Loren Booda said:
The object which forces space to expand is a scalar field. This scalar field is (re)acted by the expansion giving rise to a specific spectrum of vacuum fluctuations. I am not sure this has something to do with Newton’s third law, but it sounds to me as something heuristically related to action and reaction.Loren Booda said:
But one has to postulate the existence of some initial patch which must have been in some sort of equilibrium, as the exponential expansion of space does not favor the establishment of thermal equilibrium. However, the regions outside the patch must not have been in thermal equilibrium with the inner parts.SpaceTiger said:
hellfire said:
I do not understand why do you write that these are fluctuations prior to inflation. To calculate how fluctuations are defined, how they evolve, their amplitude and how they are frozen, one has to define a quantum field theory of a scalar field in a de-Sitter background and find out (or actually define) the mode functions of the field expansion (the basis functions which are acted by creation and annihilation operators). These modes have a temporal evolution and some of them, at long wavelengths, freeze. These will determine the spectrum of density perturbations. Basically the whole issue here is a consequence of the QFT on a de-Sitter spacetime.SpaceTiger said:
Actually me neither, I was just speculating with the idea that the field causes expansion and expansion causes the specific shape or temporal evolution of fluctuations (or mode functions).SpaceTiger said:
Well I was talking only about thermal equilibrium. I thought we can assume a thermal equilibrium prior to inflation due to the causal contact with a very small scale factor. Are you telling me that if we assume a patch which is not in thermal equilibrium, inflation will lead to a thermal equilibrium between its parts?SpaceTiger said:
hellfire said:
Condensation is the process in which gas or vapor turns into a liquid. During the initial big bang expansion, the universe was extremely hot and dense, filled with particles and radiation. As the universe cooled and expanded, these particles began to clump together through the process of condensation, eventually forming larger structures like galaxies and stars.
No, condensation did not occur until a few hundred thousand years after the big bang. At the very beginning, the universe was too hot and dense for particles to form into any kind of structure.
As the universe continued to expand and cool, the clumps of particles that formed through condensation began to attract more matter through gravity. This led to the formation of even larger structures, like galaxies and stars, which are still being shaped by the process of condensation.
Yes, in addition to condensation, other factors such as the density and distribution of matter, dark matter and dark energy also play a role in the formation of structures in the universe. These factors work together to shape the universe on a large scale.
Yes, we can observe the effects of condensation in the current universe through various observations and experiments. For example, the presence of galaxies and stars, as well as the distribution of matter in the universe, are all evidence of the role of condensation in shaping the universe. Additionally, scientists are able to simulate the conditions of the early universe to better understand the process of condensation and its effects.