NGC 1 and 2

"Professor does cold exist?"
The professor replied "Of course it exists. Have you never been cold?"
The students snickered at the young man's question.
The young man replied, "In fact sir, cold does not exist. According to the laws of physics, what we consider cold is in reality the absence of heat. Everybody or object is susceptible to study when it has or transmits energy, and heat is what makes a body, or matter, have or transmit energy.
Absolute zero (- 460 degrees F) is the total absence of heat. Cold does not exist. We have created this word only to describe how we feel if we have no heat".
The student continued. "Professor, does darkness exist?"
The professor responded, "Of course it does."
The student replied, "Once again you are wrong sir. Darkness does not exist either. Darkness is in reality the absence of light. Light we can study, but not darkness. In fact we can use Newton's prism to break white light into many colors and study the various wavelengths of each color.
You cannot measure darkness. A simple ray of light can break into a world of darkness and illuminate it. How can you know how dark a certain space is? You measure the amount of light present. Isn't this correct? Darkness is a term used by man to describe what happens when there is no light present".