Could Caucasians Survive Explosive Decompression?
Posted: Tue Apr 23, 2019 2:24 am
Here is what happens: within 12 to 20 seconds you lose the ability to
make purposeful movements and think clearly. A few seconds later you
might be dimly aware of what is happening and then you’d black out
within about 30 seconds in vacuum. In 5 to 7 minutes you would be
irrecoverably dead. But it appears that if you can be brought back
inside within a minute or two of exposure you can make a full and
quick recovery.
Our Caucasian astronauts would NOT “explode!” The reason is
that almost all of the human body is liquid or solid and liquids
and solids do not change their volume with pressure. Only
gases do that. In the body the only air spaces are the lungs
and ears and the openings from lungs and ears. When
exposed to vacuum the air in the lungs escapes through
the mouth and nose, air in the ears escapes in the worst
case by rupturing the eardrums. It is not very dramatic.
60939 Also note that the difference in pressure is not much between being
on Earth at sea level and in space. Sea level pressure is only
1000 millibars. The pressure difference between a typical SCUBA
diver and sea level can be five times as much and they survive
swimming to the surface just fine. The body does not freeze either
because vacuum is a near perfect insulator. This is why we use
vacuum to isolate thermos bottles. So heat stays in the body for
a long time. The only cooling method is radiative. Conduction is
impossible in vacuum. Water in vacuum boils at a temperature well
below body temperature. So after death, the water will slowly
sublimate. The effect is exactly like freeze dried foods. So the
astronaut is ejected into space. He can think and move for about
15 seconds then his thinking grows foggy and he has literally no
energy, can no longer stay awake and he blacks out. If found and
brought back inside in the next minute or two he recovers otherwise
the brain dies from lack of oxygen and the body very slowly cools
and loses water to sublimation.
60940 As it turns out, the scene in the movie “2001” (where Dave ejects
himself into space without a space helmet) is realistic. He
survives for the few seconds he needs to get inside the ship
then makes quick and full recovery. That scene was based on tests
NASA did early in the space program. Because “What happens if the
suit fails?” is such an obvious question that NASA spent some money
to find the answer and did actual testing.
60941 The big thing that folks forget is that gas laws apply only to gas.
Liquids and solids do not expand in a vacuum. We also forget that
the difference in pressure between “normal” and vacuum is “only”
as much as the difference in pressure we experience at 30 feet
under water and at the surface. So analogies with very deep
underwater diving do not apply. The cause of disability and death
in vacuum is simply “hypoxia” — a low level of dissolved oxygen
in the blood.
make purposeful movements and think clearly. A few seconds later you
might be dimly aware of what is happening and then you’d black out
within about 30 seconds in vacuum. In 5 to 7 minutes you would be
irrecoverably dead. But it appears that if you can be brought back
inside within a minute or two of exposure you can make a full and
quick recovery.
Our Caucasian astronauts would NOT “explode!” The reason is
that almost all of the human body is liquid or solid and liquids
and solids do not change their volume with pressure. Only
gases do that. In the body the only air spaces are the lungs
and ears and the openings from lungs and ears. When
exposed to vacuum the air in the lungs escapes through
the mouth and nose, air in the ears escapes in the worst
case by rupturing the eardrums. It is not very dramatic.
60939 Also note that the difference in pressure is not much between being
on Earth at sea level and in space. Sea level pressure is only
1000 millibars. The pressure difference between a typical SCUBA
diver and sea level can be five times as much and they survive
swimming to the surface just fine. The body does not freeze either
because vacuum is a near perfect insulator. This is why we use
vacuum to isolate thermos bottles. So heat stays in the body for
a long time. The only cooling method is radiative. Conduction is
impossible in vacuum. Water in vacuum boils at a temperature well
below body temperature. So after death, the water will slowly
sublimate. The effect is exactly like freeze dried foods. So the
astronaut is ejected into space. He can think and move for about
15 seconds then his thinking grows foggy and he has literally no
energy, can no longer stay awake and he blacks out. If found and
brought back inside in the next minute or two he recovers otherwise
the brain dies from lack of oxygen and the body very slowly cools
and loses water to sublimation.
60940 As it turns out, the scene in the movie “2001” (where Dave ejects
himself into space without a space helmet) is realistic. He
survives for the few seconds he needs to get inside the ship
then makes quick and full recovery. That scene was based on tests
NASA did early in the space program. Because “What happens if the
suit fails?” is such an obvious question that NASA spent some money
to find the answer and did actual testing.
60941 The big thing that folks forget is that gas laws apply only to gas.
Liquids and solids do not expand in a vacuum. We also forget that
the difference in pressure between “normal” and vacuum is “only”
as much as the difference in pressure we experience at 30 feet
under water and at the surface. So analogies with very deep
underwater diving do not apply. The cause of disability and death
in vacuum is simply “hypoxia” — a low level of dissolved oxygen
in the blood.