The amount of heat from the sun that strikes the
surface of the earth each day expressed as calories per square centimeter
of earth surface per minute. The actual amount is 1.94 cal/ cm2/min.
Recently, astronomers specializing in solar phenomena have discovered
that this “constant” can and does change slightly from moment
to moment, perhaps altering the energy budget for the planet and giving
rise to small differences that might reflect themselves later in larger