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Curious that both average inputs and outputs match to exactly 5.74 kg. I had intuitively assumed there would be a significant difference, but I suppose that even if a lot of energy is extracted, the mass difference will be negligible, mc2 and all.

I'm also surprised that the vast majority of the output carbon is in the form of CO2 rather than feces.

It's all rather obvious in retrospect, it was just nice to see crystallized like this.

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> I'm also surprised that the vast majority of the output carbon is in the form of CO2 rather than feces.

Not sure if you know, but in the same vein, I was shocked when I learned ~50% of the biomass of trees is carbon (right, we knew that), but also that the carbon came from CO2 the tree respirated. Also makes total sense in hindsight, but still think it's so cool.

The trees literally build their mass from the air and sunlight (and yes, obviously also water and trace minerals from the roots).

There is a nice Feynman children's lecture about this [0] from the series "Fun to Imagine" [1]

0. https://www.youtube.com/watch?v=ITpDrdtGAmo

1. https://www.bbc.co.uk/programmes/p0198zc1

And when you set them on fire, it lets the air and sunlight back out!

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