Nicolas Alvarez nous apporta ses lumieres en ce 2007/11/09 10:19:
> Gail Shaw escribió:
>> "Invisible" <voi### [at] devnull> wrote in message
>> news:47342cbb$1@news.povray.org...
>>> For light, the velocity varies a little, but it's roughly 300,000 km/s.
>>
>> Ur, no. The speed of light in a vacuum doesn't vary at all. It's a 
>> universal
>> constant.
>>
>> 299 792 458 m.s^-1
> 
> ...
> 
> How the HECK did they measure that o_O
A stationary mirror and a spinning rotor holding 8 others. Shine a light on the 
spining mirror so it encounter the stationary one. With the spining mirror 
stoped, mark where the return beam goes. Start the rotor and look as the return 
beam move.
At stop, the light hit rotor mirror #1, reatch the stationary one, return on 
rotor mirror #3. When the rotor is spining, it have moved before the light that 
hit the frist surface can return, so, it's reflected in a slightly different 
direction.
I've redone the experiment in colege. The aparatus is not that large, nor 
costly, and you only have to look in the eye piece to clearly see the movement.
You could do it yourself. You need: some mirrors, 2 razor blades, a drill, an 
eye piece, a light source, a plank of wood and some nails or screws, a dark room 
or the night. Some flat black paint is recomended.

-- 
Alain
-------------------------------------------------
Commercialism: Let's package this shit.

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