this post was submitted on 28 Dec 2024
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Greentext

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This is a place to share greentexts and witness the confounding life of Anon. If you're new to the Greentext community, think of it as a sort of zoo with Anon as the main attraction.

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If you find yourself getting angry (or god forbid, agreeing) with something Anon has said, you might be doing it wrong.

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Anon's in trouble (sh.itjust.works)
submitted 3 months ago by Early_To_Risa@sh.itjust.works to c/greentext@sh.itjust.works
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[–] starman2112@sh.itjust.works 21 points 3 months ago (3 children)

Not at 15 feet. I don't know enough to say how fast the water would be leaving that hole, but it's maybe a couple hundred pounds of pressure. If he even got caught, it would be super uncomfortable, but he ain't about to get ∆p'd

If you wanna see a real crab-in-a-pipe situation, look up that Byford Dolphin everyone's talking about

[–] anindefinitearticle@sh.itjust.works 7 points 3 months ago* (last edited 3 months ago) (2 children)

Let's convert to metric so we can tell.

15 ft is about 5 m.

Water pressure increases by 10,000 pa per meter (rhogh, rho=1000 kg/m^3, g~10m/s^2), so total pressure is 50 kpa, or 1/2 earth atmospheric pressure.

One side of that hole has ambient pressure of 1 atm. The other side has that plus water pressure totalling 1.5 atm.

A pressure is just an energy density. Multiply by the cross-sectional area of the interface to get the energy gradient across the interface. An energy gradient is a force. We don't have a measure of the cross-sectional area of the hole, but if we expect a person to fit through let's call it 1m^2.

50 kpa = 50 kJ/m^3, so total force felt across this opening is 50kN which is the equivalent weight of five metric tons.

Size of the hole absolutely matters. If it's only the size of a fist (10cm x 10cm) then instead of 5 metric tons it's only 50 kg of equivalent weight, or about the weight of a person and easily survivable.

[–] victorz@lemmy.world 2 points 3 months ago (2 children)

Let's convert to metric so we can tell.

15 ft is about 5 m.

Water pressure increases by 10,000 pa per meter (rhogh, rho=1000 kg/m^3, g~10m/s^2), so total pressure is 50 kpa, or 1/2 earth atmospheric pressure.

This is very interesting. I like unit conversions.

What I did was just take 21-14 psi, and then converted that to bar or atm. I got a number close to ½.

I was like, half an atm? Can't be that bad? I can handle 1 full mf atm literally all mf day mf.

But I guess that's different somehow? I just don't understand how yet. If anyone would care to go into it with me... 🙏

[–] weker01@sh.itjust.works 2 points 3 months ago

Remember a vacuum does not have suction it's the air that presses things under vacuum together. One atm is actually quite a lot but we can withstand that as it's pressing at us from all sides including inside.

See this example of how strong 1 atm can be

[–] spiritsong@lemmy.world 4 points 3 months ago (1 children)

Yeah I read the entire Wikipedia entry on the Byford Dolphin and I almost threw up because how vivid the description is. I think this would be my third time saying this but that's not a nice way to go (to die) at all.

[–] victorz@lemmy.world 2 points 3 months ago (1 children)

You weren't kidding. Real horror movie shit.

[–] Dasus@lemmy.world 2 points 3 months ago (1 children)

You aren't kidding that they weren't kidding. I genuinely felt a bit of a ping of nausea and had to mentally distance myself a bit from imagining it too vividly.

[–] victorz@lemmy.world 1 points 3 months ago (1 children)

I hope you'll be able to forget, bud. ❤️

[–] Dasus@lemmy.world 1 points 3 months ago

I genuinely had already forgot this and to look what you we're concerned I'd remember.

I've been smoking daily for uhm, a few years now.