One we'd gotten our microwave oven working, we of course tested by making grape plasma.

The process is simple, you merely cut a grape in half so that only a small section of the peel connects the two parts. Then you put it in a microwave, and turn it on. After a couple of seconds, there will be a flash of light as the air around the piece of peel is ionized, and briefly becomes plasma.

What we've always thought to be the reason for this, that the grape becomes polarized, and rapidly inverts polarity, creating a high alternating current through the bridge, turned out not to be the full story when a physics professor from the local university who happened to come by to see what we were up to said it wasn't that simple. Although we always hear that the speed of light is constant, the constant C is really the speed of light in vacuum. But light has different speeds in different materials–all slower than C of course. That means that light traveling between different materials bends (as those of us who've had physics know, that's how lenses work). And it turns out that the speed of light in grape is just right that a typical grape can act like a resonant cavity at the frequencies of a microwave oven. So sort of like we were thinking, but with added complexity if you know what's going on in more detail.

This experiment is not particularly dangerous, as the grape stops producing plasma after immolating, but a... chaotic force... in the community has previously destroyed a microwave's emitters by doing this. We don't know how, but count yourself warned.

This led to the immolated grape taste test.