Illustration of Tribology

1699 Tribology

The book of science

Tom Sharp

Leonardo da Vinci, Guillaume Amontons physics Illustration of Tribology

Tribology

Leonardo da Vinci started the study of rubbing surfaces, measuring the forces needed to pull different blocks across a surface, and finding that friction increases according to the weight of the object and not according to the size of its rubbing surface. Two centuries later, Guillaume Amontons added that friction doesn’t depend on speed.

Tribological experiments

Da Vinci pulled blocks across a level table with no lubrication. Next, we pull blocks down an inclined table, and we test the effects of lubricating the table. We try different materials to find each combination has its own coefficient of friction. Rubber on clean dry concrete has thirty-three and a third times the friction of steel on ice, but rubber on wet concrete has only ten times the friction of steel on ice. If you put ice on that concrete then it’s even worse, so it’s good to do these experiments on table tops instead of in cars over icy bridges.

Waste

Friction, wear, and corrosion, what happens from rubbing the cat the wrong way, rowing upstream, letting tires go flat, ignoring conflicts instead of resolving them, letting irritations accumulate into irreconcilables, and becoming irritable about unimportant things, makes a philosophy of life, remembering to check the air, lubricate the bearings, close the windows to conserve heat and reduce drag, smoothe out the wrinkles in the fabric, declutter, avoid meaningless minutia, and slip through obstacles like greased pigs.

Much of the waste in our society is excused by convenience. It is more convenient to drive a car to the convenience store, more convenient to eat packaged meals, more convenient to send recyclable packaging to a landfill.

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