Okay. I need a physicist. How does that relate to the heat death of the universe. Is all iron-56 the most probable distribution of energy in the universe (max entropy)?
Not a physicist yet, temporarily a high school physics and maths teacher until I can start my PhD
Fe-56 is the heaviest nucleus that releases energy when other nuclei fuse into it. Everything heavier requires energy, that has to come from somewhere else, to fuse. All things tend to keep doing stuff that release energy, and they don’t like to do stuff that requires energy. So, in a long enough amount of time, nuclei keep fusing together while it releases energy, and stop when it starts to require energy.
At least that’s what happens inside regular old stars. The vast majority of them will have an iron core after a certain amount of time.
It pretty much only takes nuclear physics into account though, whereas the actual universe is a lot more complicated and will thus probably not turn itself into all iron.
Not a physicist, but I thought the heat death of the universe also involved all the matter being sucked into black holes and turned into pure energy. There’s a big chunk converted up front in the accretion disk, then the rest is converted into hawking radiation as the black hole(s) evaporate over the oodles and oodles of years.
Whether or not there are also lumps of iron-56 or other matter floating around in the cold void probably depends on the real truth behind dark matter and dark energy and their long-term behavior.
The heat death has everything spread out so your visible universe holds only you more or less. The most extreme models say matter to be torn to atoms, the less extreme expect solar systems to survive, maybe even galaxies.
Both agree the black holes will evaporate to nothing but Hawking radiation
Yeah the whole “big rip” or whatever the colloquial term is, is an interesting one to think about if the expansion just keeps on accelerating.
But from what science news I follow, I think our models and theories in that area are in for a shake-up. It will be interesting to see!
I think that is kind of orthogonal to the concept of heat death, though, which is more about entropy. Any universe that has a solar system or galaxy in it is far from reaching the state of heat death.
Astronomer here, not necessarily. Generally, heat death just means entropy goes maximal, as in everything is as spread out as it can be and the heat everywhere in the universe is the same.
Not sure if on those time scales all gets sucked up by BH
Okay. I need a physicist. How does that relate to the heat death of the universe. Is all iron-56 the most probable distribution of energy in the universe (max entropy)?
Not a physicist yet, temporarily a high school physics and maths teacher until I can start my PhD
Fe-56 is the heaviest nucleus that releases energy when other nuclei fuse into it. Everything heavier requires energy, that has to come from somewhere else, to fuse. All things tend to keep doing stuff that release energy, and they don’t like to do stuff that requires energy. So, in a long enough amount of time, nuclei keep fusing together while it releases energy, and stop when it starts to require energy.
At least that’s what happens inside regular old stars. The vast majority of them will have an iron core after a certain amount of time.
It pretty much only takes nuclear physics into account though, whereas the actual universe is a lot more complicated and will thus probably not turn itself into all iron.
Not a physicist, but I thought the heat death of the universe also involved all the matter being sucked into black holes and turned into pure energy. There’s a big chunk converted up front in the accretion disk, then the rest is converted into hawking radiation as the black hole(s) evaporate over the oodles and oodles of years.
Whether or not there are also lumps of iron-56 or other matter floating around in the cold void probably depends on the real truth behind dark matter and dark energy and their long-term behavior.
The heat death has everything spread out so your visible universe holds only you more or less. The most extreme models say matter to be torn to atoms, the less extreme expect solar systems to survive, maybe even galaxies.
Both agree the black holes will evaporate to nothing but Hawking radiation
Yeah the whole “big rip” or whatever the colloquial term is, is an interesting one to think about if the expansion just keeps on accelerating.
But from what science news I follow, I think our models and theories in that area are in for a shake-up. It will be interesting to see!
I think that is kind of orthogonal to the concept of heat death, though, which is more about entropy. Any universe that has a solar system or galaxy in it is far from reaching the state of heat death.
Astronomer here, not necessarily. Generally, heat death just means entropy goes maximal, as in everything is as spread out as it can be and the heat everywhere in the universe is the same.
Not sure if on those time scales all gets sucked up by BH
Least Energy. I.e. yes. Does be pretty good.
This is an important question with real-life implications.