"There is no better way to answer the question “what is energy?” than by referring to one of the most insightful physicists of the 20th century—to the protean mind of [[Richard Feynman]], who (in his famous Lectures on Physics) tackled the challenge in his straightforward manner, stressing that “**energy has a large number of different forms, and there is a formula for each one. These are: gravitational energy, kinetic energy, heat energy, elastic energy, electrical energy, chemical energy, radiant energy, nuclear energy, mass energy**.” "And then comes this disarming but indubitable conclusion: **It is important to realize that in physics today, we have no knowledge of what energy is. We do not have a picture that energy comes in little blobs of a definite amount. It is not that way. However, there are formulas for calculating some numerical quantity, and when we add it all together it gives … always the same number. It is an abstract thing in that it does not tell us the mechanism or the reasons for the various formulas**." ([Location 593](https://readwise.io/to_kindle?action=open&asin=B08SGC3TD3&location=593)) --- **Tags** -- [[quotes]], [[energy-conversion]], [[gravitational-energy]], [[kinetic-energy]], [[heat-energy]], [[elastic-energy]], [[electrical-energy]], [[radiant-energy]], [[nuclear-energy]], [[mass-energy]], [[physics]], [[epistomelogical-challenge]] **Source** -- [[202412030828 - B - How the World Really Works]]