On Food and Cooking

temperature of the food as a whole quickly
rises.
Metal foil and utensils can be put in the
microwave oven with moist foods without
causing problems, provided they’re
reasonably large and kept some distance from
the walls and each other to prevent arcing.
Fine metallic decoration on china will spark
and suffer damage. Foil is useful for partly
shielding some foods from the radiation, the
thin edges of fish fillets, for example.
Microwave ovens are a recent invention. In
1945 Dr. Percy Spencer, a scientist working
for Raytheon in Waltham, Massachusetts,
filed a patent for the use of microwaves in
cooking after he had successfully popped corn
with them. This kind of radiation had already
been used in diathermy, or deep heat
treatment for patients with arthritis, as well as
in communications and navigation.
Microwave ovens became a popular appliance
in the 1970s.