Misleading headline alert
This is not new, we were taught this 30 years ago.
Another old theory found again. People are desperate to find a way to make interstellar travel seem possible.
Just the other day I was driving in the desert at night and I kept outrunning my headlights. Here I thought I was nuts but now I know why.
In one of the new studies, researchers established a detailed quantum mechanism that would explain the magnetization and polarization of the vacuum, referred to as vacuum permeability and permittivity, and the finite speed of light. It suggests that there exist a limited number of ephemeral particles per unit volume in a vacuum
If they were proof, then there wouldn't be a "may" involved. Perhaps the author meant "evidence" or "suggestive".
Old news really about the small variations, but one wonders if there may be larger variations under some circumstances and in different regions of space..............Just wondering.
It is well established that the speed of light is slower in a neutral plasma than in a vacuum. In the ionosphere (an example of a neutral plasma) the effect is proportional to the square of wavelength and something like the squareroot of the charge divided by the mass of the electron. The positive ions, being so much more massive have little effect. See: http://farside.ph.utexas.edu/teaching/315/Waves/node48.html for details and equations 593 and 596 for the exact equations.
This paper seems to be saying that the presence of short lived quantum mechanical virtual particles delays the speed of light in a vacuum (plausible) but the delay is independent of the mass of the particles. Not enough details are supplied to evaluate the claim.
Pinging my favorite cosmologists. In the past, we have had some discussions where I posited that the speed of light is not really a constant.
Pretty damn cool.
To quote the late Zaven Margosian:
and Variables don’t.”