From: Eric Walker
* The wiki article gives the proton (rest) mass as being 938.272046(21) MeV/c^2 * If this value is accurate, at that precision I believe we have +/- 1 0.21 eV to use for free energy speculation. That is CODATA. Of course, it is no less accurate than any of the others. Unfortunately, it is no more accurate either. How can it be when quarks have variable mass? For instance, Jefferson Lab uses the value of 938.256 MeV. Other Labs, especially overseas have their own values. Some are measured, some calculated, some averaged. I’m in the process of a paper on this, but I can tell you – I have high level estimates within a range, and am convinced that there is at least 70 ppm which is in play, as excess above a median value. That can be called a narrow range, or a wide range, depending on one’s mindset. The only value not in dispute in 2014 goes to the first four digits - 938.2xx MeV … almost everything thereafter, in terms of mass variation, is in play. In fact NASA put men on the moon using a value that was pretty way off from what is now considered reliable. Jones
