1. Black Holes This one’s green. I like green.

2. What happens after a SN? Material remaining after a supernova is 3 times more massive than the sun or more Pressure is strong enough to collapse the star beyond the neutron-degenerate pressure. Star remnant collapses and vanishes.

3. Characteristics of a black hole MATTER IN A BLACK HOLE LOSES ALMOST ALL OF ITS ORIGINAL CHARACTERISTICS! Retains only: –Mass (therefore the gravity) –Its angular momentum *** All other characteristics no longer exist! concepts like protons, electrons, neutrons, molecules, compounds etc. no longer apply.

4. ??? I have a headache. Escape Speed- speed needed for an object to escape the gravity of another. –Bigger mass= bigger grav, then bigger ES –Smaller radius= bigger grav, then bigger ES The escape speed for a black hole is greater than the speed of light. Nothing can exceed the speed of light (except Bause when he runs towards the lunch line) SO nothing can escape a BH

5. Singularity General relativity (Einstein) predicts that in creating a black hole, matter compresses to infinite density. ALL known laws of physics are invalid. Recall Relativity explains the behavior of the really massive, quantum mechanics explains the behavior of the really small (subatomic stuff). A black hole is both REALLY massive and REALLY small.

6. Schwarzschild radius The radius that matter (any matter, does it matter?) must be compressed for it to have an escape speed equal to the speed of light. All objects have a SR –Earth = 1 cm or a grape –Jupiter = 3 cm or 3 grapes (I’m not creative) –Sun = 3 km

7. Event Horizon The location around a black hole where the escape speed EQUALS the speed of light. Everything in the EH is lost forever. No information can be gathered from within. Outside of the EH, everything appears to “slow”… called gravitational redshift

9. Gravitational Redshift Speed of light is CONSTANT through constant medium. In order for light to escape gravity it must work (use energy). Greater the grav, more energy. SO, light will lose energy and shift towards red portion of electromagnetic spectrum (longer wavelength)

10. Gravitational Lens Gravity can bend light rays. This can allow us to see objects normally too far for us to see. Bause diagram.

13. All galaxies… ranging from 3 bill. ly to 9 bill ly.

14. Sphagettification?

15. Infalling Matter Matter closest to the BH will be pulled greater, stretching the matter. Eventually pulled apart, atom by atom.

16. Does a black hole last forever? Nope. They can evaporate through Hawking Radiation (more in your lab). Process takes a LONG time. A 5 solar mass black hole would take 10 62 years to evaporate. So, black holes that have formed, still exist today.

17. Supermassive Black Holes All elliptical and spiral galaxies seem to have one in the center. Irregular galaxies (aka dwarf galaxies) do not. A black hole with the mass of millions to billions of Suns!