1. CO-The Big Bang Theory LO-Describe the events leading to the formation of the Universe. 1

2. What is it? A theory that the universe started from a single point, and has been expanding ever since. It is sciences’ best explanation of how the universe was created 2

3. Our entire universe was created when very small, very hot, very dense mass exploded and began expanding at a very fast rate. 3

4. Eventually the matter began to cool and formed the stars and galaxies that we can see today! This is thought to have happened 15 billion years ago 4

5. Who thought of this? The theory was developed by Georges-Henri Lemaitre A Belgian catholic priest and astronomer In the late 1920’s 5

6. Evidence The Big Bang Theory is supported by 2 major pieces of evidence 1 st - All galaxies are moving away from each other. The light from these galaxies shows “Red Shift” Edwin Hubble (1929) 2 nd - Cosmic microwave background radiation The “Echo” (1965) 6

7. RED SHIFT When an object such as a star or galaxy is moving away the light waves are stretched out, increasing the wave lengths. This apparent shift in the wavelength is called Red Shift because the light appears redder in color. Edwin Hubble observed that distant galaxies all display Red Shift indicating that they are all moving away from each other. Blue Shift occurs when an object is moving towards you. 7

8. Misconceptions This theory explains the origin of the universe It attempts to explain how the universe was created from a very small & dense state to what it is today This theory was a big explosion It describes the expansion of the universe at a very rapid rate (possibly faster than light). 8

9. How it works Singularity In the beginning, all of the stars and galaxies that we can see today, were compacted into an area of zero volume. Results of the big bang formed 4 basic forces Electromagnetism Strong nuclear force Weak nuclear force Gravity 9

10. What happened before the big bang? No one know what the universe was like before it happened. According to scientists space didn’t exist before the big bang. 10