Dark Energy: Big Bang, Big Crunch & Expansion

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The discussion centers on the fate of the universe, questioning whether a Big Crunch could occur or if dark energy will lead to continuous expansion. Current measurements indicate that the universe is expanding at an accelerated rate, suggesting a future filled with darkness rather than a Big Crunch. The role of black holes is clarified, emphasizing that they do not act as vacuum cleaners consuming all matter but instead have a gravitational pull that remains unchanged outside their event horizon. Additionally, black holes can eventually evaporate over time due to Hawking radiation if they lack matter to consume. The conversation highlights the complexities of cosmic evolution and the nature of black holes in the context of the universe's fate.
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Is the reverse of big bang that is big crunch likely to happen??or will dark energy dominate the gravity and the space will coninuoisly expand?
 
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current measurements indicate that the universe is expanding at an accelerated rate so the end will be like the big nothing (from the Neverending story) darkness everywhere.
 
but won't black holes(after many of them are formed in each galaxy) consume all the matters(/antimatters) of the universe to form the tiny condensed form of vast energy as it was before the big bang?isnt it possible?
 
mysteriously said:
but won't black holes(after many of them are formed in each galaxy) consume all the matters(/antimatters) of the universe to form the tiny condensed form of vast energy as it was before the big bang?isnt it possible?

No, this is not how a black hole works. If we took the Sun and compressed it until it reached a density high enough for it to form a black hole, the gravitational pull measured from the old surface and out would be unaffected. (Meaning that the Earth and other planets would not change in their orbits) Since we compressed all the matter into a tiny area it is only from the old surface of the Sun to the new surface (which in this case would be the event horizon) that the gravity would change. Black holes are NOT voracious vacuum cleaners sucking up all the matter around them like they are commonly portrayed.
 
https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
Why was the Hubble constant assumed to be decreasing and slowing down (decelerating) the expansion rate of the Universe, while at the same time Dark Energy is presumably accelerating the expansion? And to thicken the plot. recent news from NASA indicates that the Hubble constant is now increasing. Can you clarify this enigma? Also., if the Hubble constant eventually decreases, why is there a lower limit to its value?
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