1. Big Bang …..was actually very small and quiet

2. Atoms are mostly empty space

3. Early Universe: a strange place Photons are particles of light that behave like waves Early universe was so HOT that when 2 photons collided, they made matter E = mc 2 2 photons make an electron-antielectron pair (antielectron = positron) Matter and antimatter

4. Early Universe In reverse, the 2 particles annihilate each other and create photon energy There are also proton and antiprotons Neutrons and antineutrons

5. Quantum Mechanics The theory of the very small Subatomic particles

6. General relativity Einstein Theory of the very big Gravitational fields warp space and time

7. The Theory of Everything Someday scientists may be able to merge Quantum Mechanics with General Relativity Until then, science can not describe the very very early Universe

8. The 4 Forces Today Gravity is the dominant force on large scales Electromagnetic force dominates biological and chemical reactions Strong and Weak forces determine what happens in the atomic nucleus, important in fission and fusion

9. GUT Force: GUT force = all the forces in the early universe merged together : a Superforce Gravity Electromagnetism Strong force Weak force

10. The First Instant: Planck Time Named after Max Planck, one of the fathers of Quantum Mechanics Universe is 10 -43 second old “Creation” of the Universe During the Planck era (up to 10 -43 seconds) gravity force “freezes out” as a separate force

11. GUT era: 10 -43 -10 -35 seconds 2 forces exist: Gravity and GUT Lasts until universe cools to 10 27 K At 10 -35 seconds, strong force “freezes out” 3 forces now exist: gravity, strong and electroweak Freezing out of strong forces releases a huge amount of energy, causing rapid expansion of universe

12. Inflation Universe expands suddenly and dramatically In 10 -33 second, a piece of the universe the size of an atomic nucleus would have expanded to the size of our solar system

13. The Electroweak era Electromagnetic and weak forces are still merged Gravity and strong force are separate Intense radiation fills space Matter and antimatter particles are created and immediately destroyed Universe expands and cools to 10 15 K, which is 100 million times hotter than sun

14. Particle Era: 10 -10 seconds The end of the electroweak era and beginning of particle era have been confirmed in experiments at CERN particle accelerator At this temperature, the electromagnetic force freezes out, and now the 4 forces are all present as separate forces

15. Particle Era: 10 -10 seconds Tiny particles are now abundant: electrons, neutrinos, quarks, antimatter, and other building blocks of protons and neutrons. At.0001 seconds, temperature has cooled so that quarks can no longer exist on their own, and combine to form protons and neutrons

16. Particle Era: ends at.001 seconds Temperature = 10 12 K No longer hot enough to spontaneously produce matter from energy Matter annihilates antimatter, making photons There are more protons than antiprotons Leftover matter makes up all the matter in the Universe, including us!

17. Era of Nucleosynthesis Protons and Neutrons left over try to fuse together to make heavier particles, but it is still too hot, and they break up Density in expanding universe has dropped so much that fusion stops despite temperature of 10 9 K (hotter than sun)

18. Era of Nucleosynthesis 75 % are Hydrogen nuclei 25% Helium nuclei Some Lithium This composition of the universe is essentially the same today, except for the small amount of heavier elements made by stars Era ends at 3 minutes

19. Era of Nuclei Universe is now a hot plasma of Hydrogen and Helium nuclei Electrons roam free from neutrons If a nucleus captures an electron to make an atom, a photon quickly ionizes it Era lasts 300,000 years as universe expands and cools to 3000 K (half the temperature at the sun’s surface)

20. Era of Atoms Universe is now cool enough that the Hydrogen and Helium nuclei capture electrons for good, making the first stable atoms Photons stream freely across the universe (Cosmic Background Radiation)

21. Era of Atoms Universe is a mix of neutral atoms and plasma Gases assemble to make protogalactic clouds Stars begin to form in these clouds Era ends at about 1 billion years old

22. Era of Galaxies Lasts from 1 billion years old till today (about 15 billion years old) Stars make heavier elements Planets form from these around stars Life forms on planet(s) Here we are!

23. Carl Sagan: “ These are the things that Hydrogen atoms do, given 15 billion years of cosmic evolution”

24. Evidence for Big Bang 1965 Bell Labs, New Jersey Penzias and Wilson working on satellite antennas detect “noise” in all directions Meet Princeton team on airline flight working on theoretical calculations that show there should be leftover radiation from Big Bang Win Nobel Prize in Physics 1978 for discovery of Cosmic Background Radiation

25. Evidence for Big Bang 1990’s COBE Cosmic Background Explorer Maps temperature of sky 2.75 K Shows variations in density of universe

26. Questions Why matter and not antimatter? Particle accelerators create equal amounts of both

27. Questions Will the Universe expand forever “Open Universe” or reverse itself?

28. Possible end….. 1.Stars will die, distances increase 2.All that is left is massive black holes 3.Most protons will fall apart by 10 40 years 4.Black Holes will evaporate (Hawking Radiation) by 10 100 years 5.All that will be left: photons and subatomic particles separated by enormous distances 6.Nothing more will change = end of time? 7.or will there be a rebirth of the Universe?