1. Black Holes Shannon Schmoll University of Washington Department of Astronomy

2. Special and General Relativity SPECIAL RELATIVITY  Nothing Can Travel Faster than the speed of light, 300,000,000 km/s GENERAL RELATIVTY  Extension to SR that includes a theory on gravity  Explained why it’s the only force that acts instantaneously 2

3. Gravity in General Relativity Gravity is a ‘warp’ in space-time caused by mass: MORE MASS = MORE WARP = MORE PULL TO FALL IN

4. So…What is a Black Hole ? A HOLE! First what it’s not: IT IS: A lot of mass pushed into a itty-bitty amount of space

5. Why are Black Holes Black? The Escape Velocity of the black hole is greater than the speed of light Things on earth can escape with a certain velocity V > 11.2 km/s Wheeler coined the term “black hole” in 1969 V < 11.2 km/s V > c V < c

6. What are Black Holes Made Of? Most Black Holes in the universe are made of collapsed stars ANYTHING with mass can be a Black Hole! Just make it small enough using the Schwarzchild Radius: RsRs = 2GM c2c2 e-e-

7. Where Can Black Holes be Found? In the Center of our Home, the Milky Way. Sagitarius A* In the Center of Other Galaxies! Usually in the form of “Active Galatic Nuclei or Quasi-Stellar Radio Sources” …

8. …And Coming Soon to Earth!… …With the Large Hadron Collider at CERN, opening in 2007 in Geneva LHC Facts  Circular Particle Accelerator  27 km Circumference  Will run 4 experiments including creating black holes smaller than a proton

9. What did we learn?  Black Holes are not Holes, but compressed matter  They cause gravitational forces so large that light can’t escape their pull  They can be made of anything…even humans!  They can be really tiny Future Reading