Incandescent light bulbs are officially banned in the U.S.::America’s ban on incandescent light bulbs, 16 years in the making, is finally a reality. Well, mostly.
It’s an old riddle where a room has three lights and outside the room is the panel with three switches. They’re not labeled and you don’t know which switch controls which bulb. You’re allowed to switch any two, then you get to open the door and you have to determine which switches control which lights.
The solution is, that you flip switch #1, wait five minutes and then flip switch #2. Then you immediately go into the room.
Two lights will be on, meaning the bulb that’s off is the third switch. Then you feel the bulbs that are on: the one that’s warm already is the #1 and the other that’s on but still cool is #2.
LEDs don’t heat up like that so this technique is broken.
