Book on the history of making precise objects, from making a mechanical clock that would help sailors tell their longitude position while out at sea, to the lens for the Hubble telescope and of course today’s transistors.
It contains many interesting stories and tidbits. For example:
- The making of precise objects today, using machine tools, is impressive. But even more impressive to me is making them by hand — for example John Harrison, who in the early through mid 1700s (over 45 years) made a sequence of time-pieces, culminating in a watch-sized timepiece that was only off by mere seconds after a few months’ long journey on a ship.
- I had vaguely known of the Hubble telescope lens problem and the fix, but this book told the whole story. See here for a summary, but long story short: the main optical mirror — about 2.4 m in diameter — was about 2200 nano-meters out of shape, about 1/50 of the width of a human hair. It of course was fixed during the first scheduled maintenance mission, salvaging the multi-billion dollar project and producing the crisp space images we enjoy to this day.
- Those who remember their high school chemistry will recall that there are 7 fundamental SI units, for mass (kg), length (m), time (s), temperature (K), amount of substance (mole), electric current (ampere), and brightness (cd). As of late 2018, the meter and second are defined as fundamental, constant physical quantities (e.g. a second is “the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom”). Of course, these definitions used to be less fundamental — for example the meter was originally in the late 1700s defined as a function of the distance between the north pole and the equator across a certain longitudinal line.
A kilogram is still literally defined as the mass of a literal, specific piece of metal sitting in Paris somewhere. This arrangement leads to weird occurrences, such as when this standard changes over time. For potentially obvious reasons, a group is currently working on re-defining a kilogram (kg) into a more fundamental quantity.
Similarly but perhaps less egregiously, a kelvin is defined as a function of the triple point of water; but not just any water — the Vienna Standard Mean Ocean Water, which at one point was just a distilled mixture of the world’s ocean waters in a set ratio. The rest are defined as functions of Newtons and other physical phenomena, and one will recall that a Newton has kg in its formulation.
I found the book well worth reading. The author does go on a half-baked tangent near the end on whether pursuing precision (e.g. smaller transistors for faster computers) is “good” for humanity, but otherwise I found the story-telling to be great. And from what I’ve read separately, the book seems accurate.