Richard P. Feynman Quotes about Energy
It is important to realize that in physics today, we have no knowledge of what energy is
Richard P. Feynman, Robert B. Leighton, Matthew Sands (2013). “The Feynman Lectures on Physics, vol. 1 for tablets”, Basic Books
Energy is a very subtle concept. It is very, very difficult to get right.
Richard P. Feynman (2015). “The Quotable Feynman”, p.70, Princeton University Press