"Something's more'n we bargained for," he said.
"What?" asked Christine.
"Why, that area we're chilling off is cooling far too fast."
"I should think that would be an advantage," said Christine.
"Maybe—and maybe not," said Walt. "The big thing is that things should behave according to rules. When they do not, then's when people make discoveries that lead to new rules."
"That I don't follow," said Christine.
"Well, in this case we know to several decimal places the heat equivalent of electrical energy. Three thousand, four hundred thirteen kilowatt hours equals one B.T.U.—a British Thermal Unit. We know the quantity of electrical power—the number of kilowatts—being coursed through the tubes en route to Pluto. We know by calculation just how many calories of heat there are in the area we're cooling off—and therefore we can calculate the time it will take to reduce the temperature of that area a given number of degrees centigrade. We're about double."
"And—you were starting to explain something different," said Christine.
"Oh—yes. Well, for a number of years—several thousand, in fact—it was taught that a heavy mass falls faster than a light mass. Then Galileo tossed rocks off of the Tower at Pisa and showed that a small stone and a large stone fall equally fast. That was a case where definitely provable evidence was at variance with the rules. They couldn't revise the actuality, so they had to revise the rules."
"I see. And now because that area is cooling off much faster than anticipated, you anticipate that something is not behaving according to the rules?"