On Thu, 5 Oct 2017 02:14 pm, Stefan Ram wrote: > Chris Angelico <ros...@gmail.com> writes: >>You can get through a lot of life believing that mass is conserved, >>but technically it is not, as can be proven. > > Well, in fact, it is conserved.
It certainly is not. The whole point of Einstein's equation E = mc² is that energy and mass are freely convertible. Neither energy nor mass alone are conserved. > When an electron and a positron annihilate to give a gas of > two photons, this gas as a whole still has the same mass as > the electron before. And its center of gravity moves with > less than c. That doesn't sound like any description of matter/anti-matter annihilation I've every seen before. I think you may be conflating the concepts of clouds of virtual electron/positron particles with actual annihilation events between real electron/positron particles. In actual annihilation events, there is (as far as I know) generally a single real photon produced, with momentum equal to the sum of the momentum vectors of the original electron and positron. That moves away from the point of production at the speed of light. -- Steve “Cheer up,” they said, “things could be worse.” So I cheered up, and sure enough, things got worse. -- https://mail.python.org/mailman/listinfo/python-list
