Causes acceleration or speed G Force

Series: Curious experiments on humans: the human crash test dummy

When the famous jam roll lands on the floor with the coated side, when the apartment key breaks in the lock while you stand in front of it with two full shopping bags and the phone rings inside, and the garbage disposal shows up in front of you on the street just when you are in a mad hurry has - then it is not uncommon for this one sentence to pop through your head: "Everything that can go wrong will go wrong." Murphy's law was originally not so much responsible for the small and medium-sized mishaps - its purpose was once to give life rescue. For example that of John Paul Stapp, the head of the proverb inventor Edward A. Murphy and formerly “fastest man on earth”, who drew attention to himself in the middle of the 20th century with daring - and important - experiments.

When asked by a journalist why nobody had been seriously harmed in such life-threatening attempts, Stapp replied that his team always took Murphy's law into account beforehand and everything possible that could happen. And that was quite a lot, because during the tests he sped through the desert at top speeds of more than 1,000 kilometers per hour.

This article is included in Spectrum Compact, Curious Experiments

The record hunt by John Paul Stapps was not an end in itself - and certainly not a pleasure: the studied medicine and biophysicist wanted to find out what such speeds can do to the human body. Especially what happens when you come to an abrupt stop at this rate.

65 hours at an altitude of 13 kilometers

Born in 1910 to a missionary couple in Brazil, Stapp has been researching how the human body behaves in extreme environments since the spring of 1946. At first, however, he dealt with the burdens at height. On behalf of the U.S. Air Force he flew with a B-17 bomber that had been reduced to the essentials, for example no longer had any weapon systems, into the stratosphere at an altitude of about 12,000 meters. The pilots sat in a cockpit in which the pressure in the cabin was not equalized. In the thin air, Stapp carried out a series of experiments to clarify how a person could endure this altitude permanently without losing consciousness or being overwhelmed by decompression sickness - also known as diving sickness. After a total of around 65 hours of flight at this altitude, he had an answer to that question: If a pilot inhales pure oxygen half an hour before the flight, then he prevents the formation of bubbles in the blood - an important finding for later space travel.

Survivors who shouldn't even exist

After this work, Stapp changed his field of activity, because the Second World War, which had just ended, had revealed a need for further research in aviation: The safety technology on board combat aircraft had been continuously improved in previous years - but in some cases under incorrect basic assumptions regarding the g-forces. This parameter indicates the stress that is placed on the human body when the speed or direction of movement to which it is subjected changes, for example when it is accelerated or braked in a moving car. Until then, it was assumed that a person could survive a maximum of 18 g - that is, 18 times the acceleration due to gravity, which affects a person on earth in a resting state. When building military aircraft, the designers based themselves on this value; all safety precautions were designed for this. But pilots repeatedly survived crash landings - even though much higher g-forces had acted. Others, however, died in similar incidents because, for example, the seats or cockpits failed at forces above 18 g. A readjustment was therefore urgently required - because the aircraft occupants were in danger of surviving the effects of the physics, but then of being killed due to inadequate safety precautions.

When John Paul Stapp arrived at Edwards Air Force Base in California's Mojave Desert, plans for experiments on the effects of acceleration forces were well advanced. Engineers had already converted a 600-meter-long rail line, on which the army had previously tested German V1 rockets, into a "human decelerator" by installing a 15-meter-long braking system. The scientists were able to accelerate test objects to a high speed and bring them to a standstill again in a very short time.