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[-] themeatbridge@lemmy.world 17 points 5 months ago

Unless you panic and thrash about. The force required to pull your leg out is more than the force of buoyancy keeping you up. So if you are up to your hips, and you just try to step out, you will keep sinking. Once your chest is under, it will be hard to breathe and the panic gets worse.

[-] Xephonian@retrolemmy.com 1 points 5 months ago

Nope. Sand+water is less buoyant than you. You float. Death comes from dehydration or exhaustion. Not from drowning.

[-] themeatbridge@lemmy.world 7 points 5 months ago* (last edited 5 months ago)

I'm not sure you read my comment.

Sand and water forms a non-newtonian fluid that compresses under pressure. Once you sink into it, pulling out requires exponentially more force. You're correct that you would float on quicksand if buoyancy was the only force involved. However, if you end up with both feet in, and you're sinking, the first impulse is to try to step up and out. Unfortunately, lifting one foot pressed the other deeper into the quicksand. If you remain perfectly still, you'll stop sinking at your waist. But if you move your legs, you will sink further down and your buoyancy won't lift you back out unless and until the quicksand gels again.

[-] Xephonian@retrolemmy.com 1 points 5 months ago

If you remain perfectly still, you’ll stop sinking at your waist

I'm not sure you understand buoyancy. Floating objects float, they don't sink no matter how much thrashing about. And while quicksand is denser than water, it's still not dense enough to float a human at their waist, it's actually around their chest.

Nobody dies from drowning in quicksand. Ever. It's always dehydration/fatigue.

[-] themeatbridge@lemmy.world 0 points 5 months ago

I'm not sure you understand what a non-newtonian fluid is. A toothpick would float on jello, but if you stick it down into the jello, its buoyancy doesn't factor in. Quicksand compresses and becomes solid under force, and if you try to walk out, you're more likely to pull yourself deeper. The force of you floating is weaker than the force of compressed quicksand keeping you down.

And I didn't say that anyone drowns, I said it gets hard to breathe if you manage to sink up to your chest. You're right about the dehydration and fatigue, but it is due to panic. If you can float, then you could just lie on your back and roll your way to the edge. But once you're in deep, it would take a tow truck to drag your legs out against the force of the gelled quicksand.

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this post was submitted on 23 May 2024
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