Yes, You Can Go Faster Than Speed Of Light

[Moronium]

No, it would be .9c in B's frame.

 

Because you'd already given the velocity between A and C as .9c and the velocity of one of them relative to B as .45c so the velocity between the other one and B would be more than .45c.

 

It's exactly the same! You've got three objects, one central and the other two moving at .45c relative to it in the central objects frame. So the two outside objects are moving at .75c relative to each other in their frames.

 

So the velocity between B and A would be .3c in C's frame and the velocity between B and C would be .3c in A's frame.

 

You're all over the lot.  You make no sense.

[Moronium]

Because you'd already given the velocity between A and C as .9c and the velocity of one of them relative to B as .45c so the velocity between the other one and B would be more than .45c.

 

 

Why would it be MORE THAN .45c?  And what would it be?  Farsight seems to disagree with you.

Edited June 27, 2018 by Moronium

[Moronium]

No, it would be .9c in B's frame.

 

So the two outside objects are moving at .75c relative to each other in their frames.

 

Which is it?  .9c or .75c?

 

You're just making my point for me.  You are reiterating your position that what B sees dictates the relative speed of A and C and that what A and C see is irrelevant.  Why?  Because B has a formula, and it, not facts existing in the external world, dictates the speed of A and C, according to your telling of this tale.

Edited June 27, 2018 by Moronium

[Moronium]

 So the two outside objects are moving at .75c relative to each other in their frames.

 

 the velocity between B and C would be .3c in A's frame.

  

We started out with the premise, which you readily accepted, that Both A and C gauge their relative speed to be 9c.  Suddenly it's down to .75c.  How did that happen?  Magic?

 

Another question.  First you said that the relative speed between B and C would somehow (magic, again?) be MORE THAN .45c.  Now it's only .3c, you say.  Which is it?  And, again, how did that even happen?

Edited June 27, 2018 by Moronium

[Farsight]

I must admit, Farsight, that I'm a little frustrated with your answers so far.

I answered your question step by step. You complained that nobody answered your question, and now somebody has, you're still complaining. You're missing the point of the velocity addition formula, and it is this: when you're moving fast, your measurements of speed give the wrong answer. If two ships are moving apart at 0.45c one way and 0.45c the other, they're moving apart at 0.9c. Each ship will measure the other ship to be moving at 0.9c relative to them. Putting something in the middle doesn't change this. But if one ship fired a projectile at what it thought was 0.45c, that projectile wouldn't actually be moving at 0.45c. 

 

The whole thing is a waste of time anyway. Everybody can gauge their true speed relative to the universe by looking at the CMBR. See http://www.astro.ubc.ca/people/scott/faq_basic.html  and https://en.wikipedia.org/wiki/Cosmic_microwave_background#CMBR_dipole_anisotropy   

[Moronium]

Here's what it looks like to me: 

 

We have two observers each of whom measures their relative speed, directly, not indirectly, and they agree on their relative speed.  But they are wrong.  Why?

 

Because some third party will tell them they're wrong, based on a formula.  That third party, who has no direct way seeing what they see, tells them what they see, based on a formula.

 

Who's right?  The guy with the formula.

 

Why, because that's the math required to make the theory work.

[Moronium]

I answered your question step by step. You complained that nobody answered your question, and now somebody has, you're still complaining. You're missing the point of the velocity addition formula, and it is this: when you're moving fast, your measurements of speed give the wrong answer. If two ships are moving apart at 0.45c one way and 0.45c the other, they're moving apart at 0.9c. Each ship will measure the other ship to be moving at 0.9c relative to them. Putting something in the middle doesn't change this. But if one ship fired a projectile at what it thought was 0.45c, that projectile wouldn't actually be moving at 0.45c. 

 

The whole thing is a waste of time anyway. Everybody can gauge their true speed relative to the universe by looking at the CMBR. See http://www.astro.ubc.ca/people/scott/faq_basic.html  and https://en.wikipedia.org/wiki/Cosmic_microwave_background#CMBR_dipole_anisotropy   

 

 

If somebody answered my question, it certainly wasn't you.  Again, I didn't ask about, and have no concern whatsoever with, what happens when a projectile is fired.  My question didn't contain that scenario. 

 

You say putting something in the middle doesn't change anything. I agree, 100%.  But that's not my question either.

 

My question is about the application of the velocity addition formula from the perspective of B, as it relates to A and C (not some projectile, which you've introduced for no apparent reason).

Edited June 27, 2018 by Moronium

[Moronium]

The whole thing is a waste of time anyway. Everybody can gauge their true speed relative to the universe by looking at the CMBR. See http://www.astro.ubc.ca/people/scott/faq_basic.html  and https://en.wikipedia.org/wiki/Cosmic_microwave_background#CMBR_dipole_anisotropy   

 

 

What you're saying when you say this, as you surely must know, it that SR is totally wrong.  I agree.  But everyone else here disagrees.  Actually, you seem to hedge and adhere to SR yourself, insofar as you treat the velocity addition formula and providing the "true" answers to questions about projectiles (which again, I didn't ask about), and such.

Edited June 27, 2018 by Moronium

[Moronium]

What you're saying when you say this, as you surely must know, it that SR is totally wrong. 

 

Well, maybe you don't know this.  Here's what the source you cited says, and it may have misled you:

 

The theory of special relativity is based on the principle that there are no preferred reference frames. In other words, the whole of Einstein's theory rests on the assumption that physics works the same irrespective of what speed and direction you have. So the fact that there is a frame of reference in which there is no motion through the CMB would appear to violate special relativity!

 

 

However, the crucial assumption of Einstein's theory is not that there are no special frames, but that there are no special frames where the laws of physics are different. There clearly is a frame where the CMB is at rest, and so this is, in some sense, the rest frame of the Universe. But for doing any physics experiment, any other frame is as good as this one. So the only difference is that in the CMB rest frame you measure no velocity with respect to the CMB photons, but that does not imply any fundamental difference in the laws of physics.

 

 

The first paragraph of this is essentially correct (apart from the "in other words" portion, i.e., the second sentence in it).  That's not "the whole" of SR.

 

The second paragraph is not. It says:  "However, the crucial assumption of Einstein's theory is not that there are no special frames..."

 

But that IS the crucial assumption.  Without that assumption, SR falls apart completely.

 

The question which the part I just quoted purports to respond to, is this:

 

How come we can tell what motion we have with respect to the CMB?

Doesn't this mean there's an absolute frame of reference?

 

 The assumption that there is no such thing as absolute motion (in inertial frames)  is absolutely essential to SR.  That means there can be no frame which can be used to tell that you are moving.  Using the CMB to ascertain the earth's absolute motion is strictly prohibited by SR.  The second paragraph says:  "There clearly is a frame where the CMB is at rest, and so this is, in some sense, the rest frame of the Universe."  

 

That is the part which invalidates SR, notwithstanding the author's attempt to say that this is not "crucial" to SR.

 

The tendency to deny the validity of SR, while also denying that you are denying it, is not uncommon among some physicists.

Edited June 27, 2018 by Moronium

[A-wal]

You're all over the lot.  You make no sense.

:)

 

Why would it be MORE THAN .45c?  And what would it be?  Farsight seems to disagree with you.

Because you already said A and C have velocity of .9c and that the velocity between one of them and the central B object is .45c so the velocity between the other one and B has to be higher than .45c, it should be around .8c, roughly.

 

Which is it?  .9c or .75c?

 

You're just making my point for me.  You are reiterating your position that what B sees dictates the relative speed of A and C and that what A and C see is irrelevant.  Why?  Because B has a formula, and it, not facts existing in the external world, dictates the speed of A and C, according to your telling of this tale.

The speed of A and C are dictated by the speed they're moving at relative to each other, the formula allows you to work out would this speed would be, .75c roughly.

 

We started out with the premise, which you readily accepted, that Both A and C gauge their relative speed to be 9c.  Suddenly it's down to .75c.  How did that happen?  Magic?

You started by saying that the velocity between A and C is .9c and  that the velocity between one of them and the central B object is .45c so the velocity between the other one and B has to be higher than .45c, it should be around .8c, roughly.

 

Then you said the velocity between A and B is 4.5c and the velocity between C and B is 4.5c, that makes the velocity between A and C .75c, not .9c so those are two completely different scenarios.

 

Here's what it looks like to me: 

 

We have two observers each of whom measures their relative speed, directly, not indirectly, and they agree on their relative speed.  But they are wrong.  Why?

 

Because some third party will tell them they're wrong, based on a formula.  That third party, who has no direct way seeing what they see, tells them what they see, based on a formula.

 

Who's right?  The guy with the formula.

 

Why, because that's the math required to make the theory work.

Not true. The relative velocity between any two observers is unaffected by the presence of other objects.

 

Their relative velocities aren't determined by the formula, they're determined by the relative velocities between the objects. The velocity addition formula simply allows you to work out what the relative velocity will be.

 

Strawman!

 

If somebody answered my question, it certainly wasn't you.  Again, I didn't ask about, and have no concern whatsoever with, what happens when a projectile is fired.  My question didn't contain that scenario. 

 

You say putting something in the middle doesn't change anything. I agree, 100%.  But that's not my question either.

 

My question is about the application of the velocity addition formula from the perspective of B, as it relates to A and C (not some projectile, which you've introduced for no apparent reason).

It's exactly the same!

It's exactly the same! You've got three objects, one central and the other two moving at .45c relative to it in the central objects frame. So the two outside objects are moving at .75c relative to each other in their frames.

 

So the velocity between B and A would be .3c in C's frame and the velocity between B and C would be .3c in A's frame.

 

What you're saying when you say this, as you surely must know, it that SR is totally wrong.  I agree.  But everyone else here disagrees.  Actually, you seem to hedge and adhere to SR yourself, insofar as you treat the velocity addition formula and providing the "true" answers to questions about projectiles (which again, I didn't ask about), and such.

The assumption that there is no such thing as absolute motion (in inertial frames)  is absolutely essential to SR.  That means there can be no frame which can be used to tell that you are moving.  Using the CMB to ascertain the earth's absolute motion is strictly prohibited by SR.  The second paragraph says:  "There clearly is a frame where the CMB is at rest, and so this is, in some sense, the rest frame of the Universe."  

 

That is the part which invalidates SR, notwithstanding the author's attempt to say that this is not "crucial" to SR.

 

The tendency to deny the validity of SR, while also denying that you are denying it, is not uncommon among some physicists.

Any object can measure its velocity relative to any other object, measuring their velocity relative to the CMB is no different than measuring their velocity relative to anything else. The CMB is supposedly everywhere so it allows you to have a universal frame to use as a standard but that's purely for convenience, it is not a preferred frame. You could use a group of distant galaxies that are rest relative to each other to do exactly the same thing.

 

Strawman!

Edited June 27, 2018 by A-wal

[Farsight]

The assumption that there is no such thing as absolute motion (in inertial frames)  is absolutely essential to SR.  That means there can be no frame which can be used to tell that you are moving.  Using the CMB to ascertain the earth's absolute motion is strictly prohibited by SR.  The second paragraph says:  "There clearly is a frame where the CMB is at rest, and so this is, in some sense, the rest frame of the Universe."  

 

That is the part which invalidates SR, notwithstanding the author's attempt to say that this is not "crucial" to SR.

 

The tendency to deny the validity of SR, while also denying that you are denying it, is not uncommon among some physicists.

Moronium, you're tying yourself up in argumentative knots, and being abusive to boot. See the https://einsteinpapers.press.princeton.edu/vol7-trans/156?'>Einstein digital papers where Einstein said this: "The theory of special relativity, therefore, applies only to a limiting case that is nowhere precisely realized in the real world". Did you get that? Nowhere precisely realized in the real world. But you will find a way to complain about that, won't you? Just as you complain when people don't answer your question, and then when they do. It's clear you're just banging on and on writing multiple argumentative posts about things you don't understand, and don't want to understand. So you can do your banging on and on without me. 

Edited June 27, 2018 by Farsight

[Moronium]

 Just as you complain when people don't answer your question, and then when they do. So you can do your banging on and on without me. 

 

I'm not banging on you.  Don't be so sensitive.  I merely said that you didn't answer my question, because you didn't.  You don't understand the question.

 

A-wal understands it, and has answered it.

 

In just the way I predicted.  He ignores his own self contradictions, restates the premise in question (that the addition formula must prevail over direct measurement), and pretends to have proved his point.  His "explanation" for every claim he makes is just what I already said it would be, to wit;

 

We know all this because the velocity addition formula tells us it's true, and because we know that formula has been CONCLUSIVELY PROVEN to be true.  What A sees doesn't matter at all.  It's what B tells us that A will see that is "really true."

 

 

http://www.scienceforums.com/topic/32241-yes-you-can-go-faster-than-speed-of-light/page-13 (post 209)

Edited June 27, 2018 by Moronium

[A-wal]

I'm not banging on you.  Don't be so sensitive.  I merely said that you didn't answer my question, because you didn't.  You don't understand the question.

 

A-wal understands it, and has answered it.

 

In just the way I predicted.  He ignores his own self contradictions, restates the premise in question (that the addition formula must prevail over direct measurement), and pretends to have proved his point.  His "explanation" for every claim he makes is just what I already said it would be, to wit;

 

 

http://www.scienceforums.com/topic/32241-yes-you-can-go-faster-than-speed-of-light/page-13 (post 209)

There are no contradictions you ungrateful shite! You asked what their relative velocity would be in a given situation and I answered you. The velocity addition formula tells you what the direct measurement would be because it tells you their exactly relative velocity.

 

What the **** is wrong with you?

Edited June 27, 2018 by A-wal

[Moronium]

As I've pointed out to you, Farsight, you and A-wal disagree on a crucial point.  He makes assumptions which you don't.  If you'd look at that disagreement, you might get a better idea of what the issue is.

 

The basic issue is this:  If a third observer sees two different objects moving with respect to him as what appears to be a certain speed (.9c, for example), then they CAN'T be moving at that speed.   And since they are NOT moving at that speed with respect to each other, they could not possibly see themselves to be moving at that speed.

 

You answered all of my individual questions is such a way as to indicate that you disagree with this contention.  However, you did not answer the question I asked (and which I have spelled out several times).  

 

A-wal's answer is this:  Since B will "see" A and C receding from each other at a rate of .9c, then it can't be that.  It must be .75c. B can't simply add their two speeds as he measures them to be. He must first massage them with his formula.

 

The next step is to say that since B, applying the velocity addition formula, "calculates" the relative speed of A and C to be .75c instead of .9c, then by God it IS .75c, and, by God, that's the way A and C will see it too.

 

What A and C calculate it to be is irrelevant.  What they actually see becomes irrelevant.  The all-powerful formula prevails over all, and dominates all things.

Edited June 27, 2018 by Moronium

[A-wal]

As I've pointed out to you, Farsight, you and A-wal disagree on a crucial point.  He makes assumptions which you don't.  If you'd look at that disagreement, you might get a better idea of what the issue is.

 

The basic issue is this:  If a third observer sees two different object moving with respect to him as what appears to be a certain speed (.9c, for example), then they CAN'T be moving at that speed.   And since they are NOT moving at that speed with respect to each other, they could not possibly see themselves to be moving at that speed.

The basic issue is this: You don't have the capacity to understand the simple explanations that have been given to you and you're confusing two completely different scenarios. You've give two DIFFERENT scenarios and you're mixing them together to claim there's a contradiction.

 

I'm going to give you the benefit of the doubt and assume that you're not doing deliberately and are just confused but you really need to realise that the apparent "contradictions" you think you see are nothing but symptoms of your own inability to understand what you're being told.

[Moronium]

Yeah, right, A-wal.  All you do, as always, is go around in never-ending circles saying " the velocity addition formula is right because we know it it is right. It can't be questioned."

Edited June 27, 2018 by Moronium

[A-wal]

You asked what the velocity would be and I told you. Then you just turn around and say that I'm going round in circles. It's hardly my fault that you're simply too stupid to understand the answers to your questions.

 

Somebody really needs to teach you some manners.