What is Energy?

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Energy is the most powerful and useful concept in all of physics, but what exactly is it?

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Kronos: Devourer of Worlds

Written and Hosted by Matt O'Dowd

Produced by Rusty Ward

Graphics by Matthew Ranker

Assistant Editing and Sound Design by Mike Petrow and Meah Denee Barrington

Made by Kornhaber Brown (www.kornhaberbrown.com)

In physics energy is not a substance, nor is it mystical. Energy is a number. A quantity. And the quantity itself isn’t even particularly fundamental. Instead, it’s a mathematical relationship between other, more fundamental quantities. It was 17th century polymath Gottfried Leibnitz who first figured out the mathematical form of what we call kinetic energy – the energy of motion. He realized that the sum of mass times velocity squared for a system of particles bouncing around on a flat surface is always conserved, assuming no friction and perfect bounciness. Leibnitz called this early incarnation of energy vis viva – the living force.

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