Relativity

[CharlesChandler]

Do you think you've just managed to refute the most profound and beautiful theory ever conceived with an analogy of ripples on a bloody pond?

I'm not trying to refute anything -- I'm trying to determine the derivations of the conclusions. Is there anything to understand here, or do you have to take it all on faith? If so, it isn't science -- it's a religion. And as religions go, relativity sucks. No hymns, or choirs, or bake sales -- just priests who talk nonsense and deride people for not understanding nonsense. No thanks.

If two pebbles are tossed into a pond, and hit the surface at points equidistant from an observer, with the observer traveling towards one of the stones at half the speed of the waves, does the observer; 1, measure the waves coming from the stone they're heading towards passing them at the same velocity as the waves coming from the stone they're heading away from, or 2, measure the relative velocities of the waves coming from the stone they're heading towards and of the stone they're heading away from passing at different relative velocities, depending on the relative velocity of the observer?

That's a poorly formulated question. Wave transmission speed is a function of the medium, not the thing that caused the waves, nor the thing that measures them. If the measuring instrument is moving relative to the medium, it will detect faster/slower frequencies of waves. But that isn't wave transmission speed.

[A-wal]

Wtf are you talking about? Have it all on faith. This is how it HAS to work with a constant relative velocity of energy. You don't get to disagree and deserve to be taken seriously at the same time. You've got some nerve to claim that believing in relativity is a religious stance when I've pointed out what it's based on, taken you through precise examples of how it applies in real terms, asked for an alternative which you haven't given because there is one, and offered to explain it further if you're interesting in actually learning something amazing and what do you do? Compare to god worshipping! Your arrogance is well beyond a joke. To think that relative is nonsense and you know better is so much more than ridiculous that no word has been invented that even comes anywhere close to describing it.

Poorly formulated question? OMFG! You gave an example of waves on a pond, insinuating that it's comparable to measuring a constant speed of light because the ripples move at the same speed if the stones that cause them have different relative velocities to the water so I gave the example of the observer moving relative to the water to show that speed of the ripples is in no way constant. If the measuring equipment is moving relative to light it will NOT detect faster or slower relative velocities of the light waves! Do you understand the difference now?

[CharlesChandler]

If the measuring equipment is moving relative to light it will NOT detect faster or slower relative velocities of the light waves! Do you understand the difference now?

Perhaps I'm almost there... I can understand waves traveling at a constant speed in an homogenous medium. I can understand waves traveling at different speeds in different mediums. And I can understand waves getting refracted when crossing the boundary between two different mediums. All of these behaviors have been demonstrated, for p-waves, s-waves, and for light. That, of course, is why people started thinking of light as waves.

http://en.wikipedia.org/wiki/Speed_of_light#In_a_medium

The sticking point here is that I "think" that you're saying that the speed of a light wave is constant, even if the observer is moving through the medium, and I'm questioning how that was determined.

Back to the analogy of ripples on a pond: suppose the wave speed relative to the water is 1 m/s, but suppose you're moving through the water at .5 m/s. This will cause the frequency of the waves to be shifted, by 1/2 or by 3/2, depending on whether you're moving with the waves, or against them. And we observe such a shift in light waves, which is known as the Doppler effect. (Relative velocity might not be the only thing that can shift frequencies, but it is certainly one of them.)

But I "think" that you're saying that the wave transmission speed is the same, regardless of motion of the observer through the medium, and regardless of frequency shifting due to that motion. And that's where I'm getting confused. I need to know how the speed of light is measured, and how the speed of the medium is factored out. You said earlier that it wasn't.

So you're talking about Earth-based measurements of the speed of light from the Sun. This means that the instrumentation was swimming in a static medium -- the Earth's atmosphere. So how was the effect of the medium ruled out?

It wasn't. The point is that relative the velocity of the source of the light has no influence on the relative velocity of the light...

That's true of all waves, even in classical mechanics. That's why I conjured up the analogy of pebbles hitting a pond, and I stipulated that they had relative velocities, while noting that this doesn't affect the wave transmission speeds.

...and is also unaffected by the relative velocity of the observer.

Unaffected in what sense? Light travels at different speeds in different mediums. You're saying that this is true, regardless of the velocity of the observer. Well, that's true is classical mechanics as well. Ripples on a pond travel at the same speed relative to the pond, regardless of the motion of the observer. The frequency is shifted by relative velocity of the observer, but not the wave transmission speed of the water. But I "think" that you're saying that the wave transmission speed is always the same, to every observer, regardless of motion through a medium. I just don't see how the measuring instrument wasn't inside the medium, and thus got the same number every time, since the speed of light in a given medium is always the same, fully matching classical expectations.

For example, the speed of light in air (given that the wavelength being measured is 589 nanometers, temperature is 0 °C, and the pressure is 1 atm) is about 299,704,644.53915 m/s. This is true regardless of whether the light source is moving toward us, or away from us. Well of course it is -- that's the classical expectation, just like the ripples in the pond moving at the same rate, regardless of the relative velocities of the pebbles. So that doesn't prove Einstein -- it proves Newton.

The real question here is do we get 299,704,644.53915 m/s, plus or minus the speed of the measuring instrument through the air? So I want to know how speed of light is measured, such that a difference is detected between classical and relativistic expectations. This means that relative velocities through the medium have to be measured, and the different expectations have to be noted.

If you're going to bother to respond, don't just produce another knee-jerk reflex, sensing that I still don't "understand", and going straight into the repetition of relativistic assertions, as if saying it enough times will finally get the point through. I have already heard the assertions many times -- I'm not questioning whether or not you can repeat yourself over and over. I'm searching for the derivations. In all other disciplines, the presentation of a principle starts with a description of the way the effect was measured. For example, the laws of EM induction are typically explained by describing (or even re-creating) Ørsted's experiment in which a compass needle was deflected by current in a nearby wire. Then you do the math, and consider the practical applications. So the understanding of the principle is in terms of how its effects are observed. As concerns relativity, it all seems to trace back not to a physical experiment, but rather, to things that Einstein thought, as he was imagining what it would be like to ride on a beam of light. But I'm having difficulty figuring out where that intersects with the physical world.

[A-wal]

Okay, sorry I got a bit frustrated. I'm basically in love with special relativity and need to stop being so offended when people question it.

If the measuring equipment is moving relative to light it will NOT detect faster or slower relative velocities of the light waves! Do you understand the difference now?

Perhaps I'm almost there... I can understand waves traveling at a constant speed in an homogenous medium. I can understand waves traveling at different speeds in different mediums. And I can understand waves getting refracted when crossing the boundary between two different mediums. All of these behaviors have been demonstrated, for p-waves, s-waves, and for light. That, of course, is why people started thinking of light as waves.

http://en.wikipedia.org/wiki/Speed_of_light#In_a_medium

The sticking point here is that I "think" that you're saying that the speed of a light wave is constant, even if the observer is moving through the medium, and I'm questioning how that was determined.

Yes that's exactly what I'm saying, and there's absolutely no distinction between the observed object moving in relation to a static observer and a a moving observer measure the velocity of light from a static source because all inertial motion is relative. No test can be performed to determine which one's moving so there's no difference. All you can say is that they're in motion relative to each other. That's basic Galilao relativity which is the bases for special relativity. This relative motion has no affect on the velocity that light passes both of them, and if both are measuring the same thing passing them at the same relative velocity despite their velocity relative to each then they have to be indiagreement over the lengths in time and space that the light is traversing.

Back to the analogy of ripples on a pond: suppose the wave speed relative to the water is 1 m/s, but suppose you're moving through the water at .5 m/s. This will cause the frequency of the waves to be shifted, by 1/2 or by 3/2, depending on whether you're moving with the waves, or against them. And we observe such a shift in light waves, which is known as the Doppler effect. (Relative velocity might not be the only thing that can shift frequencies, but it is certainly one of them.)

Doppler shift doesn't effect the velocity of light though, it affects the frequencey of the waves only.

But I "think" that you're saying that the wave transmission speed is the same, regardless of motion of the observer through the medium, and regardless of frequency shifting due to that motion. And that's where I'm getting confused. I need to know how the speed of light is measured, and how the speed of the medium is factored out. You said earlier that it wasn't.

I meant that the medium that light the light is moving through does have an affect on it's relative velocity. It moves slower through air than it does through a near vaccum for example. It's speed isn't constant in that sense, but that's nothing to do with what's meant by the constant speed of light. It's talking purely about the fact that the velocity of the sourse and the observer relative to each other has no affect on the velocity of an energy wave relative to either. Actually in reality light isn't slowed at all through any medium, it's just that the refraction gives it a longer path to follow in order to traverse the same distance, so it only appears to be slowed.

So you're talking about Earth-based measurements of the speed of light from the Sun. This means that the instrumentation was swimming in a static medium -- the Earth's atmosphere. So how was the effect of the medium ruled out?

It wasn't. The point is that relative the velocity of the source of the light has no influence on the relative velocity of the light...

That's true of all waves, even in classical mechanics. That's why I conjured up the analogy of pebbles hitting a pond, and I stipulated that they had relative velocities, while noting that this doesn't affect the wave transmission speeds.

Think of the pebbles moving through the water releasing periodic ripples as they travel. Their motion in the water does affect the speed that the waves move away from them. It makes the waves slower relative to them in the direction they're travelling in and faster in the opposite direction. The light waves coming from them are unaffected by their motion relative to anything.

...and is also unaffected by the relative velocity of the observer.

Unaffected in what sense? Light travels at different speeds in different mediums. You're saying that this is true, regardless of the velocity of the observer. Well, that's true is classical mechanics as well. Ripples on a pond travel at the same speed relative to the pond, regardless of the motion of the observer. The frequency is shifted by relative velocity of the observer, but not the wave transmission speed of the water. But I "think" that you're saying that the wave transmission speed is always the same, to every observer, regardless of motion through a medium. I just don't see how the measuring instrument wasn't inside the medium, and thus got the same number every time, since the speed of light in a given medium is always the same, fully matching classical expectations.

No, the speed of the source of the ripples relative to the water affects the speed of the ripples relative to that observer, but the light from that observer is unaffected by the velocity of the emitter and the observer relative to each other.

For example, the speed of light in air (given that the wavelength being measured is 589 nanometers, temperature is 0 °C, and the pressure is 1 atm) is about 299,704,644.53915 m/s. This is true regardless of whether the light source is moving toward us, or away from us. Well of course it is -- that's the classical expectation, just like the ripples in the pond moving at the same rate, regardless of the relative velocities of the pebbles. So that doesn't prove Einstein -- it proves Newton.

The speed of the observer of the light has no affect on the velocity of the light relative to that observer. That in no way supports the clasical (actually relativity is classical, it's quantum machanics that isn't) view.

The real question here is do we get 299,704,644.53915 m/s, plus or minus the speed of the measuring instrument through the air? So I want to know how speed of light is measured, such that a difference is detected between classical and relativistic expectations. This means that relative velocities through the medium have to be measured, and the different expectations have to be noted.

No, like I said, the velocity of the source and the observer relative to each other has no affect in any situation.

If you're going to bother to respond, don't just produce another knee-jerk reflex, sensing that I still don't "understand", and going straight into the repetition of relativistic assertions, as if saying it enough times will finally get the point through. I have already heard the assertions many times -- I'm not questioning whether or not you can repeat yourself over and over. I'm searching for the derivations. In all other disciplines, the presentation of a principle starts with a description of the way the effect was measured. For example, the laws of EM induction are typically explained by describing (or even re-creating) Ørsted's experiment in which a compass needle was deflected by current in a nearby wire. Then you do the math, and consider the practical applications. So the understanding of the principle is in terms of how its effects are observed. As concerns relativity, it all seems to trace back not to a physical experiment, but rather, to things that Einstein thought, as he was imagining what it would be like to ride on a beam of light. But I'm having difficulty figuring out where that intersects with the physical world.

It all traces back to the fact that light passes every non accelerating observer at the exact same speed relative to all of them. It's been tested in a lot ways and it's always the case. I the only one I can think of off hand other than in a lab is the using the motion of moons relative to us, but that's a good one.

[CharlesChandler]

The sticking point here is that I "think" that you're saying that the speed of a light wave is constant, even if the observer is moving through the medium, and I'm questioning how that was determined.

Yes that's exactly what I'm saying, and there's absolutely no distinction between the observed object moving in relation to a static observer and a a moving observer measure the velocity of light from a static source because all inertial motion is relative.

No, I'm not asking about the relative motion between the source and the observer. I'm asking if the observer is moving through the medium.

This relative motion has no affect on the velocity that light passes both of them, and if both are measuring the same thing passing them at the same relative velocity despite their velocity relative to each then they have to be in disgreement over the lengths in time and space that the light is traversing.

Or both instruments were bathed in a medium which forced the consistency of the speed of the waves.

Doppler shift doesn't effect the velocity of light though, it affects the frequency of the waves only.

Correct. But if you manipulate distance and time to get the same speed of light, despite relative motion between the source and the observer (and irrespective of the issue about the speed of light in a medium), why doesn't this also manipulate the distance between wave crests, eliminating the Doppler effect? I'm so confused...

I meant that the medium that light the light is moving through does have an affect on it's relative velocity. It moves slower through air than it does through a near vacuum for example. It's speed isn't constant in that sense, but that's nothing to do with what's meant by the constant speed of light. It's talking purely about the fact that the velocity of the source and the observer relative to each other has no affect on the velocity of an energy wave relative to either.

That isn't relativity -- that's classical mechanics.

Actually in reality light isn't slowed at all through any medium, it's just that the refraction gives it a longer path to follow in order to traverse the same distance, so it only appears to be slowed.

What does refraction have to do with it? For example, when Armand Fizeau measured the speed of light in 1849 using a rotating wheel with slots in it, the light might have followed a straight path, or a curved one. In order to accurately measure the distance, they would have strung tape measures along the line of sight, which could have been just as straight, or just as curved. Either way, the distance was measured along the path traveled by the light. So refraction has nothing to do with it.

Think of the pebbles moving through the water releasing periodic ripples as they travel. Their motion in the water does affect the speed that the waves move away from them. It makes the waves slower relative to them in the direction they're traveling in and faster in the opposite direction. The light waves coming from them are unaffected by their motion relative to anything.

How is this measured?

No, the speed of the source of the ripples relative to the water affects the speed of the ripples relative to that observer, but the light from that observer is unaffected by the velocity of the emitter and the observer relative to each other.

Again, I'm not asking about the relative motion between the source and the observer. I'm asking if the observer is moving through the medium, and if that affects the measured speed of light.

The speed of the observer of the light has no affect on the velocity of the light relative to that observer.

How is that determined?

No, like I said, the velocity of the source and the observer relative to each other has no affect in any situation.

And I agreed. That isn't the question.

[A-wal]

The sticking point here is that I "think" that you're saying that the speed of a light wave is constant, even if the observer is moving through the medium, and I'm questioning how that was determined.

Yes that's exactly what I'm saying, and there's absolutely no distinction between the observed object moving in relation to a static observer and a a moving observer measure the velocity of light from a static source because all inertial motion is relative.

No, I'm not asking about the relative motion between the source and the observer. I'm asking if the observer is moving through the medium.

That question has no meaning in space. The only velocity that exists between the source and the observer is their velocity relative to each other. If the medium was moving then the speed of light wouldn't be the same regardless of the velocity and the source relative to each other. It would speed up if it was moving with the medium and slow down if it was moving against it. This isn't what happens, ever.

This relative motion has no affect on the velocity that light passes both of them, and if both are measuring the same thing passing them at the same relative velocity despite their velocity relative to each then they have to be in disgreement over the lengths in time and space that the light is traversing.

Or both instruments were bathed in a medium which forced the consistency of the speed of the waves.

No, not or. It makes no difference. The point is that if both observers are measuring the same thing moving passed them at the same velocity and they're in motion relative to each other then their measurements of length can't possibly agree.

Doppler shift doesn't effect the velocity of light though, it affects the frequency of the waves only.

Correct. But if you manipulate distance and time to get the same speed of light, despite relative motion between the source and the observer (and irrespective of the issue about the speed of light in a medium), why doesn't this also manipulate the distance between wave crests, eliminating the Doppler effect? I'm so confused...

Because you're trying to make it more complicated than it really is. If the object emitting the light is moving towards the observer the light waves gets squashed together because they're not as far apart from the perspective of the observer and the wave crests will be passing the observer more frequently, and if the object emitting the light is moving away from the observer the light waves get stretched apart because they're further apart from the perspective of the observer and the wave crests will be passing the observer less frequently.

I meant that the medium that light the light is moving through does have an affect on it's relative velocity. It moves slower through air than it does through a near vacuum for example. It's speed isn't constant in that sense, but that's nothing to do with what's meant by the constant speed of light. It's talking purely about the fact that the velocity of the source and the observer relative to each other has no affect on the velocity of an energy wave relative to either.

That isn't relativity -- that's classical mechanics.

The fact that the velocity of the source and the observer relative to each other has no affect on the velocity of an energy wave relative to either is not classical, at least not in the context that you're using the word classical. Go back to the pond. The speed of the stones producing the ripples and the speed of the observer relative to the medium affect the result of the velocity the ripples relative to both. That's totally different to the velocity of the source and the observer relative to each other having absolutely no affect on the velocity of an energy wave relative to either.

Actually in reality light isn't slowed at all through any medium, it's just that the refraction gives it a longer path to follow in order to traverse the same distance, so it only appears to be slowed.

What does refraction have to do with it? For example, when Armand Fizeau measured the speed of light in 1849 using a rotating wheel with slots in it, the light might have followed a straight path, or a curved one. In order to accurately measure the distance, they would have strung tape measures along the line of sight, which could have been just as straight, or just as curved. Either way, the distance was measured along the path traveled by the light. So refraction has nothing to do with it.

The light bounces around in the air at the speed of light creating a path that isn't straight which makes appear to slow down, but it doesn't.

Think of the pebbles moving through the water releasing periodic ripples as they travel. Their motion in the water does affect the speed that the waves move away from them. It makes the waves slower relative to them in the direction they're traveling in and faster in the opposite direction. The light waves coming from them are unaffected by their motion relative to anything.

How is this measured?

With some kind of light detection device I'd imagine.

No, the speed of the source of the ripples relative to the water affects the speed of the ripples relative to that observer, but the light from that observer is unaffected by the velocity of the emitter and the observer relative to each other.

Again, I'm not asking about the relative motion between the source and the observer. I'm asking if the observer is moving through the medium, and if that affects the measured speed of light.

No, if the observer is moving through the medium it makes no difference to the velocity of an energy wave relative to them.

The speed of the observer of the light has no affect on the velocity of the light relative to that observer.

How is that determined?

Moons! And other ways. Google it.

No, like I said, the velocity of the source and the observer relative to each other has no affect in any situation.

And I agreed. That isn't the question.

If you agree then you must also agree that their measurements of length can't be the same. Otherwise how could velocity relative to each other have no affect on how fast light passes either of them?

[CharlesChandler]

No, I'm not asking about the relative motion between the source and the observer. I'm asking if the observer is moving through the medium.

That question has no meaning in space. The only velocity that exists between the source and the observer is their velocity relative to each other. If the medium was moving then the speed of light wouldn't be the same regardless of the velocity and the source relative to each other. It would speed up if it was moving with the medium and slow down if it was moving against it. This isn't what happens, ever.

Prove it. And no, I'm not going to Google it. The onus is not on me to search for the evidence in support of your assertions. You support your assertions.

Doppler shift doesn't effect the velocity of light though, it affects the frequency of the waves only. [...] If the object emitting the light is moving towards the observer the light waves gets squashed together because they're not as far apart from the perspective of the observer and the wave crests will be passing the observer more frequently, and if the object emitting the light is moving away from the observer the light waves get stretched apart because they're further apart from the perspective of the observer and the wave crests will be passing the observer less frequently.

But you're also saying that velocity is distance over time, and for the measured velocity to be the same at all observers, distance and/or time have to vary. Yet varying the distance and/or the time to get this effect would also affect the distance between the wave crests, canceling the Doppler effect. The speed of light is the distance traveled over the time taken. The frequency is the distance between wave crests. If you vary the units for the distance traveled, you vary the units for the wavelengths.

The light bounces around in the air at the speed of light creating a path that isn't straight which makes appear to slow down, but it doesn't.

Really?

The light waves coming from them are unaffected by their motion relative to anything.

How is this measured?

With some kind of light detection device I'd imagine.

You apparently accepted this without inspecting the derivation. That is not something that I am willing to do.

Perhaps you'd understand my questioning if I quote something that my father wrote, and which had a lot to do with how I was raised. He thought that it was a reasonable position, and so do I.

Challenge what you hear, not to disagree, but to understand, and not out of arrogance, but out of humility. You have the right to demand understanding, and if something doesn't make sense to you, you have the right to say, "I am too stupid to understand what you just tried to explain to me. Can you please explain it in terms that even I can understand?" And if you still don't understand, you have the right to ask someone else. And if you still don't understand, you have the right to search the whole world for what you're missing. Just remember that sometimes, it is easier to derive understanding from what you already know. We all have more knowledge than we need, and new understanding is rarely the product of new knowledge — it's more commonly the product of a new appreciation of something that we have always known. But you must never give up trying to understand. When you understand something, you possess the object of that understanding, in a way that the legal owner might not. You know how to appreciate it, how to take care of it, how to replace it, and when to simply get out of its way. If you understand the whole world, then everything in it belongs to you. And understanding is that which one can possess, and one can share, and one can possess all the more. Physical ownership must be mutually exclusive, because each thing in this world must be the responsibility of one individual. Accountability doesn't distribute well. But the ownership of understanding is not like that. We can all appreciate everything in this world, and all the more so if we share our appreciation. If everyone thought like this, the only thing that we would not be able to understand is how anyone could have ever been any other way. The part of the world that you care to survey is yours. Go possess it in the only meaningful way possible, with your mind, at first with your humble curiosity, and then completely with your proud generosity. — Roger M. Chandler, Sr. (1925~2004)

[A-wal]

No, I'm not asking about the relative motion between the source and the observer. I'm asking if the observer is moving through the medium.

That question has no meaning in space. The only velocity that exists between the source and the observer is their velocity relative to each other. If the medium was moving then the speed of light wouldn't be the same regardless of the velocity and the source relative to each other. It would speed up if it was moving with the medium and slow down if it was moving against it. This isn't what happens, ever.

Prove it. And no, I'm not going to Google it. The onus is not on me to search for the evidence in support of your assertions. You support your assertions.

You can't prove a negative. Many tests have been performed that all confirm that the relative velocity of energy doesn't depend on the velocity of the source and the observer relative to each. It wouldn't would it because energy doesn't carry inertia like mass does. If it were possible for any test to show that the speed of light wasn't constant we'd soon know about it. That would be huge. It will never happen because it the speed of light has to be constant. It would be completely illogical if it wasn't.

Doppler shift doesn't effect the velocity of light though, it affects the frequency of the waves only. [...] If the object emitting the light is moving towards the observer the light waves gets squashed together because they're not as far apart from the perspective of the observer and the wave crests will be passing the observer more frequently, and if the object emitting the light is moving away from the observer the light waves get stretched apart because they're further apart from the perspective of the observer and the wave crests will be passing the observer less frequently.

But you're also saying that velocity is distance over time, and for the measured velocity to be the same at all observers, distance and/or time have to vary. Yet varying the distance and/or the time to get this effect would also affect the distance between the wave crests, canceling the Doppler effect. The speed of light is the distance traveled over the time taken. The frequency is the distance between wave crests. If you vary the units for the distance traveled, you vary the units for the wavelengths.

No, the distance between the wave crests is affected when the observers are moving towards each other simply because the distance between the observers is changing. Each wave has a shorter or longer distance to travel than the last one did so they get bunched up or spread out.

The light bounces around in the air at the speed of light creating a path that isn't straight which makes appear to slow down, but it doesn't.

Really?

Yep. Its relative velocity never really changes. Everything moves through space-time at a relative velocity of the speed of light and energy isn't moving through time at all, so it always moves through space at the same relative velocity.

The light waves coming from them are unaffected by their motion relative to anything.

How is this measured?

With some kind of light detection device I'd imagine.

You apparently accepted this without inspecting the derivation. That is not something that I am willing to do..

It's true that I don't know the details of the experiment apparatus involved for measuring and confirming the consistency of the relative velocity of energy waves. So what? I know that if there was anything dodgy about them someone would have spotted it by now. The constant speed of light is not a new discovery.

Perhaps you'd understand my questioning if I quote something that my father wrote, and which had a lot to do with how I was raised. He thought that it was a reasonable position, and so do I.

Challenge what you hear, not to disagree, but to understand, and not out of arrogance, but out of humility. You have the right to demand understanding, and if something doesn't make sense to you, you have the right to say, "I am too stupid to understand what you just tried to explain to me. Can you please explain it in terms that even I can understand?" And if you still don't understand, you have the right to ask someone else. And if you still don't understand, you have the right to search the whole world for what you're missing. Just remember that sometimes, it is easier to derive understanding from what you already know. We all have more knowledge than we need, and new understanding is rarely the product of new knowledge — it's more commonly the product of a new appreciation of something that we have always known. But you must never give up trying to understand. When you understand something, you possess the object of that understanding, in a way that the legal owner might not. You know how to appreciate it, how to take care of it, how to replace it, and when to simply get out of its way. If you understand the whole world, then everything in it belongs to you. And understanding is that which one can possess, and one can share, and one can possess all the more. Physical ownership must be mutually exclusive, because each thing in this world must be the responsibility of one individual. Accountability doesn't distribute well. But the ownership of understanding is not like that. We can all appreciate everything in this world, and all the more so if we share our appreciation. If everyone thought like this, the only thing that we would not be able to understand is how anyone could have ever been any other way. The part of the world that you care to survey is yours. Go possess it in the only meaningful way possible, with your mind, at first with your humble curiosity, and then completely with your proud generosity. — Roger M. Chandler, Sr. (1925~2004)

That's really good.

[Sparky]

https://www.thunderbolts.info/wp/2013/1 ... -einstein/ : In July 1925, Dr Einstein wrote in a letter to Edwin Slossen: “My opinion of Miller’s results is the following… Should the positive results be confirmed, then the special theory of relativity, and with it the general theory of relativity, in its current form, would be invalid.”

In 1998, the highly respected physicist and Nobel laureate Maurice Allais published a rigorous analysis of Miller’s 1925-26 experimental results in the magazine 21st Century Science & Technology. His conclusion is that Miller’s results are indeed authentic and cannot be attributed to any spurious or fortuitous effects.

Allais wrapped it up thusly: “Consequently, the Special and General Theory of Relativity, resting on postulates invalidated by observational data, cannot be considered as scientifically valid.”

Awal":

I know that if there was anything dodgy about them someone would have spotted it by now.

As far as the laws of mathematics refer to reality, they are not certain; as far as they are certain, they do not refer to reality.
~Albert Einstein

[Aardwolf]

I didn't claim they didn't use GR, I provided a link from NASA JPL that said they didn't use GR. Where's your link that says they do calculate relativistic adjustments to the spacecraft manoeuvres etc?

As for your proof, those papers are calculating theoretical epheremis of planets and are nothing to do with spacecraft manoeuver/trajectories. And how accurate are they? Here's what is says about Mars on the first page in the abstract;

Because of perturbation of the orbit of Mars by asteroids, frequent updates are needed to maintain the current accuracy into the future decade

Their predictive abilities with or without GR are garbage.

No you provided a link which said they "can" use Newtonian dynamics to put a spacecraft on Mars. They may have back in the days of Viking and Mars. It did not say they did not use GR.

So they add the GR calculations for fun now I assume. After all, why not generate more complicated and unnecessary calculations when simple calculations work just as well.

I've already given you the link that say's they use relativistic adjustments.

Oh yes. Yet in the same post you happily admit;

At low speeds and large distances from the Sun Newtonian dynamics is fine, there GR reduces to Newtonian dynamics

Planetary ephemeris DE424 for Mars Science Laboratory early cruise navigation

There it is all you had to do was look.That does not say their predictive abilities are "rubbish", what it says is small errors grow over time. We know this, that's why there are so many versions. Again I never made any claims about the accuracy of this system.

I said the predictions were rubbish; because they are. If they were any good they wouldn't need to "update frequently" to find out where Mars is. Your'e stuck on the minor relativity reference (because it suits you to do so even though its negligible if anything at all as it's lost in much larger errors) but won't even engage on the entirety of the excercise which is a "current best estimate" and shouldn't even be used for future positioning except as a rough planning guide.

[Aardwolf]

The speed of the observer of the light has no affect on the velocity of the light relative to that observer.

How is that determined?

Moons! And other ways. Google it.

I tried with no luck. Do you have a link for this experiment as I am curious to know how they counteracted the slowing of light through our atmosphere.

[A-wal]

https://www.thunderbolts.info/wp/2013/1 ... -einstein/ : In July 1925, Dr Einstein wrote in a letter to Edwin Slossen: “My opinion of Miller’s results is the following… Should the positive results be confirmed, then the special theory of relativity, and with it the general theory of relativity, in its current form, would be invalid.”

In 1998, the highly respected physicist and Nobel laureate Maurice Allais published a rigorous analysis of Miller’s 1925-26 experimental results in the magazine 21st Century Science & Technology. His conclusion is that Miller’s results are indeed authentic and cannot be attributed to any spurious or fortuitous effects.

Allais wrapped it up thusly: “Consequently, the Special and General Theory of Relativity, resting on postulates invalidated by observational data, cannot be considered as scientifically valid.”

Awal":

I know that if there was anything dodgy about them someone would have spotted it by now.

As far as the laws of mathematics refer to reality, they are not certain; as far as they are certain, they do not refer to reality.
~Albert Einstein

Nothing is truly certain, that's not the point.

Details. What exactly did they measure? What was their claim? That they got a different velocity for the speed of light? Is the test repeatable? Has it been verified? How did Allais manage to retroactively confirm an experiment that he wasn't a part of? Does anyone else agree with him?

The speed of the observer of the light has no affect on the velocity of the light relative to that observer.

How is that determined?

Moons! And other ways. Google it.

I tried with no luck. Do you have a link for this experiment as I am curious to know how they counteracted the slowing of light through our atmosphere.

The loss of velocity in the atmosphere would probably be negligible. Also it wouldn't cause the velocity of light reflecting off of a moon to be unaffected by the velocity of that moon relative to us. The only thing that alters the duration for light to reach us is the distance it has to travel to get here, not the velocity of the source relative to us.

[Aardwolf]

The speed of the observer of the light has no affect on the velocity of the light relative to that observer.

How is that determined?

Moons! And other ways. Google it.

I tried with no luck. Do you have a link for this experiment as I am curious to know how they counteracted the slowing of light through our atmosphere.

The loss of velocity in the atmosphere would probably be negligible.

Lets see. Assuming it's our Moon a quick calculation shows that the fastest recessional velocity is about 20,000 km in 7 days or say 0.03 km/s. The speed of light in air is slowed by about 88 km/s. The atmospheric error is 2,900 times greater than the effect we are looking for and you say it's negligible.

Also it wouldn't cause the velocity of light reflecting off of a moon to be unaffected by the velocity of that moon relative to us. The only thing that alters the duration for light to reach us is the distance it has to travel to get here, not the velocity of the source relative to us.

We're not interested in the velocity of the source. The question surrounds the velocity of the observer relative to the light.

Link to the experiment please.

[A-wal]

The speed of the observer of the light has no affect on the velocity of the light relative to that observer.

How is that determined?

Moons! And other ways. Google it.

I tried with no luck. Do you have a link for this experiment as I am curious to know how they counteracted the slowing of light through our atmosphere.

The loss of velocity in the atmosphere would probably be negligible.

Lets see. Assuming it's our Moon a quick calculation shows that the fastest recessional velocity is about 20,000 km in 7 days or say 0.03 km/s. The speed of light in air is slowed by about 88 km/s. The atmospheric error is 2,900 times greater than the effect we are looking for and you say it's negligible.

No I said it's probably negnigible. 88 km/s? Wow. I wouldn't of thought it would make that much diffierence, although with a speed of 186,000 miles per second I suppose it doesn't really. It's not our moon, it's to close, it's a moon of Saturn or Jupiter, can't remember. Anyway it's hardly going to cancel out the velocity of the moon relative to us, it makes no difference.

Also it wouldn't cause the velocity of light reflecting off of a moon to be unaffected by the velocity of that moon relative to us. The only thing that alters the duration for light to reach us is the distance it has to travel to get here, not the velocity of the source relative to us.

We're not interested in the velocity of the source. The question surrounds the velocity of the observer relative to the light.

Same thing! The velocity of the receiver relative to the velocity of the source IS the velocity of the source relative to the receiver. Velocity relative to the light? That always going to be the speed of light.

Link to the experiment please.

Search for the speed of light, moon and Jupiter. If that doesn't work try Saturn.

[Aardwolf]

The speed of the observer of the light has no affect on the velocity of the light relative to that observer.

How is that determined?

Moons! And other ways. Google it.

I tried with no luck. Do you have a link for this experiment as I am curious to know how they counteracted the slowing of light through our atmosphere.

The loss of velocity in the atmosphere would probably be negligible.

Lets see. Assuming it's our Moon a quick calculation shows that the fastest recessional velocity is about 20,000 km in 7 days or say 0.03 km/s. The speed of light in air is slowed by about 88 km/s. The atmospheric error is 2,900 times greater than the effect we are looking for and you say it's negligible.

No I said it's probably negnigible. 88 km/s? Wow. I wouldn't of thought it would make that much diffierence, although with a speed of 186,000 miles per second I suppose it doesn't really. It's not our moon, it's to close, it's a moon of Saturn or Jupiter, can't remember. Anyway it's hardly going to cancel out the velocity of the moon relative to us, it makes no difference.

Not sure why it's too close but anyway the speed of Saturn or Jupiters moons compared to Earth would be maximum of 18 km/s. Still far too small considering light is slowed by the atmosphere. We have no way of knowing what the measured speed would have been prior to entering the atmosphere.

Also it wouldn't cause the velocity of light reflecting off of a moon to be unaffected by the velocity of that moon relative to us. The only thing that alters the duration for light to reach us is the distance it has to travel to get here, not the velocity of the source relative to us.

We're not interested in the velocity of the source. The question surrounds the velocity of the observer relative to the light.

Same thing! The velocity of the receiver relative to the velocity of the source IS the velocity of the source relative to the receiver. Velocity relative to the light? That always going to be the speed of light.

And there's the assumption again. We're trying to establish an experiment that supports that assumption. Stating it doesn't make it proof. Your moon experiment can't prove it because we already ascertained light is slower by 88 km/s in air, how can we know the velocity of Earth doesn't affect the observers measurement of light speed?

Link to the experiment please.

Search for the speed of light, moon and Jupiter. If that doesn't work try Saturn.

Why do I have to find your proof? I can only assume you're just making it up.