Silva Neves said his "cosmological model was built from studies in regular black holes," and avoids the need for a singularity in both black holes and the beginning of universal expansion. He notes, however, that this is still purely hypothetical.
"There is no empirical evidence for bouncing cosmologies today," he said. "But there is no evidence for the initial singularity as well."
"The Big Bang as the initial singularity is only a speculation," Silva Neves told Space.com. He said that "there are many observations in cosmology" that support the hypothesis that the universe went through a period of rapid expansion, but that there is no direct evidence that this expansion started with a singularity.
newjerseyrunner said:I’m confused by what they mean it didn’t have to “start at a singularity.”
Orodruin said:Furthermore, a cyclic universe generally has a contraction phase. Given that the universe is currently undergoing accelerated expansion, this seems unlikely.
Because from our limited understanding of dark energy, it seems to be a constant value. So as space continues to expand, there will be more and more dark energy. The ratio of dark energy to matter (regular and dark) is always climbing so gravity’s effect on the evolution of the universe will slowly deminish, making it impossible to ever start shrinking or even decelerate.ISamson said:Why does the cyclic model seem unlikely?
And I believe you would have to propose some mechanism for decreasing the entropy so that the contracted universe would once again start in a low entropy state.ISamson said:Why does the cyclic model seem unlikely?
Because of dark energy, will galaxies move far apart from each other, or will it result in a big rip tearing apart the nucleus of atoms?newjerseyrunner said:Because from our limited understanding of dark energy, it seems to be a constant value. So as space continues to expand, there will be more and more dark energy. The ratio of dark energy to matter (regular and dark) is always climbing so gravity’s effect on the evolution of the universe will slowly deminish, making it impossible to ever start shrinking or even decelerate.
That’s got to be taken with a grain of salt because we have no idea what dark energy really is.
Phys12 said:Because of dark energy, will galaxies move far apart from each other, or will it result in a big rip tearing apart the nucleus of atoms?
The alternative theory proposed is called the "Big Bounce" theory, which suggests that the universe undergoes a series of cycles of expansion and contraction, with each cycle starting from a "bounce" instead of a singularity like in the traditional Big Bang theory.
The main difference is that the "Big Bounce" theory suggests that the universe has no beginning or end, but instead goes through cycles of expansion and contraction. This is in contrast to the traditional Big Bang theory which suggests that the universe began from a singularity and will continue to expand indefinitely.
Currently, there is no direct evidence for the "Big Bounce" theory. However, some theoretical models such as loop quantum gravity and string theory provide mathematical support for the idea of a cyclical universe. Additionally, observations of the cosmic microwave background radiation, which is leftover radiation from the Big Bang, have shown some anomalies that could potentially be explained by a cyclical universe.
If the "Big Bounce" theory is proven to be true, it would fundamentally change our understanding of the universe. It would mean that the laws of physics and the behavior of the universe are not constant, but instead fluctuate over time. It could also potentially solve some of the mysteries of the Big Bang, such as what caused it and what existed before it.
More research is needed in the fields of cosmology and theoretical physics to gather more evidence and develop more accurate models for the beginning of the universe. Additionally, advancements in technology and observations, such as the development of more powerful telescopes, could provide more data and insights into the nature of the universe and its origins.