Slaying Dragons #28 – Laws of Physics

John Watkinson considers crossing disciplines.

The most useful knowledge a technologist can have is knowledge of the laws of physics, not least because they don’t recognise man-made boundaries or distinctions. Whilst it would be almost impossible for a lawyer to move from say, Washington D.C. to Copenhagen, a physicist wouldn’t have a problem.

Boundaries between disciplines aren’t recognised either. The design of aircraft, the power of a piston engine and the configuration of a loudspeaker are all affected by the speed of sound. In audio we are comfortable with the concept of impedance, but an automotive gearbox is also an impedance converter, matching the road load to the impedance of the engine. In aircraft, induced drag is the reflected impedance of the lift-creating mechanism.

Something learned in one area may well be relevant to another. The corollary is that a technocrat with sufficient knowledge of physics can move from one field to another or one place to another without too much trouble. 

There are advantages in moving into another field, not least the need for great caution to avoid making a mistake. This means going back to first principles, which is always better than relying on assumptions or rules of thumb.

There are plenty of examples of crossing between disciplines. An aerodynamicist by the name of Malcolm Sayer left the Bristol Aircraft Company and joined Jaguar. The result was the E-type and the XJ-S.

The iconic Vespa scooter was put together by a helicopter designer. The boxer engine of the Subaru reflects the roots of that company in the Nakajima Aircraft Co, which built the famous Zero.

Once upon a time it wasn’t unusual for the same company to make cars and aerospace components.  

(contd)
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