Transcript Black Holes - miamioh.edu

Black Holes
Dennis O’Malley
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
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
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
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
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
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
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
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
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
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?