<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>\nThere has been concern for years that particle colliders might create mini\nblack holes. However, the energy required seemed impossible. Recent\ndevelopments in string theory have removed the aura of impossibility. Some\nstring theorists now predict that upcoming colliders will be "black hole\nfactories". (Google that quote.) These theorists expect mini black holes to\nevaporate via Hawking radiation. But Hawking radiation has not been\ndemonstrated experimentally. Five physicists recently estimated the\nprobability that Hawking radiation would work as expected at 50%, 70%, 98%.\n99%, and 100%, an average of 83.4%. Another supposed reason not to worry is\nthat cosmic rays in the energy range of upcoming colliders have been hitting\nthe earth (and the moon, where they are more likely to hit heavy atoms) for\nbillions of years without adverse effect. But there is reason to think that\na mini black hole would be about as reactive as a neutrino. A mini black\nhole created by a cosmic ray would retain the momentum of the cosmic ray,\ndistributed over the cosmic ray particle and the earth particle it impacted.\nIt would be moving faster than escape velocity from earth. It would have to\naccrete many particles to slow below escape velocity, impossibly far out on\nthe Poisson distribution in one pass through earth at neutrino-like rates of\nimpact. On the other hand, a mini black hole created by two particles moving\nin opposite directions would (sometimes) be moving at less than escape\nvelocity from earth. Depending on its momentum, it would orbit or oscillate\nwithin the earth. It would accrete matter at a rate that would be slow\ninitially, but that would increase exponentially.\n\nWhy is this not dangerous?\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>There has been concern for years that particle colliders might create mini
black holes. However, the energy required seemed impossible. Recent
developments in string theory have removed the aura of impossibility. Some
string theorists now predict that upcoming colliders will be "black hole
factories". (Google that quote.) These theorists expect mini black holes to
evaporate via Hawking radiation. But Hawking radiation has not been
demonstrated experimentally. Five physicists recently estimated the
probability that Hawking radiation would work as expected at 50%, 70%, 98%.
99%, and 100%, an average of 83.4%. Another supposed reason not to worry is
that cosmic rays in the energy range of upcoming colliders have been hitting
the earth (and the moon, where they are more likely to hit heavy atoms) for
billions of years without adverse effect. But there is reason to think that
a mini black hole would be about as reactive as a neutrino. A mini black
hole created by a cosmic ray would retain the momentum of the cosmic ray,
distributed over the cosmic ray particle and the earth particle it impacted.
It would be moving faster than escape velocity from earth. It would have to
accrete many particles to slow below escape velocity, impossibly far out on
the Poisson distribution in one pass through earth at neutrino-like rates of
impact. On the other hand, a mini black hole created by two particles moving
in opposite directions would (sometimes) be moving at less than escape
velocity from earth. Depending on its momentum, it would orbit or oscillate
within the earth. It would accrete matter at a rate that would be slow
initially, but that would increase exponentially.
Why is this not dangerous?
Frank Hellmann
Jul12-04, 04:44 AM
<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>\n\nRemember that the gravitational pull of a black hole particle\n(whatever that might be) is no bigger from outside the schwartzschild\nradius then that of a normal particle. The gravitational pull of a\nmini black hole is no bigger then that of a normal atom, which is\nquite small.\n\nf\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>Remember that the gravitational pull of a black hole particle
(whatever that might be) is no bigger from outside the schwartzschild
radius then that of a normal particle. The gravitational pull of a
mini black hole is no bigger then that of a normal atom, which is
quite small.
f
Dave Snead
Jul12-04, 04:44 AM
<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>\n\n"James Blodgett" <bjames1@nycap.rr.com> wrote in message\nnews:000501c46659\\$c3896360\\$471dc318@nycap.rr.com...\n>\n> Five physicists recently estimated the\n> probability that Hawking radiation would work as expected at 50%, 70%,\n98%.\n> 99%, and 100%, an average of 83.4%.\n\nWhere are you getting these statistics from?\nWould like a reference!\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>"James Blodgett" <bjames1@nycap.rr.com> wrote in message
news:000501c46659$c3896360$471dc318@nycap.rr.com...
>
> Five physicists recently estimated the
> probability that Hawking radiation would work as expected at 50%, 70%,
98%.
> 99%, and 100%, an average of 83.4%.
Where are you getting these statistics from?
Would like a reference!
Uncle Al
Jul12-04, 04:44 AM
<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>\nJames Blodgett wrote:\n>\n> There has been concern for years that particle colliders might create mini\n> black holes. However, the energy required seemed impossible.\n\nNot energy, energy density. Colliding hyper-relativistic gold\nnuclei on Long Island are within the mini-\nBlack Hole envelope. So? The doomsday argument is silly at face\nvalue. The experiment is routinely peformed at *much* higher\nenergies/nucleon, 3x10^20 eV recorded. That is 3x10^11 GeV.\n\nhttp://www.fourmilab.ch/documents/ohmygodpart.html\n\nLong Island doesn\'t even worry about paricle energy vs. radius of\ncurvature and synchrotron radiation - for obvious reasons.\n\n[snip Chicken Little]\n\n> Why is this not dangerous?\n\nLife is dangerous. Look what happened to Aeschylus (525-456\nBC). Do you wear a helmet?\n\n--\nUncle Al\nhttp://www.mazepath.com/uncleal/\n(Toxic URL! Unsafe for children and most mammals)\nhttp://www.mazepath.com/uncleal/qz.pdf\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>James Blodgett wrote:
>
> There has been concern for years that particle colliders might create mini
> black holes. However, the energy required seemed impossible.
Not energy, energy density. Colliding hyper-relativistic gold
nuclei on Long Island are within the mini-
Black Hole envelope. So? The doomsday argument is silly at face
value. The experiment is routinely peformed at *much* higher
energies/nucleon, 3x10^20 eV recorded. That is 3x10^11 GeV.
Long Island doesn't even worry about paricle energy vs. radius of
curvature and synchrotron radiation - for obvious reasons.
[snip Chicken Little]
> Why is this not dangerous?
Life is dangerous. Look what happened to Aeschylus (525-456
BC). Do you wear a helmet?
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
Alan
Jul12-04, 02:00 PM
<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>> Not energy, energy density. Colliding hyper-relativistic gold\n> nuclei on Long Island are within the mini-\n> Black Hole envelope. So? The doomsday argument is silly at face\n> value. The experiment is routinely peformed at *much* higher\n> energies/nucleon, 3x10^20 eV recorded. That is 3x10^11 GeV.\n\nWhy is the argument silly at face value?\n\nThe fact that much higher energies have been routinely generated\nis not a convincing disproof. Suppose we accept that if mini-Black Holes\ncould be produced, they already have been many times on Long Island,\nand in cosmic rays: let\'s say 100,000 times. Suppose the chance that one of\nthem would then accrete to macroscopic size is 100 million to 1.\nThen, why isn\'t producing N more of them, where N is large,\na potential problem?\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>> Not energy, energy density. Colliding hyper-relativistic gold
> nuclei on Long Island are within the mini-
> Black Hole envelope. So? The doomsday argument is silly at face
> value. The experiment is routinely peformed at *much* higher
> energies/nucleon, 3x10^20 eV recorded. That is 3x10^11 GeV.
Why is the argument silly at face value?
The fact that much higher energies have been routinely generated
is not a convincing disproof. Suppose we accept that if mini-Black Holes
could be produced, they already have been many times on Long Island,
and in cosmic rays: let's say 100,000 times. Suppose the chance that one of
them would then accrete to macroscopic size is 100 million to 1.
Then, why isn't producing N more of them, where N is large,
a potential problem?
Deborah Goldsmith
Jul13-04, 03:37 AM
<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>\nIn article <e2b39847.0407110752.4e1edf4b@posting.google.com>,\nCerthas@gmail.com (Frank Hellmann) wrote:\n> Remember that the gravitational pull of a black hole particle\n> (whatever that might be) is no bigger from outside the schwartzschild\n> radius then that of a normal particle. The gravitational pull of a\n> mini black hole is no bigger then that of a normal atom, which is\n> quite small.\n\nThat doesn\'t matter. The only thing that matters is whether the decay rate is\nhigher or lower than the rate at which it would accrete. If the decay rate is\nzero, then if you put a black hole inside the Earth, no matter how small, it\'s\nonly a matter of time before it eats the planet. Purely by chance, particles in\nthe neighborhood are going to wander through the event horizon. The bigger it\ngets, the faster that happens.\n\nThe fact that this hasn\'t happened yet is probably a good argument for the decay\nrate of mini black holes being high enough for them to evaporate before they can\nget bigger. As someone else pointed out, there is more than enough energy in\ncosmic rays to create them at least occasionally.\n\nDeborah\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 <e2b39847.0407110752.4e1edf4b@posting.google.com>,
Certhas@gmail.com (Frank Hellmann) wrote:
> Remember that the gravitational pull of a black hole particle
> (whatever that might be) is no bigger from outside the schwartzschild
> radius then that of a normal particle. The gravitational pull of a
> mini black hole is no bigger then that of a normal atom, which is
> quite small.
That doesn't matter. The only thing that matters is whether the decay rate is
higher or lower than the rate at which it would accrete. If the decay rate is
zero, then if you put a black hole inside the Earth, no matter how small, it's
only a matter of time before it eats the planet. Purely by chance, particles in
the neighborhood are going to wander through the event horizon. The bigger it
gets, the faster that happens.
The fact that this hasn't happened yet is probably a good argument for the decay
rate of mini black holes being high enough for them to evaporate before they can
get bigger. As someone else pointed out, there is more than enough energy in
cosmic rays to create them at least occasionally.
Deborah
Greg Neill
Jul13-04, 03:37 AM
<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>\n"Alan" <info@optioncity.REMOVETHIS.net> wrote in message\nnews:utWdnaADO-zRW2_dRVn-ig@adelphia.com...\n> > Not energy, energy density. Colliding hyper-relativistic gold\n> > nuclei on Long Island are within the mini-\n> > Black Hole envelope. So? The doomsday argument is silly at face\n> > value. The experiment is routinely peformed at *much* higher\n> > energies/nucleon, 3x10^20 eV recorded. That is 3x10^11 GeV.\n>\n> Why is the argument silly at face value?\n>\n> The fact that much higher energies have been routinely generated\n> is not a convincing disproof. Suppose we accept that if mini-Black Holes\n> could be produced, they already have been many times on Long Island,\n> and in cosmic rays: let\'s say 100,000 times. Suppose the chance that one\nof\n> them would then accrete to macroscopic size is 100 million to 1.\n> Then, why isn\'t producing N more of them, where N is large,\n> a potential problem?\n\nConsider that cosmic rays would have been doing this\nfor *billions* of years, in fact, throughout the\nexistence of the Earth even during its formation from\nits primordial cloud of material. Jupiter has been an\neven larger target for just as long or longer.\n\nI doubt that our own paltry efforts can even hope to skew\nthe statistics in any measurable way.\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>"Alan" <info@optioncity.REMOVETHIS.net> wrote in message
news:utWdnaADO-zRW2_dRVn-ig@adelphia.com...
> > Not energy, energy density. Colliding hyper-relativistic gold
> > nuclei on Long Island are within the mini-
> > Black Hole envelope. So? The doomsday argument is silly at face
> > value. The experiment is routinely peformed at *much* higher
> > energies/nucleon, 3x10^20 eV recorded. That is 3x10^11 GeV.
>
> Why is the argument silly at face value?
>
> The fact that much higher energies have been routinely generated
> is not a convincing disproof. Suppose we accept that if mini-Black Holes
> could be produced, they already have been many times on Long Island,
> and in cosmic rays: let's say 100,000 times. Suppose the chance that one
of
> them would then accrete to macroscopic size is 100 million to 1.
> Then, why isn't producing N more of them, where N is large,
> a potential problem?
Consider that cosmic rays would have been doing this
for *billions* of years, in fact, throughout the
existence of the Earth even during its formation from
its primordial cloud of material. Jupiter has been an
even larger target for just as long or longer.
I doubt that our own paltry efforts can even hope to skew
the statistics in any measurable way.
Uncle Al
Jul13-04, 03:37 AM
<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>Alan wrote:\n>\n> > Not energy, energy density. Colliding hyper-relativistic gold\n> > nuclei on Long Island are within the mini-\n> > Black Hole envelope. So? The doomsday argument is silly at face\n> > value. The experiment is routinely peformed at *much* higher\n> > energies/nucleon, 3x10^20 eV recorded. That is 3x10^11 GeV.\n>\n> Why is the argument silly at face value?\n>\n> The fact that much higher energies have been routinely generated\n> is not a convincing disproof. Suppose we accept that if mini-Black Holes\n> could be produced, they already have been many times on Long Island,\n> and in cosmic rays: let\'s say 100,000 times. Suppose the chance that one of\n> them would then accrete to macroscopic size is 100 million to 1.\n> Then, why isn\'t producing N more of them, where N is large,\n> a potential problem?\n\nTry using fact-based reasoning instead of Chicken Little\npolitical manipulation of the mob. How would you accrete to a\nnanoscopic black hole after its formation? What is the half-life\nre Hawkiing radiation of a black hole with the mass of a gold\nnucleus? What would its event horizon external temperature be?\nGo ahead, find the equation and work it out. Looks adequately\nsafe to me. While it is decaying nothing can get close from the\nlight pressure. It\'s a short decay time.\n\nHow would you accrete a nanoscopic black hole? Drop in onto a\nten foot thicknes of reinforced concrete. How long does it take\nfor the first contact to penetrate the event horizon? Forever.\nDid you ever see water swirling down a drain? This drain is 3\npicometers across. Angular momentum is conserved. It isn\'t a\nproblem.\n\nThere are 280 million American citizens. Statistically a\none-in-a-million chance happens 280 times a day. Does it?\n\n--\nUncle Al\nhttp://www.mazepath.com/uncleal/\n(Toxic URL! Unsafe for children and most mammals)\nhttp://www.mazepath.com/uncleal/qz.pdf\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>Alan wrote:
>
> > Not energy, energy density. Colliding hyper-relativistic gold
> > nuclei on Long Island are within the mini-
> > Black Hole envelope. So? The doomsday argument is silly at face
> > value. The experiment is routinely peformed at *much* higher
> > energies/nucleon, 3x10^20 eV recorded. That is 3x10^11 GeV.
>
> Why is the argument silly at face value?
>
> The fact that much higher energies have been routinely generated
> is not a convincing disproof. Suppose we accept that if mini-Black Holes
> could be produced, they already have been many times on Long Island,
> and in cosmic rays: let's say 100,000 times. Suppose the chance that one of
> them would then accrete to macroscopic size is 100 million to 1.
> Then, why isn't producing N more of them, where N is large,
> a potential problem?
Try using fact-based reasoning instead of Chicken Little
political manipulation of the mob. How would you accrete to a
nanoscopic black hole after its formation? What is the half-life
re Hawkiing radiation of a black hole with the mass of a gold
nucleus? What would its event horizon external temperature be?
Go ahead, find the equation and work it out. Looks adequately
safe to me. While it is decaying nothing can get close from the
light pressure. It's a short decay time.
How would you accrete a nanoscopic black hole? Drop in onto a
ten foot thicknes of reinforced concrete. How long does it take
for the first contact to penetrate the event horizon? Forever.
Did you ever see water swirling down a drain? This drain is 3
picometers across. Angular momentum is conserved. It isn't a
problem.
There are 280 million American citizens. Statistically a
one-in-a-million chance happens 280 times a day. Does it?
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
Serenus Zeitblom
Jul15-04, 04:57 AM
<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>\nUncle Al <UncleAl0@hate.spam.net> wrote in message > >\n>\n> Try using fact-based reasoning instead of Chicken Little\n> political manipulation of the mob. How would you accrete to a\n> nanoscopic black hole after its formation? What is the half-life\n> re Hawkiing radiation of a black hole with the mass of a gold\n> nucleus? What would its event horizon external temperature be?\n> Go ahead, find the equation and work it out. Looks adequately\n> safe to me.\n\nIt\'s slightly hilarious that you taunt our friend for his\nlack of formulae and then blandly fail to tell us how\nsafe "safe" is supposed to be. Suppose there is a one\nin a quadrillion chance that something will go wrong in\nthe course of the experiments. That is a huge number in\nview of what is at stake. So tell us: what probability\ncorresponds to "safe" in the Aliverse?\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>Uncle Al <UncleAl0@hate.spam.net> wrote in message > >
>
> Try using fact-based reasoning instead of Chicken Little
> political manipulation of the mob. How would you accrete to a
> nanoscopic black hole after its formation? What is the half-life
> re Hawkiing radiation of a black hole with the mass of a gold
> nucleus? What would its event horizon external temperature be?
> Go ahead, find the equation and work it out. Looks adequately
> safe to me.
It's slightly hilarious that you taunt our friend for his
lack of formulae and then blandly fail to tell us how
safe "safe" is supposed to be. Suppose there is a one
in a quadrillion chance that something will go wrong in
the course of the experiments. That is a huge number in
view of what is at stake. So tell us: what probability
corresponds to "safe" in the Aliverse?
Frank Hellmann
Jul15-04, 03:23 PM
<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>\n\n> That doesn\'t matter. The only thing that matters is whether the decay rate is\n> higher or lower than the rate at which it would accrete. If the decay rate is\n> zero, then if you put a black hole inside the Earth, no matter how small, it\'s\n> only a matter of time before it eats the planet. Purely by chance, particles in\n> the neighborhood are going to wander through the event horizon. The bigger it\n> gets, the faster that happens.\n>\n> The fact that this hasn\'t happened yet is probably a good argument for the decay\n> rate of mini black holes being high enough for them to evaporate before they can\n> get bigger. As someone else pointed out, there is more than enough energy in\n> cosmic rays to create them at least occasionally.\n>\n> Deborah\n\nYou are assuming that we are dealing with a process in equilibrium.\nThis might not be the case. Even without evaporation it might simply\nbe that the interaction between a single atom black hole and earth\nwould be so small as to be only relevant on time scales beyond caring\n(e.g. longer then the lifetime of the universe).\nRemember that gravity is the weakest force by many orders of magnitude\nit only becomes noticable if there are many many particles grouped\ntogether, as in humans and the earth.\nFor a single atom black hole consider the scattering probability of\nneutrinos who interact through the weak interaction when passing\nthrough earth. This scattering should roughly scale with the\ninteraction strength, and now consider that the coupling constant of\ngravity is 33 orders of magnitude lower then that of the weak\ninteraction!\nThe point is gravity is incredibly weak and only get\'s relevant if you\nhave damn many particles around bounding together more then just\nmacroscopical, astronomical really. (electro magnetism is a lot\nstronger but doesn\'t accumulate, which is why macroscopically it\'s\nless apparent).\n\nThere\'s bound to be a lot more going on, but this simpleconsideration\nof the order of magnitude of the coupling constant and the involved\nmasses (single atom/molecule) tells you that it can\'t really be\ndangerous even without any evaporation whatsoever.\nThe interaction between two gravitationally interacting particles is\n33 orders of magnitudes lower then that of two weakly\ninteractingparticles, i.e. neutrinos.\n\n\nThis is far far far from rigorous and the estimate herein can probably\nbe sharpened considerably, but one of the problems really is that to\nknow what\'s going on we would need to know what the quantum theory of\ngravity is, and whatever effects this does entail, they are bound to\nbe small or we would have seen them.\n\n---\nfrank\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>That doesn't matter. The only thing that matters is whether the decay rate is
> higher or lower than the rate at which it would accrete. If the decay rate is
> zero, then if you put a black hole inside the Earth, no matter how small, it's
> only a matter of time before it eats the planet. Purely by chance, particles in
> the neighborhood are going to wander through the event horizon. The bigger it
> gets, the faster that happens.
>
> The fact that this hasn't happened yet is probably a good argument for the decay
> rate of mini black holes being high enough for them to evaporate before they can
> get bigger. As someone else pointed out, there is more than enough energy in
> cosmic rays to create them at least occasionally.
>
> Deborah
You are assuming that we are dealing with a process in equilibrium.
This might not be the case. Even without evaporation it might simply
be that the interaction between a single atom black hole and earth
would be so small as to be only relevant on time scales beyond caring
(e.g. longer then the lifetime of the universe).
Remember that gravity is the weakest force by many orders of magnitude
it only becomes noticable if there are many many particles grouped
together, as in humans and the earth.
For a single atom black hole consider the scattering probability of
neutrinos who interact through the weak interaction when passing
through earth. This scattering should roughly scale with the
interaction strength, and now consider that the coupling constant of
gravity is 33 orders of magnitude lower then that of the weak
interaction!
The point is gravity is incredibly weak and only get's relevant if you
have damn many particles around bounding together more then just
macroscopical, astronomical really. (electro magnetism is a lot
stronger but doesn't accumulate, which is why macroscopically it's
less apparent).
There's bound to be a lot more going on, but this simpleconsideration
of the order of magnitude of the coupling constant and the involved
masses (single atom/molecule) tells you that it can't really be
dangerous even without any evaporation whatsoever.
The interaction between two gravitationally interacting particles is
33 orders of magnitudes lower then that of two weakly
interactingparticles, i.e. neutrinos.
This is far far far from rigorous and the estimate herein can probably
be sharpened considerably, but one of the problems really is that to
know what's going on we would need to know what the quantum theory of
gravity is, and whatever effects this does entail, they are bound to
be small or we would have seen them.
---
frank
Frank Hellmann
Jul16-04, 12:23 PM
<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>\n\nDeborah Goldsmith <dgoldsmithSPAM@IYAmac.com> wrote in message news:<dgoldsmithSPAM-904DFA.22005012072004@netnews.comcast.net>...\n\n> That doesn\'t matter. The only thing that matters is whether the decay rate is\n> higher or lower than the rate at which it would accrete. If the decay rate is\n> zero, then if you put a black hole inside the Earth, no matter how small, it\'s\n> only a matter of time before it eats the planet. Purely by chance, particles in\n> the neighborhood are going to wander through the event horizon. The bigger it\n> gets, the faster that happens.\n>\n\nOk some classical estimates (and an introduction to the google\ncalculator).\nAssume a black hole of proton mass m_p is produced at surface. It will\noscilate through the planet. Let\'s assume that on avarage half it\'s\npotential energy in the earths gravitational field is velocity, then\non avarage during the oscilation it\'s got the speed:\n1/2m_p v^2 = m_p M_e G/R_e => v = sqrt (2 G M_e/R_e)\nM_e and R_e being the mass and radius of earth respectively.\nnow it\'s Schwarzschild radius will be 2Gm_p/c^2 per unit time it will\nthus sweep a volume of\npi * (2G m_p /c^2)^2 * sqrt (2 G M_e/R_e)\nNow the number of particles per unit volume in earth is assuming the\nparticles to be protons/neutrons rho_e/m_p\nThus it eats up:\npi * (2G m_p /c^2)^2 * sqrt (2 G M_e/R_e) * rho_e/m_p\n\nparticles per unit time.\n\nLet\'s put that into a calculator, using meters, kilogram and seconds\nthroughout:\npi * (2 * (gravitational constant) * (1.6726 * 10^(-27) kg) /(c^2))^2\n* (2 * (gravitational constant) * (5.98*10^24 kg)*2/(12753 km))^(0.5)\n* (5515 (kg / (m^3)))/(1.6726 * 10^(-27) kg)\n\n\ngoogle (just copy and paste it in!) tells us this is\n7.14894378 × 10-73 per second.\nThis means it will take on avarage 1.39880803 × 10^72 seconds till it\neats up a single particle.\nThis are 4.43264986 × 10^64 years\n(just ask google what "1/(7.14894378 * 10^(-73) hertz) in years" is).\nThe age of the universe is currently estimated to be about 1-2 * 10^10\nyears.\n\nThe sun will blow up long before that timeframe into the future.\nThus if you are worried about mini black holes, you might rather worry\nabout the sun being extinguished it will happen a LOT sooner.\n\n---\nfrank\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>Deborah Goldsmith <dgoldsmithSPAM@IYAmac.com> wrote in message news:<dgoldsmithSPAM-904DFA.22005012072004@netnews.comcast.net>...
> That doesn't matter. The only thing that matters is whether the decay rate is
> higher or lower than the rate at which it would accrete. If the decay rate is
> zero, then if you put a black hole inside the Earth, no matter how small, it's
> only a matter of time before it eats the planet. Purely by chance, particles in
> the neighborhood are going to wander through the event horizon. The bigger it
> gets, the faster that happens.
>
Ok some classical estimates (and an introduction to the google
calculator).
Assume a black hole of proton mass m_p is produced at surface. It will
oscilate through the planet. Let's assume that on avarage half it's
potential energy in the earths gravitational field is velocity, then
on avarage during the oscilation it's got the speed:
1/2m_p v^2 = m_p M_e G/R_e => v = \sqrt (2 G M_e/R_e)M_e and R_e being the mass and radius of earth respectively.
now it's Schwarzschild radius will be 2Gm_p/c^2 per unit time it will
thus sweep a volume of
\pi * (2G m_p /c^2)^2 * \sqrt (2 G M_e/R_e)
Now the number of particles per unit volume in earth is assuming the
particles to be protons/neutrons \rho_e/m_p
Thus it eats up:
\pi * (2G m_p /c^2)^2 * \sqrt (2 G M_e/R_e) * \rho_e/m_p
particles per unit time.
Let's put that into a calculator, using meters, kilogram and seconds
throughout:
\pi * (2 * (gravitational constant) * (1.6726 * 10^(-27) kg) /(c^2))^2* (2 * (gravitational constant) * (5.98*10^24 kg)*2/(12753 km))^(0.5)
* (5515 (kg / (m^3)))/(1.6726 * 10^(-27) kg)
google (just copy and paste it in!) tells us this is
7.14894378 × 10-73 per second.
This means it will take on avarage 1.39880803 × 10^72 seconds till it
eats up a single particle.
This are 4.43264986 × 10^64 years
(just ask google what "1/(7.14894378 * 10^(-73) hertz) in years" is).
The age of the universe is currently estimated to be about 1-2 * 10^10
years.
The sun will blow up long before that timeframe into the future.
Thus if you are worried about mini black holes, you might rather worry
about the sun being extinguished it will happen a LOT sooner.
---
frank
Patrick Van Esch
Jul20-04, 04:25 AM
<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>\n\n> This means it will take on avarage 1.39880803 × 10^72 seconds till it\n> eats up a single particle.\n> This are 4.43264986 × 10^64 years\n\nBut that means that if ever there\'s now Hawkin radiation, there might\nbe myriads of mini black holes already swarming around and through the\nearth :-)\n\ncheers,\nPatrick.\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>This means it will take on avarage 1.39880803 × 10^72 seconds till it
> eats up a single particle.
> This are 4.43264986 × 10^64 years
But that means that if ever there's now Hawkin radiation, there might
be myriads of mini black holes already swarming around and through the
earth :-)