Jim Kelley wrote:
True, but we shouldn't go so far as to infer that 1 Hz might sometimes
have more or less than one cycle in a second - no matter how much
different each second might be from the next.

We often infer that a frequency has lessened due to
the red shift which could certainly be a shortening
of a second from the time the light was generated
until now.
--
73, Cecil, http://www.qsl.net/w5dxp

Cecil Moore wrote:

We often infer that a frequency has lessened due to
the red shift which could certainly be a shortening
of a second from the time the light was generated
until now.

The phenomenon of red shift is readily observable - that's how it was
discovered. Line spectra from known elements is observed to be
shifted in wavelength down from where it appears in the rest frame.
The cause could be doppler shifting due to relative motion, or some
other reason. If the length of the second were different, then so
would be the speed of light as well as the constant of proportionality
between frequency and wavelength at the source. In fact all kinds of
physics would have to be different. There is certainly a probability
for either case. Whether the probabilities are of the same magnitude
is debatable.

73 de ac6xg

Jim Kelley wrote:
If the length of the second were different, then so would be the speed
of light ...

To see why that is false, refer to Lorentz's
transformation for time at a velocity near
the speed of light. Time can vary all over
the universe while the speed of light remains
constant (at least by definition :-). Since
time is one dimension for the speed of light,
the problem is self-correcting.

If tomorrow's second were 1/2 half of today's
second, nobody would even notice.

If someone used a cesium clock near a black
hole to come up with a "standard" second, it
would be nowhere near the same length of time
as a cesium clock on Earth. Time passes very
slowly near the event horizon of a black hole
but light keeps on trucking at the speed of
light.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:

Jim Kelley wrote:

If the length of the second were different, then so would be the speed
of light ...


To see why that is false, refer to Lorentz's
transformation for time at a velocity near
the speed of light. Time can vary all over
the universe while the speed of light remains
constant (at least by definition :-). Since
time is one dimension for the speed of light,
the problem is self-correcting.

If the second were "smaller", then light could obviously no longer
travel 3x10^8 of our meters in one of them. Try not to lose track of
the reference frame, Cecil. (Remember, it's the one in which the red
shift is being measured).

73, jk

Jim Kelley wrote:
If the second were "smaller", then light could obviously no longer
travel 3x10^8 of our meters in one of them.

It is the frequency that is red-shifted, not the
velocity. A shorter second results in a lower
frequency. Relativity won't allow the velocity
of light to change but everything else changes
including meters and seconds.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Jim Kelley wrote:
If the second were "smaller", then light could obviously no longer
travel 3x10^8 of our meters in one of them.

It is the frequency that is red-shifted, not the
velocity. A shorter second results in a lower
frequency. Relativity won't allow the velocity
of light to change but everything else changes
including meters and seconds.


Quantum mechanics does however:


http://science.nasa.gov/headlines/y2..._stoplight.htm

On a more humble level, Light changes speed as it passes through
different mediums, such as water.


- 73 de Mike KB3EIA -

On Fri, 02 Feb 2007 12:26:48 -0500, Michael Coslo
wrote:

On a more humble level, Light changes speed as it passes through
different mediums, such as water.

WOW!

According to Cecileo, does this mean that time slows down (speeds up?)
TOO? Does the Vatican know about this?

Must be why bath time is resisted by so many children.

73's
Richard Clark, KB7QHC

Cecil Moore wrote:
If someone used a cesium clock near a black
hole to come up with a "standard" second, it
would be nowhere near the same length of time
as a cesium clock on Earth. Time passes very
slowly near the event horizon of a black hole
but light keeps on trucking at the speed of
light.

Jim

Don't bother. Cecil has his own, very special, form of Relativity.

tom
K0TAR

Jim Kelley wrote:
If the length of the second were different, then so would be the speed
of light ...

Cesium clocks at sea level, on a mountain top, and
in an airplane all measure different lengths of the
second. Are you saying the speed of light is different
at those three locations?
--
73, Cecil, http://www.qsl.net/w5dxp