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Announcements. Exam 3 is Thursday April 11. Tentatively will cover Chapters 7, 8, 9 & 10 Sample questions are posted May change format of Exam 3 to mostly essay and only a few multiple choice. . The Schwarzschild black hole is a non-rotating black hole. The Schwarzschild radius is
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Announcements • Exam 3 is Thursday April 11. Tentatively will cover Chapters 7, 8, 9 & 10 Sample questions are posted • May change format of Exam 3 to mostly essay and only a few multiple choice.
The Schwarzschild black hole is a non-rotating black hole The Schwarzschild radius is The Schwarzschild metric is
A rotating black hole is a Kerr black hole Solution developed by Roy Kerr (NZ) while at UT (the REAL UT) in 1963
The Kerr black hole has two photon spheres depending on which way the photon is rotating Photons whose orbital axis is the same as the black holes lie on the “spheres”. Those with different orbital axis lie between the “spheres”. The photon “spheres” are actually ellipsoids of revolution
Each time an event horizon is crossed the roles of space and time reverse The ring singularity is repulsive!!!
Rotating black holes drag spacetime around with them This rotating space-time is called frame dragging
Black Hole Thermodynamics Hawking Radiation has a blackbody characteristic curve which implies that a black hole has a temperature. The temperature is given by h is Planck‘s constant c is the speed of light k is Boltzman’s constant G is the gravitational constant M is the mass of the black hole A one solar mass black hole has a temperature of about 100 nanokelvin
Hawking radiation is a very slow process The time required for a black hole to evaporate is given by
Wormholes and other space-time exotica Black hole Wormhole
We can see black holes by the matter falling into them A black hole is invisible but you can hear the screams of its victims as it eats them. Watch Black Hole Accreting From Companion, Black Hole Eats Star, Black Hole Eats Neutron Star and Sgr A Star Flare Videos
We can see black holes by their gravitational effect on nearby stars Watch Galaxy Center Star Orbits video
The biggest black holes are located at the centers of galaxies Watch Journey to a Galactic Black Hole video
Black holes often form jets of relativistic particles Watch Formation of a Black Hole Jet video
The clearest evidence of a black hole is from spectra Extreme redshift to extreme blueshift in a small space is the fingerprint of stuff orbiting a black hole
Quasars are supermassive black holes at the centers of galaxies