Yes, You Can Go Faster Than Speed Of Light

[Vmedvil2]

OK, thanks.  I think your opinion is much better than Vic's, for what it's worth.  He said there would be no redshift at all without gravity because gravity was the only thing that could cause a doppler shift, as I understood him.  I don't buy that.

 

Dark Energy and Gravity are truly the only things that cause a redshift or doppler in space, which are both functions of Space-time changing you better believe it.

[Moronium]

Dark Energy and Gravity are truly the only things that cause a redshift or doppler in space, which are both functions of Space-time changing you better believe it.

 

Maybe I "better," but I don't.

Edited June 29, 2018 by Moronium

[sluggo]

In the one-dimensional case,[2] the velocities are scalars and the equation is either:

{\displaystyle \,v_{rel}=v-(-w)} \,v_{rel}=v-(-w), if the two objects are moving in opposite directions, or:

{\displaystyle \,v_{rel}=v-(+w)} \,v_{rel}=v-(+w), if the two objects are moving in the same direction.

 

The quote from wiki is false. There is no speed <0! The +and - signs correspond to directions, just as they indicate. They contradict themselves, and one reason not always reliable.

[Moronium]

 

In the one-dimensional case,[2] the velocities are scalars and the equation is either:

{\displaystyle \,v_{rel}=v-(-w)} \,v_{rel}=v-(-w), if the two objects are moving in opposite directions, or:

{\displaystyle \,v_{rel}=v-(+w)} \,v_{rel}=v-(+w), if the two objects are moving in the same direction.

 

The quote from wiki is false. There is no speed <0! The +and - signs correspond to directions, just as they indicate. They contradict themselves, and one reason not always reliable.

 

 

I didn't look at it closely before, but if you subtract a negative you get a positive, which is what you're looking for (i.e. the relative speed), right?

Edited June 29, 2018 by Moronium

[Moronium]

Calling it the closing/opening speed instead of relative velocity does kind of make sense because it prevents mixing up speeds that are relative to the observer with speeds of two other objects relative to each other, but the fact remains that they're moving at 1.2...c relative to each other in B's frame of reference.

 

I agree, and since Popeye gave this post a rousing cheer, it appears he now agrees, too.

 

It's a speed, whatever adjective you want to preface it with.  The idea behind qualifying it with the word "closing," is, I take it, merely a way of warning you that it can't be "real" since it exceeds light speed.

Edited June 29, 2018 by Moronium

[DaveC426913]

Well, to me it kinda does.  I'm trying to tie this all together.  That's why I asked the question you answered here.  I want to know if someone is measuring their speed by calculating it from some a priori assumption, or if it's actually backed up by empirical observation somehow.

 

Because I'm trying to tie it all together, the method is also of interest to me, especially as it pertains to the speed of light.  I just asked another question, which relates to that.  What you be your answer to that, if you have one and don't mind revealing it.

 

You could literally have a very long yardstick, stationary with respect to you, with sensors along it that trigger when an object passes them.

 

Since it is stationary wrt you, you observe no length contraction of the yardstick. You will however, observe the retreating craft craft asymptotically approaching c.

 

It's asymptotic because, as it nears c, it acceleration will decrease.

 

The reason it will decrease (from your point of view) is because everything on the ship is time dilated (to you). You will (if you could) observe the passenger moving slower - but more significantly the rocket ejecta moving slower out of the exhaust - which is why its acceleration is slowing. At you approach c, exhaust particles will be exiting the rocket much less often (and much slower) than they were when it started.

 

The pilot, aboard the ship sees no such drop off in his motor, since as far as he is concerned, he is stationary. He does not know or care that you are seeing him take a breath only every ten minutes, and his rocket spit out a kg of exhaust over a long time.

Edited June 29, 2018 by DaveC426913

[Moronium]

.The reason it will decrease (from your point of view) is because everything on the ship is time dilated (to you). You will (if you could) observe the passenger moving slower - but more significantly the rocket ejecta moving slower out of the exhaust - which is why its acceleration is slowing.

 

 

So, Dave, what you're saying then, is that he will measure the speed of light in his frame to be c, but that's only because his clocks have slowed down to beat hell, eh?  And his yardsticks have shrunk, but he just doesn't know it, right?

Edited June 29, 2018 by Moronium

[A-wal]

It's a speed, whatever adjective you want to preface it with.  The idea behind qualifying it with the word "closing," is, I take it, merely a way of warning you that it can't be "real" since it exceeds light speed.

It is real. The reason I said it makes sense to calling it a closing/opening speed is because it's not a velocity relative to an observer, it's the speed of the relative motion of two objects other than the observer. Giving it a different name just makes it clearer that you're talking about a frame of reference not belonging to one of the objects in question.

 

So, Dave, what you're saying then, is that he will measure the speed of light in his frame to be c, but that's only because his clocks have slowed down to beat hell, eh?  And his yardsticks have shrunk, but he just doesn't know it, right?

But from that observer's perspective any other objects in motion will be the ones that are time dilated and length contracted, all by the exact amount that makes the speed of light the same in each one's particular reference frame. None of their perspectives are privileged because there's nothing special about any of them. The technical phrase is no preferred frame.

[Moronium]

But from that observer's perspective any other objects in motion will be the ones that are time dilated and length contracted, all by the exact amount that makes the speed of light the same in each one's particular reference frame.

 

What you're calling "that observer's perspective" is no such thing.  If I'm on a moving train, I'm free (theoretically) to say, and will always say, that, as between myself and the earth's surface, the train I'm on is moving.  THAT is my perspective, not that I'm at rest, while everything attached to the earth's surface moves past me.   But SR, by fiat, prohibits me from taking that perspective, and says I MUST consider myself to be at absolute rest.

 

So it's not my perspective at all, it's SR's perspective which it forcefully imposes on me whether I like it or not, or agree with it or not.

 

You should never say "from that person's perspective."  To be accurate, you should say from "the perspective that SR imposes on that observer...."

Edited June 30, 2018 by Moronium

[Moronium]

. None of their perspectives are privileged because there's nothing special about any of them. The technical phrase is no preferred frame.

 

If SR truly adhered to that catchy notion, then I would be free to consider myself to be moving if I'm on a train. I could say that the earth is "at rest." Why not?  They're "equally valid" and both correct, aren't they?

 

NO!!  ABSOLUTELY NOT!  You can NEVER deem yourself to be moving unless you're accelerating.  You are always in the one and only preferred frame.  Everything is the universe that is moving with respect to you is moving.  YOU are at absolute rest.  You are the ether.

 

Well, I guess that does make me feel kinda *special,* after all, so I have to disagree when you say "there's nothing special about any of them."  MY frame is special, dammit!

Edited June 30, 2018 by Moronium

[DaveC426913]

So, Dave, what you're saying then, is that he will measure the speed of light in his frame to be c, but that's only because his clocks have slowed down to beat hell, eh?  And his yardsticks have shrunk, but he just doesn't know it, right?

If you provide your own answers and get the results you expect, what's the point?

 

 

I thought you wanted to run through a scenario of your choosing.

[DaveC426913]

If SR truly adhered to that catchy notion, then I would be free to consider myself to be moving if I'm on a train. I could say that the earth is "at rest." Why not?  They're "equally valid" and both correct, aren't they?

 

NO!!  ABSOLUTELY NOT!  You can NEVER deem yourself to be moving unless you're accelerating.  You are always in the one and only preferred frame.  Everything is the universe that is moving with respect to you is moving.  YOU are at absolute rest.  You are the ether.

 

Well, I guess that does make me feel kinda *special* anyway, so I have to disagree when you say "there's nothing special about any of them."  MY frame is special, dammit1

 

For a while, I thought you'd studied up on SR so that you could argue against it effectively. But this is a genuine shock.

 

You seem to have completely failed to understand what a preferred frame is. That's pretty crucial. How can you hope to discredit something when you don't actually know the thing you are discrediting?

 

And not understanding it certainly makes it clear why you reject it. This whole campaign of yours is one massive straw man. You're not arguing against Einsteinian relativity at all; you're arguing against your own misguided ideas.

 

Discussing this with you needs to take a whole different tack. We have to unteach what you have learned in error.

Edited June 30, 2018 by DaveC426913

[Moronium]

If SR truly adhered to that catchy notion, then I would be free to consider myself to be moving if I'm on a train. I could say that the earth is "at rest." Why not?  They're "equally valid" and both correct, aren't they?

 

NO!!  ABSOLUTELY NOT!  You can NEVER deem yourself to be moving unless you're accelerating.  You are always in the one and only preferred frame.  Everything is the universe that is moving with respect to you is moving.  YOU are at absolute rest.  You are the ether.

 

Well, I guess that does make me feel kinda *special,* after all, so I have to disagree when you say "there's nothing special about any of them."  MY frame is special, dammit!

 

For a while, I thought you'd studied up on SR so that you could argue against it effectively. But this is a genuine shock.

 

You seem to have completely failed to understand what a preferred frame is. That's pretty crucial. How can you hope to discredit something when you don't actually know the thing you are discrediting?

 

And not understanding it certainly makes it clear why you reject it. Anyone would, if it were as you think it is.

 

Discussing this with you needs to take a whole different tack. We have to unteach what you have learned in error.

 

Lot of words there, Dave.  Unfortunately there's no substance.  Is there something I said which you dispute?  Give me the benefit of your superior wisdom and tell me what it is, why don't ya?  What is  a preferred frame?  Would the definition of a "preferred frame," as you would define it, change a single point that I've made?

Edited June 30, 2018 by Moronium

[DaveC426913]

Lot of words there, Dave.  Unfortunately there's no substance.  Is there something I said which you dispute?  Give me the benefit of your superior wisdom and tell me what it is, why don't ya?  What is  a preferred frame?  Would the definition of a "preferred frame," as you would define it, change a single point that I've made?

The fact that you can only take in so many words is not my problem.

 

Yes. You have got preferred frame completely wrong.

 

How is it possible that we are coming up on 400 posts in this thread, and you don't actually understand the thing you are arguing against?

 

Good God, man.

Edited June 30, 2018 by DaveC426913

[Moronium]

Yes. You have got preferred frame completely wrong.

 

 

OK.  How have I got it wrong, and what difference does it make?

[DaveC426913]

OK.  How have I got it wrong, and what difference does it make?

The difference it makes is that this has not been a discussion about whether the theory is valid, or whether you have any objections to it. It's been simply you arguing your misconceptions. 

 

It is beyond the scope of this thread to teach you basic physics from the ground up. Grab a book on relativity.

 

Meanwhile, you have a lot of people to apologize to, who have been trying, in vain, to set you straight, only to get abuse and insults in return.

Edited June 30, 2018 by DaveC426913

[Moronium]

The difference it makes is that has not been a discussion about whether the theory is valid, or whether you have any objections to it. It's been simply you arguing your misconceptions. 

 

And you have a lot of people to apologize to, who have been trying, in vain, to set you straight, only to get abuse and insults in return.

 

It is beyond the scope of this thread to teach you basic relativistic physics from the ground up. Grab a book on relativity.

 

I asked you what a preferred frame is.  You can't answer.  In other words, you don't know.  OK, thanks for your "input."