred frame doesn't foliate all of spacetime, so black holes, wormholes and such cannot exist.
Same issue there - you're still misunderstanding absolute/preferred frames. In an expanding frame, one type of "absolute frame" can be a different frame for each location because a photon moving north at A and a photon moving north at B in the same direction are moving relative to each other. What do you do though every time I explain these nuances? You fail to take them in (perhaps deliberately), and then you try to make out I'm imposing one such frame on the whole universe as a universal absolute frame, but I've made it clear dozens of times that I do nothing of the kind.
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There can be no black hole event horizon at all.
There are things that ordinarily go by the name "black hole" and they have a boundary layer on them ordinarily known as the "event horizon", and no theory is going to change the fact that these things exist in some form - they merely question the form (the business of what they actually are).
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The big bang must be replaced by a big bounce, perhaps to solve the issue of 'something from nothing' that you get with a model with the universe being contained by time, instead of time being contained by the universe as in GTR, but I didn't actually see if SET posits universe contained by time. LET doesn't posit this, but nLET (another incomplete theory) does.
The big bounce itself is an unresolved issue, but certainly a lot of what's said about the "initial" condition of the universe is different with LET because in that type of model time did not start at the big bang.
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QuoteLET describes what you get in that 3D Euclidean viewThat's the claim that needs the reference.
It doesn't. Because the same maths is used to generate that 3D Euclidean view as is used by GTR, there is no question of any divergence.
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A 3D Euclidean view with slowed physics makes different predictions, such as the angles of physical rigid triangles adding up to 180°. You're essentially making claims of a nonexistent theory.
There are apparent angles and actual angles. If you build your triangle in a gravity well where the speed of light variations distort its sides and make them curved while they look straight to you, the sum of the angles that you measure actual shape in such a way that and measure the angles, you can measure can be greater than 180 degrees. In the Euclidean view for an eternal observer, the triangle has curved sides though, so again your making up claims that aren't mine and then attributing them to me in order to attack them. That's something you specialise in doing.
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If space is Euclidean but light (and other motion) merely slows down based on the dilation equations for gravitational potential, you'd get different times for light to get from A to B through a gravity well. By positing this Euclidean assertion, you throw away all the mathematics of GTR that uses a different geometry, and yes, this completely new way of doing it very much does need a reference.
You do get different times for light to go through a gravity well depending on how deep it goes, though the bending of the path means they won't all reach B, so I don't know what specific action you're picturing there. If you send clocks through the gravity well, the lower speed of light where the lower clock goes will slow its ticking. If you send light, that light will record no timing difference as it registers no time passing for it at all.
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QuoteThe two ways of looking at it necessarily map to each other and you don't need a reference to understand that.I actually agree with this, but if they map to each other, then the space under gravity is necessarily non-Euclidean.
In one theory, but not in the other. The universe does whichever it actually does.
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SET (the only generalization of LET of which I am aware) does not agree with your assertions.
Doug Marett put up his information on LET before CLET (which you call SET) was published, and it's all based on the speed of light slowing down in gravity wells. I contacted him to try to find his sources, but he was uncommunicative and I don't pester people. This is a common trait when trying to hunt down the people who did the initial work on this. Whether Schmelzer was involved in driving that I do not know, but he may just be doing a rehashed version of other people's work.
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QuoteThat's why whenever I employ LET as a tool for viewing the actionIf you're matching GTR descriptions, then you’re using GTR despite calling it LET.
Not at all. The maths that fits spacetime bending also fits what the universe does (because it would be rejected as wrong if it failed to fit), and it also fits how light slows down in gravity wells. Using that maths that fits what the universe does does not mean you are using any specific theory that uses that maths. The maths is theory-independent.
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If you're making up new rules that contradict GTR, then it needs an actual theory behind it to make the new predictions since the GTR mathematics no longer apply. That needs justification, or it is just 'making up your physics'.
The theory-independent maths continues to apply and there is no need to make anything up. All that changes between the theories is the description of what might actually be going on. The 3D Euclidean view will not be affected by any of that.
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QuoteWhen LET and STR tell you what these lines of black holesNeither LET nor STR deal with black holes.
Both have to be able to handle black holes, although STR doesn't need to account for the gravity aspects of them - it can restrict itself to things like length contraction issues on gravity wells, orbits and event horizons. LET goes further though by predicting what's inside event horizons (i.e. that they're packed with stuff all the way through and that there's no singularity). Claiming that that can't be called a black hole is a linguistic error on your part.
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Quote... what these lines of black hole look like as they approach each other before the gravitational interaction becomes significant (due to the extreme contraction of the gravity wells - no amount of applying GTR can change that because the gravity acting on each line from the other is so weak up to that point and cannot affect the 3D Euclidean view of the action)This assertion not backed by mathematics. I tried to point this out in an earlier post, but you don't seem interested in actually working it out. This is another reason for the topic to be in new theories.
It absolutely is backed by mathematics, and any serious physicist who knows their stuff about this will back me up on that point. The high speeds of travel can flatten the entire gravity wells almost to discs in precisely the way that I said, and for them to fail to do so at the relevant speeds would enable the absolute speeds of travel of the black holes to be pinned down with ease. That is another illustration of why you should not be a moderator. You are making judgements about hiding scientific discussions based on errors in your understanding of physics.
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This is entirely valid. Based on the definition of sailing boat you gave, the thing you describe isn’t a sailing boat. Ditto for event horizon.
It remains a sailing boat or event horizon and the original definition is revealed to be incompetent, so it gets adjusted to accommodate the improved understanding of what the thing is.
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We did have a thread on a sailing ‘car’ that did go directly down wind (no tacking) faster than the wind, or even directly upwind. With a similar definition, we’d have to call it something else.
And that one is called something else, but we also have AC40s, AC50s, AC75s, etc. sailing downwind faster than the wind while remaining as sailing boats.
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Ah, an actual reference! I was actually wondering if you would bring up this crackpot site.
It's a much more serious physics site than the establishment ones which push disproved theories, so you're calling the establishment crackpots by extension.
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conspiracyoflight is very much a science denial site. It asserts that GTR and even STR is wrong
Any site that fails to do so is automatically wrong because those theories have both been disproved.
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It became a classroom exercise to take any random article listed on that site and find the flaw in it. It isn’t difficult. Pick one if you want a demonstration. This is actually the site you choose to back your claims?
It's possible to find flaws on any establishment site in the same way, but of greater magnitude. They're pushing theories that have been disproved and should not still be on the table.
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Quotethe necessity of both theories to generate the same 3D view of the action as they're applying the same maths, there is no cause to dispute them.But you’re asserting an alternate 3D view, so the dispute stands.
I have not asserted an alternative 3D view. I have pointed out how you can see more easily what that 3D view must look like and how you can use that to spot errors in your attempts to generate it through GTR. It's much easier to simulate the action in your head by seeing what the speed of light is doing in gravity wells instead of trying to imagine things in 4D with a weird fourth dimension which doesn't behave like the other three. If you were actually able to process the action through GTR in your head correctly (while also remembering to apply STR within it), you would see that the gravity wells contract to thin discs at extreme speeds of travel and that their interactions aren't significant until the last moment of approach. Run your model correctly and it will match up to the LET description of the 3D Euclidean view of the action. You simulate it incorrectly in your head because you can't handle the 4D, and then you tell me I'm wrong and that you've flung this into new theories because I'm wrong, but you're the one representing what your theory says.
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QuotePeople who actually work on LET with this simple addition of having light slow down in gravity wells do call it LET.OK. That claim come right from GTR, so they can stick on the label if they want, despite the lack of an actual theory that does it. But when the claims diverge from GTR, then it becomes something that needs backing since the backing of GTR is lost.
Again, there is no divergence in this case and that's the whole point: it's easier to run the action correctly in your head using LET, so the divergence here is caused by you failing to run the GTR action correctly in your head. And GTR does not say that light slows down in gravity wells. GTR may well says that that's how it looks in the 3D Euclidean view of events, but GTR insists that light does not slow down in gravity wells and that extra space is packed in there instead, whereas LET says that light actually is slowed down there - that is the driving difference between the theories.
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QuoteI did explain why your idea that a line of black holes doesn't suddenly have a single singularity in it the moment the event horizons connect.I never asserted otherwise.
The text I quoted says otherwise.
Post by: David Cooper on 25/07/2022 21:29:27
I have my account set up so it tells me about any new posts; it doesn't look at which sub-forum they are in.
Since what you asked has a very obvious answer, I would have commented on it regardless- even if you had accidentally put it in biology or whatever.
Well, we'll never know if that last bit's the case, but most readers of the forum look at new theories once and once only.
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You need to get over yourself.
I don't come into it. This is all about doing and discussing science properly while maximising the utility of the forum for readers and putting the right ideas and questions in the right places for them to find them with minimal effort.
Post by: Eternal Student on 25/07/2022 23:48:50
This is all about doing and discussing science properly while maximising the utility of the forum for readers and putting the right ideas and questions in the right places for them to find them with minimal effort.
I quite like this forum but I think you might be over-estimating the readership. For example, most people lecturing or actively engaged in research in Physics don't make a routine of logging in to this site on a Monday morning to discuss what's new in it with other members of staff. Their time is better spent checking the new research papers that come through the established journals and they still can't be expected to check everything. So some major developments won't come to their attention for several years. If something is important then it will be mentioned in more than just one paper and might even come up as a topic of discussion in some conference.
What do you think the readership of this forum is? Who are you trying to get this information to?
In one of your earlier posts you asked if someone has suitable simulation software to test something. If you really want to attract the attention and expertise of someone with that sort of software then the "new theories" section is probably exactly where your post needs to be. The average reader of the main sections isn't some Physics professor looking for information about .... how an oscilloscope works, or indeed, if a photon can escape from a black hole.... they have access to textbooks, libraries and email they can send to other experts if they want answers for that sort of thing. Quite possibly the best chances of getting your thread noticed by that sort of person would be to have it presented in the "new theories" section.
Well, we'll never know if that last bit's the case, but most readers of the forum look at new theories once and once only.I'm sorry if you feel your time was wasted. Everyone who has spent some time here adding replies is suffering the same fate. I know I put in a few hours trying to create some good replies including diagrams and animations. Halc's replies also look like they took him some time.
Overall this forum is a forum. It's a place for discussion with others and also where some questions from the general public could be posted and hopefully answered. It never was intended as a place to host some monologues or anything that might be remotely like a repository of authoritative articles. There are some forums that will try and do precisely this but Naked Scientists doesn't have any such repository.
If you were trying to deposit something like that here, then you are wasting your time. It would be better to set up your own website (there are some freely available services, I believe) then the content stays put and has the same URL for ever (or as long as the service provider lets you have it, or stays in business etc.)
It hardly matters which section your thread is put in. Once it gets old and falls off the 1st page of the board because newer threads have appeared - then it will rarely be read by anyone ever again anyway.
Best Wishes.
Post by: Colin2B on 26/07/2022 09:25:42
David,This is all about doing and discussing science properly while maximising the utility of the forum for readers and putting the right ideas and questions in the right places for them to find them with minimal effort.Quite possibly the best chances of getting your thread noticed by that sort of person would be to have it presented in the "new theories" section.
Welcome back, long time no see.
Chris has made changes over the years to how the forum should be run and new advice given to moderators. Although it is possible to debate the placement of some topics @Eternal Student is right in that topics in New Theories are not disadvantaged.
I regularly keep an eye on which topics are being viewed and a snapshot last night gave:
General science 30
Physics Astronomy 63
Physiology 60
New theories 50
So, you can see that New Theories was getting a fair share of viewers. Just to be clear, there was a very low incidence of bots at the time.
I would certainly be interested to see a serious, in detail discussion on how LET handles gravity.
Post by: David Cooper on 27/07/2022 00:03:51
I quite like this forum but I think you might be over-estimating the readership. For example, most people lecturing or actively engaged in research in Physics don't make a routine of logging in to this site on a Monday morning to discuss what's new in it with other members of staff.
One of the purposes of posting this was just to get at time and date stamp on the idea in case it's new, so it doesn't matter where it's put for that purpose. The other purpose was just to put it out there as an interesting possibility for the general reader. The odds against getting it from here to someone with the right simulation software were always extreme. What I find disappointing about this is that the general reader is not being served well by things of this kind being hidden from them, and they are being hidden. The people who read the new theories section are dominated by people who post their broken theories there and not the general readers looking for interesting science ideas - they are two different sets of people, though the worse the general readers are served, the fewer of those there will be. Their numbers need to be encouraged to grow by providing the right environment for them where if they dare to comment on things they don't end up with a pack of attack dogs tearing into them. I suspect most of them were scared off long ago.
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I'm sorry if you feel your time was wasted. Everyone who has spent some time here adding replies is suffering the same fate. I know I put in a few hours trying to create some good replies including diagrams and animations. Halc's replies also look like they took him some time.
I don't feel it was wasted at all - I just think there are better ways to run things. But you're also right - I should thank you, Halc and others for their contributions. You have all been doing your best to take this somewhere. The only disappointment is that the general reader has had what I think is an interesting question hidden from them. It certainly can't go back there now though due to all the diversions that took it over due to misguided attacks on it, so that's one that they'll just have to do without.
Post by: David Cooper on 27/07/2022 00:49:28
David,
Welcome back, long time no see.
Thanks. I haven't been well but am on the mend. Hope all's well with you. What happened to Pete? I'm worried at the lack of any sign of him.
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I would certainly be interested to see a serious, in detail discussion on how LET handles gravity.
Well, there might be something new on the horizon. Gravitational lensing from the changing speed of light acts on the waves that make up particles such that they're lensed downwards just as light is - that accelerates particles down, but there also has to be a medium involved in this to set the local speed of light, so it's that medium that's the interesting thing being explored today, and it's led to discoveries like the frame dragging mechanism - that was always problematic in the past because the aether is static and can't be dragged round and round massive bodies, but we now have two mediums interacting with the second one being fully capable of moving. The place where the biggest breakthroughs will doubtless come though is with black holes because you can't lens down a black hole into another one if it's full of frozen waves that don't move - no movement means no bending of their paths, and that means no acceleration down, so something has to keep moving, and perhaps it's the medium moving while itself being unaffected by the slowing of light. (There's always been a problem for both LET and GTR as to how the content of black holes can govern their gravity wells when no signal can get out of them, so clearly something has to be able to move out of them faster than the slowed speed of light within them. GTR doesn't actually have slowed light in it as it's always moving at c, so there simply are no possible paths in them for any signals to get out to control the gravity well, but in LET there is an option for control signals to get out by going faster than the slowed light while not exceeding c.) If you want to lens a black hole down, you could achieve that by moving the medium about such that the static waves you want to lens with it are moving relative to it and can then accelerate downwards. But what happens to a "frozen wave" anyway? When you halt light in the lab using some kind of medium that stops it, the photon ceases to exist while the medium takes up a different configuration to hold the photon's energy, and then the medium can adjust back to recreate the photon and let it continue on its way, so when a light stops at the event horizon, it likely ceases to exist and transfers its energy to the medium that stopped it, and the same will apply to all the waves of energy that make up every particle that falls onto the event horizon, so it becomes something else. That's what physics needs to be exploring, and the people working on string theory are likely on the right path with this. Pinning down the nature and functionality of the medium that slows light will be the key to the next big advances in physics.
Post by: Bored chemist on 27/07/2022 08:59:30
Well, we'll never know if that last bit's the case, but most readers of the forum look at new theories once and once only.For a start, you do know it's the case, because I told you it is.
But let,s just check.
Is there anyone here who agrees with your claim that "most readers of the forum look at new theories once and once only"?
Post by: Colin2B on 27/07/2022 11:27:39
Sorry to bring sad news, Pete died after a long illness.David,
Welcome back, long time no see.
Thanks. I haven't been well but am on the mend. Hope all's well with you. What happened to Pete? I'm worried at the lack of any sign of him.
Glad to hear you are improving, had intended to reply to your other post, but the covid hit and I’m just recovering.
Post by: David Cooper on 27/07/2022 18:20:20
Sorry to bring sad news, Pete died after a long illness.
I thought that was likely the case as he had lots of medical problems and suffered a lot, but I'd have liked to have got in touch with him if he was still hanging on just to try and give him a boost.
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Glad to hear you are improving, had intended to reply to your other post, but the covid hit and I’m just recovering.
Hope your recovery is good - it can still be a rough ride even with the vaccines.
One of the other things I've been up to recently is redesigning the wheel so that it can roll up and down stairs easily by adapting to the shape of the stairs in such a way that the hub follows an approximately straight path at a constant speed, so I now have to try and build a working model. I can't describe it until it's patented, but it could make a big difference for disabled people and for robotics, while ideally the royalties would all go from the latter application to subsidise the former. I'd like to hand the idea over to a university that can develop a complete demonstration device (ideally an electric wheelchair). First to ask will be first to get.