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Space Elevator

(neal.fun)
1773 points kaonwarb | 2 comments | 20 Oct 25 04:42 UTC | HN request time: 0.417s | source
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jvanderbot ◴[20 Oct 25 13:03 UTC] No.45643427[source]▶
Very cool. One thing I wish was better shown: space is close, it's just hard to go up. Our liveable breathable atmosphere is razor thin compared to the size of earth.

In most cases, 100km is less than the distance between sizeable metropolitan areas. It's a day long bike ride. Air runs out less than a bus ride across town. A 15k jog/hike would put you in the stratosphere. Those jet aircraft that seem so high are closer than that. Closer than your friends house or the local stadium probably.

Look at a map or globe with that in mind and everything feels so thin!

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rich_sasha ◴[20 Oct 25 17:45 UTC] No.45646829[source]▶
Likewise, it is crazy to me when I realised how thin our oceans are. I used to think of them as super deep (I mean, they are) but even the Mariana trench is a mere 0.2% of the Earth's radius. Average ocean depth is more like 0.05%.
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1. arkmm ◴[20 Oct 25 21:10 UTC] No.45649429[source]▶
As a follow-up to this, even though water makes up 70% of the Earth's surface, it's only 0.02% of the Earth's mass.
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2. rich_sasha ◴[21 Oct 25 08:47 UTC] No.45653775[source]▶
I might have messed it up, but as a follow up to your follow up, I think the depth of the ocean is comparable to the width of a single human hair compared to the head.

If you inflate a 18cm diameter head to the size of our planet, a 75um hair would be about 5km wide - which is about the average depth of our oceans.

It's one hair, not a whole head of hair!