It’s safe to say that the microwave was one of the most revolutionary appliances ever made. This tiny oven makes it possible for people to toss their ingredients together, punch a few buttons, and have a meal ready in a couple of minutes! When they were introduced to kitchens in the 1970s, microwaves took convenience and ease to a level previously unseen.
Though several generations have enjoyed the advantages of microwave ovens, few have stopped to ask: just how does this appliance work? They warm up and cook food much the same way the sun warms up something left out on a clear day – with radiation.
How Microwaves Use Science To Cook Food
Microwave ovens use channel heat energy directly to the molecules inside the food, and the form of heat energy is in the name: microwaves. These waves are much like the electromagnetic 
waves that zap through the air from TV and radio transmitters, and they race through the air at the speed of light (300,000 kilometres per second). While radio waves can be kilometres long, they can also be tiny, and the microwaves in the name microwave oven are the shortest radio waves on the spectrum – only 12 cm long.
When you activate your microwave oven, a generator called a magnetron takes electricity from the power supply and converts it into short radio waves. The tiny, high-powered waves of radiation, combined with the slowly spinning turntable, helps the microwave oven cook food evenly and quickly. The microwaves bounce around the metal walls of the oven, but they penetrate inside the food when they hit it. The waves pass their heat energy to the molecules in the food, heating it.
We can contrast the effects of microwaves with conventional ovens: your large oven heats food very slowly from the outside, which takes more time. A microwave can cook a piece of meat almost six times faster than a conventional oven!
How Are Microwave Ovens So Powerful?
Microwave ovens use powerful waves of energy, and as such, manufacturers encase the microwave in metal to prevent this energy from escaping. One drawback to microwave energy is that it can damage living tissue and cells; think about what happens to the skin when it’s exposed to the sun. When you hear this, you may want to ask another question about the appliance: is it safe?
The short answer is yes! The long answer: a microwave oven is harmless, and plenty of research shows that food cooked in it poses no threat to human health. Companies design and manufacture these appliances so that there’s no chance for the magnetron to spread the microwaves outside the cooking “cavity”; they are sealed metal containers! There’s no danger in getting too close to it, either.
Like the stove or conventional oven, the microwave is only dangerous if someone improperly uses or fools around with it. You have nothing to fear, and the convenience of microwaves gives it a place in kitchens everywhere!
