Bill's right on this one. Except in an exceptional vacuum (deep space), the
speed of light is always less than the official "Speed of light".

To my knowledge, nobody on earth has moved anything at the speed
of light yet...but they have moved a few things very close to it... in a 
well-
prepared lab.

Light in a fibre optic cable constantly bounces  off of each inner side 
of the
fibre, so travels much farther than the distance of the cable.

--Bob

William Chops Westfield wrote:

> On Oct 22, 2005, at 12:54 AM, Wouter van Ooijen wrote:
>
>>
>> That's why I suggested fiber, in which light travels
>>  with the speed of light...
>
>
> But it doesn't.   In fact, IIRC, an ethernet signal on coax (sorry; old
> knowledge) travels at about .77c while light down a glass fiber only
> travels at about .67c
>
> (index of refraction is ration of speed of light in substance to speed of
> light in vacuum.  For glass it's about 1.5)
>
> BillW



-- 
Note: To protect our network,
attachments must be sent to
attach@engineer.cotse.net .
1-520-777-7606 USA/Canada
http://bem.to/azengineer

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist