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Earth and space science

Earth and space science. Formation of the Universe. Big Bang Theory. We know the universe is expanding. Astrophysicists have been able to work backwards to determine the starting point of the universe and roughly how long ago it was formed.

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Earth and space science

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  1. Earth and space science Formation of the Universe

  2. Big Bang Theory • We know the universe is expanding. • Astrophysicists have been able to work backwards to determine the starting point of the universe and roughly how long ago it was formed. • It makes sense to assume the universe was once closer together. • The Big Bang Theory is the most widely accepted theory. • About 15-20 billion years ago, some event occurred that created the universe and all matter in it. • No atoms or galaxies existed at time zero.

  3. History of the big bang • Georges LeMaitre proposed the first workings of the Big Bang in the 1930’s. • George Gamow extended this theory in the 1950’s and 1960’s. • In the 1960’s Arno Penzias and Robert Wilson discovered radiation in space left over from the Big Bang. • This microwave radiation is called background radiation.

  4. Stages of the big bang • Stage 1: Planck Time = 10-43 seconds, the temperature of the Universe is 1032 oC and only energyexisted. • Stage 2: Rapid expansion cools the Universe, particles slow down and attract because of gravity. (Quarks and leptons formed). • Stage 3: Matter has cooled enough to allow protons (hydrogen nuclei) to form. Neutrons also form. (10-4 s)

  5. Stages of the big bang • Stage 4: After 3 minutes, the universe has cooled to 10 million degrees Celsius. Helium nuclei can bemade as neutrons and protons attract. • Stage 5: Cooling has now stopped the conditions needed for helium to form (one hour) • Stage 6: In half a million years, the universe has cooled to 3000 oC. Electrons now combine with nuclei to form atoms. They are now electrically neutral. • Stage 7: After 1 billion years, gravity forms the first stars and galaxies.

  6. Quasars • Quasi-stellar radio sources – exist deep in space and emit huge amounts of radiation. • It is believed they exist at the very edge of the universe and may be the result of colliding galaxies 12 billion years ago. • The James Webb telescope should reveal more information on these objects.

  7. Missing mass • The total observable mass of the universe is too low to explain why galaxies cluster together and the expansion rate of the Universe. • Dark matter and dark energy is the leading theory to account for this. • Neutrinos, string theory, dark stars and other theories exist, but dark matter is the leading theory.

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