[nandomrumber]

Just be careful doing this if there’s a radio telescope nearby:

However, about 25 FRBs detected mainly by the Parkes Radio Telescope and a few other observatories presented signatures that were very different. Although they covered a wide frequency range just like the other FRBs, the frequency-time structures of many of these events defied any physical model, and they did not show differences in the arrival times between the higher frequencies and the lower frequencies of the burst. Also, the location of these FRBs was difficult to pinpoint; the radiation seemed to come from all directions. The Parkes astronomers, mystified, dubbed these "abnormal" FRBs "perythons" after a mythical figure invented by the Argentinian author Jorge Luis Borges. The perythons’ signatures caused astronomers to doubt the extragalactic origin of FRBs [PDF] althogether. They might originate on or nearby Earth, the scientists began to believe, and some astronomers even suggested that these strange bursts might be produced by extraterrestrial civilizations.

Not long after focusing their attention on the perythons, the Parkes astronomers noticed that these FRBs seemed to take off during weekends. In 2014, they installed a radio frequency interference monitor at the observatory and decided that the culprits were probably some microwave ovens inside the observatory building. Tests with these microwave ovens yielded nothing—they emitted no radio pulses while they were running. The astronomers were flummoxed—that is, until one of the testers, during a third attempt, opened the door of a microwave oven before the magnetron was shut off by the timer.

https://spectrum.ieee.org/microwave-ovens-posing-as-astronom...

[taneq]

I know it's silly, but I always used to open the microwave door to stop it, and since reading that story, these days I always stop the microwave with the 'stop' button before opening the door. Just in case. :)

[ebiester]

I heard a story from someone whose relative was in the Korean War - apparently people manning radar stations used to warm up by getting in between some microwaves. I just looked it up and the danger isn't cancer - but you stay too long you can get unexpectedly cooked (particularly eyes) because your body isn't detecting being warmed up like that.

[sandos]

Seriosly? They leak emissions if you OPEN THE DOOR WHILE ITS RUNNING?

I thought they were actually, like, certified? How can this not have been tested and fixed... shutting down the magnetron can not take long, right? Making it react fast enough doesnt feel like an intractable problem at all!

[WorldMaker]

Having been trained to listen to the hum of the magnetron for several reasons (among them: it affects how popcorn pops and if you are in lunch room setting with a complete mixture of models you have to listen to know which sort of microwave you "lucked" into that day and adapt to its challenges to avoid burning popcorn) it takes a surprising amount of time for even a good one to spin up to full speed as much as a quarter second. As microwaves age or get cheaper some of them take a full wall clock second or two. Some of the cheap models even lie to you and don't start their own timers until after the magnetron hits full speed.

Something that becomes more apparent the more you listen (but also if you actually pay attention to diagrams of how a microwave works): the magnetron is a spinning thing with its inertia. Even if you immediately cut power to it, it still spins on its own for some amount of time. Given how much energy and wall clock time it takes to spin up to full speed, it shouldn't be surprised it needs similar wall clock time, if not energy to full stop.

But also, yeah the door pull sensor is a classic analog latch detector that has a slower sensing time than a button would by its very nature (and trying to avoid false positives from a loose/vibrating door). It's an easy thing to cut corners on and some sensors are worse than others.

(And also, safety certifications include a margin of error that it still "generally regarded as safe", what's a few extra microwaves escaping into your body among friends as long as it isn't full power?)

[post-it]

If I'm understanding the paper correctly, the bursts had a mean duration of 0.14 seconds, which for a 1000 W microwave would expose you to 140 joules, enough to heat about a shot's worth of water by 1°C. Seems plenty fast to me.