8 ms·
A photon from an electron-positron anihilation has frequency around 10^20 Hz, somewhat higher frequency than what we usually call x-rays. Some of them do get ab
by eigenket 3y ago
A photon from an electron-positron anihilation has frequency around 10^20 Hz, somewhat higher frequency than what we usually call x-rays. Some of them do get absorbed by the body, but enough pass through to be detected usefully.