The Relativity of Simultaneity

[Motor Daddy]

I deny a point in space can be identified without reference to an object.

So you emit a light from a point in space, and then deny that point exists.

Too funny, Pete. That is absolutely hilarious!

Yes, I should be preparing for exams. Procrastination is ruining my life.
I gave up on our discussion because following through your sidetracks is a tremendous waste of time.
Take the time the race started, for example.
It's irrelevant. The race was run separately. They didn't necessarily start at the same time. If you think it's important, then you pick a starting time yourself, and follow it through.

Stop wasting my time.

Quitters never win and winners never quit!

 

[Motor Daddy]

Now. Can you explain how the GPS system maintains its accuracy without accounting for absolute velocity at all? Thanks.

Are you asserting that GPS maintains its accuracy, without having to constantly update the system?

 

[Pete]

So you emit a light from a point in space, and then deny that point exists.

Too funny, Pete. That is absolutely hilarious!

If you can't respond to what I actually write, then don't bother.

Quitters never win and winners never quit!

If you never win and never quit, you're an idiot.

But I'm not here to win arguments, I'm here to learn.

If I argue the wrong side of an argument, and win the argument, then everybody loses.

 

[Motor Daddy]

If you can't respond to what I actually write, then don't bother.

I responded appropriately.

A light source emits light in space. Are you saying the source is always at the center of the expanding light sphere? You must be if you claim the light always travels at c and every frame measures light to be traveling at c in that frame.

In other words, is it possible in your world for the source to move away from the center of the light sphere while the light sphere is expanding? Don't duck the question, answer it directly.

 

[Motor Daddy]

If I argue the wrong side of an argument, and win the argument, then everybody loses.

...and likewise, if I argue the right side of an argument, and lose the argument, then everybody loses.

 

[Pete]

You responded to something I didn't say.
Try again.
I deny a point in space can be identified without reference to an object.

I'm not interested in chasing you in circles again, MD.
Go away, come back when you've looked at actual measurements of the speed of light.

 

[Motor Daddy]

You responded to something I didn't say.
Try again.
I deny a point in space can be identified without reference to an object.

I'm not interested in chasing you in circles again, MD.
Go away, come back when you've looked at actual measurements of the speed of light.

Again you avoid the question.

Is it possible in your world for the source to move away from the center of the light sphere while the light sphere is expanding?

 

[Neddy Bate]

Are you asserting that GPS maintains its accuracy, without having to constantly update the system?

I never said they don't have to update the system periodically. Why? Are you claiming that the GPS system performs those updates because, according to your theory, the speed of light is not constant in different directions, or at different times of the year, due to the earth's absolute velocity?

 

[Motor Daddy]

I never said they don't have to update the system periodically. Why? Are you claiming that the GPS system performs those updates because, according to your theory, the speed of light is not constant in different directions, or at different times of the year, due to the earth's absolute velocity?

So you acknowledge that the system doesn't maintain its accuracy on its own?

 

[arfa brane]

I think this thread is a good demonstration of how some people are simply beyond help.

 

[Pete]

Again you avoid the question.

Is it possible in your world for the source to move away from the center of the light sphere while the light sphere is expanding?

*sigh*

You just don't get it, do you MD.
Your questions have been answered. Repeatedly. You choose to misinterpret or ignore them.
You ignore the questions you don't like, such as the results of experiments that demonstrate a constant measurement of the speed of light in all reference frames.

Last reply, then I'm done with you.

Is it possible in your world for the source to move away from the center of the light sphere while the light sphere is expanding?

It is definitely possible to measure the source moving away from the centre of the light sphere.

Note that this measurement is meaningless unless you know the reference standard it is based on.

You can also choose a reference standard so that you measure the source to stay at the centre of the light sphere.

All these reference standards are interconvertible. They do not contradict each other.

Goodbye.
Good luck.
I hope you win something real, not just a meaningless argument.

 

[Neddy Bate]

So you acknowledge that the system doesn't maintain its accuracy on its own?

Don't be silly. Each GPS satellite contains multiple atomic clocks. They are extremely accurate. They were designed to provide 180 days of operation without any external contact, and still maintain accuracy. The GPS satellites orbit the earth every 12 hours.

Now please explain to me how GPS can maintain accuracy under your theory. You claim that the absolute speed of the earth causes the signal transit time to vary constantly over every 12 hour orbit of each satellite. Yet, the satellites are capable of going 180 days without being updated. How is this possible?

 

[Motor Daddy]

*sigh*

You just don't get it, do you MD.
Your questions have been answered. Repeatedly. You choose to misinterpret or ignore them.
You ignore the questions you don't like, such as the results of experiments that demonstrate a constant measurement of the speed of light in all reference frames.

Last reply, then I'm done with you.


It is definitely possible to measure the source moving away from the centre of the light sphere.

Note that this measurement is meaningless unless you know the reference standard it is based on.

You can also choose a reference standard so that you measure the source to stay at the centre of the light sphere.

All these reference standards are interconvertible. They do not contradict each other.

Goodbye.
Good luck.
I hope you win something real, not just a meaningless argument.

Goodbye Pete. Thanks for playing.

I couldn't care less about winning something real, I simply want the problem fixed, and yes, it is a problem. Maybe someday you'll understand it. Good luck.

ps, Here's a tip for you:

The Earth came from the Sun!!

 

[quantum_wave]

Don't be silly. Each GPS satellite contains multiple atomic clocks. They are extremely accurate. They were designed to provide 180 days of operation without any external contact, and still maintain accuracy. The GPS satellites orbit the earth every 12 hours.

Now please explain to me how GPS can maintain accuracy under your theory. You claim that the absolute speed of the earth causes the signal transit time to vary constantly over every 12 hour orbit of each satellite. Yet, the satellites are capable of going 180 days without being updated. How is this possible?

I see this as a strawman argument. MD has developed his scenario based on a single transmission of light that expands spherically from its point of origin. You are talking about multiple and continuous transmissions from a point of origin that is continually changing and whose purpose has played out by the time they travel for a second or so down to earth. Each of those transmissions continues on its path far into space and if you consider one single transmission then you are apples and apples with MD.

Do you understand why I say your argument is not apples to apples with MD?

 

[Neddy Bate]

I see this as a strawman argument. MD has developed his scenario based on a single transmission of light that expands spherically from its point of origin. You are talking about multiple and continuous transmissions from a point of origin that is continually changing and whose purpose has played out by the time they travel for a second or so down to earth. Each of those transmissions continues on its path far into space and if you consider one single transmission then you are apples and apples with MD.

Do you understand why I say your argument is not apples to apples with MD?

I don't understand why you think it's not apples to apples. Just look at one satellite signal going from satellite to earth. That signal carries crucial information to earth, such as the exact current time on the atomic clock aboard the satellite, and the position of the satellite relative to earth.

MD says that the satellite signal expands as a sphere in the absolute frame. But the earth is not at rest in the absolute frame, so the earth might be moving away from the sphere, for example. So, let's say the signal takes one second longer to reach the earth than we would expect if the speed of light were constant relative to the earth. The GPS receiver would fail miserably, because nanosecond accuracy is required. Nanoseconds are 0.000000001 seconds long. You can't just have a signal take an extra whole second and still expect the system to work.

Do you understand my point better now?

 

[quantum_wave]

I don't understand why you think it's not apples to apples. Just look at one satellite signal going from satellite to earth. That signal carries crucial information to earth, such as the exact current time on the atomic clock aboard the satellite, and the position of the satellite relative to earth.

MD says that the satellite signal expands as a sphere in the absolute frame. But the earth is not at rest in the absolute frame, so the earth might be moving away from the sphere, for example. So, let's say the signal takes one second longer to reach the earth than we would expect if the speed of light were constant relative to the earth. The GPS receiver would fail miserably, because nanosecond accuracy is required. Nanoseconds are 0.000000001 seconds long. You can't just have a signal take an extra whole second and still expect the system to work.

Do you understand my point better now?

I do, and thank you but ...

That single transmission is the one that is of consideration and its speed is c as agreed upon by MD from the point of transmission. You point out that the earth may be moving relative to that single transmission source and that, according to MD would make the speed of the single light sphere if measured from earth appear to be c +or- from the frame of earth. The fact that those satellites are in geosynchronous orbits keeps them an exact distance form a point on the surface of the earth which would mitigate your argument, I think.

 

[Neddy Bate]

I do, and thank you but ...

That single transmission is the one that is of consideration and its speed is c as agreed upon by MD from the point of transmission. You point out that the earth may be moving relative to that single transmission source and that, according to MD would make the speed of the single light sphere if measured from earth appear to be c +or- from the frame of earth. The fact that those satellites are in geosynchronous orbits keeps them an exact distance form a point on the surface of the earth which would mitigate your argument, I think.

If the satellites were in geosynchronous orbit, then they would be rotating once every 24 hours relative to the sun. I think this means that any one satellite's transmission time would change significantly over any given 12 hour period, (approximately), if MD's idea were to be correct.

But the GPS satellites are not in geosynchronous orbit around the earth. They actually complete an orbit around the earth every 12 hours, relative to the earth's surface. So, I think MD's idea would predict satellite transmission times to change significantly over any given 6 hour period. Sorry MD!

 

[quantum_wave]

If the satellites were in geosynchronous orbit, then they would be rotating once every 24 hours relative to the sun. I think this means that any one satellite's transmission time would change significantly over any given 12 hour period, (approximately), if MD's idea were to be correct.

But the GPS satellites are not in geosynchronous orbit around the earth. They actually complete an orbit around the earth every 12 hours, relative to the earth's surface. So, I think MD's idea would predict satellite transmission times to change significantly over any given 6 hour period. Sorry MD!

Thanks Ned, that is true as confirmed here. That link, BTW, gives an account of the SR and GR effects in play which are interesting. SR time dilation and gravitational time dilation both in play and taken into consideration by the software. Impressive for sure.

As far as the point that the reference body is not just the earth, but includes the effect of the sun and the changing position of the satellites relative to the earth may not be a deal breaker for MD though. I can't help but remember the single transmission of a light sphere expanding from an defined absolute position in space that is crucial to MD's view. That single transmission is what MD is following as it expands into space. He says that if you were to measure the speed of that light from a frame moving relative to the absolute point in space, you would get a slightly different result than you would from the fixed point in space. Further, he agrees that it would travel to earth at c from the point of origin.

You refer to a scenario of multiple transmissions that are affected by forces inherent in the reference body and say that there would be fluctuations in the speed of light due to MDs postulate that would affect the accuracy of the system. As I recall, there are anomalies in the measurements that are attributed to frame dragging, there are the influences that you mention, time dilation, and there is the fact that MD only needs one single emission of a sphere of EM to deal with while you are suggesting multiple emissions and saying problems would creep in if MD was right.

I can't concede MD's whole argument on your scenario yet. I would like some more analysis that considers the points I have mentioned that differ from your scenario but you certainly are bringing up what could be a troubling scenario to MDs postulate if my hesitation is set aside.

 

[AlexG]

Now, has everyone gotten the point, that you can't argue with a crackpot?

There has NEVER, in the history of the internet, been a crank who has ever conceeded that he was wrong. Their pathologies don't allow for it.

 

[quantum_wave]

Now, has everyone gotten the point, that you can't argue with a crackpot?

There has NEVER, in the history of the internet, been a crank who has ever conceeded that he was wrong. Their pathologies don't allow for it.

I take it your are referring to me. FYI I have conceded I was wrong twice today and I can spell conceded.