SYMPHONY OF MATTER

According to the Big Bang theory, after inflation stopped, the universe consisted of a quark–gluon plasma, as well as all other elementary particles. A few seconds later, quarks and gluons combined to form baryons such as protons and neutrons. The first nuclei were formed about three minutes after the Big Bang; neutrons combined with protons to form the hydrogen and helium content of the first stars. This process is called Big Bang nucleosynthesis. In the Big Bang nucleosynthesis isotopes of hydrogen and helium, with trace amounts of lithium, were formed. This process peaked after about five minutes. Any leftover neutrons underwent negative beta decay with a half-life of about a thousand seconds, releasing a proton and electron in the process. For about the next 300,000 to 400,000 years, the excess electrons remained too energetic to bind with atomic nuclei. What followed is a period known as recombination, when neutral atoms were formed and the expanding universe became transparent to radiation. Roughly one million years after the Big Bang, the first generation of stars began to form. With the formation of stars, heavier nuclei were created from hydrogen and helium by stellar nucleosynthesis. Stellar nucleosynthesis is the process by which new nuclei are produced by nuclear reactions. It occurs naturally in stars during stellar evolution. It is responsible for the galactic abundances of elements from carbon to iron. Supernova nucleosynthesis occurs in explosive environments in supernovae, in which the elements between magnesium and nickel are synthesized. Supernova nucleosynthesis is also thought to be responsible for the creation of elements heavier than iron and nickel, including formation of the heaviest elements known in the solar system, such as the long-lived primordial element radionuclides uranium and thorium. In a flight of imagination to the beginning of the universe submerge your mind in the vastness of the newly formed space. Imagine you can see the constituents of the first atoms: electrons, protons, and neutrons. Now imagine the first atom as an electron surrounding a proton: hydrogen has been created…Add a second proton and two neutrons to the hydrogen nucleus, then add another electron around it, and helium is formed…And as the daydream continues the next element can be created by the addition of one proton and one neutron to the nucleus, and one electron to the orbit, and so on until the entire periodic table is formed. This visualization of an atom as a central nucleus with a number of electrons revolving around it in definite orbits (the Rutherford and Bohr planetary model) was the best theory explaining the atomic structure in the 20th century, until deeper analyses were done under the light of quantum mechanics. The electron is now described as having a dual nature: it behaves both as a particle and as a wave. Heisenberg’s Uncertainty Principle led to calculation of electronic positions in terms of probabilities, rather

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JAIME AGUIRRE
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Jan 30, 2013

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