The Big Bang Textbook Pages 18-19, 22, 320, 324, 408, 452, 516

Hubble’s Law - 1929 Doppler shift of light allows us to tell if object is coming towards us or away from us Moving away = shift to red, wavelength appears longer Moving towards us = shift to blue, wavelength appears shorter Hubble discovered greater red shift of objects further away The further an object, the faster it is moving away from us Debate began: Steady State versus Big Bang

The Big Bang Theory Best theory to explain the origins of the universe 13.7 billion years ago entire universe was a single point Giant explosion created the universe Everything has been expanding since then What evidence is there to support this theory?

Cosmic Microwave background Recombination era = 100-200 million years after the big bang Cold and dark, stars hadn’t formed yet Space was very transparent to photons Scientists predicted there would be a residual glow from this era Temperature of residual glow = 3-5 Kelvin Glow would emit in the microwave range

Horn Antenna at Bell Labs in Holmdel, NJ

Arno Penzias and Robert Wilson find proof of big bang

Discovery of Cosmic Microwave Background Detected using the Antenna Horn at Bell Labs in Holdel, NJ Scientists who detected it were Arno Penzias and Robert Wilson They won the 1978 Nobel Prize in Physics Provided proof of the Big Bang Theory Disproved the Steady State Theory

That explains how the universe may have began, but… How will it end???

How will the universe end?? How will our solar system end? How will the Earth end? These are questions that we have pondered for many centuries Many possible theories exist!

Research Assignment/Argument Using the textbook, go to the table of contents. You will see that the last several pages of the book explain the possible theories answering the questions from the previous slide: “how will the solar system/universe/everything end?” Look up one of these theories that seems most plausible or just plain interesting to you and read up on it. Create a presentation to convince the rest of the class that this is the way that it will happen. You must create something the class can see to present your argument, (poster, diagram, handouts, computer presentation, etc.) You will be graded on your ability to effectively present your theory in a way that teaches the rest of the class the specifics of what will occur