Category Archives: Efficiency

How the bicycle beats evolution and why Steve Jobs was so taken with this fact

Chart from Scientific American, 1973
Chart from Scientific American, 1973

Apple’s late leader Steve Jobs loved to liken the computer to the bicycle (“the computer … is the equivalent of a bicycle for our minds”) and there are two films of him recounting a fact he’d picked up from Scientific American. Below I’ll quote from the article Jobs was referring to – which showed that a person on a bicycle was more energy efficient than a condor in flight and many times more energy efficient than a person in an automobile – but first here are the films, clearly shot some years apart:

“I read a study that measured the efficiency of locomotion for various species on the planet. The condor used the least energy to move a kilometer. And, humans came in with a rather unimpressive showing, about a third of the way down the list. It was not too proud a showing for the crown of creation. So, that didn’t look so good. But, then somebody at Scientific American had the insight to test the efficiency of locomotion for a man on a bicycle. And, a man on a bicycle, a human on a bicycle, blew the condor away, completely off the top of the charts. And that’s what a computer is to me. What a computer is to me is it’s the most remarkable tool that we’ve ever come up with, and it’s the equivalent of a bicycle for our minds.”
Steve Jobs

The “somebody” at Scientific American was S. S. Wilson and the eleven-page article in question, on bicycle technology, was printed in the March 1973 edition of the magazine. Wilson was a lecturer in engineering at Oxford University and a fellow of St. Cross College. S. S. Wilson said: “My interest in bicycles dates back to school days. I have always owned and used a bicycle; during World War II, I several times cycled more than 100 miles in a day as a means of transport.”


Wilson was also an enthusiast of human-powered flight and, had he been alive today, he would have no doubt worked on solar-powered flight. For all of the bicycle’s efficiencies, as stated by Wilson, the bicycle is nowhere near as efficient as Solar Impulse, the aircraft currently attempting to fly around the world.

[Wilson is not the Wilson who wrote the seminal Bicycling Science of 1974, that was David Gordon Wilson. Both Wilson’s were at the very first Velocity conference, held in Bremen, Germany in 1980.)

It’s worthwhile reading what S.S. Wilson had to say about the efficiencies of cycling:

“It is worth asking why such an apparently simple device as the bicycle should have had such a major effect on the acceleration of technology. The answer surely lies in the sheer humanity of the machine. Its purpose is to make it easier for an individual to move about, and this the bicycle achieves in a way that quite outdoes natural evolution.

“When one compares the energy consumed in moving a certain distance as a function of body weight for a variety of animals and machines, one finds that an unaided walking man does fairly well (consuming about .75 calorie per gram per kilometer), but he is not as efficient as a horse, a salmon or a jet transport. With the aid of a bicycle, however, the man’s energy consumption for a given distance is reduced to about a fifth (roughly .15 calorie per gram per kilometer).

“Therefore, apart from increasing his unaided speed by a factor of three or four, the cyclist improves his efficiency rating to No. 1 among moving creatures and machines.

“For those of us in the overdeveloped world the bicycle offers a real alternative to the automobile, if we are prepared to recognize and grasp the opportunities by planning our living and working environment in such a way as to induce the use of these humane machines.

“The possible inducements are many: cycleways to reduce the danger to cyclists of automobile traffic, bicycle parking stations, facilities for the transportation of bicycles by rail and bus, and public bicycles for “park and pedal” service. Already bicycling is often the best way to get around quickly in city centers.

“If one were to give a short prescription for dealing rationally with the world’s problems of development, transportation, health and the efficient use of resources, one could do worse than the simple formula: Cycle and recycle.”

Wilson’s article was later picked up by philosopher Ivan Illich who, in his 1978 pamphlet Toward a History of Needs, wrote:

“Man on a bicycle can go three or four times faster than the pedestrian, but uses five times less energy in the process. He carries one gram of his weight over a kilometer of flat road at an expense of only 0.15 calories. The bicycle is the perfect transducer to match man’s metabolic energy to the impedance of locomotion. Equipped with this tool, man outstrips the efficiency of not only all machines but all other animals as well.

“Bicycles let people move with greater speed without taking up significant amounts of scarce space, energy, or time. They can spend fewer hours on each mile and still travel more miles in a year. They can get the benefit of technological breakthroughs without putting undue claims on the schedules, energy, or space of others. They become masters of their own movements without blocking those of their fellows. Their new tool creates only those demands which it can also satisfy. Every increase in motorized speed creates new demands on space and time. The use of the bicycle is self-limiting. It allows people to create a new relationship between their life-space and their life-time, between their territory and the pulse of their being, without destroying their inherited balance. The advantages of modern self-powered traffic are obvious, and ignored.”


The Kickstarter for Bike Boom finished on March 17th 2015. The book will be published in 2016. Put your email in one of the boxes to be notified of the book’s progress.


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