On the outside, a Geiger counter seems like a complicated thing. And you might think a device that detects a dangerous, mostly invisible threat like radiation should be complicated. But they’re ...

With all the focus on biological problems, we might forget that sometimes it’s handy to know about radiation hazards, too. [Ryan Harrington] shows us how to make a Geiger counter with very few parts, ...

"Hearst Magazines and Yahoo may earn commission or revenue on some items through the links below." Geiger counters are used to detect and measure levels of radioactivity. Scientists invented the ...