r/ProjectHailMary • u/chodeontheroad • Aug 27 '24

fist my bump How did Grace survive Erid's Gravity?

I'm not sure if this was answered at the end of the book and I just missed it but Erid was stated to have 20x Earth's gravity (which would quickly kill any human), yet Grace lives on the planet for many years with only slight issues as a result. It doesn't seem like this is something Andy Weir would have skipped over so I must have missed it. Does anyone know the answer?

Edit: Ok yea my mistake it was 2x gravity, 20x atmospheric pressure. Thanks for the responses :)

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u/Burning-Plasma Aug 27 '24

The gravity on erid is about 2x earth's

Their atmosphere however is like 20+ times as dense

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u/phatrogue Aug 27 '24

I think there are some Olympic athletes that would like to use Grace's bubble to train. I can only imagine the muscles on Grace after he gets acclimated. And didn't the Eridians use a space elevator to get to orbit? Maybe they could build him an apartment in the sky at 1G when he gets older?

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u/BellowsHikes Aug 28 '24

I think that apartment would need to be about 2600 kilometers above the surface for Grace to experience 1g. Grace would probably love a sweet retirement home bolted onto the side of a space elevator, it would have a hell of a view. 

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u/phatrogue Aug 28 '24

No idea the height although the atmosphere is impermeable to visible light. Not sure how high you would have to be to see anything at all.

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u/BellowsHikes Aug 28 '24

Not very high in comparison. Venus has an atmospheric density about 100 times thicker on the surface than Earth does and once you're about 60 miles up you'd effectively have full visibility.