Post Tagged with: "experiment"

Why do grapes and microwaves = plasma?

If you:

  1. Take a grape
  2. Cut it equatorially, but just leave a bit of skin connecting the two hemispheres.
  3. Dry the new surfaces with a paper towel.
  4. Stick the grape in a microwave oven.
  5. Turn it on.

You get flashes of plasma emerging from the grapes. Like this…

But why does this happen? There are plenty of attempts to explain it all over the net e.g. here, here and here. But none of the explanations quite satisfy me. And what causes this plume when you put a glass over the grapes?

I’ve tried a few variations on the method. For example, you don’t have to leave the skin bridge as long as the two hemispheres are touching. Cutting the grapes longitudinally doesn’t seem to work. And I’ve never managed to get the addition of the glass to make a difference.

Anybody got a good explanation or further refinements?

 

p.s. The grapes get very hot and don’t do this in a microwave oven that you are particularly attached too.

By July 9, 2012 9 comments fun