As a child, I was studying in a rural school, in the primary classes, we quietly put the lighting lamps under the contacts of the humidifier, soaked with salt water. While the wet pump was wet, the lamp burned, and when it dried out from heating, it suddenly went out. And in the winter, the first 2-3 lessons without lamps are dark. So I walked through the lessons and at the same time loved applied physics - from the private memories of a famous academic, nuclear physicist.