1

Physics, Astronomy & Cosmology / Re: What is the exact cause of the time dilation of the twin?

« on: 02/10/2024 16:50:54 »

Oh dear, here we go, again. Word salad.

Indeed.  The prior posts have been removed for several reasons.

1) Nonsense in the main sections of the forum
2) Contained personal information
3) Had nothing to do with the topic title, hence is a hijack of a topic
4) Contained a bibliography which was nowhere referenced
5) Contained no content from any of said bibliography
6) Word salad as Paul points out
7) Duplicate posts

At least the first three of those violate forum rules.

2

New Theories / Re: Gravity In Relative Motion - is there any solution?

« on: 28/09/2024 02:51:02 »

So does it mean that kinetic energy starts to be added to the inertial mass/energy of a body only when a certain velocity is reached?

No.  It would violate energy conservation if I did work on an object and no energy was transferred to it because it wasn't yet moving fast enough. This again is not unique to relativity theory.

If total relative velocity of our (me and the object in question) motion is equal to 0,99c - how can we know how our velocities are distributed in other frames?

The relative velocity addition formula can do the frame transforms for velocity.  Lorentz transforms are for coordinate transformations between frames.

Is there any difference between me incoming towards the object at 0,99c and object incoming towards me at 0,99c?

Yes.  The vector of one velocity is the opposite of the other.  Different objects are stationary in the two respective frames.

And what if in some other frame we (me and object) are incoming at each other with equal speed? Where the additional mass/energy will be added?

Each object contributes its own kinetic energy in that frame.

[/quote]And coming back to ISS and your answer - can you help me finding the fragment of text telling that relativistic mass becomes a 'thing' only at extremely high velocities and that it's effect is completely non existent below some specific velocity?[/quote]It doesn't have a minimum speed. It's a thing at any speed (even zero), but not very significant at low speeds where classical approximations are sufficient to express the KE of the object (E=mv?).

And if not that - should I understand that classical mechanics might lead to effects that are contradictory to effects of SR?

Classical mechanics is a good approximation at low speeds. Neither classical nor relativistic mechanics says that objects gain no kinetic energy until some minimum speed is reached.

So until some particular value adding velocity allows escaping gravity but then and then just like that - "Flop!" - and now adding velocity will start increasing gravitational pull?

Yet again, this is totally wrong. Stop asserting this.

Nope. [Einstein is] completely and utterly wrong about it. There's only 'as much' energy, that 'fits' into a given amount of mass (matter).

Only so much in stationary matter. There's no limit to KE, else again, energy conservation would be violated.

You simply can't get more energy from a given amount of matter than energy released due to annihilation - in which mass is literally turned into photons and stops existing as matter.

A fast moving small thing emits more energy (higher energy radiation) in such an annihilation. There's no limit to it. You seem to be in continuous denial of a simple theory, rather than taking the position of trying to learn about what you don't want to accept. You cannot falsify a theory that you refuse to attempt to understand.  I see little point in responding to somebody so closed to learning.

Your chosen quotes from wiki do not contradict this, except in their using the word mass to mean relativistic mass, which is an unconventional usage of the term.

3

New Theories / Re: Gravity In Relative Motion - is there any solution?

« on: 27/09/2024 23:38:45 »

I can defend relativty

1. there's a definitive & limited amount of energy in matter (according to Einstein it's unlimited) - equal to (half of) energy released to matter-antimatter annihilation.

Einstein is right. There is no limit to how much say kinetic energy one can give to a given object.  One can always apply a force on it to make it go faster, assuming one can find an energy source to do so.  So in the frame say some neutrino, the small bunny in my front yard perhaps has more energy than one stationary anti-bunny.

2. Body moving at 100% c

A 'body' has mass and cannot move at c, as Paul has pointed out. This is really basic stuff that shows you apparently know nothing about relativity theory.

gravitational attraction decreases gradually as source-object accelerates from 0 to 100%c

Gravitational attraction isn't a function of acceleration. Not one bit.

Because I really despise making theoretical calculations with real-life units like (kilo)grams, meters or seconds, I made myself a simplified system of units based on constant c (moving 1 space unit in 1 time unit).

They're called natural units, and in such a system, c=1 and can be treated as such in all equations.  But you assign c=10, which isn't a natural unit.

let me show you an example:
https://en.wikipedia.org/wiki/Mass_in_special_relativity#Relativistic_vs._rest_mass

Relativistic mass has been depricated since about 70 years ago.  By definition, mass is proper mass, and is frame invariant.  What varies from one frame to the next is momentum.  This is not a change in theory (The original SR paper did not treat mass as proper mass), but rather a standardization of convention.  Nevertheless, the idea of relativistic mass has an incredible presence on the internet, which is why chat bots use it so much.

Gravity is not a function of mass in relativity theory. It is a function of stress energy, which is frame invariant.

Basically according to Einstein there's no limit to the energy for any amount of mass (matter) - you can pack infinite amount of Giga-Joules into a single proton (or electron).

Or negative even. Potential energy is negative and there's no limit to the depth of a hole you can drop a proton into.

Well, sorry but in  my uneducated opinion, matter/antimatter annihilation turns WHOLE mass into energy and there's ALWAYS a finite & measurable amount of it released

Because you started with finite energy. Einstein doesn't say you can get more energy from a stationary thing. It has to be moving fast to have more energy than the stationary one.  If it's fast enough, you can do more work with it than the anti-matter thing, and it doesn't even have to disappear to do it.

and it's theoretically IMPOSSIBLE to get any more energy from matter.

So this assertion is clearly wrong.

Thing is, that for some reason physicists keep thinking that mass has a definitive amount energy at rest (inertial frame) but then you can 'pack it' with potential and kinetic energy to infinity.

If it has KE, it isn't at rest is it?  If it has PE, that is negative.  There's a limit to how close to zero PE can get, but it isn't really defined where zero is. I.E. there's not a place you can be that is free from gravitational potential.

Let's take a theoretical comet/asteroid entering edge of Earth's atmosphere at a relatively small (flat) angle - question: Will making the asteroid/comet faster increase or decrease the chance of it hitting Earth?

Bunch of problems with the pic:  The comet cannot be a comet since it is moving too slow. It is clearly in eccentric orbit about Earth, while comets orbit the sun and move much faster relative to Earth when in its proximity.
The tail of the comet points the wrong way. It should extend to the right, not down where you drew it. A comet tail is not a wake, despite all the popular images depicting it that way.

That aside, if the comet takes the same initial trajectory but is moving only a tad faster, it will have less time to accelerate to the right as you depict. It will miss. This is basic Newtonian mechanics and all of this has squat to do with relativity theory.

In Einstein's model increasing speed = increasing energy = increasing mass what should lead to stronger gravitational attraction

This is completely wrong. Relativity theory says no such thing. Mass is not a function of speed. Gravity is not a function of mass, at least not directly.
Please do not say what Einstein's model predicts if you don't know how (and when) to apply the model. It is a straw man fallacy.

My model predicts something directly opposite - the faster the comet moves, the less it is attracted to Earth

This is also wrong. Yes, it will miss, but because of what Newton says, not because the attraction is less.

What Einstein's model is suggesting is that the faster the interplanetary bearing ball will be moving in relation to Earth (stripped out of the atmosphere), the stronger it will be attracted to the surface - and that a slower cosmic bearing ball has bigger chance of escaping Earth gravity.

Totally wrong. Relativity theory says no such thing.

Ok, here's question to those willing to stand in defense of Einstein's model - let's have 2 bodies of equal mass accelerated simultaneously at the same rate to relativistic velocities - so that both are moving at the same speed next to each other (appear stationary to each other)

Gravity isn't a function of acceleration.  So you're saying that you still have two objects that remain relatively stationary.  Gravity between them (in their own frame) will be unaffected per the first postulate of SR.

- will the increased velocity of those objects (observed in some other frame) have any effect on gravitational interactions between those accelerated bodies or they won't observe any difference?

In a frame in which the two objects are moving fast, the two objects will accelerate towards each other more slowly.  Less acceleration, not more like you describe.  It will take more time for them to collide than they would in a frame where their mutual center of mass was stationary.  In a frame where they're moving at 0.866c, they'll take twice as long to collide with each other.

I'm pretty sure (like 85-90%) that not even the most loyal supporters of Einstein's model  can tell with >50% certainty what the model actually predicts - and if some actually can make such prediction, it will most likely go against predictions of some other Einstein supporters...

The validity of a model has nothing to do with a vote of support. Plenty of people support relativity without understanding it. Some support alternative theories, and a small fraction of those understand both Einstein's theory and their own choice.  Supports relativity does not imply that one can make correct predictions.

As for myself - I literally have no idea what Einstein's Relativity tells us about such/similar scenario

You're sure making an awful lot of incorrect assertions about it for somebody who admits a lack of understanding.

So ok, one more 'scenario' - what would happen with ISS if SuperMan or some other OmniMan would simply stop it's motion around Earth?

Hope they take their time about it.  The ISS is delicate and does not take kindly to large forces being applied to a small area.  Irrelevant, I know.  We assume it is sturdy for this exercise.  We assume Superman can exert reactionless force, but only because it doesn't change the answer.

Let's say it would stop moving right above my house and then would be left 'hanging there' not moving in relation to surface (at least horizontally) - what would happen then with it?

Nothing to do with Einstein.  It would fall somewhat to the east of your house after around 5 minutes.  East is due to Coriolis force.
If the object has sufficient altitude, it won't hit Earth at all. If it has even more altitude, it won't even lose altitude, which is how geosync satellites manage to stay put despite not moving in relation to surface.

Now, in this case I can at least try figuring out what Einstein's model predict in similar situation..I'd say that according to Einstein, ISS would simply keep 'hovering' there endlessly or maybe even it would slowly 'drift away' from Earth.

Seriously, you thing Einstein would suggest that??  This is pretty hard evidence of crackpottery.

Why I'd say so? Well, since it stopped moving in relation to Earth's surface, it's energy decreased and so did the gravitational pull towards Earth - that's how I'd see Einstein's model..

A stopped thing still has mass, which is non-zero energy. Surely you don't think otherwise. OK, it seems you do...
If you want us to take your posts seriously, take seriously the thing with which you disagree.

What my model predicts however, is that I'd have at best 10 minutes to move most important stuff from my house before couple hundreds (thousands?) tons of 'space junk' would turn it into a landing pod (although 'falling pod' seems to fit better) - it would simply start falling down from it's orbit like 2 seconds after it's motion would stop...

1) half that time  2) it will miss  3) it starts falling right away (just as it is doing now), not after 2 seconds.


I cannot quote the copilot answer since it isn't text, but almost everything in it is completely wrong, and is a fine example of why it is terrible to ask any chatbot questions on theories about which it has no actual understanding.

4

Question of the Week / Re: QotW - 24.10.04 - Do snails get dizzy?

« on: 27/09/2024 12:56:21 »

do snails get dizzy?'

No. Getting dizzy is a byproduct of a vestibular system, a feature of vertebrates.  This system detects angular acceleration, and it is the detection of the angular acceleration of the cessation of spinning that makes one dizzy.

Snails instead have statocysts which detect linear acceleration, which gives them a sense of orientation, but not of spinning.  A snail in a car wheel would feel heavy linear acceleration, but essentially constant orientation (radially outward).

5

Physics, Astronomy & Cosmology / Re: what organic substance/biofilm could stay on the skin for 9 years

« on: 17/09/2024 19:59:47 »

Long time no see, Harry!

You already know a forum is not a substitute for professional help, but it sounds like you're not exactly getting any workable results from the professionals.

You can try some better clues.  I suppose the jar is gone, else the substance could be identified.  Do you remember the consistency (slimy, but thick paste, a lotion, or more of a runny liquid)?  How long was it on you before first trying to remove it?  How long before you noticed an undesirable reaction?

What was the shape of the container?  Even that can give a decent clue.  Was it stored with medical jar, food, or with automotive chemicals, or what?  What possessed you to apply it to you skin without knowing what it was?  I presume that wasn't intentional, but hard to avoid given the actual intended purpose of the stuff.  (Instructions: Use gloves when applying this to your bricks).

6

New Theories / Re: What's the unit of Torque?

« on: 13/08/2024 02:54:21 »

This thread is so full of erroneous comments and outright speculation that I'm moving it to the lighter side.  I mean, 50 posts, and what has been answered?

An error laden quote from Gemini in the OP mentions the Newton-meter, but post 10 (a wiki quote) identifies the Newton-meter (with force being a vector) as the unit of torque.
End of story.  The rest seems to be yet another blog seeking to get off track in as many ways as possible, which is not the intent of the main sections of the forum.

The units of both are mass length squared per time squared.

This is so wrong.  It seems to presume that energy and torque are the same thing, and then applying a relativistic notion of mass-energy equivalence to torque.

Once you have started a circularly symmetric body rolling on a horizontal frictionless surface,

If the surface is frictionless, the wheel will probably just slide and not roll at all. Which way the body rotates (if at all) depends on where relative to the CoM the impulse is applies.

7

General Science / Re: what is Nothing or ?energy landscape.? or waves

« on: 04/07/2024 21:45:20 »

Do particles pop in and out of existence? Virtual particles aren't actually particles, apparently.

Good question. Much depends on the view one takes. Current theories depend on the existence of virtual particles, so one can perhaps wave away (declare to be just a mathematical tool) all theories and presume some alternative which doesn't predict them.

They cannot be detected by experiments, right?

This depends on your interpretation of experimental results. For instance, anomalies in the measurements of magnetic moment of muons can perhaps best be explained away as virtual particle detection.

Any detection of Hawking radiation or Unruh radiation would be a direct measurement, but neither can be observed in a lab, and such radiation is currently significantly colder than the background radiation. Observation of a very tiny end-of-life black hole would be solid confirmation.

Technically, every measurement of quarks and gluons in a bit particle smasher experiment constitutes such a detection.

So, how do we know that it's correct?

One can never be sure that an interpretation of experimental results is the correct interpretation. But our best theories, the ones that make the best predictions, also predict the existence of virtual particles, parallel universes, and other things that cannot be directly measured.

If partials do appear and vanish back to wherever, what replaces the void they occupied?

Not always. They need positive energy from somewhere, else yes, they're just transient.

If the universe is just made up of waves

Over simplification, and no, I don't think I can explain all of quantum theory in a forum post, or at all for that matter.

8

Just Chat! / Re: Fed up with the lack of reasoned discourse

« on: 29/06/2024 21:11:25 »

I usually stay away from electrical topics since I'd probably get the magnetism parts wrong. I am not, for instance, qualified to critique the post done by E-S above.  But this situation is pretty basic.

Em fields have finite speed and this means there is a time lag between action and reaction although in almost all cases this will not be detectable.

Fields are by definition everywhere and don't 'go' anywhere. Changes to the field do travel, and yes, at c.  All this is true to everything from gravity to the strong force.

So there is no action/reacton going on here. There is say two similarly charged objects moving towards each other. There is always a force between them, so at no point does an 'action' by one of them commence. But the force grows as they approach, and maybe, due to the speed of the field change, the force between them may be less when they're X-distance apart than the force that would be between them at the same distance, but they're relatively stationary. This is due to the change of the field not getting to either of them yet. So still balanced forces, but not the same force if they were not approaching.

There is no cause/effect distinction. The situation is symmetrical so the ball acts on the bat as much as the bat on the ball.


Now let's change frames and see what relativity of simultaneity says.
In one frame, the two objects (synced clocks actually) are identical and moving toward each other at the same speed. The symmetry means they must always be moving at the same speed. The net momentum is always zero in this frame. The acceleration of each is continuously going up until the point of closest approach.  So lets consider this approach from a different frame.

From some different frame, the left object is say momentarily stationary, and accelerating to the left.  The right object, in that frame, is simultaneously accelerating less since from its perspective, the separation of the objects is greater. The time on the right clock is less than the time on the left one.  Is this a problem?  If it's accelerating less, it first appears that momentum of the system is not conserved, but momentum under relativity is γmv, and since the right mass is moving, momentum is exactly conserved in this case as well.

he says that if the field is changing during such an interaction the action and reaction will not be equal and hence the conservation of momentum will be violated.

That statement is wrong just for calling out a nonexistent action-reaction relationship.  The field change is entirely symmetrical in the frame where the interacting identical charges (almost 'touching' electrons say) have a net momentum of zero.

My counter argument is that em fields carry momentum

Here's where I get shaky since it gets into quantum mechanics and force carrier particles and charges that don't have measured locations. I'm not sufficiently knowledgeable to comment about such things. The post by ES does very much imply that say spinning magnets (even orbiting masses) radiate away energy and angular momentum, but I'm not sure if any of that is applicable to a standard bat/ball collision. My reasoning above is classical, not quantum.

If this thread needs to be split now, i'm fine with that.

I can do that, or re-title the thing (and perhaps move it) to reflect its changed purpose. Let me know what you'd like.

9

Just Chat! / Re: Fed up with the lack of reasoned discourse

« on: 28/06/2024 23:23:01 »

The discussion was about possible exemptions to the conservation of momentum because of the finite speed of em propogation

That can be an interesting discussion. Don't know the scenario specifics, but my gut feel is that no exception can be identified, leaving one to explain different times of accelerations of separated objects from one frame to the next.

I here got into a pretty heated investigation into angular momentum conservation due to acceleration of spinning things, which have frame dependent centers of gravity. Ouch. I think bOng would have a low probability of producing a good answer to that one.


In the end, AI (real AI) is going to outdo us, and your best conversations (such as the one you want with Einstein or somebody) will be with the artificial thing. I don't think the chatbots can do that since they don't surpass anything, just sort of average it all out, which only works well if the consensus matches what the bulk of the training material says. How does a chat bot weed out the true crap when it finds so much of it in its training material?

10

Just Chat! / Re: Fed up with the lack of reasoned discourse

« on: 28/06/2024 18:38:20 »

On a different forum I had to put a poster on ignore after he repeatedly posted reams of rubbish from bOng co-pilot, despite my request for person to person discourse only.

A supposedly bannable offense on several sites, but it's not going to happen here since, well, the entire mod staff being made entities, and not famous ones either.

Side note: Ah... Bing. Had to look it up. Didn't know the MS product was called co-pilot.
What sort of topic was being discussed that this poster had to resort to using such a source?

11

Just Chat! / Re: What keeps a bicycle stable in the vertical orientation?

« on: 25/06/2024 13:16:13 »

The resulting centrifugal force on the rider opposes the lean

Rider not even needed. A bicycle, riderless, at sufficient speed (about a running pace) will stay up on its own.
Excellent answer BTW. Yes, it's all in the angle of the steering tube, coupled with the curve of the fork, putting the hub off center of the axis of the steering rotation.

12

Question of the Week / Re: QotW - 24.06.28 - Are there stars which aren't part of a galaxy?

« on: 23/06/2024 19:14:54 »

stars are formed from gas and soot, where does the soot come from? (intergalactic burning of fossil fuels no doubt, when will they ever learn)

The 'soot' is from burning of the hydrogen and helium, the virgin gasses. So these later stars are built from the expelled remnants of the earliest starts. Our entire solar system is built from such material.

A common on earlier info:

We can consider ever larger structures (regions of space) until we identify regions we call Clusters or Super-Clusters.   All the mater in these regions is gravitationally bound together, they do not tend to drift apart, but they appear much as many seperate galaxies orbiting around each other in some complicated way (literally "a cluster of  galaxies").

Our local group (Us, Andromeda, all the little guys hovering nearby) are gravitationally bound, and thus, given enough time, will merge into one object, minus the odd stars that get flung away at escape velocity by 3+ body encounters of really massive objects. Yes, as has been pointed out, many of those not-in-galaxy stars have been flung out of galaxies, but they can only last so long before burning out. There is gas out in deep space, and new stars, not part of any galaxy do form out there.

Back to the gravitational binding: Our local group is it. We are not gravitationally bound to anything else, not the Virgo supercluster, the Great Attractor, and other 'nearby' super-high mass areas. We (our local group) are moving at greater than escape velocity from any of them, so we'll never be part of them. Given enough time, they'll disappear over our event horizon and will cease to have further causal effect on us.

There's always the off chance that our solar system will be flung out of the local group not only in the direction of Virgo some day, but fast enough for our system to suddenly be gravitationally bound to it. Better do it quick if you want it to happen before Earth dies. Any mass large enough to do that (*cough* Andromeda *cough*) will likely be here after Earth is gone.

13

Physics, Astronomy & Cosmology / Re: Where did the big bang come from?

« on: 25/05/2024 05:28:44 »

You say time dilation is a coordinate effect and not a physical one. However if I start with two synchronised clocks, keep one in my house and send the other off on a zillion mph hi tech craft for lets say, one year, and then reunite them there will be a physical difference. What say you?

The dilation is due to the speed difference. In one frame, the zoomy clock is moving at a zillion mph and runs slower, but relative to a different inertial frame, the zoomy outgoing clock is stationary and it is your house clock that is moving, and is thus running slow. That's what I mean by it being a coordinate effect. Which clock runs faster during some duration depends on the choice of coordinate system.

The comparison when the two clocks are reunited is the example of differential aging, and that is objective, since the different readings of the two clocks at that event is the same regardless of choice of coordinate system. So differential aging is physical, objective, and frame invariant.

14

Physics, Astronomy & Cosmology / Re: What empirical evidence led to Einstein's choice of postulates for SR?

« on: 23/05/2024 14:10:44 »

Thanks Halc, you may rename it as you choose and move it

OK, this is the new topic, split off, leaving not much in chat. A post or two here could have been left with the old thread.


As for me bringing up LET, I did so as an example of absolutism (not relativity), and not because aether had anything to do with the points I was trying to make, which is that one can have an equivalent theory without the postulates of SR, which results in a valid interpretation of the same data, and oddly enough, without relativistic velocity addition.
The reason nobody seems to go with any form of absolutism is because it renders it impossible to measure any distance or duration. Lacking a test for the absolute frame, all empirical tools give wrong values.

15

Physics, Astronomy & Cosmology / Re: What empirical evidence led to Einstein's choice of postulates for SR?

« on: 23/05/2024 13:22:54 »

you did say "light does not radiate from a moving object at c" in reply #9. Am I missing something?

Semantics
I was perhaps ambiguous in my reply.
The separation between moving object and the light pulse increases at the rate of 1.5c in my example. The light pulse of course is moving at c, the rate of change in its separation from the point in space where it was emitted.

As for moving the topic, I can do that, but I would like to re-title it at the same time, and that means you have to select a title more appropriate for the main sections. I suggested one, but it wasn't clear if that conveyed your actual question.

16

Physics, Astronomy & Cosmology / Re: What empirical evidence led to Einstein's choice of postulates for SR?

« on: 23/05/2024 11:20:03 »

I certainly was not considering LET(aether! God forbid!).

I never tried to imply that you were. I just bring up LET because (never mind the aether part), it is an absolutist way of looking at things, a valid way of looking at things which denies all premises of special relativity. So Einstein making those premises was a choice, not something that was obvious from the evidence.

I am somewhat confused by your statement that light emitted by a moving body does not travel at c: suppose an observer measures a body passing by at 0.5c and then this body emits a pulse of light- surely in both the frame of the observer and the frame of the emitter the speed of said light pulse will be c?

According to Einstein's premises, yet, it will be c, and I didn't say otherwise. But I said that it would distance itself from said moving object at some rate other than c.

I had the object moving east and the light west, so after a second, the two are 1.5 light seconds apart. Sure, in the frame of the object, the pulse is 1 light second away after a second, but the object isn't a moving object in that frame.

One final request, Halc, refresh my ageing brain as to the conflict between Maxwell and Newtonian mechanics.

Maxwell's equations are frame invarint under Lornentz transformations. Newton's equations are not. That's the best I can do. I'm actually not familiar with Maxwell's equations, and I don't do electrical problems because I'd get things wrong.


and I've never detected signs of aging brain from you.

17

Physics, Astronomy & Cosmology / Re: What empirical evidence led to Einstein's choice of postulates for SR?

« on: 21/05/2024 14:31:57 »

What I want to know is, in the early developmental stages of relativity(ie the work of Lorentz), when and how it was determined that in the case of light hitting a moving object the speeds would no longer be additive/subtractive.

That was derived from the postulates. It is only true under Einstein's postulates, and not under say LET, a form of absolutism which does not accept either of Einstein's premises.

(1) does not, in my opinion, require any postulate from relativity: once emitted the speed of the radiation will be determined solely by μ and ε.

Einstein could have instead just accepted Maxwell's equations as a postulate instead (Maxwell's work conflicts with Newton's) of the frame invariance of light speed since the latter can be derived from the first, but the theory wasn't about electromagnetism, so it was simpler to cut to the chase.

On another note, I don't know how you are using the word 'impinge' in your posts above.

The speed of light,(1) radiating from a moving object

Light does not radiate away from a moving object at c.  If an object is moving at say 0.5c east, then light that is at the object (coming from it or not) moving west will be 1.5 light seconds away one second later.
The postulate says light moves at c relative to any inertial frame, and the object is said to be moving, meaning we're using a different inertial frame than the one in which the object would be stationary.

LET does not accept any of the above. It is an absolutist theory, so light moves at c period, relative to the one and only preferred frame, and not relative to any other non-preferred frame. Velocities are still additive under LET. This doesn't make LET wrong.

What experiments/theory led to the conclusion that light impinging on a moving object at any arbitrary speed( <c) would always arrive at c? I have struggled with the wording of this question and am still not satisfied with it. 

It's a postulate. If there was hard evidence behind it, it wouldn't need to be a postulate. So it is merely an assumption, and one that not all competing theories accept.
I'm pretty sure that Maxwell's work was a heavy influence on the choice, but it's frame invariance does not prove the absence of a preferred frame.

18

Physics, Astronomy & Cosmology / Re: Where did the big bang come from?

« on: 18/05/2024 06:10:31 »

Both clocks are at an airport. One remains at the airport (the one I said is stationary)

Earth is spinning, so relative to any inertial frame, that airport is accelerating. it isn't stationary at all.
So if your Blackbird flies west, it will meet the airport after 12 hours on the other side, and both Blackbird and airport got there in about the same time, same speed, different directions. I could not say which clock would read the greater elapsed time.

The exercise is to meditate going with the clock on the plane then repeating while staying on the ground in hopes to reconcile how the 2 clocks would not indicate the same time has passed.

A human keeping the clocks company would have no effect on the experiment.

My conclusion was that time contracts, that you call dilation.

The rest of the world calls it dilation, so best not to make up new words for established concepts.

But now, I can't understand what you are saying about it being relative to the observer.

It's relative to an inertial frame. The typical 'observer' is often just there to identify the frame: "The frame in which Bob is stationary". Bob could be a cardboard picture of a guy. His presence or absence does not affect the physics.

The basic gist under special relativity is that relative to any inertial frame, fast moving clocks tick slower than slower clocks. But this is relativity, so relative to that 'fast moving' clock, it is all the other clocks that tick slower. Any clock is stationary in its own frame by definition, so it runs at 'normal' speed in that frame.

The 2 clocks show a different time but relative to the observer. So how are the 2 clocks off?

The two clocks in say the airplane experiment show different times. This comparison is objective, not relative to anything.
How much apart? It depends on the situation. For your west-flying Blackbird, I could not say which clock would log more elapsed time. If the plane flew west, the Blackbird clock would show less elapsed time.
The famous HK experiment that first did this had slow airplanes that landed periodically, but eventually made it all the way around. The time difference was 59 nanoseconds less if eastbound, and 273 nanoseconds more if westbound.

Like if someone lives at the top of the Himalayas and another lives in an underground cave, time would not pass the same for the 2.

That's time dilation due to gravity, yes. The HK thing had to take that into account since the airplane was often at higher altitude than the clock on the ground.

How about a spaceship that goes far away at high speeds and comes back, wouldn't the time it was gone be different from the time that passed on earth by years?

Yes, it can be much less. If your ship is fast enough, you could age 1 year and you find that 200 years has passed on Earth when you get back.

19

Physics, Astronomy & Cosmology / Re: Where did the big bang come from?

« on: 17/05/2024 01:44:28 »

Good to see your return. Been a while it seems.

According to the theory of relativity, time isn't a constant

According to relativity, time isn't absolute. According to some alternate, but still valid, theories, time and space are both absolute. Nobody in the cosmology field ever seems to use these alternate theories, especially since they lagged relativity theory by almost a century.

when the jet lands at the airport and you compare the clock that traveled and the one that didn't they will show a different amount of time has passed.

Yes, this has been demonstrated, but it takes really accurate clocks to measure the difference. It's far more noticeable with say GPS satellites, all of which contain such accurate clocks.

Even though each second that passed was a full second relative to the person experiencing it, the actual time that passed isn't the same as the clock that remained stationary.

Time and space is not absolute, remember? So there is no 'clock that remained stationary'. Stationary relative to what?

So in essence, because time contracted for one clock, the other had less time pass.

No, the length (interval) of the spacetime path traversed by one clock is shorter than the other. This is a physical effect. Time isn't something that 'contracts'. There is time dilation, but that is a coordinate effect, not a physical one.

I couldn't figure out what it was growing into but had to accept it. My thoughts were always directed towards the end of infinite because well, it had a beginning, a fixed point attaching it to reality that was actually wrongfully ignored. My mind (would suspect most of us) is linear with space and time, everything has a beginning. I kept meditating on infinite in every form I could imagine. Still the question of what the universe is growing into remained

No valid model has the universe expanding into some otherwise unoccupied space. Instead, space itself is expanding. There can be no edge to the universe, be it finite or not. That just doesn't work.

The universe has a beginning so to speak, yes. It was never a point. The big bang happened everywhere, not at a point in space. Relativity theory has time as part of the universe rather than the universe occurring in time. That means it is meaningless to talk about 'before the universe', or it being created, or some such.
The alternate (absolute) models do support a universe contained by time, so such language is appropriate if you're using those models.

Hope some of this helps.

20

Plant Sciences, Zoology & Evolution / Re: What Organisms Have The Most Dissimilar DNA ?

« on: 14/05/2024 16:12:30 »

When I look at the picture of Ben and his banana together I am convinced. I find it difficult to tell the difference between the two

I see a difference. The bananas need two condoms, and Ben doesn't need any because, well just look....

So, can ewe think of a few organism's with such fundamentally  disparate and incongruous DNA

I came up short on this.  I looked at a biological tree.

The banana and Ben are both close together there on the upper right, neighbors except for that fungus amongus.

So what was furthest away?  All that bacteria it seems, but then it comes down to how the difference is measured.
I mean, we have different number of chromosomes than most things, and all those of different lengths. How do you line them up and decide this one is shared and that one is not?  You pick a method of doing that and get around 50% for the banana.

But there apparently is this concept of a 'particular gene', and regardless of the volume of genetic literary works you gots, a thing has that gene or it doesn't. I think that's where the numbers come from.  So it turns out we have a bunch of genes (not a lot) that is unique only to humans and bacteria.  It wasn't carried up that tree pictured, else everything on the path would have it. So we share some unique genes with bacteria precisely because bacteria probably transferred it to us at some point in history. It was advantageous, so it spread to most/all of the species. It shows that genetic variation isn't accomplished only by random alterations to genes from say cosmic rays or something. They can be gifted.