1. Black Holes: The Information Paradox Andrew Buccilli PH2010 Sophomore Seminar October 26, 2007

2. What is a Black Hole? Region of extremely dense packed matter Gravity so strong that nothing can escape it Gravitation balances EM radiation

3. Sizes 1. Supermassive Black Holes –millions to billions of times the mass of our sun –believed that most galaxies contain one at their galactic center –the slow acceleration of matter is one way of formation

4. 2.Intermediate-Mass Black Hole –mass is significantly more than SBH yet far less than SMBH –less evidence for existence not clear how they form –too massive –lack extreme environment conditions 3.Stellar Black Hole –at least 1.5 solar masses –largest is 17.5 solar masses –formed by gravitational collapse of massive star

5. 4. Quantum Mechanical Black Hole –BH could exists at any mass in theory lower mass, higher density of matter –Smallest mass is the plank mass ~2 × 10^−8 kg less mass: inconsistent and incomplete –BH mass < few times solar mass no know processes to produce –Brian Greene (PhD. at Oxford University) electron might be a micro black hole –mass, charge, spin Note : Primordial black hole –extreme density of matter

6. Black Holes Have No Hair Complicated formation- Simple stationary state Can be characterized by: –Mass –Angular momentum –Electric charge Same properties –Unknown how formed i.e. matter or antimatter

7. Event horizon of the region of escapeBoundary of the region of escape “point of no return” –WARNING : “point of no return” Not a solid surfaceNot a solid surface –does not obstruct or slow down matter Singularity Point where mass is entirely compressedPoint where mass is entirely compressed –zero Volume –infinite gravitational pull and density General relativity breaks downGeneral relativity breaks down

8. Vacation Through a Black Hole Traveling through [T] - Outside observer [O] –[T] approaches “c” approaching BH –[T] experiences nothing abnormal through horizon –[O] sees [T] acting in a bizarre way Spaghettification –Newton’s law of gravitation explains principles [T] appears to slow down [T] is spaghettified [O] never sees anything inside the horizon –[T] appears flattened and frozen at horizon [T] sees nothing unusual until reaching the singularity –All components of [T] are torn before striking –At the singularity- ?????????

9. Hawking Radiation Black holes slowly radiate away energy –Increases as mass decreases Not actually black Particle- antiparticle pair –both pulled in –both escape –one pulled in one escapes BH lost minute amount of mass –radiation comes from the horizon

10. The Beautiful Equation –Thermodynamics –Gravity –Quantum Physics –Relativity Eventually a BH will radiate away all of its mass –Only thermal energy would remain There is trouble on the horizon…

11. The Information Paradox Physics doesn’t work?! Conservation of energy –Reversibility Information cannot be destroyed

12. Video Clip!

13. Black Hole Complementarity Opposing point –Info. never reached the horizon Vaporized and radiated Vacation revisited –Person falling in would be dead and alive? Both points are true String Theory –Agrees with both observers

14. Video Clip?

15. Our Memories Are Safe? Parallel universes Quantum gravity