[ISL]

I assumed that someone had made a sensitive bolometer.

https://en.wikipedia.org/wiki/Bolometer

Wood is a thermal insulator, so with care, one might be able to build a thermistor bridge capable of detecting the differential temperature rise between pieces of brass when a source was placed near one brass-piece.

I, too, found that the expectations framed by the title were not met by the article. It's a pretty box, though.

[Blahah]

Yeah, I feel like listing out the "raspberry pi, brass and wood" created the expectation that those were the crucial elements. Really the crucial element is a pre-made geiger counter and what they built is a beautiful enclosure and display. It's a cool project and they didn't lie, but it was misleading, and it seems it was the author of the piece who posted it so the confusion is reasonable to call out.

[acidburnNSA]

I thought it would be a gold leaf electroscope

https://en.wikipedia.org/wiki/Electroscope#Gold-leaf_electro...

[trhway]

>By 1880, Langley's bolometer was refined enough to detect thermal radiation from a cow a quarter of a mile away.

Sidenote: that sounds like even F-22/35 should be visible half a globe away in IR

[schoen]

Be careful of that inverse square law—it's a doozy!