During a recent trip to Bhutan, [electronut] wished for a device that would show the temperature and altitude at the various places he visited in the Kingdom. Back home after his trip, he built this ...

According to [Dr. Tom Lehrer’s] song Pollution, “Wear a gas mask and a veil. Then you can breathe, long as you don’t inhale!” While the air quality in most of the world hasn’t gotten that bad, there ...