youtube really understands me
youtube really understands me
this guy is systematically undoing the world
Dear Webbers, I would be interested to hear where you think this whole WWW thing is headed—in one year, five years, ten years? ☯93NOV
” You do not have the password…”
keep you bodice safe from ripping with our patented bodice kitten.
Looks like what we have here is a…
one more thought on the teeth are cool train of thought: human teeth are in fact some of the boringest teeth around! like there’s a whole world of crazy ass shapes and specializations to do whacky things and we’ve just got mostly flat lazy-ass mouthrocks. this is probably related both to how our diets have evolved throughout human evolution and the relatively recent development of cooking.
why can’t people have magnetite teeth like that other animal. that shit would own
This question owns! Let’s talk about tooth function and kick-ass metal mollusc teeth a bit!
This is a chiton, an ancient group of mollusks with a fossil record of nearly half a billion years. You can see in these pictures a chiton’s radula, it’s chainsaw-like tongue filled with individual radular teeth. Those teeth are actually constantly replaced in a conveyer belt fashion, with the newest teeth at the front and the oldest at the end. The coolest part of chiton radular teeth is that they’re covered in a thin layer of magnetite that via complicated processes is actually pulled out of the surrounding environment and biologically laid down as the outer shell of the tooth. And for those who might not have known about this before, yes this literally means magnetic fucking black metal teeth
Wau. So, why can’t we have this? Well actually there are a couple of different answers to that!
First, let’s talk about a functional reason (like, why it would not work so well for us maybe). As most people probably know, the purpose of teeth is to break down food to smaller chunks for digestion. We don’t often think about this much when eating because our cooking turns food into extra-soft easy mode, but in nature food DOES NOT want to be eaten and so teeth are engaged in this constant war of fracture or be fractured with other objects. And teeth regularly do get fractured! To really get into how this works, we need to borrow some concepts from materials engineering.
Tooth enamel (which makes up the outer layer of your teeth) is very hard, which means it resists cracks forming in it. But it’s also reasonably tough, which means cracks that are formed don’t get very far. For examples of this in action, think of a leaf and glass. A leaf is very soft (easy to make cracks in) but very tough (cracks don’t go far on their own after you make them), while glass is surprisingly hard to put cracks in but once you do it they spread on their own and the whole thing shatters. This is a bit of a simplification, but still! Turns out magnetite is SUPER hard, the hardest tissue ever seen in an animal body. But it’s probably not the toughest, cracks made in it go quickly through. This is why even the chitons only have a thin veneer of it, cracks in the magnetite get stopped when they hit the softer stuff underneath because interfaces between different types of tissues are good at that stuff.
The other reason why we don’t get cool-ass black metal magnet teeth is frankly one of evolutionary inertia. All of the hard bits in our bodies - bones and teeth - are the gift of an invertebrate hundreds and hundreds of millions of years ago who somehow figured out how to precipitate calcium carbonate (a pretty cool mineral, certainly no metal, but it’s an unsung hero in vertebrate evolution) out of the fucking water and use it to make hard bits, namely shells. HOW COOL IS THAT. it’s actually the same general sort of thing chitons are doing precipitating magnetite out of stuff. and once we had the ability to take in calcium carbonate, we discovered we could all kinds of kickass things like make teeth and bones and shit. Maybe if evolution had gone differently we could have started with magnetite and now have wolverine bones, but once you get on a path sometimes you just keep going down your road. Also, as mentioned above magnetite may well not just be as well suited to varied biological needs as our dependable old friend, calcium carbonate.
But as a bonus so this isn’t too disappointing, we actually do biologically collect some amount of magnetite in our brain cells of all places. And it may have something to do with detection of electromagnetic fields?? We certainly know bio-magnetite in honeybees is likely a factor in their navigation sense. Also there are colonies of compass bacteria that use bio-magnetite to array themselves. life is weird
the new “cosmos” was great
that cat looks like it’s bout to send the kid to the shadow realm
YEAH DUDE I’M GONNA PWN SOME N00BS IN A HARDCORE GAME OF WIKIPEDIA
Just a friendly reminder that u should call ur animals by gender-neutral or multiple pronouns. They CAN understand you and YES it is possible for an animal to be trans. Your cat having a penis does not make it male. It is straight up animal abuse to deliberately misgender your pets so please do not do it.
4/20? You mean 1/5 reduce your fractions did you even learn math
Sailor Moon cosplay for tiny dogs.