IT'S an odd thought that the banana on your kitchen counter, squished in your lunch bag or tucked away in your desk drawer is the embodiment of one of the universe's great mysteries, just waiting to be unpeeled.It is an odd thought, but then again, we generate our own too:
Whatever its state of ripeness, that banana is made of particles of matter, just like you: its intrinsic matteryness is why you can see, feel and taste it. What you don't see is what a banana does 15 times a day or so. Blip! It produces a particle of something else, something that vanishes almost instantaneously in a flash of light.
That something else is antimatter.
This occurs because bananas contain a small amount of potassium-40, a naturally occurring isotope of potassium. As potassium-40 decays, it occasionally spits out a positron in the process.
Our bodies also contain potassium-40, which means positrons are being emitted from you, too. Antimatter annihilates immediately on contact with matter, so these antimatter particles are very short-lived.