Possible Hole in Black Holes

jd writes "Researchers have found what they believe may be a MECO (Magnetic, Eternally Collapsing Object) inside of a quasar. MECOs are rivals to black hole theory and involve plasmas that never reach the state of being a singularity. The most obvious differences between them are that MECOs have a magnetic field and do not have an event horizon. The problem lies in that the Universe cannot have both MECOs and black holes — it can only have one or the other. If this object truly is a MECO, then black holes do not exist. Anywhere. (Furthermore, this would require Professor Hawking to return a year's subscription to Private Eye and give Professor Thorne a year's subscription to Penthouse.) On the other hand, if this thing isn't a MECO, it's behaving very very oddly for a black hole."

Penthouse

[gamer4Life]

I was reading it fine until I hit the word "Penthouse", then I forgot everything else and had to look it up:

http://science.slashdot.org/article.pl?sid=04/07/1 4/2330221 [slashdot.org]

http://en.wikipedia.org/wiki/Stephen_Hawking#Losin g_an_old_bet [wikipedia.org]

Re:Okay, dumb question then.

[Pacifist Brawler]

I think (if I remember this correctly, which I doubt) that the bending of light that we attribute to black holes could just be anything else of massive, well, mass in a rather small space. We know gravity warps light, and we see light being warped by something we can't see, that doesn't actually tell us the dimensions of it. I do know that all spherical masses (which would include most things in space) act as a point mass, so unless the light had to get really close it would be possible.

Re:Why...

[NecroPuppy]

Seriously, if this thing really is an MECO then what are all of the things that we've thought were black holes?

Probably MECOs.

Because it's 3 AM, and I don't have the energy to reproduce all the math, there's two main theories about super-massive objects (simplifying a lot).

One: Black holes. You've got an event horizon. Anything passes that point is gone forever. And they don't have magnetic fields. (remember, simplified massively)

Two: MECOs. No event horizon, instead the matter pulled in is spun for a while then ejected at near lightspeed. They do have magnetic fields.

Everything we know about black hole candidates falls into one of two sets of mutally exclusive equations (in large part to the magnetic field thing).

That this object appears to have a magnetic field supports one set of Einsteinian equations; the one that supports MECOs.

Re:Ha!

[Anonymous Coward]

Dear mac.convert

Contact was a book before it was a movie.

Regards,

A.C.

Re:Why...

[buswolley]

God.

the bet

[Seto89]

Accorfing to Stephen Hawking's Universe series Hawking was the one who bet that Black Holes don't exist (as some kind of insurance, so if they don't exist and all his work is useless, then he at least would get a subscription to a nice magazine) and he then gave the other guy (forgot his name) 1 year subscription to Penthouse, so if this is true and black holes don't exist, he would get the Penthouses back + a 4 year subscription to Private Eye. Why can't they co-exist though? Can't there be a reasionable scientific explanation that would allow both of these to live???

Occam's Razor

[astrogirl2900]

Preface: I have a Ph.D. in Astrophysics and my ressearch has to do with computer models of black holes.

This is yet another one of these things where an observational astronomer who just doesn't like black holes comes up with some incredibly complex theory to explain their oberservations so they don't need a black hole to explain them. There is an incredible resistance towards black holes in some parts of the astronomical community. Saying that "A black hole can't do this" when our models of accretion discs arount black holes are still at the state they are in i.e. fixed background metric, many models are only HD not MHD (no magnetic fields in the disc) is just not backed up by the facts.

This reminds me of the whole "we don't need black holes to explain jets" discussion a couple of years back.

Besides I do not se how the existence of Mecos would prevent the existence of black holes in general. We are still using the same Einstein Equations, right?

I think the operand word in the article is "controversial". Occam's Razor is a good rule of thumb.

Re:Occam's Razor

[astrogirl2900]

Jets from AGN (Active Galactic Nuclei) are thought to be generated by a rotating black hole winding the magnetic field from the accretion disc up in a tight beam. The beam contains accelerating particles at incredibly high speeds.

Re:Why...

[lanswitch]

Not snowballs, but meatballs (http://www.venganza.org/)

Paper explaining MECO's

[Anonymous Coward]

Here is a direct link to a (free) pdf paper describing the idea of a MECO in all the gory details:
http://www.citebase.org/fulltext?format=applicatio n%2Fpdf&identifier=oai%3AarXiv.org%3Aastro-ph%2F06 02453 [citebase.org]

As a physicist (though not a cosmologist) it looks not at all convincing.

Re:Question...

[agurkan]

Is it possible that, as I think I once read here on Slashdot, some cosmological constants may really be variables that shift very slowly as the universe ages, and that MECOs were thus possible then, but no longer are
I am an astrophysicist but not a general relativity (GR) or cosmology person; take the following with a grain of salt. As far as I understand all solutions of GR equations involving singularities require some assumptions, since they need to take quantum effects into account and we do not have a theory of quantum gravity. So, we should be living in a very interesting universe if a few parameters about quantum gravity had such values and changed in such a way that MECOs were possible in the past and black holes are possible now. It is certainly possible, but if this happened I would suspect that there is a deeper reason for this.

Re:Unless...

[xouumalperxe]

FTFA: Black holes is collapsed matter, MECOs stand on the idea that matter CAN'T fully collapse like that and stays in a permanent state of collapsing (but is never actually done collapsing).

Re:Okay, dumb question then.

[xouumalperxe]

No, spherical masses do NOT act as point masses. They can be modelled by them without too much loss of detail if the difference between the radius of the sphere and the distance to the other body is big enough, but ultimately the two are mathematically different (if infinitesimally so). When the very thing you're trying to determine is that difference, you're suggesting we toss out the baby with the bath water.

Re:Why...

[Fallen Seraph]

The event horizon is something that any object with mass has, as well. Of course, not on the same scale as a black hole, yet, come to close to the sun and you are doomed. A comet slammed in to Jupiter and disappeared. It will never be seen again. Our moon is stuck to the earth. Without adding energy to the system, the moon will always be a part of the system. The event orizon of a black hole is important because light cannot ever leave the system once inside this critical boundary. That does not mean that other systems possess no event horizon. Errr, that's not true. By definition, the event horizon is the theoretical threshold of a black hole's gravity well from which point nothing can ever escape under any circumstances under its own power (we're ignoring the ocassional black hole emmission jets which form for now). The Sun has no event horizon, and neither can anything else because light can always escape it. Saying "if you get to close to the sun, you're doomed" means nothing because we're arbitrarily picking the amount of energy human technology can generate to escape the forces of gravity. In the span of a few decades, which, by the standards of the Universe, is almost an instant, that may no longer be true. The reason it's special is because one of only true constants we know of is the speed of light. It never changes; except when undergoing refraction through materials. And in addition, any object with mass can never match its speed, therefore, when light can no longer escape a black hole's gravity well, nothing else can either.

Re:Paper explaining MECO's

[astrogirl2900]

Just skimmed it. This theory definitely does not exclude the existence of black holes. This is just another solution to the Einstein equations, involving matter.

If the contraints they impose on the stress-energy tensor (i.e. the the assumptions they make about the behavior of matter) are always enforced in the universe, I think they'd have a problem with creating neutron stars.

Re:Okay, dumb question then.

[Mark Maughan]

No, you are wrong. In both Newtonian and Einstein Gravity, you can use the point mass solution for a spherically symmetric mass as long as you don't extend your coordinates to beneath the surface. Outside the surface they are identical.

Re:Particles popping in and out of existence???

[Theaetetus]

A. the law of thermodynamics is broken? since new particles enter the universe, the amount of energy in the system is not constant.

Not broken... Thanks to work by Feynman, Heisenburg, and Hawking (among others), we know that empty space isn't really empty. The *vastly* simplified version is that the lowest energy state of empty space isn't at 0... it's slightly above. And if there's energy there, then there are particles, since they're really one and the same... So, if you were to look really closely at empty space, you'd find a sea of particle-antiparticle pairs popping spontaneously into existance (both have to form, to keep conservation laws intact), then colliding back into each other and causing mutual annihilation. Net gain is 0, and if you were to take an average over time or a decent sized area, you'd get 0 also, so there's no problem with thermodynamics.

Now, the really funky part is Hawking Radiation... You take a black hole with its event horizon, and at the edge, you have a particle-antiparticle pair form... They fly apart, and one of them crosses the line, getting sucked into the black hole, while the other escapes - and now you've actually gained a particle "radiating" away from the black hole. Because of a whole bunch of complicated stuff, this means that the black hole itself eventually evaporates (bigger it is, the longer it takes, though).

Oh, and this has been confirmed, since it's the driving force behind the Casimir Effect... Put two parallel plates close together, and the spontaneous particles between them can only form in wavelengths equal to multiples of the distance they're apart. But, outside the plates, any wavelength can form. So, you end up with more pressure outside the plates than between them, and they get pushed together. What makes it really stand out is, unlike gravity and magnetism with their inverse-square laws, the Casimir Effect has an inverse-fourth relationship. Halve the distance between the plates, and the force is 16 times stronger.

Re:Why...

[agibbs]

"consensus" is a fourth declension noun (in Latin) so it's plural, properly, is "consensus." No change. Who knows what it is in English though.

Re:Why...

[i kan reed]

IANAP(physicist) but my understanding of black holes is that the angular momentum is what causes ejections. A non-spinning black hole would have a perfect event horizon and nothing could ever leave even as elementry energy carrying particles. The "poles" are just like earth's rotational poles, they form the endpoints(when extended to the even horizon) of the axis of rotation. Why this affects gravitation (or the escaping particles) I don't know, but it probably has something to do with that satelite they sent up that measured the effect of the earth's rotation on it's gravity

Re:let's side with caution for now

[iabervon]

A MECO is an odd variant of a black hole. The matter under debate is not whether these things exist, since we have plenty of evidence for them, but what happens to physics in these extreme conditions. The standard black hole theory, in addition to being the first to propose that there can be so much mass in a region that light can't escape, proposes details on what is going on inside this region. MECO theory proposes different details. Of course, they agree for most observed effects (the event horizon, bending light, Hawking radiation, and so forth); the main difference seems to be whether they can have a magnetic field: a standard black hole would have all of the mass at a single point, and therefore doesn't have room for charged particles to spin, so there's no magnetic field; a MECO would have the mass spread over an extremely small area, which is sufficient to have spinning charges and therefore generate a magnetic field. Of course, it's a bit tricky to determine if an object like a black hole has a magnetic field, because that field, if it exists, is practically in the noise compared to the gravitational field.

Re:speed of light

[Mark Maughan]

First of all, no.

http://en.wikipedia.org/wiki/Kerr_metric [wikipedia.org]

I have thought for a long time that singularities were impossible due to conservation of angular momentum. Velocity is all relative, so if you have a spinning basketball and squish it down to half it's original circumference, the relative velocity of two opposing points on it's equator will double. Divide the circumference again and the relative velocity will double again. There is a lot of dividing that can be done between any rational number and zero (the theoretical diameter of a singularity), and if you have any spin in the original matter that relative velocity is going to hit the speed of light long before you hit zero.

Your mistake is that you are using a Newtonian definition of angular momentum, L = m r × v.
L = r × p, where p is the relativistic momentum. This p is not m v, but gamma m v and can become arbitrarily large.

Re:Why...

[dmartin]

The definition of a black hole does NOT require a singularity. What the strict defintion requires (as in Hawking and Ellis, or Wald's "General relativity) is that the black hole region in an asymptotically simple spacetime is the region that is causally disconnected from future null infinity.

In English: once you go into one, you can never get back out if you believe that nothing can travel faster than light. If you CAN get out, the thing you started with was not a black hole!

Notice that for the concept of black hole to make sense, you do not need general relativity. You do need to believe that there is an ultimate speed limit, and then the black hole of any theory is the region you cannot escape from.

It is then a THEOREM of (classical) general relativity that such a region contains a singularity. If GR is corrected by some version of quantum gravity where there are no singularities, then this theory can still have black holes (regions of no escape).

Now this is a stricter sense in which black holes are talked about currently. The article mentions Hawking and Thorne's disagreement: is information carried off by Hawking radiaiton? The answer is no: if the information goes in then it cannot come out by (the strict) definition of what a black hole is. Technically, the argument about the information loss problem is whether or not black holes (as originally defined) exist at all!

However, this is an arguement purely at the level of sematics. There is very little observational difference between a real black hole [one that locks information up forever] and an information returning black hole [one that locks up and processes particles for a long period of time, but the end result of this process is re-emission as Hawking radiaiton]. Because the definition given above is one made for convience, most researchers in the field take a somewhat more pragmatic definition of a black hole.

The theory of MECOs seems to still be built on General Relativity. It claims that radiation increases to stop complete collapse. This does not preclude the existence of black holes! It just means that they are unlikely to form as the end result of astrophysical processes. However, there are situations where you can make black holes at very low temperatures, or ones that you can do in flat space (although these tend to be somewhat artificial).

    The moral is
        * MECOs are built on GR. If MECOs exist, then black holes are still solutions to GR
        * The MECO advocates claim that this is a universal process for very hot and dense gas. We should not expect that black holes are a typical end of stellar product.
        * MECOs may exist, but the process may not be universal (i.e. it may require particular thresholds of energy/pressure). This would allow a mix of black holes and MECOs.
        * There may be no MECOs at all.

    Personally I am dubious that MECOs exist at all. Pressure *can* support a star against collapse, but only to a certain extent in GR. After a while, the pressure required also acts as a stronger source of gravity and ends in a runaway reaction causing collapse. See this paper of mine for more details: http://arxiv.org/abs/gr-qc/0306038 [arxiv.org]

try RTF paper

[Anonymous Coward]

http://arxiv.org/abs/astro-ph/0505518 [arxiv.org]

instead of analyzing a press release...