Re: How could expansion overwhelm gravity i big bang

Cosmology has become much more difficult to understand in the last few years. The current consensus is that the Universe began in a hot Big Bang which started the expansion of the Universe. The energy of the expanding universe was part of the Big Bang. What caused the Big Bang? No one knows. One of the difficulties is that all known laws of physics break down at the immense energies and densities of the Big Bang.

Things get even more complicated, though, as astronomers now think that the energy budget of the universe is dominated not by gravity but by dark energy. Dark energy causes the expansion rate of the universe to accelerate. Many astronomers think a similar process called inflation occurred shortly after the Big Bang. During inflation, the spatial scale of the universe increased exponentially, effectively smoothing out the universe on very large scales. This is why the cosmic microwave background looks nearly identical in all directions. After the universe expanded exponentially for 0.0000000000000000000000000000000000001 second, it reverted to regular expansion. After expanding in a regular way for several billion years, the universe has resumed exponential expansion. How this exponential expansion is possible and why it "took a break" for several billion years are subjects of intense research. Stay tuned!