2018-04-05 23:26:27 UTC
Proprioception, from the Latin proprius (ones own), is the term for an organism's perception of signals originating within its own body,
and includes the sense of how each part of the body is positioned
in relation to every other part. This involves signals from an
array of "proprioceptors" measuring such things as the angle of
joints and the stretch of muscles.
In Isaac Asimov's 1952 story _C-Chute_, during an interstellar war
a human passenger liner has been captured by the enemy Kloros, who
have modified the ship's systems to have and maintain a chlorine
atmosphere such as the Kloros breath throughout most of the hull.
With the surviving humans confined to a portion of the ship still
provided with an oxygen atmosphere a two Kloran prize crew takes
the ship to Kloran space via a series of hyperspace jumps, which
will bring them to their destination in a matter of weeks.
Unexplainedly, the Klorans have left the humans in possession
of a number of functional space suits, and one of the passengers,
Randolf Mullen, suggests that he can exit the human occupied part
of the ship through a C-chute (normally used to eject dead bodies!),
walk across the outside of the hull using the suit's magnetic boots,
re-enter the ship through a maneuvering thruster nozzle, and
attack the aliens with the advantage of surprise. The plan needs
someone to operate the controls of the C-chute so as to
seal the inner door and open the outer door once Mullen is in
the lock chamber. The others agree to help, and in due course
Mullen is blown out onto the surface by the residual air pressure
as the outer door opens:
His feet swung free and threshed. He heard the clunk of one magnetic boot against the hull just as the rest of his body puffed out like a tight cork under air pressure. He teetered dangerously at the lip of the hole in the ship -he had changed orientation suddenly and was looking down on it-then took a step backward as its lid came down of itself and fitted smoothly against the hull.
A feeling of unreality overwhelmed him. Surely, it wasn't he standing on the outer surface of a ship. Not Randolph F. Mullen. So few human beings could ever say they had, even those who traveled in space constantly.
He was only gradually aware that he was in pain. Popping out of that hole with one foot clamped to the hull had nearly bent him in two. He tried moving, cautiously, and found his motions to be erratic and almost impossible to control. He thought nothing was broken, though the muscles of his left side were badly wrenched.
And then he came to himself and noticed that the wrist-lights of his suit were on. It was by their light that he had stared into the blackness of the C-chute. He stirred with the nervous thought that from within, the Kloros might see the twin spots of moving light just outside the hull. He flicked the switch upon the suit's midsection.
Mullen had never imagined that, standing on a ship, he would fail to see its hull. But it was dark, as dark below as above. There were the stars, hard and bright little non-dimensional dots. Nothing more. Nothing more anywhere. Under his feet, not even the stars-not even his feet.
He bent back to look at the stars. His head swam. They were moving slowly. Or, rather, they were standing still and the ship was rotating, but he could not tell his eyes that. They moved. His eyes followed-down and behind the ship. New stars up and above from the other side. A black horizon. The ship existed only as a region where there were no stars.
No stars? Why, there was one almost at his feet. He nearly reached for it; then he realized that it was only a glittering reflection in the mirroring metal.
They were moving thousands of miles an hour. The stars were. The ship was. He was. But it meant nothing. To his senses, there was only silence and darkness and that slow wheeling of the stars. His eyes followed the wheeling-
And his head in its helmet hit the ship's hull with a soft bell-like ring.
He felt about in panic with his thick, insensitive, spun-silicate gloves. His feet were still firmly magnetized to the hull, that was true, but the rest of his body bent backward at the knees in a right angle. There was no gravity outside the ship. If he bent back, there was nothing to pull the upper part of his body down and tell his joints they were bending. His body stayed as he put it.
It would appear from this passage that being in free fall has thrown off
Mullen's sense of proprioception, so that he was unaware that his knees
were bent. Proprioception is still an ongoing subject of research.
Was there any reason back in 1952 to suspect that this might happen?
Observation of gymnasts, trapeze artists, basketball and volleyball
players, ski jumpers, ballet dancers and other athletes suggests that
going into and out of free fall does not interfere with their body
control even for a fraction of a second. Of course, Mullen is
not described as an experienced astronaut.
Another example of this situation from written science fiction is
Edward E. Smiths novel _Second Stage Lensmen_, where a unit of
Valerian space marines led by Lieutenant Peter Van Buskirk confronts
a group of Boskonian pirates who are using unarmed civilians
as human shields. As the author describes, since Valeria is a
3-G world, and the marines train under any acceleration down to
free fall, it is a matter of routine for the Valerians to jump
over the hostages, with each leap terminating in a lethal blow
to the head of one of the Boskonians from a Valerian space ax.
In the era of manned spaceflight NASA has trained extensively
on aircraft in zero-G trajectory and underwater at neutral
buoyancy and both of these methods seem to work well.
I am interested in any other examples from science fiction
where this is described. John W. Campbell did discuss
proprioception in one of his editorials, referring to
it as a "goniometric" (angle measuring) sense.