Convection warms food in pans that are not actually touching the heating element. It uses the hot air around the element to carry heat to the pan. Your oven in your range works by convection. Most houses are warmed in winter in the same way. The heat produced in a furnace warms the air as it circulates through. This air in turn keeps your body warm. Radiation is Like the Sun Radiation heating is more difficult to explain. It results when heat or energy waves strike an object and are converted into heat. The energy we receive from the sun is a good example. When you are wearing dark clothes on a chilly day, you may become uncomfortably hot. The sunshine warms you even though the air around you has not been heated. Radiant energy has a way of being absorbed by dark objects and reflected by light colored or shiny surfaces. Did you ever notice how snow melts faster on a black top road than it does on a concrete road? The electric heat lamp is one of the most familiar sources of radiant heat. Other examples are panels and cables that are built into the walls and ceilings of homes to provide heat. Make Popcorn 3 Ways How do you make popcorn? Did you know that you can do this kind of a heating job three different ways? _Materials Needed_ Popcorn Cooking oil or shortening Salt and butter 4-qt. saucepan, with cover. (A glass cover is preferred.) Potholder Electric range 2 250-watt heatlamps 2 spring clamp type lampholders Wire mesh corn popping basket or wire mesh kitchen strainer (improvise a screen wire cover) _First_, make popcorn the way you usually do. Set a front surface unit control on the range at "medium high". Pour enough oil to very lightly cover the bottom of the pan. When the pan is hot, pour in enough popcorn to cover the bottom with one layer of kernels. Use the potholder in one hand to hold the cover on, and with the other move the pan back and forth across the unit. When the popping stops, remove from the heat. How did the heat get to the popcorn? _Second_, make popcorn in the oven. Add the oil to the pan, cover it and put it in the oven. Turn the oven on, with the automatic control set at 400°. When the oven indicator light goes off, this means that the proper temperature has been reached. With the potholder, remove the pan and add one layer of popcorn kernels. Replace the pan in the oven. When the popping stops (listen for it) remove the pan. What kind of heating took place here? _Third_, make popcorn with the heat lamps. Clamp the lampholders to the back of a chair or other vertical support. They should be 6 to 8 inches apart and pointed directly at each other. Put about 2 tablespoonfuls of popcorn in the Wire basket or strainer. Do not add oil. Hold the basket midway between the two lamps. When the popping stops, turn off the lamps. What kind of heating was this? Now, butter and salt the popcorn you have made and share it with others. What Did You Learn?