From: heathjohn2@gmail.com   
      
   On Saturday, April 7, 2018 at 5:29:29 PM UTC-4, Edward Prochak wrote:   
   > On Thursday, April 5, 2018 at 3:20:11 AM UTC-4, John Heath wrote:   
   >> On Tuesday, April 3, 2018 at 8:05:29 AM UTC-4, Gary Harnagel wrote:   
   >>> On Tuesday, April 3, 2018 at 4:50:28 AM UTC-6, John Heath wrote:   
   >>>>   
   >>>> Now that we are back on subject I would enjoy hearing thoughts on   
   >>>> this. Is it momentum or the center of mass that is being conserved?   
   >>>   
   >>> It seems they are the same thing.  If you assume center of mass is   
   >>> conserved, you can prove that momentum is conserved and vice versa.   
   >>   
   >> Yes I hear you. It is not absolutely momentum conservation or absolutely   
   >> center of mass conservation. They both work so why draw a line between   
   >> the two.   
   >   
   > Center of mass is just a reference point because real bodies   
   > are actually collections of many particles. Our means of measurements   
   > begin at the macro level so we simplify the calculations using   
   > center of mass. That you confuse them is troubling. It is like   
   > confusing the rocket for the fuel.   
   >>   
   >> On another note what about one of the masses radioactively decaying   
   >> losing mass but not violating the conservation of momentum as stated   
   >> before. It is a tricky problem with no easy answers that I can think   
   >> of. Ears open if you have a fix.   
   >   
   > I started to prepare a long presentation about this but let   
   > me just present a short description. First the problem has   
   > nothing to do with the nonradioactive object. Its momentum   
   > is obviously conserved.   
   >   
   > So consider the radioactive object let us simplify it by   
   > first giving it initial momentum of zero. IOW, it is sitting   
   > at rest. P=mv = m*0 = 0   
   >   
   > Now let's make the object itself even simpler. Assume it is   
   > a single radioactive atom. Such cases have been studied in detail.   
   > It turns out, you must apply both the conservation of momentum   
   > and the conservation of energy. When you do, it has always been   
   > found that both equations balance.   
   >   
   > The atom emits a particle. The particle travels off in one direction   
   > and the remaining nucleus moves opposite. The momentum balances, but   
   > the total mass does not seem to balance initially. The difference   
   > in the total mass turns out to balance as the source of the   
   > kinetic energy comes from a small amount of mass that is converted   
   > to energy  according to Einstein's famous E=mc^2   
   > When the measurements and calculations for both momentum and energy   
   > are completed, it has always been found that both equations balance.   
   >   
   > If you would like a specific example, this is how the neutrino   
   > particle was initially proposed. It was because certain decay   
   > events did not balance. The leftover momentum and energy was   
   > carried by a another particle. Later this other particle   
   > was detected independently of the decay experiments aand named   
   > the neutrino.  You should read about the discovery of the neutrino.   
   > I cannot do the story justice here. But it is a demonstration of   
   > how momentum and energy conservation laws always work out.   
   >   
   > But again, to truly understand these two conservation laws, you   
   > really should sit down and learn how to do the calculations.   
   > The problems can be fascinating puzzles that are very satisfying   
   > to solve.   
   >   
   > HTH,   
   >   Ed   
   >   
   > [[Mod. note -- The history of the neutrino's hypthesizing and later   
   > discovery, and then of the solar neutrino problem and its resolution   
   > with the realisation that (at least some) neutrinos have nonzero mass,   
   > is indeed fascinating.  The Wikipedia history   
   >   https://en.wikipedia.org/wiki/Neutrino#History   
   > looks like a decent starting point.   
   > -- jt]]   
      
   I would like it if you start a thread on neutrinos as I have a beef with   
   kids today going on and on about what a neutrino is while ignoring   
   flavor change problem. A tauon neutrino mass is in the 18 MeV range so   
   how could a neutrino going through flavor changes be clocked at almost c   
   with a massive 18 MeV boat anchor on it?   
      
   --- SoupGate-Win32 v1.05   
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