Burkey- ESS QUIZ Thursday At the instant of the Big Bang, all the matter, energy, time, & space in the Universe was condensed into a single, tiny point. We call this Singularity. Doppler Effect Occurs when the source of sound waves moves towards or away Sound moving TOWARDS Sound waves compressed Higher frequency Shorter wavelength Sound moving AWAY Sound waves stretched out Lower frequency Longer wavelength 1
Doppler Effect with Light is called Red Shifting Red Shift This change of light to longer wavelength Light moving away Blue Shift This change of light to shorter wavelength Light moving towards This is moving to the red-end of the light spectrum, not that it s necessarily red. This is moving to the blue(violet) end of the light spectrum, not that it s necessarily blue. Radial Velocity the speed at which objects are approaching or receding from an observer +Positive that it is receding -Negative that it is approaching. Hubble s Law Galaxies that are moving AWAY from us are shifted to the RED end of the spectrum at a speed that is proportional to their distance. Galaxies that are moving TOWARD us are shifted to the BLUE end of the spectrum v = radial velocity H o = constant d = distance to galaxy v = H 0 d 2
The Big Bang Theory NOW. prevailing cosmological model that explains the development of the Universe abundant evidence has been uncovered in support of the model ~13.75 billion years ago (also the estimated age of our Universe) Earth Space Big Bang Theory I. The Universe was once in an extremely hot and dense state which expanded rapidly. II. In an instant, the universe expanded very quickly III. Then it settled down to a slower rate of expansion, cooling all the time IV. After a few minutes it had cooled enough for protons to form Big Bang Theory V. Hydrogen and helium were the raw ingredients that were available for making stars VI. Heavier elements were made inside stars dying and exploding. VII. Then newer stars created, many of them like our solar system with abundance of complex elements. Evidence for Big Bang **ALL was observational the four pillars of the Big Bang theory" 3
Evidence #1 The Universe is expanding What color is the sky at night? As the distance between galaxy clusters is increasing today, it can be inferred that everything was closer together in the past. *Red shifting by Huble s Law and a dark night sky. DARK at night (Olber s Paradox) IF the universe were infinite in size, eternally old, and if stars shine all the time, then everywhere we look at night, we SHOULD see a star but we DON T. the sky should be as bright as the Sun s surface all of the time but it s NOT We are surrounded by a cosmic particle horizon beyond which we can t see. Solution to Olber s Paradox: 1. Much of the light is redshifted to the extent that the energy is undetectable. 2. Universe is not eternal. Light from the most distant galaxies hasn t had time to reach us. Edwin Hubble Observed that nearly all galaxies are moving away from us with red shifting. Therefore.The universe is expanding 1929 4
But, if all the galaxies are moving away from us, doesn t that make us the center of the universe??? Raisin Bread explains it all Cosmological Principle From every galaxy, at every time, the universe looks the same in all directions. Every galaxy seems to be at the center of the universe. Evidence #2 Cosmic Background Radiation The bright intense light from the Big Bang - 13.7 billion years ago, still bathes the cosmos. 5
Space has a 2.7 Kelvin uniform background radiation temperature Wilson & Penzias at 1 st thought it was background or static It is believed to be microwave radiation left over from the Big Bang because it is isotropic (everywhere) Color indicates temperature http://map.gsfc.nasa.gov/universe/bb_tests_cmb.html Evidence #3 Universe Composition The Universe should be in abundances of lighter elements. Universe is ~75% Hydrogen, ~24% Helium Nucleosynthesis Light element formation in the early universe. Nucleosynthesis Hydrogen Predicted abundance of light elements (H, He, Li) agree with observations with WMAP. Deuterium Tritium Early gas clouds contain about: 75% Hydrogen 25% Helium 6
Evidence #4 Evolution of the Universe The Universe is moving and changing. Everything is moving, orbiting, rotating around and around. Objects in motion stay in motion. Dark Matter What is it?? Pie of matter and energy [NASA] Whatever it is, it doesn t emit or absorb light like normal matter So we re calling it dark matter We think it accounts for 23% of all the matter in the universe We only can measure ~4% So how do we know it s there? Dark Matter is such a huge mass it bends light. Only know material. Acting kind of like a lens curling light around it and altering our view of distant galaxies. I LOVE memes! 7