The second Christian continues. "You can have lots of heat, even more heat, super-heat, mega-heat, white heat, a little heat or no heat but we don't have anything called 'cold'. We can hit 458 degrees below zero, which is no heat, but we can't go any further after that. There is no such thing as cold, otherwise we would be able to go colder than 458. You see, sir, cold is only a word we use to describe the absence of heat. We cannot measure cold. Heat we can measure in thermal units because heat is energy. Cold is not the opposite of heat, sir, just the absence of it." Silence. A pin drops somewhere in the classroom.
"Is there such a thing as darkness, professor?" "That's a dumb question, son. What is night if it isn't darkness? What are you getting at...?" "So you say there is such a thing as darkness?" "Yes..." "You're wrong again, sir. Darkness is not something, it is the absence of something. You can have low light, normal light, bright light, flashing light but if you have no light constantly you have nothing and it's called darkness, isn't it? That's the meaning we use to define the word. In reality, darkness isn't. If it were, you would be able to make darkness darker and give me a jar of it. Can you...give me a jar of darker darkness, professor?"