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Old April 6th 07, 05:04 PM posted to rec.radio.amateur.antenna
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Default Not understanding some parts of wave refraction

On Apr 6, 12:08 am, Richard Clark wrote:
On 5 Apr 2007 18:15:30 -0700, "K7ITM" wrote:

HE thought c was a
constant, as I would if the author didn't tell me otherwise.


Hi Tom,

The speed of light is always constant - within its frame of reference.
It is only for those that inhabit a different frame that it "appears"
to be different. By Lorentzian laws, there is no time at the speed of
light and everything is simultaneous - source and load are
inseparable.

To illustrate at a slightly slower speed (from Feynman):
"A very interesting example of the slowing of time with motion
is furnished mu-mesons (muons), which are particles that
disintegrate spontaneously after an average lifetime of 2.2 µS.
They come to earth in cosmic rays.... It is clear that in its
short lifetime a muon cannot travel, even at the speed of light,
much more than 600 meters. But although the muons are created at
the top of the atmosphere, some 10 kilometers up, yet they are
actually found in a laboratory down here, in cosmic rays. How can
that be? The answer is that .... While from OUR own point of view
they live considerably longer ... time is increased ... by
1/SQRT(1-(u²/v²))."

73's
Richard Clark, KB7QHC


Seems to me you're way off point here, Richard. I'm in my lab, my
inertial frame of reference. I send some EM waves through my vacuum
chamber and I measure their speed as 2.997...*10^8 meters/second. The
same waves continue on through the glass of the bell jar keeping air
out of my vacuum, and I happen to notice that their speed through that
glass is1.684*10^8 meters/second. I notice that light from my
hydrogen light source contains certain well-defined spectral lines,
but each of those passes through my vacuum at the same speed.
However, I notice that those lines, in a short pulse of light, come
out of the glass separated in time slightly, implying that they took
different times to get through the glass, and were therefore not even
travelling through the glass at the same velocity; I notice no such
separation for the light passing through the vacuum. Further, I
notice that light from a distant star has apparently the same set of
spectral lines, but they are shifted to slightly longer wavelengths.
However, they take the same time to pass through the vacuum as my
locally-generated hydrogen light. All my measurements are in the same
frame of reference, and IN VACUUM the speed of em radiation appears
from all my measurements to be the same, no matter its wavelength,
even for very long wavelengths, but in other media, still the same
inertial reference frame, it's different. I also happen to notice
that the light from the distant star was created in a different
inertial frame of reference...

OK, I'll shut up on this now.

Cheers,
Tom



 
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