A pyrotechnic party trick that involves grapes bursting into flame in a microwave has been explained by scientists. Instead, they found two grapes trap microwaves which cause them to heat up. By simply putting two grapes close to one another, they're the right size and shape to trap microwaves, create a 'hotspot' and generate plasma. 'Emission spectra from grape plasma suggest that potassium and sodium species, abundant in the grape skin, are field-ionised by a strong concentration of electric field near the point of contact. Two grapes trap microwaves, causing them to heat up.

Source: Daily Mail February 19, 2019 00:03 UTC