http://youtu.be/kp33ZprO0Ck If you’ve ever investigated how a microwave warms up your food, then you already know that the box fills with electromagnetic waves, which vibrate water molecules to create friction and heat. But how does the microwave’s magnetron (an energy-generating vacuum tube) produce those waves in the first place---and how can you measure them using cheese? The Engineer Guy, also known as University of Illinois at Urbana-Champaign professor Bill Hammack, has all the answers in this enlightening video.