Illustration of Parachute

1485 Parachute

The book of science

Tom Sharp

Leonardo da Vinci aerodynamics Illustration of Parachute

Parachute

An unnamed contemporary of Leonardo da Vinci depicted a conical parachute in the 1470s, but let’s say the parachute started with da Vinci because his twelve-yard pyramidal design was more well proportioned to carry the weight of a man, because the first person to test the idea, Fausto Veranzi, studied da Vinci, and because da Vinci’s design was recently proven to work.

Parachutes for war

Airmen parachute from damaged airplanes, and descend on towns with guns and grenades. Allied drops behind enemy lines have resulted in heavy losses from so-called “friendly fire.” In the turbulent wake of a jumper (the ‘burble’), a pilot chute can sometimes fail to pull out the main canopy, resulting in death. (I report this because I like the word ‘burble.’) Parachutes slow down fighter jets as they land on aircraft carriers. Ribbon parachutes are deployed to slow the descent of nuclear bombs.

Free fall

Free fall isn’t really free. By definition in free fall only the force of gravity pulls an object through space, but the force of air resistance, hot enough to burn up a falling star, supports a diver like a cushion; even, if you had no parachute, nothing would be free about plummeting to the ground.

Precaution

Pack your parachute, carry an umbrella, use safety glasses, wear your bicycle helmet, don a life-preserver, and lock your doors. It takes an effort, but then you don’t need to worry whether an accident will happen, even though accidents sometimes happen.

Skydivers put themselves in a life-or-death situation and only by careful preparation do they avoid killing themselves. They do it not only because diving is exhilarating, but also because it is the closest humans get to a feeling of human-powered flight.

Thinking about free fall led Einstein to his general theory of relativity. A man in free fall would feel no force of gravity, and, given no force, would fall at a constant speed; however, on the contrary gravity causes him to accelerate.

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