1. Vocabulary, 11/2 Big Bang- the leading scientific explanation about how the universe began; Universe started as a small singularity, then expanded over the next 13.7 billion years

2. The Big Bang Part 2 The colored words are important. They are the words you need to write on your note sheet!

3. Evidence for the Big Bang There are 3 Big Pieces of Evidence for the Big Bang Theory: A.Background Radiation: An echo from the Big Bang B.Abundance of Elements: The large amount of Hydrogen and Helium in outer space C.Redshift: light pattern indicates an object is moving away from the observer

4. You might remember that the first atoms were formed 379,000 years ago. P P P N N P P N P P NNN PP A. Background Radiation

5. P P P N N P P N P P NNN PP Helium Hydrogen You might remember that the first atoms were formed 379,000 years ago.

6. P N P P N A. Background Radiation P P N P P NNN PP

7. Scientists hypothesized that the temperature was so hot that the universe is STILL cooling. They estimated that the burst of energy was so powerful that it left an echo or fingerprint behind.

8. The electromagnetic spectrum consists of all of the different wavelengths of electromagnetic radiation Wavelength and temperature are related: hot objects omit more of their light as short wavelengths, cold objects omit more of their light at long wavelengths Astronomers use special telescopes to study this radiation- e.g. x-rays- generated by superheated gas from exploding stars (10,000,000 degrees) UV light- generated by young, hot stars radio waves- found everywhere; lowest temperature; background radiation of the universe

9. A. Background Radiation In 1964, Penzias and Wilson accidentally discovered the echo! They worked on a very sensitive radio telescope. The telescope picked up unexplainable radio static. It was later concluded that the static was an echo from the Big Bang.  WMAP- shows heat of the radiation Arno Penzias (1933) and Robert Wilson (1936)

10. A. Background Radiation This is called the W-Map. It is a map of the left over radiation from the Big Bang. It shows the temperature of the entire universe.

11. A. Background Radiation A small fraction of the static you hear on the radio and see on the TV is an echo from the Big Bang!hear on the radio

12. B. Abundance of H and He George Gamow Gamow hypothesized that the heat and energy of the Big Bang created all of the Hydrogen and Helium in the Universe. He also helped prove that today 99% of the Universe is made of Hydrogen and Helium

13. B. Abundance of H and He It makes sense that most of the universe is Hydrogen and Helium, because these two atoms are the smallest and would have been the easiest to build.

14. B. Abundance of Elements Think: What are some things that have Hydrogen (“H”) in them? Write: Make a list of substances that have Hydrogen in them. Pair: Compare your list with a partner Share: Share your answers with the class! All of the hydrogen on our class list of compounds was formed just after the Big Bang!

15. C. The Distance of Galaxies Most galaxies are moving away from Earth Galaxies that are farther away are moving faster The universe is expanding!

16. C. The Distance of Galaxies If all galaxies are moving away from each other now, then they must have been closer together a long time ago.

17. C. Distance of Galaxies Discovered that most galaxies are moving away from earth. Proposed that if all matter in space is moving away now, then it must have all started moving from the same spot…HUBBLE’S LAW! Sir Edwin Hubble

18. The stars moving the fastest are the farthest away. (The distance of the star is proportional to its redshift). Farther and Faster Closer and Slower C. Distance of Galaxies

19. How do scientists know that most galaxies are moving away from Earth?

20. C. Distance of Galaxies Read the article about Doppler Effect and answer the reading questions.