It happened to me last Christmas. And it puzzled me at first. One half of a string of mini lights in my holiday display was out. I went to inspect and saw that a large number of bulbs were severely blackened on the inside. Clearly a catastrophic failure. I wondered about a short circuit, a voltage spike, a grinch? Of course, as a physics teacher I began thinking about what would make an entire string of lights burn out so dra- matically. Here's what I figured out, which turns out to be an interesting and instructive demonstration that will only set you back about $2.00.
展开▼
