1. Black Holes Dennis O’Malley

2. How is a Black Hole Created? A giant star (more than 25x the size of the sun) runs out of fuel –The outward pressure of the nuclear fusion ceases The gravity of the star forces it to collapse into itself after an explosion The mass of the star condenses to its smallest possible size –“Central Singularity” The gravity is so strong that nothing, not even light, can escape –Therefore, black holes cannot be seen by visible light

3. The Anatomy of a Black Hole The event horizon is the edge where particles outside can escape and particles inside cannot The accretion disk is gas on the outside of the black hole that forms a rapidly rotating disk –Most doesn’t fall in so not very much energy is created from the destruction/absorption of the gas The area outside the black hole shows space as distorted, which is caused by the high gravity bending light that passes outside the event horizon –There are infinitely many images of the stars behind the black hole; they are distorted as the light from the stars orbit the black hole Gravitational Lensing

4. Theories New computer diagrams have black holes not being created by explosion and collapse, just collapse The center of the milky way galaxy has a large black hole –Originally discovered by radio waves –Could be acting as a center of gravity for our galaxy –Adaptive optics uses infrared to see many stars circling it very fast –Some astronomers believe every galaxy has a supermassive black hole at its center

5. Theories Many black holes are paired up from when galaxies passed closely by –The galaxies combine and the black holes orbit around each other Their orbits are reminiscent of how protons and neutrons act in an atom Scientists are trying to connect quantum mechanics of atoms to the most massive objects in the universe – black holes –They eventually fall into one another Become a single, larger black hole Violent, would send gravitational ripples through space-time

6. Theories Tiny particles that barely exist could create “Hawking Radiation” –Particles come into existence in pairs –End existence by coming together after a moment –If they came into existence on the event horizon, one may stay in existence The one to survive outside the event horizon would become real and emit light That could allow us to see black holes

7. Theories The conservation of information principle says that every ounce of material a black hole absorbs, it should radiate an equivalent amount of energy out of its event horizon –Black holes may defy that principle and destroy the matter altogether

8. Theories An outside observer would see something fall into a black hole in slow motion then frozen in time at the event horizon –Einstein’s theory of relativity says that a black hole would distort space and time

9. Could I Orbit A Black Hole? You need to be traveling at escape velocity –Similar to escaping the earth’s gravity into space, just more intense

10. Wormhole? Maybe, however we may never know Light from a black hole will never reach us –Gets sucked in Researchers/probes could never communicate back if they entered one –Gravity would render them useless by crushing Allow time travel? Travel to another dimension? –That would be cool

11. Personal Questions If black holes absorb all this matter, where does it go? –Condensed into “central singularity” of the black hole? –If so, how much matter can the “central singularity” contain? –Was the big bang a black hole exploding after the “central singularity” reached its breaking point?