What is the amount of energy given off when an electron and a positron anhilalate?
Asked by: Bill Devenport
Using 9 x 10-31 Kg. as the mass of each particle, and knowing that their combined mass
will be totally converted to energy, you can use Einstein's famous E = mc2 (where c = the
speed of light in vacuum = 3 x 108 m/sec) to determine the total energy output of the electron/positron annihilation:
E = (mass of electron + mass of positron) x (speed of light in m/sec)2
E = 2 x (9 x 10-31)kg x (9 x 1016)m2/sec2
E = 1.6 x 10-13 kg m2/sec2 = 1.6 x 10-13 Joules
Answered by: Paul Walorski, B.A. Physics, Part-time Physics Instructor
'The strength and weakness of physicists is that we believe in what we can measure. And if we can't measure it, then we say it probably doesn't exist. And that closes us off to an enormous amount of phenomena that we may not be able to measure because they only happened once. For example, the Big Bang. ... That's one reason why they scoffed at higher dimensions for so many years. Now we realize that there's no alternative... '