Do Not Microwave a Grape!
Put two grapes in a microwave and something amazing happens.
In a few seconds, a bright spark jumps between them, a tiny flash of lightning.
It looks like magic. But do not try it.
This trick can start a fire and destroy your microwave.
So scientists studied it instead, and it took them more than twenty years to figure out why.
What is the spark?
It is plasma, the fourth state of matter.
You may know three states: solid, liquid, and gas.
Plasma is a fourth.
It forms when a gas gets so hot, or is hit by such a strong electric field, that its atoms break into charged pieces.
Lightning is plasma.
So are the glowing signs in some shop windows.
Plasma is not rare at all.It fills the stars.
So how do two grapes make plasma?
It is not simply because grapes are salty.
First, the two grapes must almost touch.
When they sit close together, they act like a tiny resonator, a shape that traps and focuses energy.
The microwave's energy piles up in the tiny gap where the two grapes meet.
That spot grows far hotter, and the electric field there grows much stronger than anywhere else.
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