The ultimate test of special relativity

[wisp]

The whole of SR is based on two postulates.

1. All laws of physics have the same mathematical form in all reference frames moving at constant velocity
2. The speed of light in a vacuum has the same measured value in all reference frames moving at a constant velocity

Postulate 1 has been tested to great accuracy, by testing for violation of Lorentz Invariance, and to date no evidence has been found to suggest that it's wrong.

Postulate 2 has been tested mainly by two-way light speed experiments similar in type to the Michelson-Morley experiment. Results strongly support SR, but doubt remains - see a review of Dayton Miller's work by James DeMeo, see http://www.orgonelab.org/miller.htm

It should be mentioned that tests for Lorentz Invariance (LI) are not the same as tests for the speed of light. Proof of LI doesn't mean that postulate 2 is correct.

The ultimate test for SR is simply to measure the speed of light one-way, and very few experiments have been carried out to test this. Of those that have there is evidence to suggest that SR may be wrong!

Two one-way tests are:

Test 1)
Timothy P. Krisher, Lute Maleki, George F. Lutes, Lori E. Primas, Ronald T. Logan, John D. Anderson, and Clifford M. Will, "Test of the Isotropy of the One-Way Speed of Light using Hydrogen Maser Frequency Standards", THE PHYSICAL REVIEW D (RAPID COMMUNICATIONS) 42, 731 (1990)

There is an issue with the T.P.Krisher et al "laser optic one-way light experiment".

I came across this info on the net written by D.J.Larson.
" 10.3 The Experiment of Krisher et al.
A recent experiment by Krisher et al. has tested for the anisotropy of the oneway speed of light by using two hydrogen maser standards separated by 21 km. The light from each maser is split, with one-half sent to a local detector and the other half used to modulate a laser carrier signal that is sent to a detector at the distant location. The light from the local maser and the distant maser are combined, and their relative frequency difference monitored. Since all light propagation is oneway in this experiment, the node enforcement hypothesis, Postulate DJL-II, is no longer easily motivated by an analogy with a pinned string, and it is possible that the Krisher et al. experiment could yield a non-null result. (There are no longer mirrors enforcing boundary conditions at both ends of a light path, so nodes may no longer be forced to move along with the apparatus in this case.) An analysis of the Krisher et al. result using the theory presented herein shows that experimental noise is too large at present to be able to detect the Earth's motion through an ether at rest with respect to the 3 K microwave background radiation. However, further refinements in the experiment may detect such motion."

http://www.dipmat.unipg.it/~bartocci/fis/larson3.htm

It seems that the experiment was not accurate enough to detect the motion of the Earth through the ether, and the experiment only ran for 5 days. I believe the DeWitte experiment was more accurate because it ran for much longer and was able to extract the sidereal period variations from the data.

Test 2)
The De Witte experiment (a one-way electrical pulse experiment)
In 1991, Roland DeWitte carried out an experiment that proved the Earth moves through the ether. The duration of the experiment was 178 days and it's clear proof that the Earth is affected by an ether wind of galactic origin.
A 5Mhz signal from clock A is passed down a coaxial cable of length 1.5km to clock B. The signals were compared using a digital phase comparator (like those used in PLL). The result was affected by the Earth's rotation and had a period of 23hr 56min +/- 25s and is therefore the sidereal day. If the variation had a 24hr cycle - calendar day, it could be argued that the changes were due to some unknown local effect, but its period is the sidereal day, which implies its cause must be of galactic origin. For further information on this experiment, see http://ins.cornell.edu and http://home.planetinternet.be/~pin30390/belgacom.htm

The ultimate test of SR is to carry out modern one-way experiments to resolve matters. SR may fail and science may have to be re-written.

[?]

As a non-scientist I'm puzzled by the discussion of the speed of light in SR. Isn't the speed of anything dependent upon the clock? I thought SR postulated the relativity of time. I can understand the speed of light being constant within a frame of reference, but I do not understand the basis for assuming that when we look back in time that the clocks as viewed by us are running at the same speed as they are today.

[wisp]

Hi

Yes. On Earth we have what we believe to be atomic clock standards.
In 1967 a natural unit of time was adopted (SI units), based upon the caesium atom (atomic clock). One second is defined as the time required for a caesium atom to vibrate exactly 9,192,631,770 times.
Einstein predicted time dilation from SR – moving clocks run slow. And this is known to be correct.
But we cannot prove that our measure of time is correct, now or in the past. I personally think that all time measurements on the Earth’s surface are made with “relative time”, and this time runs slower than “absolute time”. Because we are moving through the ether - hence relative time.
The result is that the real absolute speed of light is slower than what we believe it to be. This could be by as much as 72 metres per second.
But you will have to wait until SR is proven false before this is taken seriously.

[ThirdWorld]

Hi I'm ThirdWorld, the new kid on the block. Concerning the two postulates of the SR theory quoted above I must say that according to my own new TOE there is nothing wrong with either of them.

The second states 'the MEASURED velocity of light' in a vacuum is a constant. It does not say that the ACTUAL velocity is constant which would have been an error.

According to my TOE the speed of EMR RELATIVE to the source ( ie atom) from which it is generated may be constant. The speed of the source, however, is generally so small compared to the actual speed of the EMR that the diference in photon velocity cannot be distinguished by MEASUREMENT. The postulate is therefore correct.

It is science fiction however to say that light does NOT obey the laws of relative motion.

It is also science fiction to say that nothing can move faster than the so called 'speed of light'. There is hope according to my TOE...spacecrafts can be made to travel many times faster than light with only moderate acceleration so that it may be possile for man to travel to planets millions of light years away.

Your Friendly Physicst, ThirdWorld.

[wisp]

Further support expressing concern about light's one-way speed being constant in all inertial frames:

"Many physicists point to the proper functioning of the International Atomic Time system (TAI) in order to support the postulate of Special Relativity Theory about the one-way isotropy of light velocity in every inertial system, which has never been demonstrated. Contrary to this view, Manaresi demonstrates that the proper functioning of the TAI system does not imply the one-way isotropy of light on the moving Earth. This means that the second postulate of Special Relativity still remains merely conventional".

Konrad Rudnicki (Editor's comment)
http://redshift.vif.com/BookBlurbs/cesenabook.htm

[dleviwing]

wisp;
It is refreshing to see someone quote postulate 2 correctly. Most of the time it is said that the speed of light is constant for all reference frames. You use the word "MEASURED" which is the key word. When using the defined method of measurement for the speed of light in a vacuum, all reference frames will render the "Same Value". This value is the correction factor used by "Relativity" to provide mathematical comparisons.
Best Regards;
Dave