Black hole matter/antimatter


by Unredeemed
Tags: black, hole, matter or antimatter
Unredeemed
Unredeemed is offline
#1
Sep11-08, 12:33 PM
P: 120
Is matter going into a black hole the same as antimatter leaving one?

This has confused me for a while...

Thanks,
Jamie
Phys.Org News Partner Science news on Phys.org
Lemurs match scent of a friend to sound of her voice
Repeated self-healing now possible in composite materials
'Heartbleed' fix may slow Web performance
George Jones
George Jones is offline
#2
Sep11-08, 12:56 PM
Mentor
George Jones's Avatar
P: 6,037
Quote Quote by Unredeemed View Post
Is matter going into a black hole the same as antimatter leaving one?
No.

Matter and antimatter falling into a black hole increase the mass of the black hole. Matter and antimatter "leaving" (Hawking radiation) a black hole decrease the mass of the black hole.
Unredeemed
Unredeemed is offline
#3
Sep11-08, 01:02 PM
P: 120
But wouldn't the antimatter and matter anihilate one another inside the black hole?

George Jones
George Jones is offline
#4
Sep11-08, 01:08 PM
Mentor
George Jones's Avatar
P: 6,037

Black hole matter/antimatter


My point was that since matter falling into a black hole increases the black hole's mass and antimatter leaving a black hole decreases a black hole's mass, these two processes are not the same
Quote Quote by Unredeemed View Post
But wouldn't the antimatter and matter anihilate one another inside the black hole?
Only if their worldlines intersect inside the black hole. Even if this happens, the mass of black hole remains unchanged from the mass just "before" the annihilation event.
Unredeemed
Unredeemed is offline
#5
Sep11-08, 01:11 PM
P: 120
Is that due to the conservation of energy and mass?
George Jones
George Jones is offline
#6
Sep11-08, 01:20 PM
Mentor
George Jones's Avatar
P: 6,037
Quote Quote by Unredeemed View Post
Is that due to the conservation of energy and mass?
Yes, this is because of (local) conservation of mass/energy.
wolram
wolram is offline
#7
Sep11-08, 01:33 PM
PF Gold
wolram's Avatar
P: 3,669
Quote Quote by George Jones View Post
No.

Matter and antimatter falling into a black hole increase the mass of the black hole. Matter and antimatter "leaving" (Hawking radiation) a black hole decrease the mass of the black hole.
What is this antimatter?
George Jones
George Jones is offline
#8
Sep11-08, 01:55 PM
Mentor
George Jones's Avatar
P: 6,037
Quote Quote by wolram View Post
What is this antimatter?
For every particle of matter, there is a corresponding particle of antimatter. The (additive) quantum numbers of an anitparticle have values that ere the negatives of the values of the quantum number for the corresponding particle.

For example, an electron has negative electric charge, and a positron (anitmatter electron) has positive electric charge. If a particle and corresponding antiparticle collide, they annihilate each other, releasing energy.
mheslep
mheslep is offline
#9
Sep11-08, 04:49 PM
PF Gold
P: 3,021
Quote Quote by George Jones View Post
...For example, an electron has negative electric charge, and a positron (anitmatter electron) has positive electric charge. If a particle and corresponding antiparticle collide, they annihilate each other, releasing energy.
Tangents, if you are inclined:
Assuming the electron and positron are the same thing(? same mass, etc) differing only in charge:
1. Why don't an electron and positron settle into quantum mechanical orbitals about each other similar to the traditional electron and nucleus?
2. If an high energy electron can in fact be made to collide with a (proton based) nucleus, why does it not 'annihilate' some 1/1800 th of the much larger proton?


Register to reply

Related Discussions
what happens to matter inside a black hole? Special & General Relativity 24