In reply to bobcook39...@hotmail.com's message of Sat, 15 May 2021 00:14:21 +0000: Hi, [snip] >The phase change noted above does NOT entail any linear momentum and hence no >energetic single particles of radiation
It's possible to eject particles as long as the *vector* sum of the linear momentum of the ejected particles remains the same as before the reaction (if the frame of reference is chosen such that the initial entity had zero linear momentum, then the vector sum of the linear momenta of the final particles must also be zero in the same frame of reference). In fact this is what happens during decay of a radioisotope. In short just because the original entity had no linear momentum, it doesn't mean there can't be any ejected particles. It only means that the ejected particles are bound by the conservation laws. If only a single particle is emitted, then whatever remains behind also counts as a particle, and can compensate for the momentum of the single particle by moving in the opposite direction. You see this when a cannonball is fired from a cannon. [snip] Regards, Robin van Spaandonk <mixent...@aussiebroadband.com.au>
