I’ve recently read the book Inventing Temperature, and very much enjoyed it. It's a book that's basically about the following problem: there was a time in which humans had not yet built accurate thermometers, and therefore weren’t able to scientifically investigate the phenomenon of temperature, which would require measuring it. But to build a thermometer and know you’ve done so correctly, it seems like you have to know that its temperature readings match the real temperature, which seemingly requires either other known-functional thermometers to calibrate (which they did not have), or a rigorous enough scientific understanding of temperature to know that your thermometer tracks it well (which is hard to obtain without having thermometers)—so it's not obvious how one could go from a situation where thermometers didn’t exist to one where they do exist, and where we are justified in believing that they accurately measure temperature.

This book has had some popularity in the rationality community as an account of applied epistemology, and in particular, for its description of how to measure something intangible. An obvious application of the book (which I won’t elaborate much on except in a footnote1) is in understanding artificial intelligence: there are various [...]

The original text contained 12 footnotes which were omitted from this narration.

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First published:
January 31st, 2026

Source:
https://www.lesswrong.com/posts/n3mvknxBcsem2ui64/on-inventing-temperature-and-the-realness-of-properties

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Narrated by TYPE III AUDIO.

“On ‘Inventing Temperature’ and the realness of properties” by DanielFilan

LessWrong (30+ Karma)