# Tag Info

### What is the cause of the constancy of the speed of light in vacuum?

The invariance of the speed of light follows from the principle of relativity. This says there is no experiment that can distinguish between inertial reference frames: physical laws are the same in ...
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### What is the cause of the constancy of the speed of light in vacuum?

The constancy of $c$ is an experimental result, verified to great precision. When we make mathematical models that assume the constancy of $c$, we get predictions that match other experimental results ...
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### What is the cause of the constancy of the speed of light in vacuum?

This is not a question of cause and effect, but a question of definition. A local inertial frame is defined as one where locally you measure the speed of light to be $c$ (among other properties). So ...
• 81.7k
Accepted

### Length contraction in special relativity- from a sphere to an ellipse

You're using coordinates named $(x_0,y_0,z_0)$ for both the primed and unprimed frames in the first two equations. Never do that or you will become hopelessly confused. I'm going to use $(t',x',y',z')$...
• 22k
Accepted

### Lorentz transformation and special relativity: Why the equations must be linear?

A linear transformation maps straight lines to straight lines, that is a straight line in the $(t, x)$ coordinates maps to a straight line in the $(t', x')$ coordinates. This is required because a ...
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The mistake is that you cannot substitute the deltas, as they refer to different quantities in each of the two equations. In the first equation, delta t refers to a time interval between two events ...
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### What is the cause of the constancy of the speed of light in vacuum?

Five year old kids asks the question "Why?" time and time again. In the Toyota production model there is an accepted way to handle root causes known as "Five Whys". What is the ...
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