Register to reply

Does a Black Hole grow in mass?

by Nova
Tags: black, grow, hole, mass
Share this thread:
Nova
#1
Jun17-14, 10:25 PM
P: 8
It is confirmed that Black Holes have variations of masses. But these masses are said to be gained from the base mass from the Supernova it's born from. Another way a Black hole gained mass was that the collisions of multiple Black Holes caused it to add on to the mass of each other, such as when two super massive Black Holes collide to form an elliptical galaxy. But if these black holes can gain mass from each other, then it should gain mass from the matter it devours, right?
Phys.Org News Partner Astronomy news on Phys.org
Planets with oddball orbits like Mercury could host life
Hubble paints a spattering of blue in irregular galaxy IC 559
The entropy of black holes
Simon Bridge
#2
Jun17-14, 10:27 PM
Homework
Sci Advisor
HW Helper
Thanks
Simon Bridge's Avatar
P: 13,051
Depends on where you are looking from and what you count as the mass of the black hole.
In the sense that black holes can "devour matter", yes, they gain mass as a result.
berkeman
#3
Jun21-14, 03:01 PM
Mentor
berkeman's Avatar
P: 41,291
Thread closed temporarily for Moderation...

DaleSpam
#4
Jun21-14, 03:37 PM
Mentor
P: 17,533
Does a Black Hole grow in mass?

A thread derailment has been removed and the thread reopened. I remind participants to limit responses to topics about which you have some mainstream scientific knowledge, and to report nonsense and speculation rather than further promulgating it.
mfb
#5
Jun21-14, 08:29 PM
Mentor
P: 12,037
Quote Quote by Nova View Post
It is confirmed that Black Holes have variations of masses. But these masses are said to be gained from the base mass from the Supernova it's born from. Another way a Black hole gained mass was that the collisions of multiple Black Holes caused it to add on to the mass of each other, such as when two super massive Black Holes collide to form an elliptical galaxy. But if these black holes can gain mass from each other, then it should gain mass from the matter it devours, right?
Right. The usual way to define "mass" here would be the Komar mass before and after matter falls in.
Simon Bridge
#6
Jun21-14, 10:39 PM
Homework
Sci Advisor
HW Helper
Thanks
Simon Bridge's Avatar
P: 13,051
I think the following discussion is relevant - particularly the last post.
http://www.physicsforums.com/showthread.php?t=355960
... the usual issue about BHs gaining mass is the observation that it takes an object an infinite amount of time, from the POV of a distant observer, to cross the event horizon.
The actual math is trickier than that.


Register to reply

Related Discussions
Black hole mass Special & General Relativity 3
Can a Black Hole really grow? Special & General Relativity 11
Relativistic mass increase appearing to form a black hole vs. a real black hole Special & General Relativity 9
Will a black hole revolve around a non-black hole object with greater mass? General Physics 2
If a black hole had the mass of the entire universe, same mass as the big bang singul Special & General Relativity 1