Question about Hawking Radiation and Iron Stars

[Khursed]

TL;DR Summary

Everything evaporates.

So, I was thinking, the most massive black holes are expected to evaporates in roughly a googol year. Fine.

But I was reading that if protons are stable, every planet and non black hole star remains are basically expected to turn into iron star from quantum tunneling after mind numbing time on the order 10^1500 years.

So my question is this, shouldn't they simply evaporate from Hawking's radiation first?

 

[martinbn]

TL;DR Summary: Everything evaporates.

So, I was thinking, the most massive black holes are expected to evaporates in roughly a googol year. Fine.

But I was reading that if protons are stable, every planet and non black hole star remains are basically expected to turn into iron star from quantum tunneling after mind numbing time on the order 10^1500 years.

So my question is this, shouldn't they simply evaporate from Hawking's radiation first?

Why do you think they will emit Hawking radiation?

 

[EmileJ]

Hawking radiation is due to an event horizon. Iron stars do not have am event horizon by themselves.

 

[Nugatory]

Hawking radiation is due to an event horizon. Iron stars do not have am event horizon by themselves.

That's right, so they don't emit Hawking radiation and therefore do not evaporate by emitting Hawking radiation. The same is true of everything else that is not a black hole: no Hawking radiation, therefore no evaporation no matter how long we wait.

 

[Khursed]

Well, from what I understand, the principle behind Hawking's radiation is that everything radiates at the very absolute least as a black body of X temperature. Since nothing can ever reach absolute zero, it follows that you must emit something that invariably means you lose mass, as energy must come from somewhere.

Which is what made me conclude that if black holes eventually evaporates from Hawking's radiation after some googol years, I can't imagine how ordinary matter would fare any better.

Hawking radiation is due to an event horizon. Iron stars do not have am event horizon by themselves.

I get that. What I'm asking, is the way I understand it, Hawking figured out that black holes had to have at the very basic and most minimum level a temperature that was not zero, which means they are radiating thermally . Thus that radiation was called Hawking's radiation.

My own thought is this, if even black hole who are the most limited emitter of radiation evaporate within some googol years, then why wouldn't ordinary matter?

Unless my premise is wrong, and ordinary matter can settle to absolute zero frozen in time and emitting absolutely nothing? Otherwise, it must evaporate as well?

 

[PeterDonis]

from what I understand, the principle behind Hawking's radiation is that everything radiates at the very absolute least as a black body of X temperature

Where are you getting that from? Hawking radiation is specific to black holes.

It is true that the "iron stars" you describe in your OP will radiate energy as long as they have a temperature above absolute zero, and that means they will lose a little bit of mass as they radiate; but the amount of energy they will radiate, compared to their mass, is tiny. They will never even come anywhere close to evaporating away completely just because they radiate energy.

 

[PeterDonis]

ordinary matter can settle to absolute zero frozen in time and emitting absolutely nothing?

No. But ordinary matter can asymptotically approach absolute zero while emitting a total amount of energy that, compared to its mass, is tiny.

Otherwise, it must evaporate as well?

Not at all. See above. The particular case of black holes evaporating away completely due to Hawking radiation is not just a general instance of "things radiate as long as they are above absolute zero".

 

[glappkaeft]

Where are you getting that from? Hawking radiation is specific to black holes.

Which is very fortunate since a new born baby would evaporate in a few femtoseconds while emitting a humongous amount of energy if it emitted Hawking radiation.