Is Faster than Light travel impossible?

[darkhorror]

I tried it and concluded:
1. While you started out with good intentions by considering the purely relativistic mechanics this theory, within nano-seconds, reverted back to the observer on the ground. This theory apparently needs someone "on the ground", which is where exactly - sitting in the ether ? is it a go9d-like Einstein. Mitchelson Morely showed us that the place where that observer is situated simply doesn't exist.
The train and track, moving relatively towards each other, that I was looking for suddenly morphed into two cars (and we dismiss their relativistic mechanics quickly) and the tracks, which have simply been renamed as a road. This is not relativity. It considers only the relative motion of objects in an absolute space. Try using ony relativity to develop your theories.

I can't really see what you are trying to say here.

2. Let the cars not collide, but pass each other very closely traveling along the same axis. The observer in Car A looks out his window and can see the light in the other car. At this point the light in car B, Car B and the observer in Car A are now all in the same frame of reference.
How fast is the light traveling - and remember that, by definition, it must be the same for both Observers A & B because they are in same same frame of reference.

ok you say the observer in car A looks out the window and can see the light in the other car. This does NOT put them in the same frame as Car B. Car A and Car B are the 2 frames, if you are in Car A you are in that frame. If you are in Car B you are in that frame. Observing doesn't change anything.

Here's the bigt problem. No-one seems to be interested in developing theories which are acyually based on relativistic mechanics. It's like the whole community just gave up looking into the subject and worshipped at the altar of Einstein, the observer who can exist in a position we have proven does not exist, sees all, knows all and has no impact on the cosmos.

We can all repeat and explain Einstein's approach. That's not the point, and I don't believe he wanted inquiry to stop there and be studied o9n faith like some kind of holy book.

If we are truly interested then we need to develop the mathematics of relativity using only relative mechanics. Let's go back the road with the 2 cars and completely remove the road as a concept. Now how do we derive the laws of mechanics. I cannot, and so far I have not yet met anyone who can, without reverting back to einstein's god-like observer.

I believe you are explaining Einsteins theory in the way he explained it, but the theory, and the math, just doesn't properly deal with relativity when it falls backn to the crutch of the stationary road, tracks, eatrth, universe.

Let's seek the mathematics of relativity by considering only relative motion.

There is no god-like observer that is the very basic premise of relativity. Look at what I was trying to get with when I said there are only 2 space ships moving twards each other at close to the speed of light in an otherwise empty universe.

 

[matheinste]

in that case there is, by definition, no observer, because as soon as you place an observer in the picture he forces the light in his frame of reference to be the same in all the frames of reference he is observing.

What force does the observer use to do this, and what does the light do when no observer is observing it.

Matheinste.

 

[jmallett]

Look at it this way instead of a train and train tracks turn those into 2 space ships in an otherwise empty universe. Have the 2 spaceships approaching each other at close to the speed of light.

DarkHorror, I like this as place for starting to think, I don't feel adequate in stopping my explorations at that.
Please develop this idea further and consider the frequency (color) of the light emanating from those ships.

 

[Doc Al]

I tried it and concluded:
1. While you started out with good intentions by considering the purely relativistic mechanics this theory, within nano-seconds, reverted back to the observer on the ground. This theory apparently needs someone "on the ground", which is where exactly - sitting in the ether ? is it a go9d-like Einstein. Mitchelson Morely showed us that the place where that observer is situated simply doesn't exist.
The train and track, moving relatively towards each other, that I was looking for suddenly morphed into two cars (and we dismiss their relativistic mechanics quickly) and the tracks, which have simply been renamed as a road. This is not relativity. It considers only the relative motion of objects in an absolute space. Try using ony relativity to develop your theories.

There's nothing special about using the ground or anything other reference frame for describing the relative motion of things. Nothing 'god-like' or absolute about it.

2. Let the cars not collide, but pass each other very closely traveling along the same axis. The observer in Car A looks out his window and can see the light in the other car. At this point the light in car B, Car B and the observer in Car A are now all in the same frame of reference.

I don't know what you mean when you say that Car A and Car B are 'in the same reference frame'. They are certainly not moving together. From Car A's reference frame, Car B is moving. And vice versa.

How fast is the light traveling - and remember that, by definition, it must be the same for both Observers A & B because they are in same same frame of reference.

Measured from Car A's frame (meaning: from a frame in which Car A is at rest) the speed of light is c. And from Car B's frame (a different frame from Car A's frame) the speed of light is also c.

Here's the bigt problem. No-one seems to be interested in developing theories which are acyually based on relativistic mechanics. It's like the whole community just gave up looking into the subject and worshipped at the altar of Einstein, the observer who can exist in a position we have proven does not exist, sees all, knows all and has no impact on the cosmos.

We can all repeat and explain Einstein's approach. That's not the point, and I don't believe he wanted inquiry to stop there and be studied o9n faith like some kind of holy book.

If we are truly interested then we need to develop the mathematics of relativity using only relative mechanics. Let's go back the road with the 2 cars and completely remove the road as a concept. Now how do we derive the laws of mechanics. I cannot, and so far I have not yet met anyone who can, without reverting back to einstein's god-like observer.

I believe you are explaining Einsteins theory in the way he explained it, but the theory, and the math, just doesn't properly deal with relativity when it falls backn to the crutch of the stationary road, tracks, eatrth, universe.

Let's seek the mathematics of relativity by considering only relative motion.

I have no idea what you are talking about here. The only motion considered in developing relativity--and certainly in the examples we've discussed here--is relative motion. The cars move relative to each other; the train moves relative to the tracks. What's the problem?

 

[Doc Al]

in that case there is, by definition, no observer, because as soon as you place an observer in the picture he forces the light in his frame of reference to be the same in all the frames of reference he is observing.

Now what are you talking about? Of course there is an observer--the one who measures the train as moving at speed v.

 

[jmallett]

What force does the observer use to do this, and what does the light do when no observer is observing it.

Matheinste.

Matheinste, Great questions, and this is something for the defenders of Einstein. By placing an observer in the picture they immediately specify that with, or without, force it must be so. The dictate is that light travels at a single and constant speed in any given frame of reference. It may, or may not, be true, but if it is true then you are right to ask - by what law, or force can the observer do this ?

The next part is the exciting part. No-one seems to be considering this, and Einstein certainly didn't, so you are beginning to think beyond the rote learning of the last 100 years.

 

[Doc Al]

So let's try this from a purely relativistic point of view. All ye who enter here first abandon stationary observers, ether, gods, train tracks, roads or other devices created for the sole purpose of being independent of relative motion.

There is nothing about train tracks or roads that makes them 'independent of relative motion'.

Two space ships are floating through the cosmos. Each has an undetermined speed both by themselves and by the other. for simplicity, and by sheer luck (for you and me but only because it simplifies our math), they are traveling along the same axis.

OK. I assume that they have some speed relative to each other.

Both send out a beam of light of the same frequency in the forward direction. Will those beams synchronize and will they synchronize independently of the speed of the two ships and without knowing anything else about the ships ?

What do you mean 'synchronize'? Note that relativity assumes that any frame of reference (each of the two ships, in this case) will measure the speed of any beam of light as moving with the same speed c with respect to that frame.

This is a simple, first step in relativistic mechanics and easily provable if we could just find light emission from bodies moving arbitrarily in a universe. Let's try some assumptions and then test them by the experiment of looking out the window.

I have no idea what you are looking for.

 

[jmallett]

Now what are you talking about? Of course there is an observer--the one who measures the train as moving at speed v.

Then by definition he sees the light in the train, and by seeing it and the train at the same time, then the speed of the light in the train is the same in the train as it is for him - (c + v) disappears and the observer in the train measures the train's length incorrectly.

 

[Doc Al]

Matheinste, Great questions, and this is something for the defenders of Einstein. By placing an observer in the picture they immediately specify that with, or without, force it must be so. The dictate is that light travels at a single and constant speed in any given frame of reference. It may, or may not, be true, but if it is true then you are right to ask - by what law, or force can the observer do this ?

The next part is the exciting part. No-one seems to be considering this, and Einstein certainly didn't, so you are beginning to think beyond the rote learning of the last 100 years.

I think it's becoming clear that you are not interesting in learning about relativity and that you have some sort of axe to grind. Please take a look at the sticky labeled "IMPORTANT! Read before posting" at the top of this forum before continuing.

 

[darkhorror]

Ok let's say they are space ships A and B moving twards each other close to the speed of light. On spaceship A a beam of light in the middle of the ship causes two clocks to start on both ends of the ship when the light hits them. In that frame both clocks are synchronized because the light travels the same distance to the back as it does to the front and light is traveling at the speed of light obviously.

With respect to spaceship B the beam of light in A has to travel different distances. This is because spaceship A is moving with respect to spaceship B. But you can do this on both spaceships and to A the B clocks are out of sync but to B they are in sync. Just as to A the A clocks are in sync, but to A the B clocks are out of sync.

I left out the word observer as it seems to be adding to confusion, having observers does nothing to change what is actually happening.

 

[jmallett]

There is nothing about train tracks or roads that makes them 'independent of relative motion'.


OK. I assume that they have some speed relative to each other.


What do you mean 'synchronize'? Note that relativity assumes that any frame of reference (each of the two ships, in this case) will measure the speed of any beam of light as moving with the same speed c with respect to that frame.


I have no idea what you are looking for.

OK, I'll step it back a little on the subject of synchronization.
Ship A creates white light.
Ship B creates white light

What color do they appear to be to each other ?

 

[matheinste]

Matheinste, Great questions, and this is something for the defenders of Einstein. By placing an observer in the picture they immediately specify that with, or without, force it must be so. The dictate is that light travels at a single and constant speed in any given frame of reference. It may, or may not, be true, but if it is true then you are right to ask - by what law, or force can the observer do this ?

The next part is the exciting part. No-one seems to be considering this, and Einstein certainly didn't, so you are beginning to think beyond the rote learning of the last 100 years.

I hope nobody else thought that was a serious question.

Matheinste.

 

[Doc Al]

Then by definition he sees the light in the train, and by seeing it and the train at the same time, then the speed of the light in the train is the same in the train as it is for him - (c + v) disappears and the observer in the train measures the train's length incorrectly.

Nothing magical happens when the observer 'sees the light'. The speed of light with respect to the outside observer is c. And the speed of light with respect to an observer on the train is also c.

(c + v) is not the speed of light. It's the rate at which the light and the train approach each other according to the outside observer. An observer on the train would describe things differently: he would say that the light approaches the train--his frame--at speed c.

Every frame sees the speed of light to be c with respect to their frame. (Not someone else's.) This is a tricky concept.

 

[matheinste]

OK, I'll step it back a little on the subject of synchronization.
Ship A creates white light.
Ship B creates white light

What color do they appear to be to each other ?

Isn't white light frequency shifted still white light.

Matheinste.

 

[Doc Al]

OK, I'll step it back a little on the subject of synchronization.
Ship A creates white light.
Ship B creates white light

What color do they appear to be to each other ?

"White" is not a good choice for a color, as it is a mix of frequencies. To understand how the frequency of light changes due to the relative speed of source and observer, look up the Doppler effect. I recommend you stick to one topic at a time.

 

[Doc Al]

I hope nobody else thought that was a serious question.

 

[jmallett]

I hope nobody else thought that was a serious question.

Matheinste.

Matheinste, It was a good question in it's obvious error, of course, and that's why it was a great question.
The answer is - there obviously is no mysterious force and therefore there is no way that an observer CAN force the light to the same speed.
Ergo those (like Einstein) who assume it to be the case need to demonstrate the existence of the force or dispense with the observer.
Einstein specifies it, but does not explain it's obvious fallacy.

I thought you were trying to be ironic, and used that irony to show that once you move down that road you are clearly in some particularly non-scientific territory.

 

[jmallett]

Isn't white light frequency shifted still white light.

Matheinste.

Whereby we are unable to determine red shift in the universe and therefore unable to determine it's rate of expansion ?

I'll let the physicists know about that one.

 

[jmallett]

Only the folks that believe in stationary observers got suckered into that. The rest used his original irony to indicate that it was, of course, an ironic question because it assumes observers with magical powers.

 

[jmallett]

Now is there anyone out there interested using relativistic mechanics in order to understand relativity ?

 

[jmallett]

"White" is not a good choice for a color, as it is a mix of frequencies. To understand how the frequency of light changes due to the relative speed of source and observer, look up the Doppler effect. I recommend you stick to one topic at a time.

It is, of course, the same subject, because the postulate at the moment is that light in a moving train is seen in one way in the train, but a different way by someone not in the train. It's just going back to some very basic stuff assumed by the experiment because there did not seem to be consensus in this forum on the understanding of the speed of light in a particular frame of reference, so I was trying, first, to define some basics which we might all agree on before jumping to the assumptions which we do not, apparently, agree on for the moment.

 

[jmallett]

It is, of course, the same subject, because the postulate at the moment is that light in a moving train is seen in one way in the train, but a different way by someone not in the train. It's just going back to some very basic stuff assumed by the experiment because there did not seem to be consensus in this forum on the understanding of the speed of light in a particular frame of reference, so I was trying, first, to define some basics which we might all agree on before jumping to the assumptions which we do not, apparently, agree on for the moment.

OK, pick a color, pick any color, hey you can even pick anything in the electromagnetic spectrum as far as I am concerned. I don't think we need to argue (yet) about the color of this light - that will change in due course anyway, although it's possible that we may disagree on the color it is going to be later.

 

[Doc Al]

It is, of course, the same subject, because the postulate at the moment is that light in a moving train is seen in one way in the train, but a different way by someone not in the train.

Nope. That might be your postulate, but it has little to do with relativity. Everyone sees the light traveling at the same speed with respect to them.

 

[jmallett]

Nope. That might be your postulate, but it has little to do with relativity. Everyone sees the light traveling at the same speed with respect to them.

No, definitely NOT my postulate.
Thank you for making the point.
It is the postulate of the stationary observer.

It is the postulate currently being made by a variety of people in this forum.

 

[Doc Al]

It is the postulate currently being made by a variety of people in this forum.

Nope, just you.

 

[jmallett]

Nope, just you.

Actually you have taken this position. Please bear with me for a moment, and please indicate at which po9int you disagree.

The "stationary observer" watched the observer take a measurement in the train.

He measured the speed of the train (in his reference frame)

He observed that the observers on the train incorrectly measured the length of the rod - when considered in the stationary observers time frame.

He then took the velocity information of his frame of reference, but used it together with the iength measurement made in another frame of reference, thereby confusing two sets of data.

Clearly he cannot derive the equation r(AB)/(c + w)

Now, why do I believe you have made that postulation ?
Because you assumed that the light in the train traveled faster than the light in the stationary frame yet both were in the same frame of reference.

OK, so let's then agree, right ? The stationary observer sees the light in the train traveling at the same speed as the light in his own frame. Do we agree ?

 

[jmallett]

It is, of course, the same subject, because the postulate at the moment is that light in a moving train is seen in one way in the train, but a different way by someone not in the train. It's just going back to some very basic stuff assumed by the experiment because there did not seem to be consensus in this forum on the understanding of the speed of light in a particular frame of reference, so I was trying, first, to define some basics which we might all agree on before jumping to the assumptions which we do not, apparently, agree on for the moment.

Oh, and by the way, any time someone says - "go back and read about..." it reminds me of the people you meet in various religions who when asked to give their view simply say - "you need to study Gospel x, chapter y"

I appreciate that you have your beliefs. I am still a skeptic. I am merely trying to understand how you believe your beliefs, because they are not to me self-evident

 

[Doc Al]

He then took the velocity information of his frame of reference, but used it together with the iength measurement made in another frame of reference, thereby confusing two sets of data.

Nope. The 'stationary' observer does not make use of any length measurements made in some other frame. All his measurements are made in his own frame.

Now, why do I believe you have made that postulation ?
Because you assumed that the light in the train traveled faster than the light in the stationary frame yet both were in the same frame of reference.

Nope. I've said as many times as possible: Viewed from any frame of reference, the light moves at the same speed. (Again, I have no idea what you mean when you talk of things being in 'the same frame of reference'.)

OK, so let's then agree, right ? The stationary observer sees the light in the train traveling at the same speed as the light in his own frame. Do we agree ?

I've been saying that all along: The 'stationary' observer sees all light travel at the same speed with respect to him (not the train!). A basic premise of relativity is that the speed of light is the same in every frame. Now if you switch to the frame of the train, then the speed of light is also c with respect to the train.

Where you are getting stuck is in not understanding how the stationary observer can see the light and the train close at a rate of 'c + v', even though both the stationary observer and the train both observe the light to move at the same speed c with respect to their own frames. This is tricky stuff.

 

[Doc Al]

I appreciate that you have your beliefs. I am still a skeptic. I am merely trying to understand how you believe your beliefs, because they are not to me self-evident

There's no requirement for science--especially relativity--to be 'self-evident'. Further, science is based on logic and evidence, not merely 'belief'.

Before calling yourself a 'skeptic' about something, why not first try to understand that something?

 

[matheinste]

Oh, and by the way, any time someone says - "go back and read about..." it reminds me of the people you meet in various religions who when asked to give their view simply say - "you need to study Gospel x, chapter y"

I appreciate that you have your beliefs. I am still a skeptic. I am merely trying to understand how you believe your beliefs, because they are not to me self-evident

If you accept the beliefs or postulates of relativity you arrive at certain logically derived consequences. You do not have to accept any postulates if you wish not to. However, you must accept the logical reasoning used. If you do not accept the postulate of light speed, which most agree is counterintuitive, so be it, but at least apply some logic in your arguments against it.

Matheinste.