As Ian has said, whole chapters have been written on relativity.
Quote:
Originally Posted by NQLD_Newby
Hi Mick,
Once again please feel free to correct me if I am missing something, but the speed of light is always the speed of light, regardless of your speed. Meaning the speed of light doesn't add itself to your own speed. If you were moving at 100km/hr and turn your lights on, the light coming from your car isn't C+100km/hr it is still C. Therefore if you are moving at the speed of light, you wouldn't see any light at all because it cannot get out in front of you because you are moving at the same speed.
|
Yes, measurement of the speed of light returns the speed of light irrespective of your speed. If you were stationary and measured the speed of light (from your headlights for example) you would find it moves at, well, the speed of light as expected. If you were travelling at 0.5c (half the speed of light) you would measure the speed of the light to be the speed of light not 0.5c as the difference between the speed of light and your speed. At the same time a stationary observer who also measures the speed of the light that you've just measured would also find it to be moving at the speed of light, not at 1.5c as the sum of your speed and the speed you've recorded for the light.
Quote:
In fact to be perfectly correct, in the scenario described in the above posts, the observers wouldn't see your lights come on at all, because you and the light from your headlights would arrive at exactly the same time.......I think?
|
The observers would see the light at the same time as they see you.
In their reference frame they see (for want of a better word) you approaching at the speed of light and the light approaching at the speed of light. In your reference frame you see the light moving away from you at the speed of light and the observer approaching at the speed of light.
What the Lorentz transformation does is give you the relative velocities as seen by different observers. Since the relative velocity of two objects can't exceed the speed of light this doesn't agree with the commonsense explanation from everyday experience and this is what causes the headaches trying to work out what's going on.

Mick