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Black Holes
http://www.nasa.gov/vision/universe/roboticexplorers/black_holes_ripple.html
Myth or Reality?
Black holes are giant,
cosmic vacuum
cleaners that swallow
up everything around
them.
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http://amazing-space.stsci.edu/resources/myths/black_holes.php.p=Teaching
Myth
Reality: Black holes do not suck up nearby
material. If the Sun were magically converted into
a black hole, Earth's orbit would not change.
Material generally falls into a black hole when it
collides with other material orbiting the black hole.
The collision alters the material's orbit. Instead of
orbiting a comfortable distance from the black
hole, the material is now orbiting too close to the
black hole. Then the black hole's enormous gravity
traps the material in a one-way spiral to oblivion.
http://amazing-space.stsci.edu/resources/myths/black_holes.php.p=Teaching+tools
Myth or Reality?
You can see a black hole.
Myth
The light produced or reflected by
objects makes them visible. Since no
light can escape from a black hole, we
can't see it. Instead, we observe black
holes indirectly by their effects on
material around them.
http://amazing-space.stsci.edu/resources/myths/black_holes.php.p=Teaching+tools
Myth or Reality?
Black holes lead to other
places.
http://amazing-space.stsci.edu/resources/myths/black_holes.php.p=Teaching+tools
Myth
In science fiction shows, people
sometimes travel through
wormholes. Many students think
black holes are wormholes and
therefore lead to other places.
Wormholes don't exist; they are
merely a hypothesis.
http://amazing-space.stsci.edu/resources/myths/black_holes.php.p=Teaching+tools
Dark Matter
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http://hubblesite.org/gallery/album/entire_collection/pr2007017a/
About 90% of
galaxies consist of
dark matter.
Black holes are a
type of dark matter.
Micro Black Holes
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These black holes
are hypothetical.
Their mass would be
less than a star.
The smallest
possible black hole.
http://www.spaceflavors.com/
Stellar Mass Black Holes
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http://www.teo.net/astronomy/stellar-mass-black-holes/
These black holes
are formed by the
gravity from the
death of a massive
star.
The star has a
supernova explosion
when it dies and the
corpse becomes a
black hole.
Intermediate Black Holes
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These black holes
have significantly
larger mass than
stellar mass black
holes.
And are significantly
smaller than
supermassive black
holes.
http://astro.ucla.edu/announcements/press.shtml
Supermassive Black
Holes
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http://www.ociw.edu/news/midweightblackhole
These are the most
massive black holes.
Scientist have
evidence that there
is a supermassive
black hole in the
center of each
galaxy including the
Milky Way.
How they are formed
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http://www.ifa.hawaii.edu/~barnes/ast110_06/bhaq.html
When a giant star
dies, all of its mass is
squeezed in a single
point.
Time and space stop
Mass has no volume
and time does not
pass
Parts of a black hole
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The center of a black
hole is called the
singularity.
Within a certain
distance from the black
hole is the event
horizon. This is where
the gravitational force
is so strong, anything
that passes will be
sucked in, including
light.
http://www.eclipse.net/~cmmiller/BH/blkbh.html
Parts of a black hole continued...
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The more massive the singularity, the
larger the event horizon.
The event horizon is the point where
nothing can go back.
Nothing gets sucked into the event
horizon, it has to pass through it to
become caught in it.
Gravitational Force
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Albert Einstein was the
first to discover gravity
in 1916.
Gravitational waves are
created when two big
masses spin, collide or
explode.
http://www.ifj.edu.pl/~stachnie/einsteine.html
Gravitational force of a black hole
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http://www.daviddarling.info/encyclopedia/S/supermassive_black_hole.html
The gravitational force of a
black hole is the same as
when it was a star.
Our sun is an average size
star, if it were to die and
become a black hole the
Earth's orbit would not
change because the
gravitational force would
not change. This is why
objects such as planets
are safe from black holes.
Spaghettification in Black
Holes
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When the gravitational
force is so strong it
stretches objects into
long, thin shapes like
spaghetti.
No object can resist this
strong gravitational
force near black holes.
http://www.youtube.co
m/watch?v=1bz8nNZr2d
4
http://www.dawn-alleria.com/viewtopic.php?id=432
Finding a black hole
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http://imagine.gsfc.nasa.gov/docs/science/mysteries_l1/massive.html
Although black holes
are black, when
matter falls into
them, it can heat up
so much that it glows
in x-rays.
In the Milky Way Galaxy
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Scientist have
evidence that they
have found a black
hole in the center of
our galaxy.
http://www.nasa.gov/vision/universe/roboticexplorers/black_holes_ripple.html
In the Milky Way Galaxy
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The evidence for this is
a star near the center
of our galaxy is
spinning at speeds of
up to 3000 miles per
second. That is REALLY
fast!
Only a black hole 3
million times the size
of our sun could cause
a star to move so fast
http://www.nasa.gov/vision/universe/roboticexplorers/black_holes_ripple.html
Questions about black holes
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If you want to know more about
black holes, ask your parents to
look at these web sites
http://imagine.gsfc.nasa.gov/doc
s/ask_astro/black_holes.html