Re: The speed of light revisited


"PD" <TheDraperFamily@xxxxxxxxx> wrote in message
news:1140116047.508586.301060@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
|
| Spaceman wrote:
| > "PD" <TheDraperFamily@xxxxxxxxx> wrote in message
| > news:1140098072.488107.216290@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
| > |
| > | Spaceman wrote:
| > | > Ok,
| > | > I will admit light always leaves it source at c.
| > | > (sound always leaves it source the same way)
| > | >
| > | > But how can a lightsource's light be constant
| > | > to say an object traveling towards it at 0.5c.
| > | >
| > | > Let's say a lightsource is here on Earth.
| > | > so it is in a rest frame WRT to Earth,
| > | > and light moving away from such a source
| > | > is traveling at c outward from it.
| > | > How could such a lightspeed still be the same speed
| > | > to an object heading towards it at 0.5c?
| > | > How can light violate relative motion like that?
| > |
| > | Well, you have one of two conclusions that you might draw from that.
| > | Either:
| > | 1. The speed of light is not constant to all observers.
| > | 2. The rule for finding relative velocity as a simple sum or
difference
| > | is wrong.
| > |
| > | The second is hard to give up,
| >
| > Then that is your problem.
| > you can't give the answer huh?
| >
| > <snipped rest of non answer>
|
| I did answer it. Light does not violate relative motion.
| The way you compose velocities to find relative motion is
| v' = (v-u)/(1-vu/c^2)
| The v of light from the lightsource is c, so we'll stick that in.
| v' = (c - u)/(1 - cu/c^2)
| The u of the object is c/2, so we'll stick that in, and then we'll see
| what that object sees the speed of light v' to be:
| v' = (c - c/2)/(1 - c*(c/2)/c^2) = (c/2) / (1 - c^2/2c^2) = (c/2) / (1
| - 1/2) = (c/2) / (1/2) = c
| So even for the object moving at 0.5 c with respect to the source, the
| speed of light is still c.

That crap violates basic addition of speed.
You are so lost it is sick.


| Ah, I get it, you thought that
| v' = (v - u)
| Well, that explains the problem, doesn't it?

No,
it explains your problem,
you forgot how basic math works.


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