# Proton electron mass ratio

1. May 3, 2006

### simon009988

There was a recent article in nature on how there was "INDICATIONS OF A CHANGE IN THE PROTON-TO-ELECTRON MASS RATIO have shown up in comparisons of the spectra of hydrogen gas as recorded in a lab with spectra of light coming from hydrogen clouds at the distance of quasars. "

I was just wondering how ture people think this is.
Could this constant really be changing?

2. May 3, 2006

3. May 3, 2006

### ZapperZ

Staff Emeritus
As with the purported claim of the changing fine structure constant with time, these things need to be verified independently using a different method to be convincing.

Zz.

4. May 4, 2006

### rbj

and, to repeat from older threads, it is these dimensionless "constants" that count. if $m_e/m_p$ changes or if $\alpha$ changes, that means something. claims made about a changing $c$ or $G$ are meaningless. we can only measure these quantities against like dimensioned standards (like a carpenter measuring length with a tape-measure) and we measure or ultiimately sense only dimensionless quanitities. if something has noticeably changed, it was a ratio of like dimensioned quantities and to blame that change on any single dimesionful component (like blaming it on $m_p$) is misleading.

so at least the OP is inquiring about a meaningful issues.

Last edited: May 4, 2006