Varying speed of light in Relativity

[Mordred]

The problem is observer a can see BOTH time dilation and length contraction. He calculates the lorentz factor into his calculations.

 

Now let's do this experiment. Observer A builds a transmitter and receiver a sufficient distance apart to measure the spreed of light. He builds a second device precisely the same.

 

He keeps one in his frame. Sets the second device into the other frame.

 

Both devices calculate the speed of light to equal c. Between transmitter and receiver.

 

However when observer a picks up his second device he notices that the number of tests is less than his own device.

 

The point is you've already compensated for the variation by changing both units used to measure the speed of light by the two formulas posted above.

 

When you state the speed of light slows down + the length contracts+ time slows down. THIS is wrong and will give you the wrong answer.

 

It would be like stating the following.

 

A high gravity well causes the following three observer effects.

 

[latex]t_o=t_f\sqrt{1 - \frac{2GM}{r c^2}}[/latex]

 

[latex]d=ds\sqrt{1 - \frac{2GM}{r c^2}}[/latex]

 

[latex]c_o=c\sqrt{1 - \frac{2GM}{r c^2}}[/latex]

 

The third equation is obviously wrong by the experiment posted above.

 

In other words you've already corrected the relativity effects by corrections to the units used to measure the speed of light.

Edited September 29, 2015 by Mordred

[Theoretical]

wait. You changed my experiment. It's not about measuring the speed light. It's about taking note that the signal clicks per second decrease when the mirror device is stationary near a massive body as compared to when it was far away. That's really all there is. So again, it took light more time to reflect a shorter distance. So what do you think about that experiment?

 

For anyone who doesn't want to read the thread to know what the mirror device is. It's two parallel mirrors where light reflects back and forth. Each time light reflects off a mirror, the mirror device emits a signal burst / click / bleep.

so the mirror device is a clock. The observer is always in the same location. The mirror device is either far away, or near the massive body. Obviously when the mirror device is near the massive body, it's emitted clicks per second decreases.

both the observer and the mirror device are always stationary, except for the brief time in between experiment when the mirror device is traveling to its other location, which is either near or far away from the massive body. So this experiment is not about relativistic velocity, but is about gravitational time dilation.

[Mordred]

Now in your light beam experiment light is no longer following a Euclidean (flat) straight line. It is following a null geodesic path. Which is a curved path.

 

Some articles will describe it as compressed space time. I personally hate that analogy as its misleading. It's better to just describe it as coordinate tranformation.

 

 

Look at the Schwartzchild Metric.

 

https://en.m.wikipedia.org/wiki/Schwarzschild_metric

 

Note the change in radius.

 

Read the section bending of light by gravity. Note the added Length it takes for light to reach your second mirror

 

"as the length-scale a goes to infinity),"

 

https://en.m.wikipedia.org/wiki/Schwarzschild_geodesics

Edited September 29, 2015 by Mordred

[Theoretical]

Now in your light beam experiment light is no longer following a Euclidean (flat) straight line. It is following a null geodesic path. Which is a curved path.

 

Some articles will describe it as compressed space time. I personally hate that analogy as its misleading. It's better to just describe it as coordinate tranformation.

Interesting. I had to look up that word, but I wonder if entering the null geodesic is path could solve this for me.

[Mordred]

This is the aspect your missing. I editted the last post see above for the relevant section in the link

[Theoretical]

This is the aspect your missing. I editted the last post see above for the relevant section in the link

Yes I'm certain it is. Thank you very much!!

[Mordred]

Your welcome another related term to study is worldline.

 

"World lines of particles/objects at constant speed are called geodesics."

 

https://en.m.wikipedia.org/wiki/World_line

 

PS +1 for your desire to study the standard model and not inventing your own, due to misconceptions.

Edited September 29, 2015 by Mordred

[hoponpop]

Does time slow down, or do other dimensions change?

 

Most generally, solely along the x-axis:

 

v=x/t

 

So, exaggerating for the sake of simplicity, if the speed of light were do double due to influence of an independent mass, we have:

 

2v=a(x/t)

 

Mathematically, it is (here) indistinguishable whether time is halved or distance is doubled.

 

2v=(2x)/t=x/(.5t)

 

There are actually infinitely many solutions to this.

 

Any fix for this? Why time and time alone? Or, more broadly, why is it said that time changes as opposed to anything else? What fundamental aspect of time makes it more likely to change than distance

[swansont]

Any fix for this? Why time and time alone? Or, more broadly, why is it said that time changes as opposed to anything else? What fundamental aspect of time makes it more likely to change than distance

 

It's not time and time alone. Length contracts as well — for the other observer. Nothing changes in your own frame. But the effects compensate for each other in inertial frames, so each observer measures c as an invariant.

[michel123456]

It's not time and time alone. Length contracts as well — for the other observer. Nothing changes in your own frame. But the effects compensate for each other in inertial frames, so each observer measures c as an invariant.

Which is interpreted by me that space and time are actually "made up of the same stuff", called spacetime.

IOW when you look at an object, the distance that you observe, that you call "space", is not only space. It is spacetime.

There is time in it.