Re: black hole originated from anti-matter colliding with black hole

John Baez

<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no,location=no, scrollbars=yes,resizable=yes,status=no,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>In article <20040330132339.17770.00000281@mb-m21.aol.com>,\nKefka G <kefkag@aol.com> wrote:\n\n>Question for someone who knows more than I do - is it expected that in a full\n>theory of quantum gravity (not just QM on a GR background) we will retain the\n>no hair theorem, or will something more complicated come out instead?\n\nOpinions vary widely here; this is a key open problem in\nquantum gravity, without much to guide us. It\'s called the\n"black hole information loss problem":\n\nhttp://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/info_loss.html\n\nSometimes really frustrated physicists call it the black hole\ninformation loss "paradox", but it\'s not really a logical paradox.\n\nHere\'s a copy of the bet that Preskill made with Hawking and Thorne\nabout this puzzle in 1997:\n\nhttp://www.theory.caltech.edu/people/preskill/info_bet.html\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">  View this Usenet post in original ASCII form </a></div><P></jabberwocky>In article <20040330132339.17770.00000281@mb-m21.aol.com>,
Kefka G <kefkag@aol.com> wrote:

>Question for someone who knows more than I do - is it expected that in a full
>theory of quantum gravity (not just QM on a GR background) we will retain the
>no hair theorem, or will something more complicated come out instead?

Opinions vary widely here; this is a key open problem in
quantum gravity, without much to guide us. It's called the
"black hole information loss problem":

http://math.ucr.edu/home/baez/physic...info_loss.html

Sometimes really frustrated physicists call it the black hole
information loss "paradox", but it's not really a logical paradox.

Here's a copy of the bet that Preskill made with Hawking and Thorne
about this puzzle in 1997:

http://www.theory.caltech.edu/people.../info_bet.html

John Baez

<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no,location=no, scrollbars=yes,resizable=yes,status=no,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>In article <3f96fbb1.0403290526.3765c2ee@posting.google.com>,\njdff <jdff1001@hotmail.com> wrote:\n\n>> [Moderator\'s note: They would form a larger black hole. There\'s an\n>> old saying, "Black holes have no hair," which means that black holes\n>> don\'t have any properties other than their mass, charge, and spin,\n>> that make them behave any differently from each other. So an\n>> antimatter black hole would behave indistinguishably from an\n>> antimatter black hole. -TB]\n\n>Does "no hair" imply any other conserved quantities? Obviously, you\n>have left out linear momentum from the above list.\n\nPeople tend to leave that out because they tend to imagine working\nin the rest frame of the black hole... but that\'s the ONLY ONE that\nTed left out.\n\n>What about e.g. colour?\n\nNope.\n\n>Presumably an accelerated observer very,very\n>close to the horizon (< 1 fm) would see virtual Hawking radiation\n>"red" quarks promoted to real red quarks. So that observer would say\n>that the black holes "hair" included colour, although for all other\n>observers obviously the black hole would be colourless like everything\n>else.\n\nThis insane observer would see Hawking radiation containing all\nsorts of crud, but no lone quarks (color is confined) and more\nimportantly, the character of this radiation would be independent\nof everything but the mass, angular momentum and charge of the\nblack hole - we think.\n\n>Not sure about lepton number conservation. A conserved quantity "hair"\n>or not?\n\nThere seems to be no way to tell the lepton number of a black hole,\nso this does not count as hair either, and it seems that lepton number\nis not conserved when the hole evaporates away.\n\nDitto for baryon number.\n\nThis is why the no hair theorem is interesting.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">  View this Usenet post in original ASCII form </a></div><P></jabberwocky>In article <3f96fbb1.0403290526.3765c2ee@posting.google.com>,
jdff <jdff1001@hotmail.com> wrote:

>> [Moderator's note: They would form a larger black hole. There's an
>> old saying, "Black holes have no hair," which means that black holes
>> don't have any properties other than their mass, charge, and spin,
>> that make them behave any differently from each other. So an
>> antimatter black hole would behave indistinguishably from an
>> antimatter black hole[itex]. -TB][/itex]

>Does "no hair" imply any other conserved quantities? Obviously, you
>have left out linear momentum from the above list.

People tend to leave that out because they tend to imagine working
in the rest frame of the black hole... but that's the ONLY ONE that
Ted left out.

>What about e.g. colour?

Nope.

>Presumably an accelerated observer very,very
>close to the horizon (< 1 fm) would see virtual Hawking radiation
>"red" quarks promoted to real red quarks. So that observer would say
>that the black holes "hair" included colour, although for all other
>observers obviously the black hole would be colourless like everything
>else.

This insane observer would see Hawking radiation containing all
sorts of crud, but no lone quarks (color is confined) and more
importantly, the character of this radiation would be independent
of everything but the mass, angular momentum and charge of the
black hole [itex]- we[/itex] think.

>Not sure about lepton number conservation. A conserved quantity "hair"
>or not?

There seems to be no way to tell the lepton number of a black hole,
so this does not count as hair either, and it seems that lepton number
is not conserved when the hole evaporates away.

Ditto for baryon number.

This is why the no hair theorem is interesting.

Serg

<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no,location=no, scrollbars=yes,resizable=yes,status=no,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>baez@galaxy.ucr.edu (John Baez) wrote in message news:<c6cfca\\$m38\\$1@glue.ucr.edu>...\n>\n> This insane observer would see Hawking radiation containing all\n> sorts of crud, but no lone quarks (color is confined) and more\n> importantly, the character of this radiation would be independent\n> of everything but the mass, angular momentum and charge of the\n> black hole - we think.\n\nBut that is only presuming black hole information loss, right ? If\nsome string theory explanation correct (black hole final state, which\nLibus Motl explaned some time ago in this ng) then the the character\nof this radiation will depend on the matter falling into black hole,\nam I understand it right ?\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">  View this Usenet post in original ASCII form </a></div><P></jabberwocky>baez@galaxy.ucr.edu (John Baez) wrote in message news:<c6cfca$m38$1@glue.ucr.edu>...
>
> This insane observer would see Hawking radiation containing all
> sorts of crud, but no lone quarks (color is confined) and more
> importantly, the character of this radiation would be independent
> of everything but the mass, angular momentum and charge of the
> black hole [itex]- we[/itex] think.

But that is only presuming black hole information loss, right ? If
some string theory explanation correct (black hole final state, which
Libus Motl explaned some time ago in this ng) then the the character
of this radiation will depend on the matter falling into black hole,
am I understand it right ?

Ralph Hartley

<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no,location=no, scrollbars=yes,resizable=yes,status=no,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>John Baez wrote:\n> jdff <jdff1001@hotmail.com> wrote:\n>\n>>>[Moderator\'s note: They would form a larger black hole. There\'s an\n>>> old saying, "Black holes have no hair," which means that black holes\n>>> don\'t have any properties other than their mass, charge, and spin,\n>>> that make them behave any differently from each other. So an\n>>> antimatter black hole would behave indistinguishably from an\n>>> antimatter black hole. -TB]\n>\n>>Does "no hair" imply any other conserved quantities? Obviously, you\n>>have left out linear momentum from the above list.\n>\n> People tend to leave that out because they tend to imagine working\n> in the rest frame of the black hole... but that\'s the ONLY ONE that\n> Ted left out.\n\nWell, it isn\'t a *conserved* quantity, but every blak hole *does* have one\nmore property not on the list. It isn\'t left off because it is obscure, but\nbecause it is obvious.\n\nEvery black hole has a Position!\n\nRalph Hartley\n\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">  View this Usenet post in original ASCII form </a></div><P></jabberwocky>John Baez wrote:
> jdff <jdff1001@hotmail.com> wrote:
>
>>>[Moderator's note: They would form a larger black hole. There's an
>>> old saying, "Black holes have no hair," which means that black holes
>>> don't have any properties other than their mass, charge, and spin,
>>> that make them behave any differently from each other. So an
>>> antimatter black hole would behave indistinguishably from an
>>> antimatter black hole[itex]. -TB][/itex]
>
>>Does "no hair" imply any other conserved quantities? Obviously, you
>>have left out linear momentum from the above list.
>
> People tend to leave that out because they tend to imagine working
> in the rest frame of the black hole... but that's the ONLY ONE that
> Ted left out.

Well, it isn't a *conserved* quantity, but every blak hole *does* have one
more property not on the list. It isn't left off because it is obscure, but
because it is obvious.

Every black hole has a Position!

Ralph Hartley

jdff

<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no,location=no, scrollbars=yes,resizable=yes,status=no,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>baez@galaxy.ucr.edu (John Baez) wrote in message news:<c6cfca\\$m38\\$1@glue.ucr.edu>...\nsnip\n> >Presumably an accelerated observer very,very\n> >close to the horizon (< 1 fm) would see virtual Hawking radiation\n> >"red" quarks promoted to real red quarks. So that observer would say\n> >that the black holes "hair" included colour, although for all other\n> >observers obviously the black hole would be colourless like everything\n> >else.\n>\n> This insane observer would see Hawking radiation containing all\n> sorts of crud, but no lone quarks (color is confined) and more\n> importantly, the character of this radiation would be independent\n> of everything but the mass, angular momentum and charge of the\n> black hole - we think.\n\nBut I deliberately chose an observer so small & close to the horizon\nthat from their point-of-view colour is _not_ confined. Colour is only\nconfined on distance scales longer than that where the energy (rising\nlinearly with distance) is less than the creation of a quark-antiquark\npair.\n\nSo I still think that this observer should observe a BH which is\ncolourless on average but with fluctuations. Every time the observer\nsees the Hawking radiation containing a "red" quark ("crud") the BH is\ntemporarily "anti-red". Until some considerable time later (~10^-23\nsecs later) they see an "anti-red" quark emitted. In fact, just like\nwhen they observe a normal proton.\n\nI don\'t know why that observer is "insane". Since when have\nfundamental laws of the universe, such as which quantities are\nconserved, depended on the size of the person who wrote the textbook?\n\nSimilarly, on lepton number. An observer very close to the horizon\nshould observe "all sorts of crud". Including for example electrons\nand anti-protons. Now, if lepton-number really isn\'t conserved, then\nthis observer will say that if the BH remains charge-neutral then for\nevery electron observed there should be exactly one anti-proton or\npositron. But it would only be statistically true that the number of\nelectrons equalled the number of positrons.\n\nBut if lepton-number is conserved, the number of leptons emitted\nexactly equals anti-leptons. These are actually two genuinely\ndistinguishable statistical distributions. If we took a histogram of\nnumber of leptons emitted then:\nif lepton number not conserved, then leptons minus antileptons on\naverage diverges as n^1/2 as number of particles detected increases.\nBut if lepton number is conserved then it doesn\'t diverge quite as\nmuch (put your hand into bag of 100 red & 100 green balls, after you\nhave withdrawn 60 red & 40 green, what are the odds you draw a red one\nnext time).\nSo this is a scientifically valid, falsifiable question, albeit very\ndifficult experiment. Observe all the particles emitted by Hawking\nradiation from a BH over at least half of its lifetime, and histogram\nover time.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">  View this Usenet post in original ASCII form </a></div><P></jabberwocky>baez@galaxy.ucr.edu (John Baez) wrote in message news:<c6cfca$m38$1@glue.ucr.edu>...
snip
> >Presumably an accelerated observer very,very
> >close to the horizon (< 1 fm) would see virtual Hawking radiation
> >"red" quarks promoted to real red quarks. So that observer would say
> >that the black holes "hair" included colour, although for all other
> >observers obviously the black hole would be colourless like everything
> >else.
>
> This insane observer would see Hawking radiation containing all
> sorts of crud, but no lone quarks (color is confined) and more
> importantly, the character of this radiation would be independent
> of everything but the mass, angular momentum and charge of the
> black hole [itex]- we[/itex] think.

But I deliberately chose an observer so small & close to the horizon
that from their point-of-view colour is _not_ confined. Colour is only
confined on distance scales longer than that where the energy (rising
linearly with distance) is less than the creation of a quark-antiquark
pair.

So I still think that this observer should observe a BH which is
colourless on average but with fluctuations. Every time the observer
sees the Hawking radiation containing a "red" quark ("crud") the BH is
temporarily "anti-red". Until some considerable time later [itex](~10^-23[/itex]
secs later) they see an "anti-red" quark emitted. In fact, just like
when they observe a normal proton.

I don't know why that observer is "insane". Since when have
fundamental laws of the universe, such as which quantities are
conserved, depended on the size of the person who wrote the textbook?

Similarly, on lepton number. An observer very close to the horizon
should observe "all sorts of crud". Including for example electrons
and anti-protons. Now, if lepton-number really isn't conserved, then
this observer will say that if the BH remains charge-neutral then for
every electron observed there should be exactly one anti-proton or
positron. But it would only be statistically true that the number of
electrons equalled the number of positrons.

But if lepton-number is conserved, the number of leptons emitted
exactly equals anti-leptons. These are actually two genuinely
distinguishable statistical distributions. If we took a histogram of
number of leptons emitted then:
if lepton number not conserved, then leptons minus antileptons on
average diverges as [itex]n^1/2[/itex] as number of particles detected increases.
But if lepton number is conserved then it doesn't diverge quite as
much (put your hand into bag of 100 red & 100 green balls, after you
have withdrawn 60 red & 40 green, what are the odds you draw a red one
next time).
So this is a scientifically valid, falsifiable question, albeit very
difficult experiment. Observe all the particles emitted by Hawking
radiation from a BH over at least half of its lifetime, and histogram
over time.

Julian

<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no,location=no, scrollbars=yes,resizable=yes,status=no,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>In message <c6ceio\\$lql\\$1@glue.ucr.edu>, John Baez <baez@galaxy.ucr.edu>\nwrites\n>In article <ba566c17.0403282345.12b66e15@posting.google.com>,\n>Daniel <ensabah6@yahoo.com> wrote:\n>\n>>i am aware of that theorem. i wonder though whether the matter in a\n>>black hole is crushed out of existence, or whether it forms a new\n>>state of matter.\n>>I know that GR predicts a singularity of infinite density, but i\n>>wonder if QM prevents this from happening, and that there is a new\n>>state of matter at the center of a black hole.\n>\n>You\'re not the only one who wonders about this. We *all* do.\n>\n>Figure out the answer, prove it\'s right, and win a Nobel prize.\n>But, don\'t give up your day job.\n\nHere\'s a suggestion that doesn\'t qualify as a "figured out" answer...\nand so is perhaps more properly "enthusiastic speculation"...\n\nThe hidden dimensions in string theory usually seem to be thought of as\nfixed in size... suppose their extents are also variables.\n\nAs the energy density rises in the creation of a black hole, as we\napproach a "classical singularity" the smallest distance one can probe\nrises, in effect causing/being equivalent to the expansion of the curled\nup dimensions (as the "normal" dimensions shrink?); as they expand\n(collectively, sequentially, according to some topological constraint\nordering?) they tend towards equality: space expands, avoiding the\nsingularity. [Energy partitioned between massive particles and the space\nitself which they effectively "open up"?]\n\nTime reverse this and one might then see the Big Bang as the result of\nspontaneous symmetry breaking in the original 10/11 dimensional space;\nand perhaps, if such things are topologically constrained, inflation\nmight be the result of a particular transition in the sequence of e.g.\nCalabi-Yau? spaces - though why 3 big and 6/7 small dimensions should be\na stable end-point, I don\'t know...\n\nIgnorance is bliss when it comes to speculation...\n\nJulian Moore - all email to news-reply automatically rejected; try\njulian.moore@...\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">  View this Usenet post in original ASCII form </a></div><P></jabberwocky>In message <c6ceio$lql$1@glue.ucr.edu>, John Baez <baez@galaxy.ucr.edu>
writes
>In article <ba566c17.0403282345.12b66e15@posting.google.com>,
>Daniel <ensabah6@yahoo.com> wrote:
>
>>i am aware of that theorem. i wonder though whether the matter in a
>>black hole is crushed out of existence, or whether it forms a new
>>state of matter.
>>I know that GR predicts a singularity of infinite density, but i
>>wonder if QM prevents this from happening, and that there is a new
>>state of matter at the center of a black hole.
>
>You're not the only one who wonders about this. [itex]We *all*[/itex] do.
>
>Figure out the answer, prove it's right, and win a Nobel prize.
>But, don't give up your day job.

Here's a suggestion that doesn't qualify as a "figured out" answer...
and so is perhaps more properly "enthusiastic speculation"...

The hidden dimensions in string theory usually seem to be thought of as
fixed in size... suppose their extents are also variables.

As the energy density rises in the creation of a black hole, as we
approach a "classical singularity" the smallest distance one can probe
rises, in effect causing/being equivalent to the expansion of the curled
up dimensions (as the "normal" dimensions shrink?); as they expand
(collectively, sequentially, according to some topological constraint
ordering?) they tend towards equality: space expands, avoiding the
singularity. [Energy partitioned between massive particles and the space
itself which they effectively "open up"?]

Time reverse this and one might then see the Big Bang as the result of
spontaneous symmetry breaking in the original [itex]10/11[/itex] dimensional space;
and perhaps, if such things are topologically constrained, inflation
might be the result of a particular transition in the sequence of e.g.
Calabi-Yau? spaces - though why 3 big and 6/7 small dimensions should be
a stable end-point, I don't know...

Ignorance is bliss when it comes to speculation...

Julian Moore - all email to news-reply automatically rejected; try
julian.moore@...

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