# Thread: On Einstein's explanation of the invariance of c

1. Originally Posted by arfa brane
Ok, let's ASSUME the stick has a "true" zero velocity.
Would you measure the LENGTH of the stick if you measured the total time for light to travel from the source to the mirror, and back?
The only way to know if the stick has a true zero velocity is to measure the one-way times.

Chances are slim to none that the stick you are measuring has a zero velocity. Measuring round trip time is completely useless!

2. Originally Posted by Motor Daddy
Measuring round trip time is completely useless!
Ok, so you have to measure the time it takes for light to travel to the mirror, then you have to measure the time it takes for light to travel back to the source?

Can you describe a method that will do this? Do you need an accurate clock, or doesn't it matter?

3. Originally Posted by arfa brane
Ok, so you have to measure the time it takes for light to travel to the mirror, then you have to measure the time it takes for light to travel back to the source?

Can you describe a method that will do this? Do you need an accurate clock, or doesn't it matter?
I repeated the procedure in this thread. Like I said earlier, I'm sure technology has a more accurate way to measure the one-way times. GREAT!!! The more accurate the measurements the better! Measure as accurately as you can!

4. Yes, sure. But what would YOU use? What technology would you employ?

That was the question. Please describe a method that uses available technology.

5. Originally Posted by arfa brane
Yes, sure. But what would YOU use? What technology would you employ?

That was the question. Please describe a method that uses available technology.
I've already described the method in this thread. Use clocks sync'd my way and record the times the signals are sent and the times they are received.

6. Originally Posted by arfa brane
p.s. a "meter" is something you find inside power distribution boxes on the side of your house, or on gas supply lines.
Really???

http://en.wikipedia.org/wiki/Meter

In 2008, the U.S. English translation published by the U.S. National Institute of Standards and Technology chose to use meter in accordance with the United States Government Printing Office Style Manual.

7. How do you synchronize clocks "your way", and what do you use to record the times?

If you use two clocks, how do you make them synchronous and how do you make sure they are accurately measuring the same intervals of time?

You see, just saying "use synchronized clocks", and "record the times" isn't very descriptive. In order to do either you need a METHOD which will necessarily involve physical uncertainty; inaccuracies and errors in measurement must be accounted for in any experiment.

If you hand in a physics lab assignment that doesn't take errors into account, you lose marks (that's at a university mind you).

8. Originally Posted by Motor Daddy
Really???
Yes, really. The metre is a unit distance the French invented. "Metre" is a French word. So is "metrology"--note how the latter isn't spelt "meterology", "metric" isn't spelt "meteric', etc.

Meters are measuring devices (but of course, so are rulers). Americans don't learn the English language, they learn "American English".

9. Originally Posted by arfa brane
How do you synchronize clocks "your way", and what do you use to record the times?

If you use two clocks, how do you make them synchronous and how do you make sure they are accurately measuring the same intervals of time?

You see, just saying "use synchronized clocks", and "record the times" isn't very descriptive. In order to do either you need a METHOD which will necessarily involve physical uncertainty; inaccuracies and errors in measurement must be accounted for in any experiment.

If you hand in a physics lab assignment that doesn't take errors into account, you lose marks (that's at a university mind you).

...and yet you choose to use round trip time and divide by two

10. Originally Posted by Motor Daddy
...and yet you choose to use round trip time and divide by two
I'll take that response as a "no, I don't have a clue" type of response?

So the message you have to give us all is, you know how to wave your hands around?

Don't forget that you have to measure the "one way" times of light in ALL POSSIBLE DIRECTIONS before you can determine the absolute speed. This makes your method more complicated, but it must be done.

Consider a train rolling through the absolute rest frame. If you measure one-way times for light traveling between the floor and ceiling, you incorrectly conclude the absolute speed of the train is zero. After that, you would calculate the height of the train incorrectly, because you would not have accounted for the train's motion through the absolute frame. So you must test light signals in all directions first. That is the only way to determine the DIRECTION of the absolute speed. After that, you can make your distance calculations, but the equations will be a little more complicated than the ones you've been using.

12. Originally Posted by arfa brane
I'll take that response as a "no, I don't have a clue" type of response?

So the message you have to give us all is, you know how to wave your hands around?
Keep doing it your way. I couldn't care less. I'm just telling you it's laughable!

...and what's even funnier is that you think if you run away from a lamp post that light still has to travel 200'.

Bwahahahahahaaha

13. Originally Posted by Motor Daddy
Keep doing it your way. I couldn't care less. I'm just telling you it's laughable!
I know you couldn't care less. I also know that most physics students couldn't care less about your version of physics.

But keep doing that limbo buddy, it's always a laugh watching someone try to bend over backwards.

14. Originally Posted by Neddy Bate

Don't forget that you have to measure the "one way" times of light in ALL POSSIBLE DIRECTIONS before you can determine the absolute speed. This makes your method more complicated, but it must be done.

Consider a train rolling through the absolute rest frame. If you measure one-way times for light traveling between the floor and ceiling, you incorrectly conclude the absolute speed of the train is zero. After that, you would calculate the height of the train incorrectly, because you would not have accounted for the train's motion through the absolute frame. So you must test light signals in all directions first. That is the only way to determine the DIRECTION of the absolute speed. After that, you can make your distance calculations, but the equations will be a little more complicated than the ones you've been using.
I never said different. As a matter of fact we talked about that earlier. I'm not Mr. Technology, I'm just telling you how to properly use light to measure velocity and length. Keep using Einstein's methods and keep wondering why science isn't making progress.

15. Originally Posted by arfa brane
I know you couldn't care less. I also know that most physics students couldn't care less about your version of physics.
That's what they call the blind leading the blind, students being taught garbage by people who don't know the correct way of doing things.

16. Keep using Einstein's methods and keep wondering why science isn't making progress.
A real howler!
The GPS system is a good example of how little progress has been made by science since 1905, folks.

Using lasers to measure distance and velocity is clearly holding us back. Whose dumb idea was that?

17. Originally Posted by arfa brane
A real howler!
The GPS system is a good example of how little progress has been made by science since 1905, folks.

Using lasers to measure distance and velocity is clearly holding us back. Whose dumb idea was that?
Clearly not yours, as you think light always takes the same time to travel each way, regardless of the velocity. Now that's a hoot!!

18. Originally Posted by arfa brane
This sentence really is what sums it all up.
Really what SR tells us is that you can only synchronize clocks in a stationary frame, or conversely, clocks are only synchronized if they're in a stationary frame.
The method was defined to synch clocks in any inertial frame, i.e., it's a relative synchronization for a frame at a particular speed, without having to know the speed (relative or absolute).

19. Motor Daddy just admitted he has no idea how a laser rangefinder works.

I wonder if he knows about how military technology uses the above, or how much "faith" a jetfighter pilot has in the technology. I wonder if he's heard of that other laughable idea, called radar?

20. Originally Posted by arfa brane
Motor Daddy just admitted he has no idea how a laser rangefinder works.

I wonder if he knows about how military technology uses the above, or how much "faith" a jetfighter pilot has in the technology. I wonder if he's heard of that other laughable idea, called radar?
So you can't find a hole in my theory, and I've proven why Einstein's is wrong, and now you are reduced to talking crap and telling lies. Whoda thunk??