I'm just waiting for the spam advertising.Already deleted. Already banned. It was in the signature.
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Any idea what distances such a thing would happen at?It's kind of like asking when normal velocity addition stops working and when relativistic addition must be used. It depends on the precision you want, but right away if you want infinite precision.
Inertial propulsion is the "graal" everyone try to discover because it can be achieved without any loss of mass.This is a claim of reactionless thrust, not 'inertial propulsion'. And the word is 'grail', not 'graal'.
But if you can retrieve electrical energy (from the sun or from nuclear reaction...), you can always recharge your battery.Indeed. If I had reactionless thrust, I could use it to generate more electricity than it costs, so no sunlight or nuclear reactor needed. The world energy problem would be solved. Isn't magic great?
As you have implied in several earlier posts, the distant scientist cannot change the way her local space behaves or the laws of physics in her local space just by changing her co-ordinates.But you are doing this in your prior posts, implying that 'the way space behaves' is a function of your frame dependent abstraction, and not a function of the physical geometry of the spacetime.
However space isn't Mnkowski space in those new co-ordinates.Here you changed your coordinate system and suggests that somehow the spacetime is different, but when I do the same and you say it hasn't changed. You need to be consistent. Is spacetime being locally Minkowskian an abstract choice, or are you referring to the fact that the physical spacetime is locally flat such that a Minkowskian metric can be meaningfully mapped to it?
They can use Kruskal co-ordinates (T,R, Ω)I was using (T,X). There is an r and t that corresponds to Schwarzschild coordinates, but those are different coordinates. The rock reaches the event horizon in finite time T as illustratred in your picture. The singularity has been omitted from your picture, but the rock also reaches that in finite time.
However they can't escape the fact that R=T is a surface where the Schwarzschild co-ordinate time, t is specified by t = +∞ and Schwarschild r = +2GM.That's right. Different coordinates are singular there, which is why I didn't choose them.
That Schwarzschild time, t, isn't unimportant or arbitrary to the scientist. That co-ordinate t is what they will experience as local time (if they hold still).This is wrong. How does one 'experience' any kind of abstract time? One experiences proper time. That's the only time that's physical. One does not 'experience' the time for some worldline not in one's presence.
The event where the rock crosses the EH never falls inside a past light cone for an observer on the blue line of constant Schwarzschild radial co-ordinate r shown.Of course not. It's a physical (coordinate independent) fact that and event on the event horizon cannot causally effect one outside that horizon. Light cones (physical) do not define simultaneity (abstract).
That's fine. Everyone agrees that there is an event with the rock on the event horizon.Not the people using the x,y,z,t or say the cosmic coordinates. There are people that very much disagree that the rock physically crosses the EH, and that the experience of falling in would be cessation of existence right there. That's a crock of course, it leading to inconsistencies.
This mean, the people can change the result of the quantic experiment (making the wave function collapse !), only by thinking about it, elsewere on earth, as if some experimentator would direct interact with the phenomenon at the place of the experience.This is just decoherence, the effect of which travels at a good percentage of light speed. If it was 'caused' by some specific distant guy thinking about it, then they must have been able to show that the same system would remain in superposition (not collapsed) indefinitely if this one distant guy was not thinking about it. They've demonstrated no such thing.
and a New Experiments Show Consciousness Affects Matter.This is pretty trivial to demonstrate, even without all the superfluous capitalized words.
team explain how they have prooved (many years of very impressiv tests) that someone can act on some quantum phenomenonLikewise, if I observe a normal distribution of light in an experiment, I paint my house one color, but if I observe an interference pattern (a quantum phonomenon), then I paint the house in stripes. I have thus acted on some quantum phenomenon, and it again didn't require 'very impressiv tests'.
I made no mention of an architecture optimized for speed. A simulation has no inherent speed requirement and can be implemented by a guy with pencils and a lot of paper if you want, or worse, by a Turing machine. Even say a 3D grid architecture with millions of processors per dimension would still require a model of:Quote from: Halca computer simulation... implementing one would typically need to implement a state to keep track of. That means no spacetime. Presentism. Faster-than-light causality. Objective state. All the things I detest.You seem to be imagining a computer simulation run on a uniprocessor, in which a single processor needs to access the entire state of the universe.
The fastest computer architectures tend to be grid computers, which only have really fast communication with their immediate neighbors,
- A 2D grid CPU has 4 immediate neighbors
- A 3D grid CPU has 6 immediate neighbors
- A 4D grid CPU has 8 immediate neighbors
- And yes, researchers have investigated 5+D grid CPUs with 10+ immediate neighbors
However, the last uniprocessor to be dubbed "fastest in the world" was the Cray 1, which only held the title until 1982, when it was overtaken by a multiprocessor computer (also from Cray).For the record, a Cray 1 (I've seen one) was a SIMD machine, which means single instruction but operating on hundreds of data elements at once, so it's very parallel despite apparently being classified as a uniprocessor by somebody. It is thus a fantastic vector processor for crunching simulations of things like the weather, but it would not be particularly good at chess, which would better be served by some sort of cloud configuration.
Suppose one person is using the co-ordinate system (x,y,z,t) which just turns out to be a set of co-ordinates that behave much as you'd expect. Specifically, their space is locally Minkowski space in those co-ordinates.OK, so you've assigned different coordinates to those same events using a system with non-orthogonal axes in which light moves at infinite speed in one (and only one) direction (which makes for an interesting sync convention). It indeed doesn't conform to the Minkowski metric, but the space itself is no different, just different abstract coordinates assigned to the physical events. The mathematics got more awkward, but not impossible.
Another person can choose to use different co-ordinates with this transformation between the co-ordinate systems:
a =x ; b = y ; c = z
T = x + t
So that their co-ordinate system will be written as (a,b,c,T) with a,b,c exactly the same as x,y,z.
The scientist should have no difficulty identifying a suitable, natural set of co-ordinates because space won't be Minkowski space in very many co-ordinates.I didn't suggest anything not 'suitable'. In fact, I chose one far more more suitable. There's questions (about objective events) that cannot be asked using those coordinates, but which can be asked using different ones. That makes the 'different ones' a better choice for this scenario.
Specifically, they can choose to use some arbitrary co-ordinates but they will know and can tell that the metric isn't Minkowski in those co-ordinates - it it will only take them a few experiments to determine that.This is an interesting assertion: that one can empirically test for an abstract choice of coordinate system without first begging the choice.
They will pick up a stop watch and set it going, they will say to themselves "that is time flowing in the positive direction".Ah. Presentist scientists. The stopwatch demonstrates no such thing. Sorry. Just pointing out that they're begging a philosophical conclusion and have not demonstrated anything scientific yet. You can't discuss a black hole using a model where time is something that flows. Any such model denies the existence of the thing.
For example they can pick up the stop watch again and try it but it doesn't record the passage of T, it only records the passage of t.If they hold it still relative to the x axis, it measures T. The Minkowskian guys don't get an accurate measurement of t either if the watch is moving. Funny that watches don't measure coordinate time.
A scientist at a distance from a black hole (where the rock was heading into) can choose to use Kruskall co-ordinates but that doesn't mean that the scientist won't experience an infinite amount of time pass before the rock reaches the EH. I don't see that there needs to be an objective reality here.Hey, this comment was on point. Yay!
I know you (Halc)Nit: Everyone knows who you're talking to, it being implicit in the quotes to which you're replying. You don't need to do that every time you use a pronoun. Sorry, I'm sounding grumpy now. Don't take this as hostility.
to phrase that another way, are you sure that you (Halc) aren't trying to be the absolutist and suggesting that there would be an objective reality.Classically, there are objective events. Its only getting down to the quantum level where I would suggests a lack of objective reality. A rock/laser/observer falling into a black hole is a classic scenario. Unruh radiation is not.
When you measure some quantum object, there is a certain probability that it will be found at one position or another (or one time or another), according to Heisenberg's uncertainty principle.The principle allows arbitrarily high precision to say position, but at the expense of knowing its momentum. It’s not something you can measure twice if you got it really precise the first time. Then again, I think Planck (not Heisenberg) put hard limits on this precision, and that precision is probably far more coarse than these ‘dots’.
Your proposed construction of discrete events for a discrete spacetime by randomly sprinkling them like dots onto a piece of paper is a little awkward and I'm not sure it achieves very much.I actually agree with this. I was just tasting the idea mostly.
This is roughly what you seemed to be suggesting:I said that. In reality, a Lorentz transform must be used to rotate the paper. It isn’t Euclidean like paper is.
Sprinkle events like dots almost at random on a piece of paper and (just for good measure?) also hold the paper at some random angle to randomise it a bit more, then have time up the vertical and space on the horizontal.
You suggested trying to start with horizontal lines across the page that are representative of lines of constant time. However the events don't usually lie nicely on a straight line, so you allow some wiggling up and down to make sure you pass through the nearest dot to what would be a horizontal line.Sure. ‘Nearly simultaneous’ (if that has any possible meaning) relative to this local frame. Gets pretty ambiguous. How do you decide which dots are near enough and which are at different times? The more picky you get about that, the more distant the possible spatial locations available at that ‘time’, and as time progresses not a whole dot forward, some dots are no longer close enough to the new ‘time’, but others still are. Event A simultaneous with B (in this given frame), and B with C, but A not simultaneous with C. All very contradictory.
Any vertical line that passes through a dot is an x-axis location we can have.Eventually. Technically dots and lines have no width, so it will be an arbitrarily long time before a random line drawn anywhere ‘hits’ anything. So now we need a ‘close enough’ value that is less than the minimum distance. Another contradiction.
Now we see a problem... Assuming the sprinkle remains of consistent density and random across every time slice, and time extends up the page indefinitely, then we will always be able to find another possible x-axis location as close as we like to the first one we started with. Overall the entire x-axis could be divided up into so many lines that it is just a continuous range of possible x-values again. That's no good, we want some discreteness in our spacetime. So we're not going to divide the x-axis up as finely as we can... we're just going to do it fairly finely.Say it’s a meter apart (a min distance). Sprinkle dots a meter apart (in a grid or randomly) and draw lines randomly through each one perpendicular to a random time axis. It will still be sliced up arbitrarily fine as there is nowhere you can choose an x that doesn’t get arbitrarily close to some dot somewhere. So don’t know where you’re going with this. Only way to avoid this is a flat regular grid perfectly lined up (the preferred frame), in which case you can walk between the trees indefinitely without every getting close to one.
How finely? As much as you like, just not so much it becomes continuous.
There's no disagreement about frames of reference and co-ordinate systems.There is if I'm choosing one that isn't singular at the event in question, and you are choosing a different one.
(r,θ,φ) will be a natural spherical spatial co-ordinate system for them (centred at the black hole admittedly rather than being centred on themselves which is a bit unusual but not totally bizarre).r is not spatial inside the event horizon, and events separated only by t are not time-like separated.
Not when the question is about what happens for the distant observer.Relativity of simultaneity says that the local time (at the distant observer) at which a distant event (object crosses EH) is coordinate system dependent. So there is no correct answer to the question unless you're an absolutist, in which case you should use the absolute foliation and no other. The coordinates you've chosen certainly do not qualify as an absolute foliation, but then I'm not suggesting one that serves that particular purpose any better.
For the distant observer (holding constant r,θ,φ ), an infinite amount of time must pass before the rock reaches the horizon.Yes, if you choose the coordinate system you indicate, then the infalling thing never gets to the EH. That's probably a problem since I can think of a few contradictions that result from that, but the absolutists do actually posit something like that, denying the existence of black holes altogether. Coordinates of r <= rs are not valid coordinates of any real event. Maybe you can get around this by suggesting the EH reaches out due to a 2nd thing dropped in later, but there'd need to be an infalling metric describing it to be sure if this works or not. As I said, the absolutists deny this effect and say the material moves outward as the BH gains mass. I don't know if they've produced a metric satisfying the field equations that supports this, but they're already in denial of relativity, so they probably don't think they have to.
The rock will reach the horizon when co-ordinate t =∞Not if the BH evaporates before then.
No. You're deliberately trying to slip something past people here by tacitly switching to the time experienced by the rock.I'm not. Everybody already knows what the rock-time will be. That's a physical thing, not frame dependent. The frame of the rock is also a poor choice. I was thinking something like Kruskal–Szekeres coordinates where events for neither the distant observer nor the infalling object are ever singular along their worldlines. OK, the infalling object eventually reaches the central singularity (which might be a line or a plane), but it does so in finite time for everybody. No infinities.
I knew "the last photon" would be mentioned before your reply appeared, it was just bound to be mentioned. I think the usual model assumes the emission of individual photons from the rock is randomYes. I also assume the rock had a light beacon on it, perhaps a well aimed laser. Lots of photons, but there's always a last one.
Then the time when the last photon is received can't be predicted and the distant observer can't be sure that this was the last photon, there could always be one more.Totally agree. The Kruskal–Szekeres picture of the exact same geometry doesn't suggest otherwise. Said 'last photon' is a physical thing, not an abstraction after all.
Is the mass on matter, at any giving instant on time, presented on the interior of the atomic structure?This was the only question I could find.
Or the mass of matter is constantly "given" to it by dark matter on the future frame?The mass of an atom has nothing to do with dark matter since an atom is not dark.
By that I mean, how one does proof, that the mass of any giving atom, at any giving instant, at any given frame of existence, is not given to it, from the next frame of existence?Existence doesn't come in frames, certainly not adjacent slices of time, which this wording seems to imply.
Well, I like where that post was heading.You do? Your post perhaps should be its own OP. It seems to convey that you've actually learned some physics, and the language for that matter, both absent in the post to which you replied.
is there a way to know how large Sagittarius A was when it formed ?It was probably one or more stellar black holes, most of which are born perhaps twice the mass of our sun. It gets larger by having other mass fall in (which is in abundance in the galactic center, especially in the early formation years.
...and then.....ewe have TON 618....... 66 TRILLION sol mass !!..... 66000000000 !!!! how is this possible ? did it swallow a few galaxies ?Lots of them I think. There are insanely large black holes at the centers of superclusters like (from small to large) Virgo, the Great Attractor, and the biggest one 'nearby', the Shapley attractor.
From what I understand it takes a long long time(millions of years ?).....just for one sol's worth of mass to be gobbled up by a black hole.Sgr-A is a known slow eater (at least currently), but nowhere near that slow. A well-aimed star will just fall straight in, so one can consume a star in moments. Most stars are not well aimed, so if they get too close they just get torn apart and distributed into the accretion disk, some of which is slowly consumed by the black hole below, but the energy released by the infalling stuff adds kinetic energy to the atoms left behind, so much of the material gets shot away at the polar jets.
what kind of commencement did TON 618 have and how large would it have been when it was ' born 'Probably the same as any other. Probably the larger 'blink out' birth of 20-100 solar masses (a guess). It probably happened earlier than almost any other black hole since for it to get that big today, it had to be near the center of an obscene density of material where stars form quickly and grow too large before they can burn almost any of their fuel. There were probably many such large-but-infant black holes formed, all of which merged after not too long. Determining which one was the original TON 618 itself is like trying to figure out which exact puddle is the head of the Thames river (without a map showing which one they picked).
The rock never reaches the black hole event horizon IF the space in that region retains its Schwarzschild geometry.I didn't say that at all. It not reaching the EH is an artifact of an abstract labeling of the crossing event in the 'frame of the distant observer' which just happens to be singular at the point of contention, making it a very poor choice to answer the question. That abstract coordinate system happens to assign infinity to the EH events, and thus no event outside is after the crossing. But that's just an abstraction, not a physical barrier to the object going in. Choose a coordinate system that isn't singular at the EH and the object goes in without any fuss, in finite time according to everybody.
Obviously that narrative is very different from the usual version of what happens when something falls towards a black hole and is said to never reach the event horizon - as far a distant observer is concerned.It all depends on the coordinate system chosen by said distant observer. I can similarly choose a coordinate system where I cannot reach the next room due to a singularity along the way, but I don't actually notice anything when I go there.
I was only stating that this is at least one way that it can happen in a finite amount of time.How long it takes is a purely abstract duration, not a physical one. Physically, it falls in without fuss, but physically there are no objective time coordinates to events, so the question of how long it takes is essentially meaningless. The proper time is not meaningless.
LIGO have strong evidence for black hole mergers and they do seem to happen in a finite amount of time.The gravitational waves quickly die down from its peak, well below the ability of LIGO to detect them. But it's the same as any light emitted near the event horizon: it never stops arriving, being red-shifted arbitrarily long. The merger, as observed by a perfect LIGO sensitive to all wavelengths, will be (classically) observed for nearly forever. But that's an observation, not what's actually going on. Observations are physically objective, and are not frame dependent.
So: Very few photons, severely red-shifted: The rock would not "float" near the event horizon, it would just disappear.Yes, since the image isn't classic, but is quantum. At some point the last photon is emitted that will reach the observer in question. Ditto for the last graviton detected by the perfect LIGO.
If you throw a rock into* a black hole does it's mass parameter ever increase? (does it "get bigger"?)This mass parameter is frame dependent, but from your distant viewpoint, the mass/energy it gains from KE is balanced by the PE mass/energy lost from it being at an ever lower potential. So no. A 1 kg rock dropped into a black hole increases the BH mass by 1 kg.
*into ---> perhaps I should have said towards the black hole, it hasn't actually gone in yet.
So how do black holes get bigger - other than through black hole mergers?Relative to a distant frame, they grow. A rock never falls into a Schwarzschild black hole, but a BH with a rock dropping into it doesn't conform to the Schwarzschild metric. I'm unfamiliar with the name of a metric describing a mass falling in. Surely somebody must have worked it out.
Something must be holding light back faster than light itself travels.Nothing 'holds back' anything. Relative to anything inside a black hole, all future events are also inside. Trying to send light 'outside' is like trying to shine a light onto 2021 from here. Light doesn't travel into the past no matter how hard you attempt it.
I understand gravitational waves propagating outside the black holeGravitational waves generated outside the black hole propage outward, yes.
so it's the propagation of internal gravity waves that stops light ?They have nothing to do with it. Gravitational waves are just another thing that moves at light speed, but also do not move into the past.
does light even exist inside a black hole ?Of course. If you jump into a big one with a set of lights (say in a room full of glow sticks), you'd not notice anything different as you crossed the event horizon. Light from the glow sticks would still reach you from every direction.
What ,then, is the effect of changes to the distribution of mass inside a BH? Anything? Do we know?Per the no-hair theorem, there is zero external effect of changes to internal mass distribution. Nobody outside could measure it.
Is gravity...travelling then ?Gravity is not something that travels. It is a distortion of spacetime.