Authentic Science Fiction Monthly No. 72 — page 86: what you’re looking at

Machine-transcribed from the original scan — historical spelling and the odd misread are preserved.

AUTHENTIC SCIENCE FICTION T don’t mean deep-sea divers, I mean ordinary swimmers. Anyone who has dived to a depth of fifteen feet has ex- perienced a gain and loss of fifteen thousand pounds pres- sure. Doubling this depth— and is quite common with native divers and those using aqualung equipment—exposes the body to even greater pressure changes. And by the same token we can get rid of the notion that bends will be a grave danger in space. Bends are caused by bubbles of absorbed nitrogen forming in the blood at the sudden release of pressure. But the United States Manual for Divers shows that bends are not to be feared from rapid ascent from depths up to around 40 feet, a pressure change greater than the sudden loss of 15 Ibs. a square inch. What would happen to a man thrust into the void is that, unless he expelled his breath, his lungs would be damaged. Lungs cannot stand more than an abrupt change of 8 Ibs. without harm, which is why all divers are taught to expel their breath, not hold it, when ascending to the surface. 85 He would lose consciousness © very quickly, in about 15 seconds, as proved by tests of personnel suddenly ex- posed to extremely low pres- sures, and his blood would begin to boil. It is this boiling of the ~ blood which makes a pres- surised suit essential. The lower the pressure the lower the boiling point, and at zero pressure blood would literally boil. So we have an anomaly. We need pressure but could operate better without it. Accepting the fact that we must have it, how little can we get away with? The atmosphere consists mainly of oxygen and nitro- gen, with oxygen, the gas we need, at about twenty per cent. Pure oxygen then, at a pres- sure of 3 Ibs. a square inch, will provide a man with all the life-giving gas he needs. A man requires approximately one ounce of oxygen an hour or, if we want to be really generous and allow for extra exertion and losses, say 3 Ibs. for twenty-four hours. This quantity of gas, if com- pressed, can be contained in comicloooks.conm