In article <gerry-17370D.firstname.lastname@example.org>, Gerry Myerson <email@example.com> wrote:
> John Baez wrote:
>> An EeV is an "exa-electron-volt", which is the energy an electron picks up >> going through a potential of 10^18 volts. 300 Eev is about 50 joules - >> the energy of a one-kilogram mass moving at 10 meters/second, presumably >> all packed into one particle! Nobody knows how such high energies are >> attained -
>How fast does, say, a proton have to be going to have that much energy?
It's sort of tiresome figuring out the right number of nines, so I won't bother with the precise figure, but it's something like .999999... times the speed of light. Fast.
Too vague for you?
The mass-energy of a proton is very roughly 1000 MeV. This particular proton had an energy of 300 EeV. So, find the velocity v, as a fraction of the speed of light, such that