hi can anyone enlighten me about the conservation of mass ( ya i do know from experiment we may know the law is right as the change in mass is so small that it cannot be detected but however is there any other better reasoning then that experimental fact ?)

Question

preetha · Answer

Well, its a fundamental principle of nature.  If you could lose mass then slowly the earth would shrink and fritter away!

anonymous · Answer

There is a general theorem, called Noether's Theorem, which says roughly that if mass were not conserved than the laws of physics would change with time.  Since the idea of a universe in which the laws of physics change seems ridiculous, we tend to believe mass msut be conserved.  But that is to some nontrivial extent just a question of taste.  It's certainly possible mass is not conserved -- in subtle ways, of course, since experimentally it's conserved to a very high degree of precision -- and we live in a truly bizarre universe.  But the smart money doesn't bet that way.