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wolram
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If theories of cosmology produce a (bounce) what happens to Black holes, it is hard to imagine that these posited things being riped apart.
wolram said:If theories of cosmology produce a (bounce) what happens to Black holes, it is hard to imagine that these posited things being ripped apart.
marcus said:black holes can MERGE to form increasingly massive black holes
wolram said:so far repulsive gravity is just a conjecture? without it bounce
can not happen.
wolram said:Is it even possible in physics for a (force) gravity being outside the accepted definition of force, to reverse sign?
marcus said:repulsive gravity is something that comes out of the math that was not intentionally put in.
it comes out of LQC----an approach to making a quantum version of classical cosmology.
LQC has to be tested, by, for example, deriving predictions about the CMB temperature map from it and then comparing with the real map.
if LQC can pass some tests then it may gain some credibility, and then one will be more inclined to trust the OTHER things derived from it, like gravity becoming repulsive at around 80 percent of the Planck density.
for now, the whole thing is hypothetical---just a possible model. so things derived from it are conjectural. there should, however, be testable predictions coming out of LQC which refer to things we can see and measure. Bojowald talks about some testable predictions in a recent paper (the one with "patchwork universe" in the title---I don't recall the full title just now.)
The black hole bounce theory suggests that instead of a singularity (a point of infinite density) at the center of a black hole, there may be a "bounce" where matter and energy are compressed but not infinitely. This means that instead of collapsing into a singularity, a black hole could potentially "bounce" and form a new, white hole on the other side.
Traditionally, black holes are thought to have a singularity at their center, which is a point of infinite density and no volume. This is based on Einstein's theory of general relativity. However, the black hole bounce theory challenges this idea by proposing that there may be a point of maximum density, but not infinite density, which allows for a "bounce" instead of a singularity.
Currently, there is no direct evidence for the black hole bounce theory. However, some researchers have used mathematical models and simulations to show that a black hole could potentially bounce instead of collapsing into a singularity. Additionally, the theory is supported by the idea that a singularity is a breakdown of our current understanding of physics, so finding an alternative explanation could help bridge the gap between general relativity and quantum mechanics.
The black hole bounce theory is often compared to the Big Bang theory because both involve a singularity and a sudden expansion of the universe. However, the black hole bounce theory suggests that the universe may have always existed and that the Big Bang was just a "bounce" from a previous collapsed universe. This is in contrast to the Big Bang theory, which suggests that the universe began with a singularity and has been expanding ever since.
If the black hole bounce theory is proven to be true, it would significantly impact our understanding of the universe. It would challenge our current understanding of black holes and the nature of singularities, and potentially bridge the gap between general relativity and quantum mechanics. It could also change the way we think about the origin of the universe and the possibility of multiple universes existing simultaneously.