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seen Jan 10 '12 at 15:28

Sep
1
revised Why would Antimatter behave differently via Gravity?
deleted 238 characters in body
Aug
23
comment What are the average matter, antimatter, and binding energy composition of protons and neutrons?
Having read a (very) little, I now assume that the 0 momentum limit will require ab initio calculations because at 0 momentum the situation is highly non linear and non peturbative approaches must be used.
Aug
23
comment What are the average matter, antimatter, and binding energy composition of protons and neutrons?
Thank you for this very patient and helpful answer, which teaches me much. Is there anyway to extrapolate this down to 0 momentum probes, e.g. nucleons in a glass of water? Does nuclear structure in the higher elements change the zero momentum limit situation much? For the zero momentum limit, are we forced back to ab initio calculations?
Aug
22
comment What are the average matter, antimatter, and binding energy composition of protons and neutrons?
Here is an example of the type of answer I was looking for, from quark.phy.bnl.gov/~pisarski/talks/Colloquia/Fodor.pdf (last slide) "95% of the mass of a proton comes from the kinetic energy within the proton: very different from any other mass" The standard model of particle physics (most particularly the theory of strong interaction, QCD) can explain this phenomena via a full ab-initio calculation of the masses. (controlling all systematic uncertainties)
Aug
21
comment What are the average matter, antimatter, and binding energy composition of protons and neutrons?
This is rather beyond me, but don't I want something like lim(scale -> infinity)
Aug
21
revised What are the average matter, antimatter, and binding energy composition of protons and neutrons?
added 374 characters in body
Aug
21
asked What are the average matter, antimatter, and binding energy composition of protons and neutrons?
Aug
21
asked Why are the antimatter compositions of neutrons and protons different? Why by about 1%? References?
Aug
19
revised Why would Antimatter behave differently via Gravity?
added 350 characters in body
Aug
19
awarded  Revival
Aug
18
answered Why would Antimatter behave differently via Gravity?
Aug
18
answered Paradox?: What is the form of radiation experienced by a harmonically accelerated observer?
Jul
15
awarded  Nice Answer
Apr
6
comment How does ATP transfer energy to a reaction?
I think you actually measure the enthalpy at constant pressure and temperature. It is then closely related to the entropy. This really requires a physical chemist. I believe
Apr
6
comment How does ATP transfer energy to a reaction?
I think you actually measure the enthalpy at constant pressure and temperature. It is then closely related to the entropy. This really requires a physical chemist. I believe
Apr
5
comment How does ATP transfer energy to a reaction?
Finally, I think you are confusing the free energy changes of the reaction with the free energy of activation. The hydrolysis of the ATP provides the first to make the reaction products more likely than the substrates, the enzyme or catalyst lowers the second to increase the rate. They are different.
Apr
5
comment How does ATP transfer energy to a reaction?
b) I just meant that there are many different mechanisms of catalysis, even when ATP is involved. You have to find out about each one individually, by searching under "reaction mechanism", or "active site". Different enzymes use fundamentally different mechanisms. c) You seem to be mostly asking about reactions in which the high free energy in ATP is transferred to another high free energy bond in another reaction product. Is that right?
Apr
5
comment How does ATP transfer energy to a reaction?
a) This is very rough, but it's the same idea as why gas molecules fill out a room, rather than stay, by chance, in one corner. There are many more ways of distributing the free energy when it's divided up into small packets, than when it's all concentrated in the one bond. So it is vastly more likely that the macrostate looks like the energy packets diffused all over. The logarithm of the number of ways (microstates) is the entropy.
Apr
5
revised How does ATP transfer energy to a reaction?
added 4 characters in body
Apr
5
answered How does ATP transfer energy to a reaction?