Comments on: Einstein’s Theory of Special Relativity (MetaLearn Podcast)

By: jak jaki

jak jaki — Fri, 26 Oct 2018 11:17:00 +0000

In reply to prettyextreme. you based your decision on other results! maybe galilian motion is not correct one!

By: Anatoli

Anatoli — Mon, 02 Apr 2018 11:24:00 +0000

In reply to prettyextreme. Honestly, I've got more insight from this comment rather than from the podcast itself.

By: Gerry

Gerry — Sat, 31 Mar 2018 09:23:00 +0000

In reply to prettyextreme. You beat me to the punch! Absolutely correct. I would also add that Einstein was unaware (apparently) of the negative result of the Michelson-Morley experiment to detect the luminiferous ether. (I think the jury might still be out as to whether he was actually aware of it or not)

By: prettyextreme

prettyextreme — Sat, 31 Mar 2018 02:34:00 +0000

As I understand it, Einstein didn’t just suddenly realize that light traveled at a constant velocity no matter the motion of the observer; he deduced that must be true, because he realized there was a contradiction between Galilean Relativity and Maxwell’s Laws with respect to the speed of light.

The speed of light is determined by the fundamental constants of electricity and magnetism (permittivity and permeability of free space, respectively). If the speed of light can be measured differently by different observers, then those observers must also measure the constants of electricity and magnetism differently. But this is not possible, because Galilean Relativity says that the laws of motion are the same in all inertial frames, and thus it is impossible to perform an experiment to determine if you are moving (the ship sailing at a constant speed on a smooth sea).

If a person who is stationary measures the speed of light differently than another person who is in motion at a constant velocity, then the person who is in motion could determine that they are in motion by measuring the strength of electricity or magnetism. But this would contradict Galilean Relativity, which says that such an experiment is not possible.

Therefore, the speed of light must be constant for all observers.