There was once a Professor who said explained to his student that “Energy” was the foundation of all things. “Energy cannot be created or destroyed. Energy holds everything together and drives all things.”
The student said, “But why can’t I see this energy? How do you know it exists? Where is the evidence?”
The professor was shocked, “Energy is contained in matter.”
“You mean it is inside that table there, but I can’t see it?” asked the student.
“Sort of” said the professor, “but that is a rather simplistic way of putting it.”
“Well can I see this energy or not” said the student. “If not, how do you know it exists?”
“If you were to burn the table energy would be released in the form of fire.”
“So fire is energy?”
“No. Fire is simply one form of energy being released.”
“So I was right. You can’t see energy. It’s an invisible force. This is beginning to sound like Star Wars. I don’t get why you think this energy thing exists if you can’t see it.”
“Why the evidence is all around you! That car you drive. That is powered by energy.”
“No it isn’t.” replied the student. It is powered by gas burning in the engine which makes the pistons go up and down. What is this strange “energy” you’re talking about?”
The professor laughed incredulously, “My dear boy, energy is not something you can ‘see’ with your eyes. Instead you see all around you the effects of energy. We deduce that energy exists because we see what energy does. When the gasoline is burned energy is released which moves the pistons.”
“Nonsense!” said the student. “The pistons go up and down because the gas exploded.” Read more.