What's the difference between a black hole and an electron?

[Mr Skeptic]

OK, here is a silly thought experiment I dreamt up. Suppose you were to create a black hole with a charge and mass equal to that of an electron. Would you then be able to distinguish the black hole from an electron? If so, how?

[Sayonara]

It would be in the box labelled "black hole creation chamber".

[vacuodynamic]

OK, here is a silly thought experiment I dreamt up. Suppose you were to create a black hole with a charge and mass equal to that of an electron. Would you then be able to distinguish the black hole from an electron? If so, how?

 

It is interesting; I think we could not distinguish the difference. Instead may be electron is a tiny black hole which was created from “something” that act as the primary substance; the substance which form to be ordinary “matters”!

 

Nimit

[insane_alien]

the blackhole would evapourate nearly instantaneously therfore providing a difference.

[Mr Skeptic]

the blackhole would evapourate nearly instantaneously therfore providing a difference.

 

I don't think so. What would happen to it's electric charge?

[ydoaPs]

Evaporate doesn't mean disappear. The mass, charge, spin, etc should be conserved.

[Kyrisch]

I don't think so. What would happen to it's electric charge?

 

In other words, they get transferred to the particles into which the black hole evapourates. AFAIK it's called Hawking Radiation and even though it's never been demonstrated it's widely accepted as fact. (I read in The Elegant Universe that he really regrets that fact that it's never been observed because he would most definitely get a Nobel Prize for his work on that as soon as it's proven to actually happen)

[Mr Skeptic]

Evaporate doesn't mean disappear. The mass, charge, spin, etc should be conserved.

 

Exactly what I was thinking. To get rid of a -e charge, it would either have to absorb a +e charge, or emit a -e charge. Since the smallest -e charge is an electron, and it's mass-energy is that or an electron, to emit its charge it would have to convert itself completely into an electron. The other things it would have to conserve would make it even harder.

[ajb]

the blackhole would evapourate nearly instantaneously therfore providing a difference.

 

Insane is right on this one. Blackholes do not appear (for sure semi-classically) stable. In collider experiments they would appear as very short lived particles. This is very different to electrons.

[vacuodynamic]

Evaporate doesn't mean disappear. The mass, charge, spin, etc should be conserved.

 

Would you please explain in detail how "evaporate" work? What "physics" behind the evaporation?

[Cap'n Refsmmat]

Take a look at the Wikipedia article on the subject of Hawking radiation, which is believed to be the way black holes could "evaporate".

[alan2here]

It seems to suggest that you can't get rid of a black hole after a certain size because it will keep expanding due to absorbing background radiation faster than it evaporates.

 

If new matter is pulled into the black hole from most of the way around except the poles of which matter is ejected at high speed then it seems logical that there is a vortex of some re-absorbed matter coming out of the edge of the output in the poles and into the edge of the input in the side?

 

I find it hard to visualize how this would lead to a black hole that doesn't pull itself apart in the middle.

Edited July 16, 2008 by alan2here

[Cap'n Refsmmat]

Black holes do not "eject" matter. Nothing can escape. The streams of particles you see exiting a black hole actually come from the accretion disk (which is outside the black hole's event horizon).

[Mr Skeptic]

I'm quite familiar with Hawking radiation. I've previously suggested using Hawking radiation to possibly turn protons into positrons and energy, which would potentially be the most useful power generator ever. But I don't know if it will work like that, as most stuff about Hawking radiation is about photons. Anyhow...

 

Lets talk some numbers now.

 

The mass of an electron is 9.11 × 10^-31 kilograms. Naively assuming a Schwarzchild black hole because that is what I am familiar with, it would have a radius of [math]r_{s} = \frac{2Gm_e}{c^{2}} = 1.35 *10^{-57} meters[/math], and a Hawking temperature of [math]T={\hbar\,c^3\over8\pi G M k} = 1.35 * 10^{53} Kelvin[/math], emitting [math]P={\hbar\,c^6\over15360\,\pi\,G^2M^2} = 4.29 * 10^{92} watts[/math], and evaporating in [math]t_{ev}={5120\,\pi\,G^2M_0^{\,3}\over\hbar\,c^4} = 6.35579642 * 10^{-107} seconds[/math].

 

It would be many orders of magnitude smaller than anything we can see yet, and so hot it's not funny, and evaporate orders of magnitude faster than we can see. It probably can't even get that hot because it wouldn't have enough mass to emit such high-energy photons. If that black hole "ate" anything, it would evaporate it out again faster than 10^^-100 seconds -- effectively, its so small that it would be amazing if it hit anything, and if it did, it would be able to re-emit it way faster than could be noticed.

 

Of course, those are the wrong equations, because the black hole has both charge and spin, but if those numbers are remotely close, it is certainly interesting.

 

Now, to be able to evaporate completely, the black hole will need to get rid of its charge. This would mean emitting an electron, as that is the lightest particle that carries a -e charge. However, it would have no extra energy or momentum, so that if it emitted an electron, the electron would not be moving, so that I doubt if anyone would notice the difference.

 

Alternately, the black hole might not be able to evaporate completely because of its charge. If it were to emit one or more photons, then it would be unable to get rid of its charge by emitting an electron. So I don't think it would be able to evaporate completely, as it would have to get rid of its charge. So at some limit, it would be a black hole that would be unable to evaporate because it cannot get rid of its charge. If the most it could evaporate was to the mass of an electron, then you would end up with something that seems to be exactly like an electron.

 

A more interesting scenario would be if the black hole manages to emit photons, thereby lowering its mass, but cannot get rid of its charge, preventing it from completely evaporating. Then you would end up with a stable "particle" of lower mass than that of an electron, which would allow for interesting and new chemical and electrical properties.

 

---

Oh, and if anyone knows the equations for a Kerr-Newman black hole, then please correct my numbers.

Edited July 16, 2008 by Mr Skeptic
multiple post merged

[vacuodynamic]

Take a look at the Wikipedia article on the subject of Hawking radiation, which is believed to be the way black holes could "evaporate".

 

Thanks for suggestion. Anyways, what my really intention for asking the problem is to open further discussion about Hawking radiation. As you know (may be from Wigkipedia) that up to now there is still some theoretical dispute over whether Hawking radiation actually exists. Further more the existence of Hawking radiation has never been observed.

 

By the way, if the primordial black holes did not evaporate but existed as electrons, this idea should be a good alternative, isn’t it?

[alan2here]

If matter exits from the ends of the disk of stuff around the black hole and nothing gets back past the event horizon then how does the black hole evaporate?

 

Also it wouldn't seem hot until you touched it and even then you would never get to know how hot it is due to the event horizon rule.

[Cap'n Refsmmat]

Remember Hawking radiation. Hawking radiation works by way of "virtual" particles -- particles and antiparticles that pop into existence for a tiny fraction of a second and then annihilate, leaving no overall change to the system. (It takes energy to make them and they give off the same energy when they annihilate.) It's possible that half of a particle/antiparticle pair could get sucked in to the black hole, leaving a particle behind with nothing to annihilate it. The energy it took to make that particle is extracted from the black hole's gravitational energy.

 

At least that's how I understand it.

[alan2here]

So it looses gravity but not mass?

[Cap'n Refsmmat]

If you steal energy from it, you also steal mass.

[DonJStevens]

Alexander Burinskii has concluded that the electron is a gravitationally confined entity (much like a black hole) but its angular momentum is so high that it is a naked singularity without an event horizon. See "Black hole electron" and Talk in wikipedia.

[Mr Skeptic]

Alexander Burinskii has concluded that the electron is a gravitationally confined entity (much like a black hole) but its angular momentum is so high that it is a naked singularity without an event horizon. See "Black hole electron" and Talk in wikipedia.

 

Not only was my clever new idea not new at all, but it even has a Wikipedia article? Thanks though, the article answered most of my questions about electron-sized black holes.

[DonJStevens]

Hi Mr Skeptic,

 

Your clever idea is not new but it is an idea whose time has come. Brian Greene, John Wheeler, Alexander Burinskii along with many other accomplished theorsts have found a connection between black holes and elementary particles.

 

We can now specify the relationship of the electron mass to the Planck mass and the relationship of the electron Compton wavelength to the Planck length. This is quite significant. These developments are needed so that we can merge general relativity and quantum mechanics.

[vacuodynamic]

Dear friends,

 

Let us talk about some general property of electron beside its technical detail, and then it may guide us for solving some of its unsolved problems.

 

For example, why electron does not suck other near by electron, but instead it repels each other!

 

Before answering the question, we have to understand how black hole suck the near by object. Someone may say that this is easy, it work via a strong gravitational field! And field concept seems to offer a good solution, but the followed problem is how it works? Actually, field concept is just an ad hog solution for replacing the “transmitting medium” needs to convey gravitational force!

 

First, let us assumed that there is “something” (mass or energy) in vacuum space (which indeed we can prove its existence), so we have a medium for handling gravitation force. Now the medium of “something” will act as the “mechanism” for gravity an also for antigravity (repelling)!

 

Actually, two near by electrons should always suck each other via the medium of “something” in between. At the same time, they also suck the surrounding medium, which appeared as electrostatic field around. But the compressing force occur in the medium (between both electrons) is less than the tensile force of the medium, so the resultant force is a repelling one!

 

Indeed, someone who familiar with Richard P. Feynman’s “Lecture on physics vol. 2), would found that he was wondered about the “strange” interaction between two near by protons. We know that two near by protons will repel each other (same thing as electron do). But if we increase the separation distance between them, we will found that “at a certain distance” their interaction will change from “repellence” to “attraction”! Why it is being so?

 

Similar to the concept of “electron is a tiny black hole” if we treated proton as tiny black hole too, but as a bigger one! Then, now we could solve the proton’s problem mentioned in the same way as we explained for electron!

Edited July 18, 2008 by vacuodynamic

[DonJStevens]

Hi vacuodynamic,

 

A quote from the book, Gravitation by Misner, Thorne and Wheeler (page 1215) relates to your post, "What else can a (subatomic) particle be but a fossil from the most violent event of all, gravitational collapse?".

 

If a proton particle is in fact, formed by gravitational collapse, then we would expect that it is gravitationally confined just as the electron appears to be. The proton is a more complex particle than the electron, so it may some significant time before relationships (equations) can be developed that could give substance to the concept, that the proton is black hole related.

 

We may be quite close however to defining the relationships to show that the muon is black hole related.

[vacuodynamic]

Hi vacuodynamic,

 

A quote from the book, Gravitation by Misner, Thorne and Wheeler (page 1215) relates to your post, "What else can a (subatomic) particle be but a fossil from the most violent event of all, gravitational collapse?".

 

If a proton particle is in fact, formed by gravitational collapse, then we would expect that it is gravitationally confined just as the electron appears to be. The proton is a more complex particle than the electron, so it may some significant time before relationships (equations) can be developed that could give substance to the concept, that the proton is black hole related.

 

We may be quite close however to defining the relationships to show that the muon is black hole related.

 

Dear DonJstevens,

 

Thanks for your information, it is new for me. By the way, we could learn some good idea from great scientists especially in the old time. For example, one unpopular idea of “Einstein’s electron theory” in W. Pauli’s book “Theory of relativity”. His idea is to assume that the “material particles are held together solely by gravitational force”! And he had derived the formula starting from the assumption of a material energy-momentum tensor.

 

Of course, Einstein’s electron theory was ignored by almost all of scientists. The reason is that “Coulomb force” of matter is much greater than its gravitational force! Anyway, the problem could be eliminated if matter is just the condensed of “something” which act as the primordial substance that forming to be all of matter.

 

Also the “something” mentioned is the same one that acting as the mechanism of gravity talked early. In this way we could view matter is just the condensed of “something” which is immerged in the same “something” that formed to be the fabric structure of vacuum space!