Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: tamsinbell on 27/09/2018 17:42:16
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David asks:
"Were Black Holes created during the Big Bang of the Universe to create the Galaxies?"
What do you think? Post below!
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Some theories suggest that tiny black holes could have been created in the Big Bang.
The smaller ones would have evaporated by now, due to Hawking radiation; but some of the larger ones could still exist.
See: https://en.wikipedia.org/wiki/Primordial_black_hole
Some theories assuming multiple dimensions suggest that tiny black holes could be created today in the LHC or cosmic rays. Most physicists think this is unlikely as the LHC doesn't have nearly enough energy; but the LHC is certainly looking for signs of any such events.
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https://en.wikipedia.org/wiki/Primordial_black_hole
“The abundance of primordial black holes could be as important as the one of dark matter, to which they are a plausible candidate.”
“Nevertheless, tight limits on their abundances have been set up from various astrophysical and cosmological observations, so that it is now excluded that they contribute importantly to the dark matter over most of the plausible mass range.”
Is it me; or is there a contradiction here?
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Consider this. Can you have a black hole inside another black hole? Say a stellar mass black hole inside a supermassive black hole. Or is it just considered part of the larger black hole once it is inside its horizon?
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Is it me; or is there a contradiction here (about black holes & Dark Matter)?
One of the early theories about Dark Matter was that it could be made up of black holes.
- I'm sure that some of the "invisible mass" in galaxies is made up of black holes
- It is thought that asymmetrical supernovas could eject black holes from the galactic disk, forming a spherical halo orbiting around the galactic core (and we may be able to detect these with LIGO).
- Studies looking at gravitational lensing of stars suggests that there aren't sufficient large black holes in the galactic disk to make up for the amount of invisible mass
- these studies would not be so effective at finding black holes outside the galactic disk
- This theory came to be known as "MACHO": Massive Compact Halo Object
See: https://en.wikipedia.org/wiki/Massive_compact_halo_object
Most cosmologists today favor the idea that Dark Matter is mostly made up of subatomic particles that don't react to the electromagnetic force or the strong force.
- This theory came to be known as "WIMP": Weakly Interacting Massive Particles
See: https://en.wikipedia.org/wiki/Weakly_interacting_massive_particles
Who says scientists don't have a sense of humor?
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Pretty shrewd question Jeffrey :)
As far i gather a black hole has a equalized gravity inside its boundary, meaning that if there was several black holes combined you should be able to notice it (tidal forces), rotations ignored for this. But I'm not sure as it depends on how you look at them. Another way is to presume them being a ball of sorts where gravity builds up towards a center. But I think the same reasoning should hold there too. You should be able to notice it.
Well, you can't ignore the rotations, so maybe I'm out in the blue younder here
I think I am as in the last cause the other black holes also would be at that 'center', but in the first cause I'm not sure..
Then again, you have to invoke frames of reference to define it. What we 'see', relative what 'happens' locally. A merging of two black holes would to us be extremely 'slow' although to those, locally at that location in space and time, possibly go with the speed of light at some imagined center, or as in the first case happen at the speed of light as soon as they merge.
Maybe :)
Actually the first cause gives me doubts ( gravity equalized inside a black holes boundary) as it should mean we never can notice two black holes merging, considering the local speed of it relative our own frame of reference. If something happens with the speed of light, which seems reasonable to me in this case, then we from our frame shouldn't be able to see it at all. As it seems to me
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David asks:
"Were Black Holes created during the Big Bang of the Universe to create the Galaxies?"
What do you think? Post below!
That seems to ask a why question in that you're asking about something happening to do something specific, i.e. has a purpose.. Black holes at the center pf galaxies may have been created by the accretion of matter. When the mass is too large it forms a star and when that is too large if collapses to form a black hole.
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My theory is that the sheer ammount of mass in a galaxy pushes the fabric of space time to gravitational collapse, where matter and space are unable to withstand the gravity involved, alot like the energy involved in super nova explosions. There must be a super super super massive black hole somewhere (edit. Because of the big bang)
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No Petro, no primordial super big black hole. If there was a 'singular point' of a Big Bang I doubt we would find the universe the same way we do at this time. Isotropic and homogeneous. And the way we find it fits to the laws we also define at this time. Conservation laws and symmetries.
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A black hole is where geometry breaks down, then again, geometry is observer defined. Meaning that if you just 'move' fast enough, nothing exist, not even you :) Well, presuming proper mass that is.
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No Petro, no primordial super big black hole. If there was a 'singular point' of a Big Bang I doubt we would find the universe the same way we do at this time. Isotropic and homogeneous. And the way we find it fits to the laws we also define at this time. Conservation laws and symmetries.
In that case we must exist within the gravitational residue of the big bang. Perhaps the big bang is loss of gravitational force (for whatever reason) leading to the expantion ? Sort of a big relax ?