Download Diapositiva 1 - ScienceinSociety

BLACK HOLES
http://www.cfa.harvard.edu/seuforum/darkenergylanding.htm
Facts about Black Holes
A Black Hole is, by
definition, a region of
space-time where
escape to the outside
universe is impossible,
an object so massive
that nothing could
escape the grasp of its
gravity.
Facts about Black Holes
The idea of a black hole dates
back to the 1700s. But the
modern story of black holes
really starts with Einstein's
revolutionary theory of
gravity, completed in 1917.
Over the past century,
scientists have used Einstein's
theory of gravity to develop a
picture of what black holes
must be like. Here are some of
the amazing properties of
black holes that they have
predicted.
Black holes are created when a
star goes supernova.
Facts about Black Holes
 The gravity of a Black Hole
is so strong that nothing,
not even light, traveling at
186,000 miles (300,000 km)
per second can escape it.
 Near a black hole, the
slowing of time is extreme
. Times stops. And at the
center of the black hole,
Einstein’s theory predicts
that time is destroyed.
Facts about Black Holes
The outer edge of a Black Hole is surrounded by the
Event Horizon.
The Photon Sphere
A photon sphere is the radius around a Black Hole
at which light paths are gravitationally bent into
a circle, thus causing the photons to orbit the
hole.
The Event Horizon
 The Event Horizon is the
gravity field of a Black
Hole, this means that,
upon entering, nothing can
return, vanishing without a
trace.
The Event Horizon
The Singularity
The “Singularity” is the center of a black hole.
The Singularity
It has been theorized that the size of the
Singularity is smaller than an atom.
The Singularity
Just imagine!
Our school, our country,
the Earth, our Sun and
millions of other Stars,
all being crushed by
gravity into a size that
too small to be seen by
any microscope.
Distance
 The nearest known Black Hole is thought to be
about 1600 light years away from Earth.
New Discoveries
 In recent studies of Black Holes, scientists have
discovered a Black Hole in the Milky Way.
 It is unique because it involves a stellar black hole,
one that resulted from the collapse of a dead star
here in our Galaxy.
New Discoveries
This picture of what is
thought to be a Black
Hole came back when
the Hubble telescope
was pointed toward
galaxy NGC 4438.
Conclusion
Not much is known about Black Holes, but science
is making new discoveries every day. This is what
they are looking at:
 What happens to space and time near a black
hole?
 What role do black holes play in the unfolding
universe?
 Can we see a black hole being formed?
 What happens inside a black hole?
Bibliography
Isaac Asimov’s Library of the Universe: Quasars, Pulsars, and Black Holes
The Children’s Space Atlas By: Robin Kerrod
The Sun’s Family- Volume 1 By: Robert Hitt, Jr.
The Universe: The Stars By: Ian Ridpath
http://64.40.104.21/blackholes/small/blackholebinary3sm.jpg
http://members.cruzio.com/~noel/views/pics/hole2.jpg
http://library.thinkquest.org/25715/swirlbh_profile.jpg
http://www.dmns.org/NR/rdonlyres/91739ACF-EFAE-4A11-903CB5D7E44C2404/775/BH35580.jpg
http://www.rdrop.com/users/green/school/horizon.htm
http://curious.astro.cornell.edu/question.php?number=473
http://www.foxnews.com/story/0,2933,253148,00.html
http://archives.cnn.com/2000/TECH/space/06/05/hubble.black.holes/index.html
Assignment
How can we see and study black holes?
Read and summarize the information that comes
here:
http://www.cfa.harvard.edu/seuforum/bh_reallyex
ist.htm
http://scienceinsociety.wikispaces.com/5.+UNIVER
SE