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Originally Posted by vinaur
Does anyone else out there think that there is something incorrect about SR. Even though it does make sense if you take it one step at a time, I still think there is something wrong. Maybe the law of propagationof light is wrong? just think of it, if it was, wouldn't it make stuff so much easier (on the daily basis anyway).
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It can be really difficult to wrap your head around it. It's taken me a few years of general physics classes to really start understanding it. So far no experiment has shown a flaw in the theory.
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Originally Posted by vinaur
Lorentz Transformation is not that hard to understand if you read the first 20 pages or so of Einstein's Relativity: The Special and General Theory . I knew nothing of it, and yet I think I'm getting it now.
BTW, there is one thing that either I don't get or Einstein got it wrong. In Chapter 9 of his book, Einstein says that When you are moving towards one flash of lightning and are right in between the two when they strike, you will see one of them faster, hence ruining the concept of simultanity. However, if the law of propagation of light is taken into account, the two beams of light from the lightningsshould reach you at the same time no matter how fast you are travelling in any direction, as long as you are right inbetween the two when they strike, since the distance between you and the lightning has to decrease at a constant rate c. |
This would be true if the events did occur at the same time as the observer on the ground sees, however, the point is the two strikes of lightning actually occur at DIFFERENT TIMES in your frame of reference. So you do see one flash before the other one, and this doesn't contradict the light propagation law because all of the light IS approaching you at a constant speed; you see one before the other because that bolt struck first. The observer also sees that the light from one bolt reaches you before the other one, even though the events are actually simultaneous in the observer's frame, because you are moving in that frame.
The basic postulate of special relativity is really quite simple and intuitive: that laws such as Maxwell's are valid in every inertial frame of reference. Maxwell's laws predict that the speed of light is constant, specifically 3.0x10^8 m/s, so the speed of light must be 3.0x10^8 m/s in every inertial frame if this is correct. The Lorentz Transformations handily resolve the apparent contradictions when you assume this.
What vexed physicists before Einstein about Maxwell's equations was that they predicted a constant speed of light and even more, they predicted EXACTLY what the speed of light would be before it could be accurately found experimentally. However, they said nothing about speed relative to what, i.e. in which frame of reference. This is where the idea of the ether came in handy; the frame of the ether was assumed to be the frame in which this was the speed of light. Michelson and Morley then famously couldn't find the ether, which made things even more confusing.
Einstein's simple genius was to propose that that was the speed in EVERY frame, and all of the consequences of special relativity such as time dilation really come from that one idea.