I- Cosmology and Physical Cosmology

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"A New Explanation<br /><br />In the beginning there was neither space nor time as we know them, but a shifting foam of strings and loops, as small as anything can be. Within the foam, all of space, time and energy mingled in a grand unification. But the foam expanded and cooled. And then there was gravity, and space and time, and a universe was created. There was a grand unified force that filled the universe with a false vacuum endowed with a negative pressure. This caused the universe to expand exceedingly rapidly against gravity. But this state was unstable, and did not last, and the true vacuum reappeared, the inflation stopped, and the grand unified force was gone forever. In its place were the strong and electroweak interactions, and enormous energy from the decay of the false vacuum. The universe continued to expand and cool, but at a much slower rate. Families of particles, matter and antimatter, rose briefly to prominence and then died out as the temperature fell below that required to sustain them. Then the electromagnetic and the weak interaction were cleaved, and later the neutrinos were likewise separated from the photons. The last of the matter and antimatter annihilated, but a small remnant of matter remained. The first elements were created, reminders of the heat that had made them. And all this came to pass in three minutes, after the creation of time itself. Thereafter the universe, still hot and dense and opaque to light, continued to expand and cool. Finally the electrons joined to the nuclei, and there were atoms, and the universe became transparent. The photons which were freed at that time continue to travel even today as relics of the time when atoms were created, but their energy drops ever lower. And a billion years passed after the creation of the universe, and then the clouds of gas collapsed from their own gravity, and the stars shone and there were galaxies to light the universe. And some galaxies harbored at their centers giant black ho