Some Important Terms and Concepts Defined


Infrared Radiationheat

    All objects around us give off or emit infrared radiation.  The warmer the object the more infrared radiation it emits.  When you sit across a room from a fire you can feel the infrared radiation it emits.  Some objects emit infrared radiation better than others.  For example, the earth's surface is far more efficient in emitting radiation than the gases in the atmosphere.  Clouds are very good at emitting and absorbing infrared radiation.

  On a clear night the surface emits infrared radiation very efficiently, with no clouds to stop it, most of this radiation is lost
to space.  Therefore the surface cools.  The air above doesn't emit radiation as well and thus cools less, that is, it ends up warmer than the surface. Thus, on clear nights the ground usually ends up colder than the air above.


     When ones heats one part of the object, its molecules move faster.