5 votes

Can we say that Black hole is a Black body?

The Hawking radiation theoretically emitted by a black hole has a black body spectrum. So in a sense we could say that a black hole is a black body, although at a really really low temperature (a tiny ...
user avatar
  • 33.9k
5 votes

Could bound and stable clusters of 6 or 8 neutrons be a good candidate for dark matter?

Such neutron clusters are baryonic matter. However, we know from measurements of the primordial abundances of helium and deuterium and within the context of big-bang nucleosynthesis models, that most ...
user avatar
  • 111k
3 votes

Could bound and stable clusters of 6 or 8 neutrons be a good candidate for dark matter?

Let’s grant you the existence of one or more stable isotopes of “neutronium,” with atomic mass six or eight, $\rm^6_0n$ or $\rm^8_0n$. Now we need to re-do our calculations for big-bang ...
user avatar
  • 71.3k
3 votes

How does an Object at event horizon stop to the observer?

Instead of dealing with light being reflected off the falling body, I'd like to give the falling body a flashlight, so we won't deal with ingoing and outgoing light rays, only outgoing. I'll give you ...
user avatar
  • 389
3 votes

How does an Object at event horizon stop to the observer?

At a correct moment enough light to last for an eternity was send after the object. A one second pulse for example, and infinite brightness of course. The front part of the pulse arrives back after 10 ...
user avatar
  • 1,566
2 votes

Surpassing 70%c of spinning black holes - projection

The quote in the OP is not exactly right. I guess this is the typical case where a scientific report is misinterpreted and reposted in a news article. The source of the article you quote is this ...
user avatar
  • 2,627
1 vote
Accepted

How does an Object at event horizon stop to the observer?

The fundamental reason for this - i.e. independent of coordinates and observation methods - is the "one-way" nature of the horizon, in that information cannot flow from the interior region ...
user avatar
1 vote

Gravitational path integral derivation of black hole temperature and entropy

You raise an excellent question in regards to how such thermodynamic quantities should be interpreted. That is, it is reasonable to ask why we attribute them directly to the black hole when we're ...
user avatar
  • 649
1 vote

What is the frequency of the light seen by an observer free-falling into a black hole?

Alfred asked: "What is the frequency of the light seen by an observer free-falling into a black hole?" The equations are already given in the answer above, but since an image says more than ...
user avatar
  • 7,757

Only top scored, non community-wiki answers of a minimum length are eligible