- #106
wespe
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grounded said:All the formula says is that light travels from the source at the speed of light. So in one second the ray of light will be 186,000 miles from the source and the observers speed cannot change this.
Oh I now see why you are saying this. It's the syndrome: thinking in absolutes. You may be over this by now, but just in case..
You assumed that there is an absolute space (aether) out there, in which things can move. The speed of an object in aether (or wrt aether) can be known. Let's call this speed "absolute speed". Absolute speed of light is somehow known and is equal to c. Then of course you would say that an observer approaching an emitted light won't change light's [absolute] speed.
But, we are not talking about absolute speeds. In fact, there is no way to measure absolute speed, because there is no way to detect absolute motion. Therefore, the existence of aether has been denied. There is no evidence that aether even exists so let's forget about it, along with absolute speed.
So now we can only talk about relative speeds. Consider: when you approach something, it also approaches you with the same speed you approach it, right? That mutual speed is the relative speed. It doesn't matter who is really approaching who, relative speed between two objects has only one single value, unlike two objects having two different absolute speed values.
Still, we can measure two different values, if we consider the relative speeds of two objects wrt a third object. Then, using these two values, we can calculate relative speed of these objects wrt each other. Galilean relativity would simply add the two values as v1+v2, which is intuitive. But when the speeds are high, it turns out that the formula does not hold true.
And the rest is history.. LOL I wrote too much.
I hope this helped.
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