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Author Topic: Would an anti matter black hole bend space the other way to a matter black hole?  (Read 5046 times)

Offline Andrew Pestell

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Andrew Pestell asked the Naked Scientists:
   Q1: If you had a X kg of matter such that adding 1 kg of matter would cause it to make a black hole and you added the 1 kg of matter to form a black hole, waited a while, then added 2 kg of anti matter (opposite spin) so that it anihilates with 2kg of matter giving a total of X-1 kg of matter (x   1 -2) what would happen?

Q2: Would an anti matter black hole bend space the other way to a matter black hole?
What do you think?


 

Offline Soul Surfer

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Q1  Nothing much because the event horizon had already formed and what was inside had already collpsed If there was an effective reduction in gravitational mass the black hole might get a bit smaller but that's about all.

Q2 No the gravitational effects of matter and antimatter are identical.
 

Offline syhprum

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"No the gravitational effects of matter and antimatter are identical"

Is this confirmed from experiment or is it from theoretical considerations ?
 

Offline Vern

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"No the gravitational effects of matter and antimatter are identical"

Is this confirmed from experiment or is it from theoretical considerations ?
Its probably just theory; but there is nothing to suggest anti-matter would behave differently toward gravity. It is simply matter with a reverse electric charge.
 

Offline Soul Surfer

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Theoretical considerations imply that both matter and antimatter are gravitationally identical

I believe it to be also true from measurements because in high energy storage rings of electrons and positrons gravitational effects have to be allowed for and if they were different the beams would diverge. However low temperature experiments with antimatter are also being planned to try to confirm this.
 

Offline Andrew Pestell

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Thankyou Soul Surfer.

From your answer to my first question that would mean that a black hole could be formed from less than the limitinng mass X in effect then ? Also from discussion I've had in the past on the subject it has been suggested that the spin direction of the particles becomes important in this scenario (hence my opposite spin) despite the compression of the mass to an an infinite density dot or what ever. Any comments?
 

Offline lightarrow

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"No the gravitational effects of matter and antimatter are identical"

Is this confirmed from experiment or is it from theoretical considerations ?
Many years ago, in the 90', there was some excitation in the physics community because of an alleged discovery of "antigravity" (also called "fifth force"), that is a difference in gravity between normal matter and antimatter. Some laboratories around the world tried to replicate the experiment, one of these was a laboratory of nuclear physics in Florence (I was studying there at the time) but they didn't find anything and the same in the other laboratories. If I remember correctly, they made measurements on a floating ball of nylon; another laboratory made measurements on a flow of antiprotons going up against the grav. field. They didn't find any difference with normal matter.
http://books.google.it/books?id=55KEjjGK3fgC&pg=PA263&lpg=PA263&dq=antiprotons+fifth+force+%22Bizzeti%22&source=bl&ots=Ipf9_NAaM6&sig=QyqLfbHM6Z57NZSOMuIoTgG9iTo&hl=it&sa=X&oi=book_result&resnum=1&ct=result#PPA264,M1
« Last Edit: 19/01/2009 13:28:57 by lightarrow »
 

Offline Soul Surfer

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A black hole can be formed from any mass of material greater than the plank mass to once the event horison has formed the loss of some mass would only cause the horizon to shrink a bit.  The larger the mass the easier it is to form a black hole.  It has been seriously suggested that the first large mass concentrations after the bib bang collapsed straight into black holes without forming stars and are currently the billion solar mass black holes at the middle of the largest elliptical galaxies.
 

Offline Obiewahn

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see newbielink:http://www.newscientist.com/article/dn16204-does-antimatter-fall-up.html [nonactive] for a new experiment to test if gravity effects anti-matter the same way as matter.
 

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