This is a linkpost for An Actually Intuitive Explanation of the Oberth Effect.

Like anyone with a passing interest in Kerbal Space Program physics and spaceflight, I eventually came across the Oberth Effect. It's a very important effect, crucial to designing efficient trajectories for any rocket ship. And yet, I couldn't understand it.

Wikipedia's explanation focuses on how kinetic energy is proportional to the square of the speed, and therefore more energy is gained from a change in speed at a higher speed. I'm sure this is true, but it's not particularly helpful; simply memorizing formulae is not what leads to understanding of a phenomenon. You have to know what the numbers mean, how they correspond to the actual atoms moving around in the real universe.

This explanation was particularly galling as it seemed to violate relativity; how could a rocket's behavior change depending on its speed? What does [...]

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Outline:

(02:06) Asymmetric gravitational effects

(03:59) It really is gravity, not speed

(05:37) Bringing propellant back into it

(08:10) Ok, maybe its about speed after all

The original text contained 5 footnotes which were omitted from this narration.

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First published:
January 10th, 2024

Source:
https://www.lesswrong.com/posts/zLnCs96b4JLwJBCTA/an-actually-intuitive-explanation-of-the-oberth-effect-1

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Narrated by TYPE III AUDIO.

“An Actually Intuitive Explanation of the Oberth Effect” by Isaac King

LessWrong (30+ Karma)