How To Synchronize FPGAs

On Mon, 27 Sep 2004 09:26:49 +0200, "Leroy Tanner"
<ikeepthespiritalive@freenet.de> wrote:

>"Paul Keinanen" <keinanen@sci.fi>:
>

>lambda = c / f
>c= 300.000 km/s
>f = 3 GHz for example, then the wavelength should be
>
>lamba = c / f = 300000/3000000000 = 3/30 = 10 cm!!!

This is true only for free space (and quite exactly for air). With
other insulators,the situation is different. 

>I assume this result is correct by all means. Where does the material come
>into play???

For instance, look up the velocity factor for various coaxial cables
with PE insulation, the velocity factor is 0.66, the signal propagates
at about 200 000 km/s in that coaxial cable.

Also light propagates at different speeds in different materials. Put
a spoon in the tea cup and it will appear as if there is a bend at the
surface. In reality, this is due to the fact that the water has a
lower propagation speed than air and thus there is also a difference
in refractive index.

Paul