Origins of the Universe

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Origins of the Universe

• Where did everything come from?

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Theories

• Creation- All powerful being made everything how
  we see it today.
• Big Bang- The Universe was once an infinitely
  dense point, then BANG!

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Why the Big Bang?

• The Big Bang is a theory that can be tested. We
  can look for evidence in the universe that we see
  today.
• Many other theories, though possible, can not be
  tested in the scientific way.

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When did this happen?

• Many scientists believe that the Big Bang
  happened sometime between 10 and 20 billion years
  ago. Well just call it 15 billion years.

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What started it?

• No one can be sure of what started the Big Bang
  off. This will probably remain a mistery
  forever. Unless one of you find the answer.

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Big Bang, then what?

• After the Big Bang came the big expansion.
• The universe was VERY hot back in the day (or
  second).
• One second after the big bang the temperature
  could have been 10,000,000,000 degrees. 1000
  times hotter than the center of our sun.

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Was there oxygen back then?

• Short answer NO!
• Long answerNO, because things were too hot to
  stick together.
• Because of this, the early universe only
  contained a few particles photons, electrons and
  neutrinos.
• Therefore, there was no protons or neutrons which
  are the building blocks of atoms.

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Questions?

• This stuff can be pretty overwhelming.

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What next?

• The baby universe kept on growing, as it
  continued to expand the particles didnt bump
  into each other as much and the universe began to
  cool.
• After 100 seconds, the universe cooled to
  1,000,000,000 degrees.
• At this temperature protons and neutrons could
  form and combine.

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Lets look at what we have so far.

• After just 100 second (about a minute and a
  half).
• The universe is expanding and cooling.
• Particles are forming, protons, neutrons,
  electrons, neutrinos
• Time keeps on tickin into the future.

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Oxygen yet?

• Not quite, but were getting closer.
• The protons and neutrons have lost enough energy
  to form heavy hydrogen nuclei.
• Hydrogen is one proton and one electron, take
  away the electron and you have just the nucleus.
• Heavy hydrogen is a proton AND a neutron.
• From here, helium and other light elements formed.

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I dont buy it.

• In 1948 George Gamow and Ralph Alpher predicted
  that left over radiation should still be visible
  in the universe.
• It was!
• In 1965 in New Jersey two physicists discovered
  microwave radiation from the early universe.
• 2006 Nobel Prize in Physics had to do with
  finding this radiation. The radiation was left
  over photons.

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Did the early universe obey the law?

• The laws of physics are pretty streamlined.
• Gravity- pulls things toward each other.
• Electromagnetic- dealing with electricity, and
  magnets.
• Weak force- plays a part in decay processes.
• Strong force- holds protons next to protons.

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So did it?

• No!
• None of these forces are thought to have existed
  in the early universe.
• Things were too hot, and hot particles move fast,
  too fast.
• Once they cooled down enough, after a couple
  minutes, the particles were moving at speeds that
  allowed gravity and other forces to act.

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What happened next?

• Once we have hydrogen, we can start to make some
  things.
• Due to inconsistencies in density of the early
  universe atoms started to drift together because
  of gravity.
• Things started to clump together.

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And then?

• Baby universe is only 3 minutes old.
• At this point the universe is about 26 percent
  helium.
• Not many elements heavier than beryllium and
  boron were around.

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Fast forward

• About 500, 000 years (give or take a few hundred
  thousand years).
• The universe has cooled enough for hydrogen and
  helium to start clumping together, and more
  clumping and more clumping.
• The first galaxies are beginning to come to life.

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To sum it all up.

• Big Bang
• Big expansion
• Big cool down
• Big clump up
• Big universe (with stars beginning to form).
• Big Crunch?