Timeline for How can the total amount of energy in the universe be zero?
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 19, 2018 at 1:06 | comment | added | probably_someone | Let us continue this discussion in chat. | |
| Jun 19, 2018 at 1:00 | comment | added | Max | @probably_someone yeah, I agree it was a bit vague. | |
| Jun 19, 2018 at 0:58 | comment | added | probably_someone | @Max So the first "it" in your comment referred to "the point mass," and then the "it" six words later referred to "potential energy," then? | |
| Jun 19, 2018 at 0:57 | comment | added | Max | @probably_someone that's not what I said. Re-read my comment. I said the gravitational potential energy cannot be converted into anything else, as it's not even really there, unlike the formula tells us. | |
| Jun 18, 2018 at 23:34 | comment | added | probably_someone | @Max There is no energy added to split the muon. The kinetic energy and mass-energy of the neutrinos and electron come from the initial energy of the muon. But you just said that a point mass "alone" in the universe cannot be converted into anything else, and that's still not correct. | |
| Jun 18, 2018 at 23:30 | comment | added | Max | @probably_someone isn't it that the kinetic energy comes either from energy added to split the muon or the mass of the muon in question being greater than that of two neutrinos and an electron? | |
| Jun 18, 2018 at 23:21 | comment | added | probably_someone | @Max That's not necessarily true. For example, a muon is a point mass that spontaneously converts into two neutrinos and an electron (all of which have kinetic energy even if the muon is initially at rest). | |
| Jun 18, 2018 at 23:09 | comment | added | Max | Again, that is a matter of definition (as far as I understand, at least). In my understanding, a point mass has no potential energy if it's alone in the universe, as it cannot be converted into anything else, e.g. kinetic energy or radiation. | |
| Jun 18, 2018 at 23:02 | comment | added | S. McGrew | Total energy of the gravitational field around a mass is the integral of the energy density of that field over all space. The smaller radius a massive object has, the more negative energy is stored in its gravitational field, because a smaller radius provides more volume over which the field energy outside that radius is integrated. Shrink the radius enough, and in principle the negative field energy can be greater in magnitude than the positive rest energy of the mass. | |
| Jun 18, 2018 at 22:49 | comment | added | Max | But isn't that energy density still proportional to the total rest mass reservoir in the universe? That would mean rest mass would always be greater than GPE. And what about my point mass example? Where would the rest mass energy go? | |
| Jun 18, 2018 at 22:46 | history | answered | S. McGrew | CC BY-SA 4.0 |