A universal constant on the move
Is the proton losing weight, or has the fabric of the Universe changed?
It seems that nothing stays the same: not even the 'constants' of physics. An experiment suggests that the mass ratio of two fundamental subatomic particles has decreased over the past 12 billion years, for no apparent reason.
Read more here.
Comments
Both Ubachs and Webb say that it is unlikely that protons are losing weight.
Why exactly do they think so? I mean, the mass of the proton is the result of very complicated processes, with non-perturbative QCD triggering the breaking of chiral symmetry. All this is not really understood. So, naively, I would expect that small changes in the strong coupling constant could have some influence on the mass of the proton, while leaving untouched the mass of the electron. Of course, that would be a rather conservative explanation of such data, as compared to extra dimensions ;-)
Are there arguments that exclude the hypothesis of a changing strong coupling constant, maybe from baryogenesis or the primordial production of elements beyond hydrogen?
Posted by: Stefan Scherer | April 22, 2006 11:28 AM
I do not wish to dive too far in interpretations but I wish to remark that it is perhaps not useful to interprete a possible variation of a mass ratio in terms of either one of the masses varying. Because what is the matter if a mass changes ? Is it the binding of the particle or the mass standard (which is currently connected to the 12C nucleus) that varies ?.
It is crucial that we look at a dimensionsless parameter here, independent of all units.
See M.J. Duff, arXiv:hep-th/0208093; 11 July 2004 for an interesting discussion.
Posted by: Wim Ubachs | April 24, 2006 02:36 PM
I always the the ratio of proton to electron mass is about 1832.820777...
Posted by: Antonio Lao | April 24, 2006 06:01 PM
Dear Dr. Ubachs,
thank you for the reference to the Duff paper, which I will look up! I would completely agree with you when talking about the ratio of the masses of the electron and the muon, for example.
What I had in mind was that - within the framework of the standard model of particle pyhsics - the electron is elementary, while the proton is not. In principle, the proton mass should somehow be calculable from other parameters of QCD, which again could be subject to change. Maybe this would induce relative shifts into the hadron mass spectrum, and it would make sense to talk about a changing mass of the proton, as gauged against the lepton masses.
I completely agree that one has to be careful before jumping into any conclusions. And let me add that I am always overwhelmed when hearing about the reach and possibilities of modern astronomical observations!
Posted by: Stefan Scherer | April 24, 2006 09:41 PM
I do not know how this could be realted to the changes of proton mass, but I want to share with you a realtion I envisioned long ago (Robledo's relation):
The second partial derivative with respect to time, of the universal gravitational constant elevated to the -1/2 power is proportional the charge volume density!!
(d2/dt2)G^(-1/2) = rho_charge (cgs units)
Humbly, I hope this will help the advancement of science.
Posted by: Victor Robledo-Rella | April 25, 2006 04:23 AM
This article says "Although the light changes frequency on its long journey through space...".
Is this accepted "fact"? If so, doesn't it dismiss the red-shift theory of Hubble and the whole "Big Bang" theory?
The article also suggested that light "slows down" over vast distances. Anyone know what evidence there is for this seemingly sensible idea?
[The effect of light changing its frequency on its long journey through space IS the red shift. As far as 'variable speed of light' theories go, there appears to be little (if any) hard evidence for this suggestion, but there's a nice explanation of the general idea here http://www.ast.cam.ac.uk/~mim/res.html by Michael Murphy at Cambridge University - Ed]
Posted by: Simon McDonald | April 25, 2006 04:30 AM
Dear [Ed],
I was under the impression that the red shift was deemed to be caused by galaxies moving away from us at great speed rather than the frequency of light "decaying". If it is caused by light travelling great distances instead there is no need for the expanding universe theory.
Posted by: Simon McDonald | April 25, 2006 07:44 PM
In his book "The Presence of the Past" (1981) british scientist Rupert Sheldrake suggests that the "Laws of Nature", as we call them, are more like habbits of nature. According to his theory, as I understand it, everything is changable and changing. Behaviour of matter, repeated countless times is reinforced and becomes predictable as if obeying a "law". Could it be that not only the speed of light but the mass ratio of particles may also be variable over time? In my view it would seem more bizzare that there is no variation in the physical "constants", yet the universe has been expanding at an ever increasing rate since it's "birth".
From a spiritual perspectve, it would be nice to believe that everything that happens, although heavily influenced by events of the past, still has an (ever-so-slight) effect on events of the future. If it wasn't so, then what would the "unity" of the universe, that some speak of, be based on?
Posted by: P.Chotchov | April 26, 2006 01:33 PM
P.Chotchov, that is a great point about Sheldrake. There is a great paper on topic on his website: The Variability of Fundamental Constants.
I think physics is slowly adopting a true evolutionary perspective. For a long time, physical constants have been seen as non-evolving - but if we take a big bang cosmology serious, I think it points to an evolutionary view of the cosmos.
Posted by: Matthew Clapp | April 27, 2006 05:30 AM
There seem to be so many bits of new data that don't fit with the big bang theory, while the ideas to make the data fit the big bang theory get more and more absurd. So now fundamental universal constants have to change to accomodate the big bang theory? Which it self is based on the red-shift observations that might simply be explained by the wave-length of light getting larger (and the frequency getting lower hence the red-shift) when light travels extremely long distances.
Posted by: Simon McDonald | May 1, 2006 09:51 PM
there is some thing which is controlling our universe some thing which can be identify so fore some thing which is constant through out this universe some thing which is constant in our senses and if we can identify that we can controll this whole planet earth
Posted by: mehdi mustafa | May 21, 2007 09:49 AM