Relativity

[fast]

There is a lexical peculiarity that I keep struggling with.

First, just to get someone to grasp what I'll be talking about might very well become an uphill battle, not because it's complicated but because of resistance to the notion that it's possible for an object to not be in motion. See, believers in relativity will vehemently declare that an object is always in motion relative to some 'other' frame of reference, but maybe with some luck, someone'll be able to get past the temptation.

To start, however, just to get my point across, I will start with the earth as a frame of reference. An object "like a car" that is moving (oh say) 30MPH across the surface of a road on the surface of earth is an object in motion while a car in park traveling at 0MPH is an object not in motion (relative to Earth). Notice I said traveling at 0MPH. Interesting wording. Seems rather odd. The speed, well, the very lack of speed, seems to suggest that particular car isn't traveling at all, so despite the equivalence between A) "traveling at" which highly suggests being in motion (and just never mind relativity for a moment) only to be explained to not be the case since it's 'traveling' at 0MPH and B) not traveling. ... .

Let's suppose something. Let's suppose that I could show that an object in space is not moving. Fat chance, I'm sure, but just for the sake of argument, let's say an object (object A) is not moving. Just ingrain that into your head. Object A is not moving. Objects B and C are moving. Lets say B is moving at 25% the speed of light and let's say object C is moving at 50% the speed of light.

I don't mind saying that all objects are moving relative to one another. Even object A is moving relative to the others even though it's not moving at all. That's the lexical peculiarity, to say "no, it's not moving" while also saying "yes, it's moving." Never mind the truth of relativity for the moment. Just assume I'm right and object A isn't moving despite there being relative movement.

See, I don't deny that an object is moving relative to other objects just because the object said to be moving isn't in fact moving at all. That sentence may be very hard to understand while trying to embrace the idea of relativity. That's why it's so important to let go of the supposed truth that there can be no object leaving a stationary coordinate.

Now, I think there is some confusion regarding the general theory of relativity. To point out what I think some people get wrong can be exemplified with the following thought experiment: let's say there is a train on a train track and it's moving at 95% the speed of light. Lets say there are 10 train cars. The front train car is the engine car and the last train car is the caboose (the 10th train car). You are on the last train car looking ahead at the engine car but can't see it because it's dark. So, you shine a light towards it. It lights up and so you see it.

Now, cut the light off. The driver of the train speeds up to the speed of light. You cut the light back on to see the back of the engine car, but this time, no light shines on the back of it. Why? Because the light is traveling at its maximum speed and cannot move past the caboose. Apparently, some people think, and hence the confusion, that the light will shoot out relative to the person shining it. Not so.

Now, I want to make the claim, crazy crazy crazy claim, that any object moving at 0% the speed of light is an object that is not moving. Don't confuse that speed with the speed of light.

If we were to (i'm imagining) create a sphere with a central light source covered with a couple layers of metal wrapping with holes such that light is funneled to protrude out to external mirrors of equal distances apart, and if it's stationary relative to Earth, then the lights should not reflect back simultaneously precisely because we are traveling through space. If we could launch it into space where thrusters were to cut on and off altering its speed until such time there was a perfect match of returning reflections, the contraption would eventually not be in motion at all--despite the peculiarity that it's still moving relative to other objects.

 

[beero1000]

The  Michelson-Morley experiment showed that your predictions are wrong.

 

[fast]

The  Michelson-Morley experiment showed that your predictions are wrong.

They didn't consider the magical horsey.

How long does it take for light to travel from the sun to Earth?

A big ship twice the size of the sun passes between the sun and earth and stops. It's located next to the sun. Then, a man riding a magical horsey goes to see what all the fuss is about. After a few drinks, the guy says to the sun, I'll race your light to the earth when the ship moves. The horsey, magical as it is, still cannot ride faster than the speed of light, so when the ship moves, both the suns light and the man on the magical horsey takes off towards earth. Half way there, the initial photons and the horsey are neck and neck, neither traveling faster than the speed of light.

What you're telling me is that if the man traveling the speed of light pulls out a super duper flashlight model 3.0 and shines it at Earth that the light of the flashlight will reach earth before either the initial photons emitted from the sun or the man. That would imply that the speed of light from the flashlight will travel twice the speed of light of the sun.

Where in the experiment does it show that the maximum speed of light can exceed the maximum speed of light?

 

[beero1000]

The  Michelson-Morley experiment showed that your predictions are wrong.

They didn't consider the magical horsey.

How long does it take for light to travel from the sun to Earth?

A big ship twice the size of the sun passes between the sun and earth and stops. It's located next to the sun. Then, a man riding a magical horsey goes to see what all the fuss is about. After a few drinks, the guy says to the sun, I'll race your light to the earth when the ship moves. The horsey, magical as it is, still cannot ride faster than the speed of light, so when the ship moves, both the suns light and the man on the magical horsey takes off towards earth. Half way there, the initial photons and the horsey are neck and neck, neither traveling faster than the speed of light.

What you're telling me is that if the man traveling the speed of light pulls out a super duper flashlight model 3.0 and shines it at Earth that the light of the flashlight will reach earth before either the initial photons emitted from the sun or the man. That would imply that the speed of light from the flashlight will travel twice the speed of light of the sun.

Where in the experiment does it show that the maximum speed of light can exceed the maximum speed of light?

It implies no such thing. Light has no rest frame, does not experience the passage of time or distance, so there are no magical horsey speed calculations to be done. On Earth, we'd see the light traveling at... the speed of light.

Seriously though, it's been 130 years since Michelson-Morley. Read the wiki, and think about what your 'sphere with reflectors' idea would actually measure. There is no luminiferous aether, and the result of that actual (not thought) experiment is what led to the development of relativity in the first place.

 

[Jon Osterman]

For fucks sake, what is this shit? We have been performing experiments that quite clearly demonstrate relativity for over a hundred years now. Do you really think experiments like those at the LHC wouldn't notice if special relativity weren't correct? In 1864 Maxwell, wrote down his relativitically covariant Maxwell equations and in 1892 Lorentz pointed out that the obey (what would be called) the Lorentz symmerty.

I suggest going back to school and learning some science.

 

[skepticalbip]

There is a lexical peculiarity that I keep struggling with.

Yes there apparently is. Your view of reality seems to be a Newtonian view. This is understandable since our normal daily experience of "reality" is quite well described by Newton. However, this is so only because we don't experience noticeable relativistic effects in our normal daily life.

There are a couple problems in your OP that, if you think a little harder on, may help you answer your questions yourself. The first is that you keep mentioning "the speed of light" but not what you are assuming the speed of light is with respect to even though you have agreed that speed has no meaning without designating a reference frame for it to be measured against. Then, very precise measurements have shown that, regardless of reference frames and their relative velocities, that measurements from those various reference frames always show the speed of light constant with respect to the reference frame from which it is measured. (In your train thought experiment, the train would be the reference frame for the guy in the caboose and his flashlight.)

This is the dilemma uncle Albert faced. His solution was his theory of relativity - and, so far, there has been no experiments that demonstrate an error though many, many have tried.

 

[fast]

For fucks sake, what is this shit? We have been performing experiments that quite clearly demonstrate relativity for over a hundred years now. Do you really think experiments like those at the LHC wouldn't notice if special relativity weren't correct? In 1864 Maxwell, wrote down his relativitically covariant Maxwell equations and in 1892 Lorentz pointed out that the obey (what would be called) the Lorentz symmerty.

I suggest going back to school and learning some science.

I'm not denying what it appears that I am denying. It appears that I'm denying relativity. I apologize for that. I'm not denying relativity. What I'm denying is something else. The problem is that when I deny what it is I'm denying, it appears that I'm denying relativity.

We are taught that saying something is moving at a particular speed is insufficient unless it's granted that it's understood to be moving relative to something. The car is moving at 80MPH is a car moving at 80MPH relative to the earths surface.

I'm not denying relativity. What I'm denying is a seeming consequence of it. I think the assertion that the car is moving relative to other objects is true, but I also think the assertion the car is moving at 80MPH can be understood and shown false without invoking relativity--even if it's moving relative to other objects at some other speed.

Epistemological failures do not negate ontological truths.

A single object is either moving or its not. The idea that it's impossible to be stationary is unacceptable.

 

[fast]

There is a lexical peculiarity that I keep struggling with.

Yes there apparently is. Your view of reality seems to be a Newtonian view. This is understandable since our normal daily experience of "reality" is quite well described by Newton. However, this is so only because we don't experience noticeable relativistic effects in our normal daily life.

There are a couple problems in your OP that, if you think a little harder on, may help you answer your questions yourself. The first is that you keep mentioning "the speed of light" but not what you are assuming the speed of light is with respect to even though you have agreed that speed has no meaning without designating a reference frame for it to be measured against. Then, very precise measurements have shown that, regardless of reference frames and their relative velocities, that measurements from those various reference frames always show the speed of light constant with respect to the reference frame from which it is measured. (In your train thought experiment, the train would be the reference frame for the guy in the caboose and his flashlight.)

This is the dilemma uncle Albert faced. His solution was his theory of relativity - and, so far, there has been no experiments that demonstrate an error though many, many have tried.

Wait a minute. I feel like an idiot from idiotsville. I thought the idea was, "here's my theory and it's based on two assumptions," where the assumptions have been proven true. I didn't realize the assumptions themselves assumed the theory itself. WTF?

That means the light traveling at the speed of light relative to a person in a very fast spacecraft passing earth is in fact calculably faster than the speed of light as observed from someone on the planet. In that case, in my horsey example, who sees objects on the planet first?

If I'm in the dark, the light from the sun hasn't gotten to me yet. For example, if it takes 8 minutes for the light to get to me, I won't see a naked girl standing before me for another four minutes. Even if the rider cuts on his light, to me, it won't be traveling faster, so from my perspective, its still going to take four minutes before I can see. The rider won't see the earth either from the sun light because it'll be another four minutes before it gets there, but if the light he shines takes off at the speed of light from his current speed, the speed of light, he should see the girl before me.

This is twisted.

 

[bilby]

For fucks sake, what is this shit? We have been performing experiments that quite clearly demonstrate relativity for over a hundred years now. Do you really think experiments like those at the LHC wouldn't notice if special relativity weren't correct? In 1864 Maxwell, wrote down his relativitically covariant Maxwell equations and in 1892 Lorentz pointed out that the obey (what would be called) the Lorentz symmerty.

I suggest going back to school and learning some science.

I'm not denying what it appears that I am denying. It appears that I'm denying relativity. I apologize for that. I'm not denying relativity. What I'm denying is something else. The problem is that when I deny what it is I'm denying, it appears that I'm denying relativity.

We are taught that saying something is moving at a particular speed is insufficient unless it's granted that it's understood to be moving relative to something. The car is moving at 80MPH is a car moving at 80MPH relative to the earths surface.

I'm not denying relativity. What I'm denying is a seeming consequence of it. I think the assertion that the car is moving relative to other objects is true, but I also think the assertion the car is moving at 80MPH can be understood and shown false without invoking relativity--even if it's moving relative to other objects at some other speed.

Epistemological failures do not negate ontological truths.

A single object is either moving or its not. The idea that it's impossible to be stationary is unacceptable.

The idea that it is impossible to be stationary is not a part of Relativity - On the contrary, in relativistic terms, you are free to declare anything to be stationary, and to start your calculations from that premise. The premise 'X is stationary' is also known as a reference frame, and all of them are valid - you can pick whichever one you like (and mostly people pick one that makes the maths as simple as possible).

The man in the caboose can do his maths based on the assumption that the train is not moving, and will get the same results as he would if he assumed that the track was not moving - assuming that he is a competent mathematician, with a sound understanding of the formulae he needs to use (according to Einstein), and that he doesn't make any errors.

Whether the train is moving at 0mph or at 99.999% of c relative to the tracks, his experience with the effect of his flashlight on his view of the locomotive will be the same. The effect of the train's velocity on his view of things not in the train is another question entirely.

When considering the interaction between caboose and locomotive, both of which have the same velocity, the maths is simplest if he assumes that both are stationary. But he is free to select another object; declare it to be stationary; and crunch the numbers on that basis - the final result will be the same.

The fact is that everything is stationary. But only when viewed by an observer with the same velocity. And it's perfectly fine to do all of the maths from that perspective - as long as you apply it consistently, and don't try to change reference frames before you finish doing the sums.

 

[beero1000]

There is a lexical peculiarity that I keep struggling with.

Yes there apparently is. Your view of reality seems to be a Newtonian view. This is understandable since our normal daily experience of "reality" is quite well described by Newton. However, this is so only because we don't experience noticeable relativistic effects in our normal daily life.

There are a couple problems in your OP that, if you think a little harder on, may help you answer your questions yourself. The first is that you keep mentioning "the speed of light" but not what you are assuming the speed of light is with respect to even though you have agreed that speed has no meaning without designating a reference frame for it to be measured against. Then, very precise measurements have shown that, regardless of reference frames and their relative velocities, that measurements from those various reference frames always show the speed of light constant with respect to the reference frame from which it is measured. (In your train thought experiment, the train would be the reference frame for the guy in the caboose and his flashlight.)

This is the dilemma uncle Albert faced. His solution was his theory of relativity - and, so far, there has been no experiments that demonstrate an error though many, many have tried.

Wait a minute. I feel like an idiot from idiotsville. I thought the idea was, "here's my theory and it's based on two assumptions," where the assumptions have been proven true. I didn't realize the assumptions themselves assumed the theory itself. WTF?

That means the light traveling at the speed of light relative to a person in a very fast spacecraft passing earth is in fact calculably faster than the speed of light as observed from someone on the planet. In that case, in my horsey example, who sees objects on the planet first?

If I'm in the dark, the light from the sun hasn't gotten to me yet. For example, if it takes 8 minutes for the light to get to me, I won't see a naked girl standing before me for another four minutes. Even if the rider cuts on his light, to me, it won't be traveling faster, so from my perspective, its still going to take four minutes before I can see. The rider won't see the earth either from the sun light because it'll be another four minutes before it gets there, but if the light he shines takes off at the speed of light from his current speed, the speed of light, he should see the girl before me.

This is twisted.

No, you are still misunderstanding - the speeds do not add. In any inertial reference frame, light moves at c.

Did you read about the experiment? I'm focusing on it specifically because it isn't a thought experiment. It was an actual, real-life test, and the results disagree with your conclusions. Reality does not care what you imagine, your philosophy, or what you think 'should be'. If an idea disagrees with experiment then it is simply wrong. Figuring out why those ideas don't work is exactly what led to relativity, and the idea that the speed of light is the same for all observers.

 

[skepticalbip]

There is a lexical peculiarity that I keep struggling with.

Yes there apparently is. Your view of reality seems to be a Newtonian view. This is understandable since our normal daily experience of "reality" is quite well described by Newton. However, this is so only because we don't experience noticeable relativistic effects in our normal daily life.

There are a couple problems in your OP that, if you think a little harder on, may help you answer your questions yourself. The first is that you keep mentioning "the speed of light" but not what you are assuming the speed of light is with respect to even though you have agreed that speed has no meaning without designating a reference frame for it to be measured against. Then, very precise measurements have shown that, regardless of reference frames and their relative velocities, that measurements from those various reference frames always show the speed of light constant with respect to the reference frame from which it is measured. (In your train thought experiment, the train would be the reference frame for the guy in the caboose and his flashlight.)

This is the dilemma uncle Albert faced. His solution was his theory of relativity - and, so far, there has been no experiments that demonstrate an error though many, many have tried.

Wait a minute. I feel like an idiot from idiotsville. I thought the idea was, "here's my theory and it's based on two assumptions," where the assumptions have been proven true. I didn't realize the assumptions themselves assumed the theory itself. WTF?

It is always good to question one's assumptions ... this is especially true if they lead to conclusions contrary to experimental findings.

That means the light traveling at the speed of light relative to a person in a very fast spacecraft passing earth is in fact calculably faster than the speed of light as observed from someone on the planet.

Such a calculation could only be made by using Newtonian assumptions (which demonstrates that Newton was wrong). If, however, the calculation is done using relativistic theory then someone on the planet would find the light traveling at c with respect to the planet but that it would be blue shifted.

 

[fast]

For fucks sake, what is this shit? We have been performing experiments that quite clearly demonstrate relativity for over a hundred years now. Do you really think experiments like those at the LHC wouldn't notice if special relativity weren't correct? In 1864 Maxwell, wrote down his relativitically covariant Maxwell equations and in 1892 Lorentz pointed out that the obey (what would be called) the Lorentz symmerty.

I suggest going back to school and learning some science.

I'm not denying what it appears that I am denying. It appears that I'm denying relativity. I apologize for that. I'm not denying relativity. What I'm denying is something else. The problem is that when I deny what it is I'm denying, it appears that I'm denying relativity.

We are taught that saying something is moving at a particular speed is insufficient unless it's granted that it's understood to be moving relative to something. The car is moving at 80MPH is a car moving at 80MPH relative to the earths surface.

I'm not denying relativity. What I'm denying is a seeming consequence of it. I think the assertion that the car is moving relative to other objects is true, but I also think the assertion the car is moving at 80MPH can be understood and shown false without invoking relativity--even if it's moving relative to other objects at some other speed.

Epistemological failures do not negate ontological truths.

A single object is either moving or its not. The idea that it's impossible to be stationary is unacceptable.

The idea that it is impossible to be stationary is not a part of Relativity - On the contrary, in relativistic terms, you are free to declare anything to be stationary, and to start your calculations from that premise. The premise 'X is stationary' is also known as a reference frame, and all of them are valid - you can pick whichever one you like (and mostly people pick one that makes the maths as simple as possible).

The man in the caboose can do his maths based on the assumption that the train is not moving, and will get the same results as he would if he assumed that the track was not moving - assuming that he is a competent mathematician, with a sound understanding of the formulae he needs to use (according to Einstein), and that he doesn't make any errors.

Whether the train is moving at 0mph or at 99.999% of c relative to the tracks, his experience with the effect of his flashlight on his view of the locomotive will be the same. The effect of the train's velocity on his view of things not in the train is another question entirely.

When considering the interaction between caboose and locomotive, both of which have the same velocity, the maths is simplest if he assumes that both are stationary. But he is free to select another object; declare it to be stationary; and crunch the numbers on that basis - the final result will be the same.

The fact is that everything is stationary. But only when viewed by an observer with the same velocity. And it's perfectly fine to do all of the maths from that perspective - as long as you apply it consistently, and don't try to change reference frames before you finish doing the sums.

But there can be truly stationary objects though. We catch the dickens pointing to one and have abandoned that idea and went on to look at the world through relevatistic eyes. That's fine. Through that lens, all objects are in motion or stationary relative to others. While you admit that an object can be stationary, you do so at the expense of the other mindset where there can be a sense in which an object can be either in motion or not in motion without invoking relativity.

If there is a single object, we cannot tell if it's moving or not, but it's the cannot part that bothers me, as not being able to tell is not sufficient grounds to throw our hands up. If an object is getting closer to another and there is a collision, we now know both are moving, and if one disappears, there's no way to MEASURE that the remaining object is moving, but TRUTH is independent of our current ability to measure.

 

[fast]

Wait a minute. I feel like an idiot from idiotsville. I thought the idea was, "here's my theory and it's based on two assumptions," where the assumptions have been proven true. I didn't realize the assumptions themselves assumed the theory itself. WTF?

It is always good to question one's assumptions ... this is especially true if they lead to conclusions contrary to experimental findings.

That means the light traveling at the speed of light relative to a person in a very fast spacecraft passing earth is in fact calculably faster than the speed of light as observed from someone on the planet.

Such a calculation could only be made by using Newtonian assumptions (which demonstrates that Newton was wrong). If, however, the calculation is done using relativistic theory then someone on the planet would find the light traveling at c with respect to the planet but that it would be blue shifted.

On the questioning assumptions part, it was my interpretation of the assumptions posed that confused me.

I thought we were supposed to accept that the speed of light was the same for all people no matter what anyone's frame of reference was, not that we were to accept that the speed of light was the same for all people no matter their frame of reference. In other words, I thought light was traveling near c, period.

 

[bilby]

The idea that it is impossible to be stationary is not a part of Relativity - On the contrary, in relativistic terms, you are free to declare anything to be stationary, and to start your calculations from that premise. The premise 'X is stationary' is also known as a reference frame, and all of them are valid - you can pick whichever one you like (and mostly people pick one that makes the maths as simple as possible).

The man in the caboose can do his maths based on the assumption that the train is not moving, and will get the same results as he would if he assumed that the track was not moving - assuming that he is a competent mathematician, with a sound understanding of the formulae he needs to use (according to Einstein), and that he doesn't make any errors.

Whether the train is moving at 0mph or at 99.999% of c relative to the tracks, his experience with the effect of his flashlight on his view of the locomotive will be the same. The effect of the train's velocity on his view of things not in the train is another question entirely.

When considering the interaction between caboose and locomotive, both of which have the same velocity, the maths is simplest if he assumes that both are stationary. But he is free to select another object; declare it to be stationary; and crunch the numbers on that basis - the final result will be the same.

The fact is that everything is stationary. But only when viewed by an observer with the same velocity. And it's perfectly fine to do all of the maths from that perspective - as long as you apply it consistently, and don't try to change reference frames before you finish doing the sums.

But there can be truly stationary objects though. We catch the dickens pointing to one and have abandoned that idea and went on to look at the world through relevatistic eyes. That's fine. Through that lens, all objects are in motion or stationary relative to others. While you admit that an object can be stationary, you do so at the expense of the other mindset where there can be a sense in which an object can be either in motion or not in motion without invoking relativity.

If there is a single object, we cannot tell if it's moving or not, but it's the cannot part that bothers me, as not being able to tell is not sufficient grounds to throw our hands up. If an object is getting closer to another and there is a collision, we now know both are moving, and if one disappears, there's no way to MEASURE that the remaining object is moving, but TRUTH is independent of our current ability to measure.

If there is a single object, then whether or not it is moving is completely irrelevant to anything, so we might as well simply declare it to be stationary, and make life simple for ourselves.

What is the difference? A single object moving through an otherwise empty universe at 99.999% of c relative to the arbitrary reference frame of an imaginary observer traveling at -99.999% of c behaves EXACTLY the same way that a single stationary object in an empty universe behaves.

All you do by invoking the imaginary observer with a different frame of reference is to make the sums harder.

The TRUTH is that velocity is not a characteristic of a single object, and that to discuss the velocity of a single object is meaningless. So if you insist on this irrelevant velocity information, you might as well save yourself some heartache, and label it's velocity '0'. That's not 'throwing your hands up' and abandoning TRUTH; It's accepting that the TRUTH is that velocity is only a meaningful entity when considered in relation to something (real or imagined) that is moving at a different velocity.

 

[skepticalbip]

It is always good to question one's assumptions ... this is especially true if they lead to conclusions contrary to experimental findings.

Such a calculation could only be made by using Newtonian assumptions (which demonstrates that Newton was wrong). If, however, the calculation is done using relativistic theory then someone on the planet would find the light traveling at c with respect to the planet but that it would be blue shifted.

On the questioning assumptions part, it was my interpretation of the assumptions posed that confused me.

I thought we were supposed to accept that the speed of light was the same for all people no matter what anyone's frame of reference was, not that we were to accept that the speed of light was the same for all people no matter their frame of reference. In other words, I thought light was traveling near c, period.

Correct. Experiments have verified that, no matter who measures the speed of light in whatever reference frame and whatever velocity they are moving with respect to other reference frames, they will measure the speed of light at c. This means that the guy in the caboose in your thought experiment will see the light leaving his flashlight at c (with respect to the train) and someone standing by the tracks watching the train go by will also measure that light from the flashlight on the moving train traveling at c (with respect to himself) too.

This makes no sense in Newtonian mechanics (although a measured and tested reality) but was one of the problems in our understanding of reality that uncle Albert resolved with his theory of relativity.

 

[fast]

It is always good to question one's assumptions ... this is especially true if they lead to conclusions contrary to experimental findings.

Such a calculation could only be made by using Newtonian assumptions (which demonstrates that Newton was wrong). If, however, the calculation is done using relativistic theory then someone on the planet would find the light traveling at c with respect to the planet but that it would be blue shifted.

On the questioning assumptions part, it was my interpretation of the assumptions posed that confused me.

I thought we were supposed to accept that the speed of light was the same for all people no matter what anyone's frame of reference was, not that we were to accept that the speed of light was the same for all people no matter their frame of reference. In other words, I thought light was traveling near c, period.

Correct. Experiments have verified that, no matter who measures the speed of light in whatever reference frame and whatever velocity they are moving with respect to other reference frames, they will measure the speed of light at c. This means that the guy in the caboose in your thought experiment will see the light leaving his flashlight at c (with respect to the train) and someone standing by the tracks watching the train go by will also measure that light from the flashlight on the moving train traveling at c (with respect to himself) too.

This makes no sense in Newtonian mechanics (although a measured and tested reality) but was one of the problems in our understanding of reality that uncle Albert resolved with his theory of relativity.

I don't think you understand the magnitude of my mistake.

I've watched garboodles of both regular videos and university lectures on the subject. I have a good sense of what's being explained. That's not the issue. The hard part has been over.

The disconnect for me has been the wording of the postulate, not the explanation. When I hear the words, "c is a universal constant," what I envision is one thing, but the explanations to follow are starkly contrasted.

It's like I'm being told that light is not subject to relativity followed by explanations showing that it is. I've been caught up in what appears to be a lexical ambiguity.

When I'm told that light is a universal constant, especially as a postulate to support a theory of relativity, I'm not thinking the universal constant itself is relative to observers as is everything else. Instead, I was thinking that the speed of light has a true maximum speed and so could not move faster. I know how that sounds. Yes, c relative to observer A flying fast cannot exceed c, and the same goes for observer G on the ground, but when observer A reports his findings to observer G, he might not have observed it, but he calculates that c exceeds c by speed of observer a, which violates what I thought the postulate was, a universal constant, but it's not a mere universal constant, is it? It's relative to the observers in such that c does not have a maximum but rather a maximum relative to the observer.

 

[Jon Osterman]

Yes, c relative to observer A flying fast cannot exceed c, and the same goes for observer G on the ground, but when observer A reports his findings to observer G, he might not have observed it, but he calculates that c exceeds c by speed of observer a, which violates what I thought the postulate was, a universal constant, but it's not a mere universal constant, is it? It's relative to the observers in such that c does not have a maximum but rather a maximum relative to the observer.

This is your mistake I think. Observer A and observer G both see light moving at speed c. However, you interpret G as being confused by this because he thinks if A sees the light moving at speed A, then G (himself) should see it moving at v+c if A is moving with speed v (in the same direction as the light). But this is G's error. G is using a theory to predict the speed he should see from A's measurement, and when he compares to his own measurement finds his prediction is wrong. G has used Newtonian mechanics (technically Galilean relativity) to make the prediction, when he should have used Einstein's theory. If he had used Einstein, he would have got the right answer.

 

[barbos]

but he calculates that c exceeds c by speed of observer a

These calculations are incorrect.

 

[Loren Pechtel]

Correct. Experiments have verified that, no matter who measures the speed of light in whatever reference frame and whatever velocity they are moving with respect to other reference frames, they will measure the speed of light at c. This means that the guy in the caboose in your thought experiment will see the light leaving his flashlight at c (with respect to the train) and someone standing by the tracks watching the train go by will also measure that light from the flashlight on the moving train traveling at c (with respect to himself) too.

This makes no sense in Newtonian mechanics (although a measured and tested reality) but was one of the problems in our understanding of reality that uncle Albert resolved with his theory of relativity.

And note that special relativity follows directly from c being equal for all observers. If you want a consistent model with c being always fixed you have to play with length and if you play with length you have to play with mass and time also.

 

[Treedbear]

Correct. Experiments have verified that, no matter who measures the speed of light in whatever reference frame and whatever velocity they are moving with respect to other reference frames, they will measure the speed of light at c. This means that the guy in the caboose in your thought experiment will see the light leaving his flashlight at c (with respect to the train) and someone standing by the tracks watching the train go by will also measure that light from the flashlight on the moving train traveling at c (with respect to himself) too.

This makes no sense in Newtonian mechanics (although a measured and tested reality) but was one of the problems in our understanding of reality that uncle Albert resolved with his theory of relativity.

And note that special relativity follows directly from c being equal for all observers. If you want a consistent model with c being always fixed you have to play with length and if you play with length you have to play with mass and time also.

That's right.

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That means the light traveling at the speed of light relative to a person in a very fast spacecraft passing earth is in fact calculably faster than the speed of light as observed from someone on the planet. In that case, in my horsey example, who sees objects on the planet first?
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Unless time is going slower for the person in the spacecraft relative to the observer on the planet. That's why he can measure the speed of light as remaining constant. (You lost me with the horsey).

ETA:

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First, just to get someone to grasp what I'll be talking about might very well become an uphill battle, not because it's complicated but because of resistance to the notion that it's possible for an object to not be in motion. See, believers in relativity will vehemently declare that an object is always in motion relative to some 'other' frame of reference, but maybe with some luck, someone'll be able to get past the temptation.
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It's worse than that. For an object to not be in motion is to say it has an absolute position. But the universe has no absolute coordinate system, as per Newton, and thus no absolute reference for motion.