yeah the big bang theory is pretty intriging. so is the thing about the universe shrinking and growing..weird stuff.
Fifteen billion years ago, give or take five billion years, the entirety of our universe was compressed into the confines of an atomic nucleus. Known as a singularity, this is the moment before creation when space and time did not exist. According to the prevailing cosmological models that explain our universe, an ineffable explosion, trillions of degrees in temperature on any measurement scale, that was infinitely dense, created not only fundamental subatomic particles and thus matter and energy but space and time itself. Cosmology theorists combined with the observations of their astronomy colleagues have been able to reconstruct the primordial chronology of events known as the big bang.
Quantum theory suggests that moments after the explosion at 10 -43 second, the four forces of nature; strong nuclear, weak nuclear, electromagnetic and gravity were combined as a single "super force"(Wald). Elementary particles known as quarks begin to bond in trios, forming photons, positrons and netrinos and were created along with their antiparticles. There are minuscule amounts of protons and neutrons at this stage; approximately 1 for every one billion photons, neutrinos or electrons (Maffei). The density of the Universe in its first moment of life is thought to have been 1094g/cm3 with the majority of this being radiation. For each billion pairs of these heavy particles (hadrons) that were created, one was spared annihilation due to particle-antiparticle collisions. The remaining particles constitute the majority of our universe today (Novikov).
During this creation and annihilation of particles the universe was undergoing a rate of expansion many times the speed of light. Known as the inflationary epoch, the universe in less than one thousandth of a second doubled in size at least one hundred times, from an atomic nucleus to 1035 meters in width. An isotropic inflation of our Universe ends at 10-35 second that was almost perfectly smooth. If it were not for a slight fluctuation in the density distribution of matter, theorists contend, galaxies would have been unable to form (Parker).
The universe at this point was an ionized plasma where matter and radiation were inseparable. Additionally there were equal amounts of particles and antiparticles. The ratio of neutrons and protons albeit small is equal. When the universe aged to one hundredth of a second old neutrons begin to decay on a massive scale. This allows for free electrons and protons to combine with other particles. Eventually the remaining neutrons combine with protons to form heavy hydrogen (deuterium). These deuterium nuclei combine in pairs and form helium nuclei. The formation of matter from energy is made possible by photons materializing into baryons and antibaryons with their subsequent annihilations transforming them into pure energy (Maffei). Because of these collisions and annihilations matter was unable to remain viable for more than a few nanoseconds before a bombardment of electrons would scatter these photons. Like water trapped inside a sponge, radiation is so dense (1014g/cm3) that no light is visible. Known as the "Epoch of Last Scattering" the temperature has now dropped to a mere 1013K with the Strong Nuclear, Weak Nuclear and Electromagnetic interactions now able to exert their force. (Chown)
As the gas cloud expands one full second after the initial explosion and the temperature of our Universe has dropped to ten billion degrees, photons no longer have the energy to disrupt the creation of matter as well as transform energy into matter. After three minutes and a temperature of one billion degrees, protons and neutrons were slowing down enough in order to allow nucleosynthesis to take place. Atomic nuclei of helium was produced as two protons and neutrons each bonded. For every helium nuclei formed there were about ten protons left over allowing for twenty-five percent of the Universe to be comprised of helium. The next important phase of the expansion occurred around thirty minutes later when the creation of photons increased through the annihilation of electron-positron pairs. The fact that the universe began with slightly more electrons than positrons has insured that our Universe was able to form the way it has (Parker).
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