Hi Tom,
  I have put suggestions within curly brackets "{ }", for consideration.
So search the document for "{" to find where I have made comments.

Of Black Holes and Time Travel
by Daybee Martin

One day, you decide to fulfill a lifelong dream-to travel to outer space
into a black hole and return to talk about it. You have read so many
science fiction books that you believe a black hole is some pathway into
another time. You read somewhere that time slows down as you enter a black
hole, and that you can possibly end up sometime in the past, and, perhaps,
have the power to change a few things.
        Time travel, time warps, spaceships... any avid science fiction fan
may have read every conceivable plot line attributed to this phenomena that
astrophysicists call black holes. A black hole is a region in space where
the gravity is so great that nothing, not even light, can escape (which
pretty much puts a damper on your return plans). And since gravity is
inversely related to time, {Well, I do not really think that it is
absolutely correct to say that gravity is related to time, but for the
purposes of brevity, this is probably close enough - the spirit is
correct} that means that when gravity increases, time
slows down. But the fact is, it isn't possible for any human to survive
such a tremendous amount of gravitational force.
        To understand just how great this force is, let's examine how a
black hole comes into being. Black holes have been called "dead stars,"
which isn't a misnomer. Stars are initially made up of large amounts of
hydrogen gas molecules moving really fast. These molecules heat up and fuse
to form another kind of gas, helium. { Remove "The heat from this fusion
causes violent explosions", with "The fusion process releases tremendous
amounts of energy, further heating the gas,"}
which counter{s} the natural {gravitational} attraction among these
particles that would otherwise cause stars to collapse. Stars live most of
their youth in this manner. As long as there's hydrogen to fuel the
explosions and prevent the collapse, they can continue their stints as
bright mainstays in the night sky.
        Alas, fate is not always kind, and the stars eventually run out of
"fuel." When this happens, it seems that nothing can stop their inevitable
death, and they begin to collapse into themselves. As their particles get
closer to each other, they get increasingly "claustrophobic." As if
repulsed, the closer they get to each other, the faster they want to run
away.  Ironically, this repulsion causes an expansion that counters the
seemingly unavoidable collapse. Like final courageous attempts at survival,
they prolong their lives by maintaining a balance between collapse and
expansion. Eventually, though, all stars meet their deaths. Some stars die
violently. They succumb to the force of gravity, and when gravity wins out
in such a violent manner, stars become black holes.

[PULL QUOTE]Some stars die violently. They succumb to the force of gravity,
and when gravity wins out in such a violent manner, stars become black
holes.[PULL QUOTE]

        The bigger a star is to begin with, the greater the amount of
gravity it will have to overcome later on. This is why scientists believe
that only the really massive stars end up as black holes. As stars collapse
they get denser, and the denser they get, the stronger their gravity
becomes. This is because just as gravity has an inverse relation with time,
it has a direct relation with how much mass anything has.

Powerful Forces
        Gravity is that mysterious entity that keeps our feet planted on
the ground. The gravity on earth is strong enough to keep us from escaping
into space, but not so strong that we get painfully squished into the
floor. To escape the earth's pull, we simply need to move faster than what
is called the escape velocity, something rockets and spaceships do
{remove "this"} all
the time.  But in a black hole, so much mass is squished into such a small
volume that there is too much gravity to overcome. When anything comes
within its vicinity, even something as fast as light, gravity just sucks it
in.
        Say you still insist that you can, indeed, travel into a black
hole. What would an observing friend see as you approach a black hole?
Well, she would see you move {Hmm... seems to be an important point, 
however, the observer would not see you move "slower and slower"
they would see you move "faster and faster"},
until you reach what is called the event horizon.
{I would finish the sentence " however the apparent passage
of time in your reference frame will appear to slow down."} 

[PULL QUOTE]Say you still insist that you can, indeed, travel into a black
hole. What would an observing friend see as you approach a black hole?[PULL
QUOTE]

        The event horizon is that region around black holes they call the
"point of no return." Once there, no matter how hard you try, you will
never be able to escape. This is where the escape velocity exceeds the
speed of light, and where, with the gravity so great, time theoretically
stops. {remove "Your friend can wait forever and never see you reach the
event horizon."} This is also the point where you get ripped apart. You
see,
gravity increases the closer you are to the center of the source. If you're
traveling feet first, the force of gravity pulling at your feet is much,
much greater than the force of gravity exerted on your head. So you get
stretched like a rubber band-end of journey. {remove "Your friend gets
tired of waiting, shrugs her shoulders and goes on with her life."}
        Say you were to survive this tremendous force, what happens next?
As you cross the event horizon, you get sucked closer to the heart of a
black hole, its singularity, where all the star mass is crushed into a
point where the radius is equal to zero. This is where the laws of physics
cease to make sense and the dimensions of space and time switch places.
        On earth, space is made of three coordinates, which you can
control. You can go from left to right and up and down. You can move
however which way in three-dimensional space, but the fourth dimension,
time, you cannot. Well, in a black hole, these dimensions are reversed.
Stuck in the singularity, unable to move along the dimensions of space, you
{add "might"} acquire the ability to move forward and backward in time
instead.

A Word on Wormholes
        A few scientists have conjectured that a black hole may be
connected to another black hole creating a connection into another set of
dimensions of space and time. The tunnel connecting these two regions of
space-time is known as a wormhole.
        A wormhole may be thought of as some sort of a time machine. The
problem is, according to some theories, wormholes collapse as soon as they
form because the gravity is just too powerful. But there is another problem
with this scenario. Physicists call it violating causality. It's the idea
that effects logically follow causes. If you stub your toe on a bedpost,
you yelp in pain. You usually don't yelp in pain before you hurt your toe.
        Suppose you go through a wormhole and end up running into yourself.
Do you invite the other you to take the trip with you? Or say that you end
up in your living room, see another you, and in your excitement, hit her,
er, you in the head, killing you, er, her in the process.  How can you kill
yourself-or better yet-how did you end up with two of you in the first
place?  This is the paradox of time travel. It violates all common sense.
        So this is where we go back to the part where I say, don't even
bother you'll never make it past a black hole anyway, and even if you did,
and even if theories of wormholes were true, why would you want to meddle
with time anyway?  So, go see your friend, and have iced mochas instead.
Life has never been better here on earth where up is up, left is opposite
right, and "The X-Files" are on Sunday.

Daybee Martin is an avid science enthusiast and writer who lives in the Bay
Area.


Explorit Science Center
3141 5th Street
P.O. Box 1288
Davis, CA 95617
(530) 756-0191
FAX (530) 756-1227