Physics is sometimes closer to philosophy when it comes to understanding the Universe. Dr. Donald Chang, a physicist at the Hong Kong University of Science and Technology, attempts to elucidate whether the Universe has a resting frame.
According to Einstein’s special theory of relativity, there should be no resting frame in our Universe.
Such an assumption, however, could be in conflict with the standard model of cosmology, which regards the vacuum not as an empty space.
“In the famous experiment conducted by Michelson and Morley in the late 19th century, it was found that the propagation of light is independent of the movement of the laboratory system,” Dr. Chang explained in a paper published in the March 2017 issue of the European Physical Journal Plus.
“This finding was interpreted by Einstein as an indication that the physical laws governing the propagation of light are equivalent in all inertial frames.”
“In a paper published in 1905, Einstein raised this understanding to the status of a postulate: ‘the same laws of electrodynamics and optics will be valid for all frames of reference.’ This postulate was known as the 1st postulate of the special theory of relativity.”
“One may notice that this postulate of relativity was originally applied only to ‘electrodynamics and optics.’ But, later, this postulate was generalized to all physical laws.”
“This thus raises a serious question: Can this generalization be justified? The results of Michelson-Morley experiment only demonstrated that the propagation of light obeys the principle of relativity. What about particles with rest mass? Can one demonstrate that the physical behavior of massive particles also obey the 1st postulate of relativity?”
“This postulate of relativity implies that there is no resting frame in our Universe; otherwise one would be able to determine which inertial frame is stationary and which frame is moving.”
“This means that the vacuum in our Universe must be an empty space and thus cannot serve as a reference system.”
“Such a requirement, however, will be in conflict with the modern view of vacuum. In the standard model of cosmology today, the vacuum is far from being empty.”
In his paper, Dr. Chang proposes to precisely measure the masses of two charged particles moving in opposite directions.
The conventional thinking assumes that the inertial frame applies equally to both particles.
If that’s the case, no detectable mass difference between these two particles is likely to arise.
However, if the contrary is true, and there is a rest frame in the Universe, the researcher expects to see mass difference that is dependent on the orientation of the laboratory frame.
This experiment, partially inspired by Michelson-Morley experiments, ‘can be conducted using existing experimental techniques.’
“For simplicity, an electron can be used as the charged particle in the experiment,” Dr. Chang said.
“Of course, the same experiment can be done with protons, which may have the advantage of higher precision, since the proton has a larger rest mass.”
Donald C. Chang. 2017. Is there a resting frame in the Universe? A proposed experimental test based on a precise measurement of particle mass. Eur. Phys. J. Plus 132: 140; doi: 10.1140/epjp/i2017-11402-4