On 01/11/2011 18:16, Szczepan Bialek wrote:
napisal w wiadomosci
...
On 31/10/2011 09:20, Szczepan Bialek wrote:

The spectra methods are a little mystery. And what with the radioscopy:
"In 1931, a Bell Telephone engineer, Karl Jansky (1905-1950), was trying
to
find where the interference disrupting transatlantic radiophone circuits
came from. He discovered that some of the radio noise was not from the
Earth--it was extraterrestrial. The primary source was the center of the
Milky Way, in the constellation of Sagittarius. In 1936, an Illinois
radio
engineer, Grote Reber (b. 1911), pursued the phenomenon farther." From:
http://physics.gmu.edu/~jevans/astr1..._txt.htm#5.2.1.

The radio frequences are easy to measure.
Are there the diurinal and annual effests?

I'm sure there are, but to detect them you would need to have a radio
receiver with good spectral resolution and a sources with narrow frequency
spectral features.

A bit of googling (using the words astronomical radio doppler effect
diurnal) has brought up the user guide for the Miriad software package
used by the Australia Telescope Compact Array (ACTA).
http://www.atnf.csiro.au/computing/software/miriad/

The section related to Spectral Line Data Reduction makes it clear that
the diurnal effect needs to be taken into account for fine velocity
resolution observations
http://www.atnf.csiro.au/computing/s...e/node134.html

The diurinal effect is confirmed by everybody.

Using words astronomical radio annual doppler effect we have:

"It is also possible to infer the position in the sky of a
spacecraft from the Doppler data. This is accomplished by

examining the diurnal variation imparted to the Doppler shift

by the Earth's rotation. As the ground station rotates underneath

a spacecraft, the Doppler shift is modulated by a sinusoid.

The sinusoid's amplitude depends on the declination

angle of the spacecraft and its phase depends upon the right

ascension. These angles can therefore be estimated from a

record of the Doppler shift that is ~at least! of several days

duration. This allows for a determination of the distance to

the spacecraft through the dynamics of spacecraft motion

using standard orbit theory contained in the orbit determination

programs."

On the page 37 is wrote: "At early times the

annual term is largest. During Interval II, the interval of the

large spin-rate change anomaly, coherent oscillation is lost.

During Interval III the oscillation is smaller and begins to die

out."

Who was right: Arago or Vogel?

Once again - they were both right.

Arago attempted to measure a predicted* diurnal variation in the SPEED
of incoming light by measuring a difference in the angle of refraction
for white light. Arago did not measure any difference. He was right.

Vogel measured a diurnal variation in the frequency/wavelength of
spectral features as a result of the movement of the Earth. He was right.

Arago was NOT looking at anything specifically related to spectral
features.




* I assume the prediction was based on a classical analysis of Snell's
law in which the ratio of light speeds in the air and in the block is
the same as the ratio of the (sine of) the angles.
The hypothesis (I assume) was that incoming light would have greater
speed when the Earth's movement had his laboratory approaching the
source; this would increase the 'effective refractive index', thus
increasing the angle of refraction. 12 hours later, when there is a
relative movement away from the source, the angle of refraction would be
reduced.