franka@mmintl.UUCP (Frank Adams) (08/05/85)
Yes, you can make a black hole out of anti-matter. But the result is just a black hole, not an anti-matter black hole. There is no way to distinguish it from a black hole made from ordinary matter. In particular, if one collided with another black hole, the result would be just a bigger black hole. Not an explosion destroying the two black holes.
wmartin@brl-tgr.ARPA (Will Martin ) (08/08/85)
I was thinking about the "anti-matter vs. matter" qualities of what is inside a black hole, and, at first, was going to agree with the contention that, no matter the nature of the matter that formed the black hole, once falls inside, it loses those qualities and becomes like unto the primordial ylem (do physicists still use that term?) or at least undefinable. Then I thought of the contentions that I have read that the entire observable universe could be inside a black hole. Since the radius goes up with the mass, the average density of a hole with the universe's mass is rather close to the real average density of the universe... So this would have to depend then on the mass of the black hole, would it not? After all, a black hole containing our universe could be orbiting a black hole containing an anti-matter universe... If the black hole is small enough, then the mass/density ratio would not let subatomic "particles" exist anymore -- I don't know if that means it would be a squish of quarks or if even quarks would have ceased to be distinct -- and then the "matter"-ness or "antimatter"-ness of the contents would no longer be definable, since that is a characteristic of a higher level of particle than could exist in there. There must be some magic size point, though, when the mass is large enough that the average internal density allows "normal" particle formation inside. I have no idea what would determine what particles would form in this environment. Gee, this stuff is fun! Now, if I only knew what I was talking about... Regards, Will
frankr@enmasse.UUCP (Franklin Reynolds) (08/09/85)
In article <530@brl-tgr.ARPA> wmartin@brl-bmd.UUCP writes: >I was thinking about the "anti-matter vs. matter" qualities of what is >inside a black hole, and, at first, was going to agree with the >contention that, no matter the nature of the matter that formed the >black hole, once falls inside, it loses those qualities and becomes like >unto the primordial ylem (do physicists still use that term?) or at least >undefinable. > >Then I thought of the contentions that I have read that the entire >observable universe could be inside a black hole. Since the radius goes >up with the mass, the average density of a hole with the universe's mass >is rather close to the real average density of the universe... So this >would have to depend then on the mass of the black hole, would it not? >After all, a black hole containing our universe could be orbiting a >black hole containing an anti-matter universe... > The way I think it is supposed to work is that there is no difference between a "normal" black hole and an anti-matter black hole from the outside. What is going on inside (within the event horizon) is undetectable to an outside observer. You can think of black holes as write-only ROMs, you can add stuff to them, but you can't get anything back. If a "normal" black hole collided with an anti-matter black hole an outside observer would see a larger black hole as the result. There is no telling what would happen on the inside of the new black hole. Franklin Reynolds Enmasse Computer Corp. genrad!enmasse!frankr
ethan@utastro.UUCP (Ethan Vishniac) (08/09/85)
[]
A few comments about Black Holes.
First, when people make comments about all BH's being alike no matter what
they are made of, they are referring to their effects on the rest of the
universe. Since physics as we know it breaks down near the center of
a BH people normally refrain from making comments about life inside a
BH. Not only is the gravitational field of an BH made from anti-matter
identical to one made from matter, but when BH's evaporate due to quantum
mechanical processes, they emit equal amounts of matter and anti-matter
*no matter what they were originally made of*.
Second, when people talk about fitting the universe inside a BH they are
not talking about conventional physics. The theory of GR says that in the
center of a BH a singularity forms in one spot and continues for all future
times (although what happens as the BH evaporates is not clear). Models
of the universe (the successful ones) have a singularity at one time over
all of space.
Third, for quantum mechanical reasons no BH can be smaller than 10^-5 grams
in weight. In fact, a BH weighing a metric ton would evaporate in
about 10^-10 seconds (the lifetime is proportional to the mass cubed).
Therefore it is probably nonsensical to talk about BH's the mass of a
subatomic particle.
--
"Support the revolution Ethan Vishniac
in Latin America... {charm,ut-sally,ut-ngp,noao}!utastro!ethan
Buy Cocaine" ethan@utastro.UTEXAS.ARPA
Department of Astronomy
University of Texaspeter@baylor.UUCP (Peter da Silva) (08/12/85)
> Then I thought of the contentions that I have read that the entire > observable universe could be inside a black hole. Since the radius goes > up with the mass, the average density of a hole with the universe's mass > is rather close to the real average density of the universe... So this > would have to depend then on the mass of the black hole, would it not? > After all, a black hole containing our universe could be orbiting a > black hole containing an anti-matter universe... Doesn't matter what's in a black hole, because it's not observable. That means antimatter black holes would behave just like matter ones. Thus I-masses are still nonesense. > If the black hole is small enough, then the mass/density ratio would not > let subatomic "particles" exist anymore -- I don't know if that means it At that point quantum mechnics takes over and everything tunnels out in a split second. > would be a squish of quarks or if even quarks would have ceased to be > distinct -- and then the "matter"-ness or "antimatter"-ness of the > contents would no longer be definable, since that is a characteristic of > a higher level of particle than could exist in there. There must be some > magic size point, though, when the mass is large enough that the average > internal density allows "normal" particle formation inside. I have no > idea what would determine what particles would form in this environment. Any REAL physicists want to comment on that? -- Peter da Silva (the mad Australian) UUCP: ...!shell!neuro1!{hyd-ptd,baylor,datafac}!peter MCI: PDASILVA; CIS: 70216,1076
hutch@shark.UUCP (Stephen Hutchison) (08/13/85)
< Line eaters are articulate black holes> In article <560@mmintl.UUCP> franka@mmintl.UUCP (Frank Adams) writes: > >Yes, you can make a black hole out of anti-matter. But the result >is just a black hole, not an anti-matter black hole. There is no >way to distinguish it from a black hole made from ordinary matter. > >In particular, if one collided with another black hole, the result >would be just a bigger black hole. Not an explosion destroying the >two black holes. Black holes have almost no properties which allow us to tell anything about them, except that they have spin, charge, and the apparent diameter provided by the event horizon, which is apparently a function of mass. I wonder what would happen if two holes with opposite spin, identical mass and neutral charge collided. Especially if the event horizon were small enough... Hutch
friesen@psivax.UUCP (Stanley Friesen) (08/13/85)
In article <447@enmasse.UUCP> frankr@enmasse.UUCP (Franklin Reynolds) writes: >to an outside observer. You can think of black holes as write-only ROMs, No, no, that's WOMs(Write-only Memory)(shades of Elmer Fudd!):-) -- Sarima (Stanley Friesen) {trwrb|allegra|cbosgd|hplabs|ihnp4|aero!uscvax!akgua}!sdcrdcf!psivax!friesen or {ttdica|quad1|bellcore|scgvaxd}!psivax!friesen
mwtilden@watmath.UUCP (K.L. Martin, Hardware) (08/14/85)
**It's my first article so please excuse any fo-pa's** In article <1497@shark.UUCP> hutch@shark.UUCP (Stephen Hutchison) writes: > >I wonder what would happen if two holes with opposite spin, identical mass >and neutral charge collided. Especially if the event horizon were small >enough... > >Hutch We don't know much about black holes but we *do* know a good bit about fluid dynamics and field mechanics. Using just a few principles from both these disiplines indicate that holes don't just 'merge'. The gravity fields set up by colliding black holes would cancel each other along the intersection axis in the time interval prior to collision. This interval is longer than you'd expect as two black holes would most likely collide at oblique angles and go into a tight spiral orbit about each other before collision. Imagine what this means! Two little mass bottles under incredible pressure suddenly having their corks pulled out. Calculations are a little intense but the result can be summed up in a word... BBBBB OOOO OOOO MM MM !! B B O O O O M M M M !! BBBBB O O O O M MM M !! B B O O O O M M BBBBB OOOO OOOO M M !! Just a bit over 27% of the total mass of both holes would be converted into PURE ENERGY! Another 18% is released as actual mass and the remaining forms into a black hole with severe spin and g-field fluctuation. We're talking here about a bang that would make a supernova seem like a fart in an elevator. :-) The values above were calculated on a Cray by a group of English Profs. at Oxford (I believe) and may not be accurate as they were pulled from the dregs of my memory. If anybody's interested I can dig up exactly who and where this info came from and provide either referances or more info. Sorry I don't know if spin or charge would make a difference but I suspect they would be negligable considering the overwhelming g-force involved. MWT "Never hit your mother with a shovel, it leaves a dull impression on her mind"
suze@terak.UUCP (Suzanne Barnett) (08/14/85)
> In article <530@brl-tgr.ARPA> wmartin@brl-bmd.UUCP writes: > >I was thinking about the "anti-matter vs. matter" qualities of what is > >inside a black hole, and, at first, was going to agree with the GET THIS DISCUSSION OUT OF NET.BOOKS! It belongs ONLY in net.physics! -- Suzanne Barnett uucp: ...{decvax,hao,ihnp4,seismo}!noao!terak!suze phone: 602 998 4800 us mail: Terak Corporation, 14151 N 76th street, Scottsdale, AZ 85260
chris@umcp-cs.UUCP (Chris Torek) (08/15/85)
Isn't everyone missing the point anyway? Procyon's Promise (and Life Probe) are predicated on the idea that when we actually go out and *observe* black holes ``directly'', we won't find what we expect. Have you checked your antimatter black hole recently? (Not that I expect later observations to disagree with current theories, but I think everyone's going a bit overboard here.) -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 4251) UUCP: seismo!umcp-cs!chris CSNet: chris@umcp-cs ARPA: chris@maryland
franka@mmintl.UUCP (Frank Adams) (08/15/85)
[this is not a spoiler] I just read _Life_Probe_, the predecesser to _Procyon's_Promise_. It is quite clear there, when McCollum first introduces the anti-matter black holes, that he knows there is no difference between matter and anti-matter black holes by current theory. He is assuming that that theory is wrong, and that anti-matter black holes have a longer lifespan. This is much the same sort of thing every science fiction writer does. Now, I think he would have been better to have been more vague about what his I-masses were (or consult a physicist to get a more plausible explanation). Firstly, the kind of difference between matter and anti- matter black holes he proposes is just not very likely. Second, the time, shortly after the big bang, when quantum black holes might have formed is well before the separation of the primal ylem into matter and anti-matter. Oh, well, at least he tried.