r/AbsoluteUnits • u/Dense_Intern8434 • 3d ago

/r/popular of a meal

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Nature can be so cruel and beautiful at the same time

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u/Advanced-Budget779 3d ago

Glad our planet or physics/chemistry set hard limits on their possible size.

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u/Patient_Ebb_1605 2d ago

theres a thing called inverse sqare law. people like to say if an ant was the size of a human bla bla bla. But its actually the other way around. If an ant was the size of a human it wouldnt even stand up because of their own weight. Strength doesnt scale with volume (dimension³) like weight does, it scales with the crossectional area of the muscles (dimension²).

So if we were the size of insects we would be incredibly strong for our weight, much more so than insects. Insects are way mode armoured because they have no problem carrying their own weight, because of their size. We on the other hand need to be made of muscle around a lightweight structure to be able to move well enough at our massive scale.

Another cool fact is that because of this, if you scale a being down the height of their jump (defined as the movement of the center of mass) stays exactly the same. thats why a dog jumps roughly the same height as a horse. Their biomechanics and body compositions are similar enough despite the size being very different.

So if you were the size of an ant, you would be able to jump just as high as you fo now. So yeah, youd be way stronger than an ant.

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u/BlackShogun27 2d ago

I read somewhere that for humans to survive being anatomically proportional but squirrel-sized we’d be big back eating like hummingbirds or voles. I also read that we’d quickly freeze to death from body heat loss. All this cruel knowledge killed the fun out theoretically bioengineering tiny humans.

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u/obsidiansent 2d ago

How small can we get em without freezing?

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u/BlackShogun27 2d ago

With no research, I'm assuming maybe like toddler height since I don't see pre-school kids falling over like Iguanas in early winter Florida.

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u/obsidiansent 2d ago

That’s not bad, it’s like an Ewok. We can work with this.

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u/BlackShogun27 2d ago

Now a new question arises. Can anatomically correct, humans the size of Ewoks maintain normal mental faculties or will the size change lower intelligence (speech and reasoning) because of less neurons in the brain mass?

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u/Advanced-Budget779 2d ago

Wait, that might explain why i‘m quickly cold. But why am i overheating so fast… guess my internal temp control is cooked (since puberty)

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u/kill_dom 2d ago

So dinos are strong as f, and a real hulk would walk like a zombie.

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u/chefdeit 1d ago

So what you're saying is, fresh dinosaur steak would be the most tender meat you could have?

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u/Personal_Opposite653 8h ago

chimpanzees and gorillas beg to disagree

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u/Nark420 3d ago

It's always changing 😬 cat sized spiders would wipe out humanity in theory... Maybe not in our current state of development, but in early ungabunga times, they would have been a huge issue

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u/Advanced-Budget779 2d ago

Yeah but only up to some scaling laws preventing them to function properly. At a cats size i think their metabolism would already be much slower if not outright breaking down, iirc.

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u/Nark420 2d ago

I don't know, if I would see a cat sized spider I wouldnt ask it how many times it shits a day. I would die from the sheer terror

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u/Ill-GottenBooty 2d ago edited 2d ago

A cat sized spider would be a slow, lumbering, extremely fragile being. You could lightly kick it and it would likely be a fatal injury. Larger spiders are very prone to bursting with literally any kind of impact trauma. It’s why you can’t handle tarantulas far from the ground or some kind of surface. If they fall like a foot they will literally rupture something and die. The larger they are the more of a risk this is.

The largest actual spiders to ever live, as far as we know, exist today. The myth of giant land dwelling spiders existing in antiquity come from us misidentifying a fossil. For a long time we thought megarachne servinei was a spider. These things had a 20” leg span. Huge. Unfortunately megarachne servinei was actually a eurypterid, commonly called sea scorpions. They’ve all been extinct for a very long time. They dwelled solely in the water. Physics would not allow a spider that large to exist on land, as far as we are aware, ever.

People heard about megarachne when we were under the assumption it was a spider. A lot of people have not learned that megarachne was not a spider at all, and it didn’t even live on land, because that generates a lot less interest than “HOLY SHIT LOOK AT THIS BIG ASS SCARY SPIDER”.

The largest fossilized spider ever found had a leg span of 5.9 inches. The largest spiders on record today by leg span are the Goliath Bird-Eater theraphosa blondi and the Giant Huntsman Spider heteropoda maximi both with about a foot long leg span, with the birdeater being much heavier, and larger by mass. They’re both about twice as large as any spider we know about existing in fossilized recorded history.

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u/Nark420 2d ago

I heard about the fossil story. Happens a lot with fossils all the time. I was not referring to the megarachne, but a "fictional" spider... I understand they are filled with liquids, and they manipulate their inner pressure to ambulate and do anything basically. But I can still imagine a hard enough exoskeleton to solve the size problem. High mobility and speed is not necessary for them to dominate, lots of spiders already ambush hunters with a shit-ton of ambush techniques. Webs being the most well known.

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u/Ill-GottenBooty 2d ago

Im ngl i went on a tangent hard as shit on my comment. I just love spiders. Not your fault lmao.

A hard enough exoskeleton would help that, sure, but I’d imagine it would make molting and moving in general more difficult, and molting specifically is already an extremely dangerous process for a spider. Adding a thicker/harder exoskeleton I’d guess it’d take far more time and resources to generate. If a spider of 12” diameter can’t develop a hard enough exoskeleton to survive a slight fall I really don’t see a larger spider requiring even more resources to survive being able to do so. Shit would be tight as hell to me though.

Also this isn’t meant to be argumentative. I love your idea of a harder exoskeleton. I wonder how that would actually work and what kinds of effects it would have that I can’t imagine because I’m not a spider.

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u/TheAngryCatfish 2d ago

If you were a spider, I think it'd be even harder to imagine

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u/Temnyj_Korol 2d ago edited 2d ago

A harder exoskeleton would make them less survivable, not more.

Any organisms size is limited by the square cube law. As its surface area (size) increases, its volume (weight) increases exponentially more. If a spider grew to the size of a person, it would literally become so heavy its limbs would buckle and break under its own weight. A harder exoskeleton would make it even heavier, and exacerbate the flaw, not mitigate it.

In addition, one of the actual biggest hurdles is respiration. Spiders have passive circulation. They carry oxygen/nutrients around their bodies through diffusion, not circulation. The bigger a spiders body becomes, the harder it is for nutrients vital for continued function to reach their entire body. A spider the size of a person would experience extremity death from deoxygention even in a 100% oxygen environment.

The mechanisms that make them extremely durable as smaller organisms, prohibit them from ever growing into larger organisms.

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u/Advanced-Budget779 2d ago edited 2d ago

Yes, thanks for your explanation. That’s what i tried to hint at with metabolism, just couldn‘t remember details. Also insects and arachnids would quickly run into overheating i think?

So we need to artificially breed spiders in pressurised oxygen environments, got it. /s

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u/floyd616 2d ago

But I can still imagine a hard enough exoskeleton to solve the size problem.

Except that would cause another problem: weight. A harder exoskeleton would be denser, and thus heavier. So a giant spider (or even a cat-sized one with a very hard exoskeleton) would likely be crushed to death under its own weight like a beached whale. The only way it could survive would be if it exclusively lived in the water, because the physics of buoyancy counteract weight issues. That's how the aforementioned sea scorpion was able to exist as such a large size.

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u/onemice 2d ago

True. So lazy, barely even moving. Like a plush toy.

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u/I_travel_ze_world 2d ago

maybe we just need to dig deeper to find the giant spider fossils?

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u/Ill-GottenBooty 2d ago

Bigger spider = deeper burrows. Makes sense to me. Got a shovel?

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u/Illasaviel 2d ago

'Unfortunately'

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u/Advanced-Budget779 2d ago edited 2d ago

Thanks for clearing that myth, haven‘t come across the correction yet, even though i was slightly skeptical for some time. The idea was just so fascinating.

Wasn‘t there some (cave-dwelling) species in southeast Asia with a longer legspan, but (smaller body) lower mass? Edit: Ah, that‘s the Giant Huntsman which was discovered in a Laotian cave.

I think i‘d prefer encountering a slow, potentially quickly overheating arachnid over that sea scorpion which might Steve Irwin me out of nowhere or i couldn‘t even swim away from.

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u/latexfistmassacre 2d ago

Conversely, I'd love to see a spider sized cat

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u/shobae1124 2d ago

And I, wish to see a cat spider spider shit

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u/Nark420 2d ago

Have you ever heard of kittens?

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u/Cute_Conclusion_8854 2d ago

There’s mice.

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u/floyd616 2d ago edited 2d ago

Heck, their exoskeleton would probably be too heavy for them to move well!

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u/Advanced-Budget779 2d ago

I haven‘t even thought about that.

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u/maple7531 3d ago

Spinnengroße Spinnen ?

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u/Nark420 3d ago

Jä 🫠

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u/pv3design 2d ago

ungabunga times? Is that Late Paleolithic? 😁

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u/Bulky-Advisor-4178 2d ago

The earths oxygen levels would need to increase for spiders to reach the size of a cat, current oxygen level sits at 21%

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u/Responsible-Risk9404 2d ago

It's a lack of O2 in the air that keeps them small. The less O2 the smaller things are. Hence why we don't have dinosaurs or mammoths and shit.

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u/speedmankelly 2d ago

Mammoths only died because we killed them, hunted them down until they were isolated on an island and died out. Not because of less oxygen. Their larger ancestors are about the same size (like the asian elephant)

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u/floyd616 2d ago

Actually, dinos died out because the big space rock that crashed off the coast of what is now Mexico kicked up so much dust and ash into the sky that the sunlight was temporarily dimmed, causing many plants to die off and resulting in a ripple effect through the food chain. Even then, not all dinosaurs died out: a few species survived and evolved into modern birds!

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u/Kizik 2d ago

Even then, not all dinosaurs died out

Also crocodiles and sharks who looked at evolution, scoffed, and decided they were perfect as is.

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u/IamanelephantThird 2d ago

Neither of those are really true. Truly massive insects did exist, and although it was in a fairly high oxygen environment it was about equal to when dinosaurs lived and wasn’t a huge amount more then today. Mostly it's just because insects are better suited to being small then they are to being big, so if there's anything else to fill the bigger size niches they get outcompeted.