Longer And Shorter Days

I was working in a scrap yard during summer vacation at an

engineering university. I worked repairing construction

equipment. One afternoon, I was taking apart a piling hammer

that had some very large bolts holding it together. One of

the nuts had corroded on to the bolt, so to free it I

started heating the nut with an oxyacetylene torch. As I was

doing this, one of the dimmest apprentices I have ever known

came along. He asked me what I was doing. I patiently

explained that if I heated the nut, it would grow larger and

release its grip on the bolt, so I could then remove it.

“So, things get larger when they get hot, do they?” he

asked. “Yes,” I said. “That’s why days are longer in

summer and shorter in winter.” There was a long pause,

then his face cleared. “You know, I always wondered about

that,” he said.