
#1
Jan2014, 04:02 AM

P: 3

Sorry, brand new here and this may be in the wrong place or very obvious. When matter and antimatter annihilate is the energy released the sum of all their potential energy? does E=MC^{2} only work because of the specifics of our universe, and if the universe were to contain more matter (and therefore gravitation) a given unit of mass would release more energy upon annihilation?




#2
Jan2014, 01:00 PM

Mentor
P: 10,846

Which potential energy?
The released energy is the total energy (mass, kinetic energy, binding energy, ...) of the annihilation partners in their center of energy frame. Potential energies relative to something else do not count  the final products are created at the same position, you don't lose or gain anything there. 



#3
Jan2014, 02:11 PM

P: 3

but the sum of the mass of the products is lower than the ingredients, so hasn't gravitational potential energy been lost? on a smaller scale is this not also the case with fusion/fission, gravitational potential energy must have been lost, or am I missing something?




#4
Jan2014, 02:37 PM

Sci Advisor
Thanks
P: 3,859

Annihilation and potential energy? 



#5
Jan2014, 03:00 PM

Mentor
P: 10,846





#6
Jan2114, 03:28 AM

P: 3

GPE of static object when 10km high = GPE of moving object 1km high + KE gained in falling + GPE of gained KE at 1km high? 



#7
Jan2114, 07:00 AM

Sci Advisor
Thanks
P: 3,859

So in the annihilation process, some of the rest mass is converted to kinetic energy but the total energy remains unchanged, and therefore the gravitational potential energy also remains unchanged. 



#8
Jan2114, 12:00 PM

P: 376

Well, sometimes potential plays a role in creation/anihillation. For example in Klein's paradox (if you adjust a constant potential to V>E+m you will have creation/anihhilation out of the energy being in the potential).
The graviational energy in particles is at ultra high good approximation negligible. 


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