These are a few of my favorite things

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These are a few of my favorite things
Black Holes and stretched space Eclipse Cruise
2009
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What is a black hole?

• A massive spacetime curvature singularity,
• Surrounded by an event horizon

(a point or ring of infinite density and tidal
acceleration) (a spacetime boundary between
causally disconnected regions of the universe)
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i was considering howwithin night's loosesack a
star'snibbling in- fin-i-tes-i-mal-ly
devours darkness thehungry starwhichwill
e.-ventu-al-ly jigglethe bait ofdawn and
be jerked into eternity. when over my head
ashootingstarBurs (tinto a stale shrieklike
an alarm-clock) -- e.e. cummings
But what is a black hole REALLY?
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What happens at the event horizon?
Be careful where you cross (Euna Lee and Laura
Ling, Korea, AP photo)
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Can matter escape from a BH?
Only by dissolving into Hawking radiation!
Quantum tunneling produces a Particle-Antiparticle
pair from the vacuum! http//superstringtheory.c
om/blackh/blackh3.html
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Black holes in Nature

• The afterlife of giant stars
• Black hole masses 3-15 solar masses
• Giant sinkholes in galaxy centers
• Black hole masses million to billion solar
  masses

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How we find black holes (and neutron stars)
X-rays!
Rossi X-Ray Timing Explorer satellite, launched
1995
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How do black holes emit X-rays?

• Rotating gas disk with frictional heating
• Artistic conception movie 1
• Artistic conception movie 2

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How can we prove these are the BH of Einsteins
theory?

• Measure the gravitational waves emitted as two
  black holes merge.

Artistic conception 3
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Prediction of gravitational waves from black hole
mergerCentrella et al, 2008
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How to describe gravitational waves
Oscillating tides
Stretching of space
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What causes the tides?Why are there two high
tides daily?
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A good try, but wrong

• Earths movement causes the oceans to slosh like
  water in a bathtub
• Galileo Galilei, 1622

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Waving Space
Cross-section of space fabric outside a pair of
orbiting black holes
Simulated drum head Dan Russell, Kettering U.
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How to measure this stretching?
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Replace rings of particles by 4 swinging mirrors
Laser Interferometer Weiss and Drever, 1970s
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Global network of detectors
GEO
VIRGO
LIGO
TAMA
AIGO
LIGO
LISA
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LIGO Laser Interferometer Gravitational-wave
Observatory
4 km
WA
LA
4 km
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Why so complicated?

• Must measure changes in mirror positions to
  within 1/1000 diameter of a proton!
• LIGO has succeeded in reaching this goal and
  now has to observe patiently for gravitational
  waves.
• When will they discover gravitational waves?
• EB prediction 2014 or sooner

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Ultimate successNew Instruments, New Field,
the Unexpected
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Additional Credits and Information

• Credits
• Rossi X-Ray Timing Explorer figure courtesy
  NASA/Goddard Space Flight Center
• LIGO and other gravitational wave images courtesy
  Nergis Mavalvala
• Books
• The Fabric of the Cosmos, Brian Greene
• The Elegant Universe, Brian Greene
• Black Holes and Time Warps Einsteins Outrageous
  Legacy, Kip S. Thorne (more advanced)

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What causes the tides?Why are there two high
tides daily?
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Gravity weakens with distance
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