Extreme Gravity Situations

A thread of 2 messages, 22 February 1994 to 23 February 1994, in the order they were sent.

#6857 Extreme Gravity Situations

Roger Sanger · 22 February 1994

To: Bruce E Johnson [email removed]


Hi, Rodge here:

One comment about your ideas concerning gaming on the surface of
a gas giant:

The gravity on the surface of a gas giant would be sufficient to
literal crush a human, or even a starship.  They are typically
MANY thousands of times greater mass than the earth.

Theorhetically, you could build something that could withstand
that kind of environment, but humans wouldn't be able to go,
because the maximum G-level that can be nullified is 6 g's.

The main problem with pulling too many G's on the human body is
when the pull of gravity is greater than the heart's ability to
pump the blood against it to the brain.  This results in not
enough blood reaching the brain, and results in the subject
blacking out.

In extreme gravity situations, providing oxygen would be a moot
issue, because the various mechanisms of cellular metabolism
would be hampered too greatly by the force of gravity to function
properly.  Just as you wouldn't be able to move due to your own
incredible weight, neither would your mitochondria.

As for the flourocarbon fluid... When cells receive either too
much or too little oxygen, free radical molecular activity
increases.  Free radicals are atoms or molecules which have an
unpaired electron in orbit, making them highly reactive and prone
to pulling an electron off of an adjacent atom or molecule
inorder to re-establish an even number of electrons.  The
molecule which just lost its paired electron has thus become a
free-radical, and the cycle of electron stealing repeats itself
in a harmful chain reaction.  Oxidation, rancidity, and
autoxidation (oxidation occuring in liquid, from the oxygen
molecules contained therein).  Free-radical activity can damage
cells, and has been linked as a cause to cancer, heart disease,
acne, dandruff, hair loss, and many other illnesses.

When a person stops breathing for so long that they are in danger
of sustaining permanent brain damage, the reason is because
free-radical activity has increased due to the lack of oxygen (a
condition known as hypoxia).  The drug Hydergine, which is a
powerful anti-oxidant, prevents autoxidation and thus can prolong
the amount of time you can go without air before sustaining
permanent brain damage to as much as 10 to 15 minutes (rather
than the usual 7 minutes).  It is used by paramedics in Europe to
reduce the risk of complications caused by circulatory failure
and trauma (insufficient blood to deliver the necessary amount of
oxygen to the body).


                             o o
                            \___/

                      Roger, Over and Out

                      Roger Sanger
                      [email removed]
                      [phone removed]
                      [address removed]

#6867 Gas Giant gravity

Timothy Little · 23 February 1994 · reply to #6857

I just have a couple of minor points of contention in Roger's informative
posting...

Roger Sanger ([email removed]) writes:
>The gravity on the surface of a gas giant would be sufficient to
>literal crush a human, or even a starship.  They are typically
>MANY thousands of times greater mass than the earth.

I think you mean the *pressure* is immense on the surface of a gas giant,
rather than the gravity.  Though gas giants may bethousands of times more
massive than earth, they are typically also much larger.  Surface gravity
increases linearly with mass, but decreases with the square of the radius.
So, a planet 1000 times more massive and 20 times larger would have a
surface gravity only 2.5 times that of Earth.  This a high gravity
situation, but not beyond all help from technology.

>In extreme gravity situations, providing oxygen would be a moot
>issue, because the various mechanisms of cellular metabolism
>would be hampered too greatly by the force of gravity to function
>properly.  Just as you wouldn't be able to move due to your own
>incredible weight, neither would your mitochondria.

Gravity becomes practically insignificant at such small scales.  The
square-cube law comes into play (gravitational force is proportional to the
cube of the length, while strength is proportional to the square).  For a
cell-sized structure the strength/weight ratio is about 1 000 000 times
greater than for a complete human body.

>Free radicals are atoms or molecules which have an
>unpaired electron in orbit, making them highly reactive and prone
>to pulling an electron off of an adjacent atom or molecule
>inorder to re-establish an even number of electrons.  The
>molecule which just lost its paired electron has thus become a
>free-radical, and the cycle of electron stealing repeats itself
>in a harmful chain reaction.

Where does the energy come from in this chain reaction?  I would expect
that only molecules with lower binding energies would be susceptible to
free radical damage, and hence less able to remove electrons from further
molecules.
Certainly free radicals damage biological molecules, but is it really a
chain reaction?

- --
Tim Little