I'm missing some points in here; there was space in singularity, wasn't it? Quoting SciAm June 2008, page 53, "at the time of inflation, our observable universe was less than a centimeter across." That's space, no?
Yes, that's the size of the observable universe -- the patch of spacetime within which all events are causally related. However, the actual universe is a patchwork of these causal regions. The big bang was not a localized event -- it happened everywhere at once. Keep in mind, that the big bang model does not address the initial singularity -- it is believed that the singularity is signalling a breakdown of the mathematical theory at this time, rather than representing something physical. So the big bang is the cosmological model that describes how the early universe expanded from a hot, dense phase into a cooler, less dense phase. This expansion, by all accounts, has been uniform and isotropic because the energy density is uniform and isotropic. An energy density of this form does not give rise to a gravitational field, and therefore does not yield black hole solutions.shazdeh said:
Indeed, but I think it's important not to put too much focus on the amount of energy, or the rapidity of the expansion, or the strength of gravity. It's really a matter of symmetry -- a uniform spacetime of critical density will expand (or contract) -- it will not form a black hole.Naty1 said:
There will always be more mass "below" you than "above" you as fall towards the center of the earth. As Naty1 says, only at the very center will the net gravitational force be zero.shazdeh said:
If the hole is completely straight through the Earth, inertia would tend to carry a body on past the center where the gravitational force is zero.and into an oscillation mode through the center. But the rotation of the Earth would keep the body scraping the side of the hole which would eventually bring the remains to rest at the bottom.bapowell said:
CBLeffert said:
derek101 said:
The early universe was extremely hot and dense, with matter and energy distributed almost evenly throughout. This dense distribution of matter and energy prevented the formation of a black hole, as the intense gravitational pull would have been counteracted by the strong repulsive forces between particles. Additionally, the universe was expanding rapidly, causing the matter and energy to spread out even further and preventing collapse into a single point.
The rapid expansion of the universe, known as inflation, caused the universe to grow exponentially within a fraction of a second after the Big Bang. This expansion caused the matter and energy to become more evenly distributed, preventing the formation of a black hole.
Dark matter and dark energy are both hypothetical substances that are thought to make up a large portion of the universe. Dark matter is believed to have a gravitational effect on visible matter, helping to keep it spread out and preventing collapse into a black hole. Dark energy is thought to be responsible for the accelerating expansion of the universe, which also plays a role in preventing collapse.
It is possible that under different conditions, the early universe could have collapsed into a black hole. For example, if the universe had not undergone rapid inflation or if the amount of dark matter and energy were different, the collapse may have occurred. However, the exact conditions that prevented collapse are still not fully understood.
It is highly unlikely that the current universe will collapse into a black hole. The expansion of the universe continues to accelerate, and the distribution of matter and energy remains relatively even. Additionally, the current understanding of the laws of physics does not suggest that such a collapse is possible. However, the fate of the universe is still a topic of ongoing research and debate among scientists.