Cooking with Convection

This weekend I helped barbecue for a family get together. As the vegetables were cooking on the hibachi grill, my friend pointed out to me that the process in which they were cooking was physics! He explained to me that they were cooking by convection. Convection is heat transfer, by mass motion of air or water. When the air is heated, it becomes less dense. This causes the hot air to rise, and push the colder air down. Later, as the colder air is heated by the fire, it becomes less dense, and rises. This causes the convection cycle, and eventually the food is cooked. The foil made it possible for the convection cycle to occur, as it was directly exposed to the fire, and it trapped the hot air inside.