The Relativity of Simultaneity

[Neddy Bate]

If the earth is in motion, and you measure the speed of light on earth to be 299,792,458 m/s, you have not measured the length properly. Do you understand that if a stick is in motion, and light takes 1/299,792,458 of a second to travel the length of the stick, the stick is NOT 1 meter.

The same applies on earth. If you measure light to travel 1/299,792,458 of a second from point a to point b on earth, that distance is NOT 1 meter.

How many times do I need to explain that to you, Ned?

I thought we discussed that idea already. The original meter was a metal bar made out of 90% platinum, held at the melting temperature of ice. They never could have changed the definition to the speed of light if light did not always travel the length of the platinum bar in exactly 1/299,792,458 of a second.

 

[Motor Daddy]

I thought we discussed that idea already. The original meter was a metal bar made out of 90% platinum, held at the melting temperature of ice. They never could have changed the definition to the speed of light if light did not always travel the length of the platinum bar in exactly 1/299,792,458 of a second.

Again, if the bar is on earth traveling with the earth, the bar is in motion. If the bar is exactly 1 meter, and in motion, the light will take more or less time to travel the length of the bar.

Likewise, if you measure the time to be 1/299,792,458, and the bar is in motion, then it is a fact that the bar is NOT 1 meter, as measured by light.

...and, if you claim the the one-way time of light travel was measured along the bar, please provide the link!

 

[Neddy Bate]

If you measure light to travel 1/299,792,458 of a second from point a to point b on earth, that distance is NOT 1 meter.

Not only is that the very definition of the meter, but that length has been found to be consistently equal to the length of the original prototype metre bar kept to this day at the Bureau International des Piods et Measures.

So, do you still want to stick with your explanation for why the speed of light is constant on earth? You are saying that a 90% platinum bar held at 0 degrees Celsius must be changing length all by itself!!!!!

 

[Motor Daddy]

Not only is that the very definition of the meter, but that length has been found to be consistently equal to the length of the original prototype metre bar kept to this day at the Bureau International des Piods et Measures.

So, do you still want to stick with your explanation for why the speed of light is constant on earth? You are saying that a 90% platinum bar held at 0 degrees Celsius must be changing length all by itself!!!!!

Again, provide the link of the measurement of the one-way time of light travel along the bar.


By the way, the bar is changing length over time. But that is another thread in itself.

 

[Neddy Bate]

So now you are back to the argument that "round trip times" are able to cancel out any differences in "one-way" times. Let's see if that is correct:


So you are saying that the light actually takes 1/290,423,944 second to travel the platinum metre bar in one direction.

And you are saying that the light actually takes 1/309,160,972 second to travel the platinum metre bar in the other direction.


That would be two meters of length traveled in this much time:
1/290,423,944 + 1/309,160,972 seconds


In other words, the round-trip speed of light would have been calculated to be:
2/.000000006677803195 = 299,499,691 meters per second

instead of c=299,792,458 meters per second. But no one noticed this error of 292,767 meters per second!!! Also, six months later, the earth would have been traveling the opposite direction compared to the sun, so the round trip time would CHANGE throughout the year!!! But that doesn't happen. WHY? If your theory can't explain it, then what is its purpose?

 

[Motor Daddy]

So you are saying that the light actually takes 1/290,423,944 second to travel the platinum metre bar in one direction.

And you are saying that the light actually takes 1/309,160,972 second to travel the platinum metre bar in the other direction.


That would be two meters of length traveled in this much time:
1/290,423,944 + 1/309,160,972 seconds


In other words, the round-trip speed of light would have been calculated to be:
2/.000000006677803195 = 299,499,691 meters per second

instead of c=299,792,458 meters per second. But no one noticed this error of 292,767 meters per second!!! Also, six months later, the earth would have been traveling the opposite direction compared to the sun, so the round trip time would CHANGE throughout the year!!! But that doesn't happen. WHY? If your theory can't explain it, then what is its purpose?

Show me the link of the measurement of the one-way time of light travel along the bar.

If you tell me the round trip time of light travel along the bar is 2/299,792,458 of a second, and the bar was on earth when the measurements were performed, and the earth was in motion when the measurements were performed, then what you are telling me is that your measurements are BS!

 

[Neddy Bate]

Show me the link of the measurement of the one-way time of light travel along the bar.

There doesn't have to be a one-way test, because I just showed you that round-trip tests do not come out to exactly 1.00000c. Round-trip testing would give different results throughout the year, if your theory were correct. Calculate some numbers yourself, using your own method, and you will see that you cannot get two different one-way measurements to come out to be exactly 1.000000c in a round-trip test.

If you tell me the round trip time of light travel along the bar is 2/299,792,458 of a second, and the bar was on earth when the measurements were performed, and the earth was in motion when the measurements were performed, then what you are telling me is that your measurements are BS!

Really? So you would rather believe your theory than REALITY? Here is a link you might find interesting:

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

 

[przyk]

quantum_wave:

The guy has absolutely no interest in making any effort to understand the theory that he is objecting to. He simply maintains that relativity *must* be wrong, basically because he says so.

Well we didn't have to wait long for yet another confirmation of that:

If the earth is in motion, and you measure the speed of light on earth to be 299,792,458 m/s, you have not measured the length properly.

See the ivory tower this guy has constructed himself? If an experimental result supports relativity and contradicts Motor Daddy, automatically it must be the experiment that was wrong!

 

[AlexG]

While James R would not classifiy MD as a wacko, I must disagree.

I think MD is the very definition of a wacko. He has no connection with reality, and is convinced beyond argument that he is right and the rest of the world is wrong.

This is again, the definition of insanity. He simply refuses to look at anything which says he's wrong.

 

[CptBork]

Our expanding universe is finite and the Hubble volume of space that contains it is causally connected to the Big Bang.

Most Big Bang models treat the universe as expanding but also already infinite, with potentially infinitely many stars, planets and galaxies. No evidence has been detected yet pointing to a well-defined centre of the universe, nor does the Big Bang require such a spatial centre to exist.

 

[Motor Daddy]

There doesn't have to be a one-way test, because I just showed you that round-trip tests do not come out to exactly 1.00000c. Round-trip testing would give different results throughout the year, if your theory were correct. Calculate some numbers yourself, using your own method, and you will see that you cannot get two different one-way measurements to come out to be exactly 1.000000c in a round-trip test.




Really? So you would rather believe your theory than REALITY? Here is a link you might find interesting:

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

You just don't get it, Ned. We know the earth is in motion. You say a bar is 1 meter, and you measure the time it takes light to travel round trip along that bar in motion, and say the round trip time is 2/299,792,458 of a second.

Do you not understand that you are measuring a bar in motion, and then claiming it takes 2/299,792,458 of a second round trip?

It is IMPOSSIBLE for a 1 meter bar to be in motion and have a round trip time of 2/299,792,458 of a second.

The ONLY way light will take 2/299,792,458 of a second to travel a meter bar round trip is IF the bar is at an absolute zero velocity. If you tell me the bar is on earth in motion, and you measured the round trip time to be 2/299,792,458 of a second, I'm calling BS!

 

[AlexG]

You just don't get it, Ned. We know the earth is in motion. You say a bar is 1 meter, and you measure the time it takes light to travel round trip along that bar in motion, and say the round trip time is 2/299,792,458 of a second.

Do you not understand that you are measuring a bar in motion, and then claiming it takes 2/299,792,458 of a second round trip?

It is IMPOSSIBLE for a 1 meter bar to be in motion and have a round trip time of 2/299,792,458 of a second.

The ONLY way light will take 2/299,792,458 of a second to travel a meter bar round trip is IF the bar is at an absolute zero velocity. If you tell me the bar is on earth in motion, and you measured the round trip time to be 2/299,792,458 of a second, I'm calling BS!

So MD simply rejects reality in favor of his own universe.

He can't except it, so the measurement is wrong.

This IS insanity.

 

[arfa brane]

The obvious objection to being unable to measure a metre length properly, because the bar which is supposed to be 1 metre length is in motion, is this:

How do we know that light travels 299,792,458 metres in 1 second if we can't measure a metre properly? How do we measure the length of anything properly? How do we know that buildings have the same height either side? Why have we managed to build railways with equal length metal tracks either side?

Since the earth is in motion, all metres on the earth must be impossible to measure accurately. This must make construction of buildings a big problem.

How do we manage?

In Motor Daddy's case, you manage by ignoring the objection, of course.

 

[quantum_wave]

Flaming has absolutely nothing to do with your definition of your "cult". Why don't you just define your cult as "people who don't flame"? Wouldn't that be more honest than pretending it has something to do with tentativeness in science?

Yes, relativity, like all of physics, is tentative to some extent. You can still annoy people who understand it by attacking it for the wrong reasons though. I don't know about you, but Motor Daddy certainly deserves all the flaming he's getting: in an exchange that lasted only a handful of posts here I saw him misrepresent what Tach said, misrepresent things I'd said, repeatedly post strawman attacks against relativity, and play deaf when he was corrected. The guy has absolutely no interest in making any effort to understand the theory that he is objecting to. He simply maintains that relativity *must* be wrong, basically because he says so. Multiply that up to 1400 posts and it is not difficult to see why some posters have reached the end of their fuses with him.


No. Saying "insane" might be an exaggeration, but not by far. Currently our best shot of observing a Lorentz violation is an accelerator on the French-Swiss border that cost billions and accelerates protons to 99.999999% the speed of light. As a rule of thumb, usually anything above about 10% the speed of light is considered relativistic.

quantum_wave:

Well we didn't have to wait long for yet another confirmation of that:

See the ivory tower this guy has constructed himself? If an experimental result supports relativity and contradicts Motor Daddy, automatically it must be the experiment that was wrong!

I don’t know much about MD or any of you for that matter, but I know he has a very high mechanical aptitude. If you don’t agree say so but it is obvious to me. Does he have any other credentials that deserve respect? Yes. Clearly he has stick-to-itiveness which is a trait that I give points for. Is he hardheaded, maybe but to put up with the trolls and you know who you are, he has to be that and thick skinned. And until he denies it, he is a fellow cult member.

I know I would rather share a brew with him than at least five who I know to be trolls on the list of posters here. I also know that I’m not allowed to say anything like that or about what I think or like because to non-cult members and trolls I am a crank and crackpot and deserve no respect. Any comment that has “I or me” is never allowed to pass without it being turned into a trolling opportunity. We who are labeled cranks and crackpots can display no form of self or we are attacked for simply existing. Respectable cult members should not allow that to go by unchallenged.

So that brings me to why you are wrong when you say:

Flaming has absolutely nothing to do with your definition of your "cult". Why don't you just define your cult as "people who don't flame"? Wouldn't that be more honest than pretending it has something to do with tentativeness in science?

No, flaming on a thread whose main premise is a balls-out confrontation with the deepest convictions of non-cult members makes their denial of tentativeness a huge issue. The people that I identify as cult members will act in several ways. They will ignore the thread which in terms of the non-cult members is called letting woo woos and trolls play, they will try to teach the declared cult members who hold the false premise why tentativeness is not the issue and how the premise of the thread has long ago been falsified, or they will post constructively in an effort to help either those teaching or those learning.

My “cult of tentativeness” is a forum related cult meaning that I think it generally applies to physics, math, and cosmology forums where non-cult members wish to be seen as experts, will not capitulate on an issue even in the face of well constructed factual responses, and where they feel free to troll because someone else has done so, i.e. tossed out an ad hom, false criticism, a twisted reference to statements made, and/or general disdain for the cult members. Once the trolling begins it always continues until the moderator finally capitulates to the trolls and closes the thread with some explanation that identifies the originator as the problem and not the trolls.

These statement do not apply to all threads and thread originators because there a lot of woo woos and anti-troll trolls out there, lol. My self-assigned roll on this thread in no way makes me a troll but look how many of you have identified me as the troll, the crank and the crackpot instead of the real trolls. I am a member of the The Cult of Tentativeness. Man up and declare yourself.

I don’t encourage more discussion pointed at me or my cult definition but I will be continuing to participate constructively and will try to acknowledge cult members who take a responsible and professional stand by declaring their cult membership, lol.

If anyone wants to troll me or discuss my off topic statements find one of my threads to do that and let’s let this thread be MD’s and about his views, not mine.

 

[Neddy Bate]

We know the earth is in motion. You say a bar is 1 meter, and you measure the time it takes light to travel round trip along that bar in motion, and say the round trip time is 2/299,792,458 of a second.

That's correct.

Do you not understand that you are measuring a bar in motion, and then claiming it takes 2/299,792,458 of a second round trip?

Well, the bar is not in motion relative to the laboratory in which it is measured. But of course the bar is in motion relative to some other frame, such as that of the sun.

It is IMPOSSIBLE for a 1 meter bar to be in motion and have a round trip time of 2/299,792,458 of a second.

The ONLY way light will take 2/299,792,458 of a second to travel a meter bar round trip is IF the bar is at an absolute zero velocity.

I agree that, ACCORDING TO MOTOR DADDY THEORY, the only way light will take 2/299,792,458 of a second to travel a meter bar round-trip is if the bar is at an absolute zero velocity. The problem is, light DOES in fact take 2/299,792,458 of a second to travel a meter bar round-trip on earth.

So apparently Motor Daddy Theory needs some small revisions in order to explain what actually happens on earth. That is why I've been asking you to elaborate on what you think might be causing this discrepancy. We have established that the "round-trip times" doesn't explain the problem, and we also know that the "wrong length measurement" doesn't work either. So I was hoping you had some other explanation.

If you tell me the bar is on earth in motion, and you measured the round trip time to be 2/299,792,458 of a second, I'm calling BS!

I know its hard to accept. But if you think about it, it makes for a pretty neat theory. You never need to know your absolute velocity to calculate how long it will take for light to get from point A to point B. It's kind of nice, really.

 

[James R]

przyk:

Do length contraction and time dilation occur in Motor Daddy's universe?

No, they don't. His universe uses Galilean relativity, combined with an absolute frame.

Has he even tried to explain the results of Michelson-Morley experiments, beyond just complaining that they're only sensitive to round trip times?

No. He doesn't seem interested in real-world experiments. He prefers to live in his fantasy land.


Motor Daddy:

James, that's a good explanation except for one point. The point of emission doesn't move away from the source, the source moves away from the point of emission.

In the embankment frame, yes. In the box frame, no.

You still haven't attempted an analysis in the box/train frame. I doubt that you can actually cope with two frames.

The point of emission is not capable of motion in space, nor is the expanding light sphere as a whole capable of traveling in space. The light sphere simply expands and the source travels away from the point of emission.

Light travels in space, doesn't it?

James, I appreciate your long responses. I think we're just repeating the same points that we've already discussed at length so I want to move away from those points and on to some different points and an example of a train in motion and an embankment in motion in the MD universe. I want to compare the two worlds using a train and an embankment that each have motion, so that it can't be said one or the other is in motion and the other is at rest, and vise versa.

You want to introduce a third frame in which box the embankment and the train have motion?

But you haven't given me your analysis of the train frame yet. All I've seen from you so far is the embankment frame.

Let's see your train frame analysis before we introduce yet another frame. Ok?

Also, you mentioned that you didn't see the acceleration calculation I performed in my world. Well, here is what I posted days ago. Do you notice that my world loves to incorporate acceleration in it, and everything matches up nice and pretty? Not one little hiccup! You know why Einstein's SR doesn't do acceleration? Because the numbers don't add up, because his world is actually wrong, you just don't want to admit it.

Einstein has no problems with acceleration. I don't know where you got the idea that SR can't handle acceleration. But let's stick to one thing at a time.

James, Here is the embankment and train scenario with both the embankment and train in motion. The diagrams may not be to exact scale. Please give me your numbers of this scenario.

I see no reason why I'd disagree with your numbers in the "space" frame. All you have done now is to separate the embankment frame from the "space" frame, so that the train has a speed v relative to the embankment, the embankment has a speed u relative to "space", and the train has speed u+v relative to "space". There's nothing fundamentally new when you add an extra frame.

Your latest diagrams show the "space" frame again. I'd like to see some diagrams from you that show the train frame. It would be easier to go back to the original scenario where the embankment was stationary in "space" for that.

If the earth is in motion, and you measure the speed of light on earth to be 299,792,458 m/s, you have not measured the length properly.

That would be true if the MD universe was reality, but it isn't. In actual fact, Einstein's universe is the one we live in.

Again, if the bar is on earth traveling with the earth, the bar is in motion.

In which frame?

It is IMPOSSIBLE for a 1 meter bar to be in motion and have a round trip time of 2/299,792,458 of a second.

In which frame? In motion relative to what? These are the questions you need to address if you want to work in the real world (i.e. Einstein's).

 

[origin]

If the earth is in motion, and you measure the speed of light on earth to be 299,792,458 m/s, you have not measured the length properly. Do you understand that if a stick is in motion, and light takes 1/299,792,458 of a second to travel the length of the stick, the stick is NOT 1 meter.

The same applies on earth. If you measure light to travel 1/299,792,458 of a second from point a to point b on earth, that distance is NOT 1 meter.

How many times do I need to explain that to you, Ned?

Really. You assume that everybody just happens to measure the length that the light travels in there measurement equipment incorrectly, such that it always comes out to c; that's a pretty astounding coincidence, huh? If light is only measured as c in a absolute motionless frame and the earths speed varies relative to that absolute frame, then how could it be by coincidence that the lengths are ALWAYS mis-measured so that the speed of light is measured as c.

I am not big on conspiracy theories, however if you are right, MD, since I think it would be impossible for it to be a coincidence that the lengths are always measured wrong so that we get c, that only leaves some sort of vast neoscience conspiracy.

What do you think?
How about that accelerating space station?

 

[James R]

quantum wave:

The Cult of Tentativeness

I declare the existence of a cult consisting of science professionals and laymen alike who adhere to the precept of tentativeness of science. In that cult are those who do not consider non-falsification of SR to equate to proof that SR is reality. If that describes you, you are a cult member in the Cult of Tentativeness.

In the case of the science of Special Relativity you have to declare yourself a non-cult member in order to be excluded from the cult. You can do that in several ways. You can deny being a cult member or simply insist that non-falsification of SR is proof of SR.

I'm not sure what you're saying.

Scientific theories are never proven in the way that mathematical theories are. The best we can say is that if a scientific theory is supported by heaps of evidence and not contradicted by any evidence, then it's a useful theory. Examples in include relativity, electromagnetism, evolution, quantum mechanics, etc. etc.

You can also declare yourself a non-cult member by proclaiming that only cranks and crackpots say the SR is theory and not fact. That releases you from the cult.

The old "just a theory" argument is a typical creationist ploy when discussing evolution, another phenomenally successful scientific theory. A "theory" in science is not the same as a guess or a tentative hypothesis. It is worth learning how scientists use the word "theory".

Many cult members, declared or undeclared, believe that SR is derived from the postulates, is mathematically sound based on the postulates, and it has not been falsified, but that it is not yet truth because of the precept of tentativeness in science or because they believe that the postulates themselves do not correspond with reality, i.e. Lorentz invariance does not equate to realty just because it has not yet been falsified.

The postulates of special relativity have been tested against reality over and over and over again. No test has falsified them. All tests give positive evidence in favour of them. So, claiming they do not "correspond with reality" is perverse.

 

[quantum_wave]

quantum wave:



I'm not sure what you're saying.

Scientific theories are never proven in the way that mathematical theories are. The best we can say is that if a scientific theory is supported by heaps of evidence and not contradicted by any evidence, then it's a useful theory. Examples in include relativity, electromagnetism, evolution, quantum mechanics, etc. etc.



The old "just a theory" argument is a typical creationist ploy when discussing evolution, another phenomenally successful scientific theory. A "theory" in science is not the same as a guess or a tentative hypothesis. It is worth learning how scientists use the word "theory".



The postulates of special relativity have been tested against reality over and over and over again. No test has falsified them. All tests give positive evidence in favour of them. So, claiming they do not "correspond with reality" is perverse.

Thank you for the response. Just trying to help. I guess I can't recruit you to the cult, lol.

 

[Motor Daddy]

Motor Daddy:

In the embankment frame, yes. In the box frame, no.

No James, I don't play the old, "which one is in motion" game, I KNOW which one is in motion. There is only one object in space, and that is the cube. The source remains at the center of the cube. The times are measured to the receivers in the cube. The motion of the cube is calculated, period. There are no other times or objects to compare to. There is no "embankment frame."

You still haven't attempted an analysis in the box/train frame. I doubt that you can actually cope with two frames.

Where do you think the times come from? When I say it takes .65 seconds, that means the receiver in the box reads .65 seconds. All I need to do is measure the time of light travel from the source to the receivers in the box and I know the motion of the box. The absolute velocity of the box is not relative to anything except the point of emission, and that is not an object. There is no object at the point of emission.

Light travels in space, doesn't it?

The light sphere expands in space, the light sphere doesn't travel as a sphere in space. The center of the sphere never changes position in space. You seem to think the light sphere is traveling in space along with the source as it expands. That's absurd, James.

You want to introduce a third frame in which box the embankment and the train have motion?

But you haven't given me your analysis of the train frame yet. All I've seen from you so far is the embankment frame.

Let's see your train frame analysis before we introduce yet another frame. Ok?

I've already showed you the train frame analyses. What do you want to know? Where do you think I get the times from? Those times were measured in the train/cube.

Einstein has no problems with acceleration. I don't know where you got the idea that SR can't handle acceleration. But let's stick to one thing at a time.

So SR can handle acceleration? Lets see some numbers of acceleration using SR.

I see no reason why I'd disagree with your numbers in the "space" frame. All you have done now is to separate the embankment frame from the "space" frame, so that the train has a speed v relative to the embankment, the embankment has a speed u relative to "space", and the train has speed u+v relative to "space". There's nothing fundamentally new when you add an extra frame.

Your latest diagrams show the "space" frame again. I'd like to see some diagrams from you that show the train frame. It would be easier to go back to the original scenario where the embankment was stationary in "space" for that.

Show me your numbers of the situation where the train and the embankment are in motion.

In which frame?

Maybe you don't understand that if the earth is in motion in space at say 1,000 m/s, and a bar is resting on the earth with no relative motion to the earth, the bar also has a velocity of 1,000 m/s in space along with the earth.

In which frame? In motion relative to what? These are the questions you need to address if you want to work in the real world (i.e. Einstein's).

You need to come to grips with the fact that an object can have a 1,000 m/s absolute velocity while it is resting on the earth with no relative motion to the earth. If a bar is rest on the earth with no relative motion to the earth, all that means is that the bar posses the same absolute velocity of the earth. Just because a bar doesn't have a relative motion to the earth doesn't mean it doesn't have an absolute velocity. Get a grip on yourself, James.