Radioactive Recoil

1.In a radioactive decay does the radioactive element feel any reaction force (from newton's third law) as particles and energy gets out of it ? or does the center of mass of that radioactive element remains same ? 2.on the basis of newtonian gravity how much time should a non symmetrical change of mass of sun take to reach earth ?
- Raktim Singha Roy (age 31)
Malda, West Bengal, India

1. Yes, there certainly is momentum conservation and thus recoil in radioactive decay.

2. Newtonian gravity includes no propagation delay. In actual gravity (general relativity) it takes about 8 minutes for some change at the Sun to propagate to Earth.

Mike W.

(published on 09/09/2014)