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TIL: Today I Learned

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@hobbsyoyo Did you see the XKCD comic? I saw it and thought of you :lol:
 
Eiderdown Is Nature’s Perfect Duvet

WSJ said:
THIS IS THE COLDEST time of year in the Northern Hemisphere. I only step outside attired in a thick cocoon of thermal insulation, including sweater, coat, hat and gloves. But even on the chilliest days, the ducks on the nearby river are squabbling and foraging in the shallows. That’s because they benefit from the warmest natural material known: down feathers. The ingenuity of down comes from the fact that it almost isn’t there. Its minimalist structure is startlingly effective.

The master of this art is the eider duck, a portly sea duck that is widespread in the Arctic and feeds by diving for mussels in frigid polar water. Its outer feathers are waterproof because of an interlocking microstructure that the duck constantly fusses over, tidying the feathers and distributing preen oil from a gland near its tail. The thick insulating layer lies just underneath, and this is the eider duck’s claim to fame— eiderdown.

A down feather is almost spherical. Long curly barbs radiate out from the center, and each one is covered in smaller barbules that stick out like the branches on a fir tree. Those barbules, in turn, have even smaller features—lumpy nodes and prongs spaced along their length. It’s a fractal structure, branches on branches on branches.

Down is full of air, but the air can barely

move because the wispy barbules extend into every bit of space at the tiniest scale, acting as a barrier to air flow. The brilliance of this structure is that it involves so little material, yet it fills the space so effectively. Each barbule is just a few percent of the width of a human hair in diameter, and it’s estimated that there could be 30 miles of barbules in just one gram of down.

This cuts out the two major routes for heat to leave the duck’s body. The first is heat transfer along the fibers themselves. The second is convection—air stealing heat from the skin and physically carrying it to the outside world. Ordinarily, the moving air in cold Arctic winds rapidly shunts heat away from any creature exposed to the icy blasts. But if you can keep the air still, as eiderdown does, it can’t conduct heat to other air nearby, so it acts as an insulator.

When eider ducks nest in hollows in the ground, the female will pluck down feathers from her own breast to line her nest with a thick natural duvet. The barbs and barbules are flexible and bend if the down is compressed, but the nodes stop them from sliding over one another. This is why down bounces back if you press it, and it means that the weight of a duck’s eggs won’t permanently squash its down duvet.

Another unusual feature of eiderdown is that the feathers cling together into a single mass. They’ve


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got far more nodes than the feathers of other species, and the barbules are more densely packed. This means that the feathers tangle slightly and therefore won’t blow away in the strong Arctic winds. If you’ve ever been lucky enough to see or use a real eiderdown duvet, you’re looking at nature’s leftovers. The nests are abandoned after the chicks have hatched, and for centuries, humans have recycled those mini-duvets into large human duvets and coats.

The ducks I see on my commute aren’t eiders, but they are kept warm by their own version of down. It still seems astonishing to me that a relatively small duck can swim for hours in freezing water—a measure of how special the structure of down is. I’ll keep my gloves on, but I love admiring the ingenuity from afar.

The eider duck’s feathers help it stay warm in frigid water.
Click to expand...
 
Josu said:
TIL that in the Spanish penal code is about to be modified and exaltation of Francoism will be included as a crime
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But Alianza/Partido Popular is still a political party, right? They're not going to be disbanded?
 
hobbsyoyo said:
TIL about the Ewing amputation.

Basically, doctors have found a way to amputate below the knee and leave the nerves intact to interface with prosthetics. People are moving mechanical feet with their thoughts alone and getting semi-elective surgery to amputate their messed up feet and replace them with bionic prosthetics.

The future is f***ing lit fam

https://journals.lww.com/prsgo/Fulltext/2018/11000/The_Ewing_Amputation___The_First_Human.22.aspx
Spoiler :
4-Figure4-1.png
Click to expand...
Were officially in a cyberpunk future.
Bruce Sterling said:
[Cyberpunk is] Anything that can be done to a rat can be done to a human being. And we can do most anything to rats.
Click to expand...
 
Technically a 'Yesterday' but I'm counting it for today because I can.

TIL the word 'Simony', but I am intensely disappointed I have very little use for it. It means purchasing ecclesiarchal (excuse my spelling) positions or power :)
 
Loerwyn said:
Technically a 'Yesterday' but I'm counting it for today because I can.

TIL the word 'Simony', but I am intensely disappointed I have very little use for it. It means purchasing ecclesiarchal (excuse my spelling) positions or power :)
Click to expand...
If you send me money, I will absolve you of any and all of your past misdeeds. If you send enough, I will include future ones too!
 
after the Washington Nationals won the playoffs LA Dodgers warned them about Houston stealing signals.

Might be why the Nationals won the World Series
 
Birdjaguar said:
If you send me money, I will absolve you of any and all of your past misdeeds. If you send enough, I will include future ones too!
Click to expand...

Skip this chiseler. I offer a group rate covering not only your misdeeds past and future, but your entire family.
 
Loerwyn said:
Technically a 'Yesterday' but I'm counting it for today because I can.

TIL the word 'Simony', but I am intensely disappointed I have very little use for it. It means purchasing ecclesiarchal (excuse my spelling) positions or power :)
Click to expand...

Birdjaguar said:
If you send me money, I will absolve you of any and all of your past misdeeds. If you send enough, I will include future ones too!
Click to expand...

Timsup2nothin said:
Skip this chiseler. I offer a group rate covering not only your misdeeds past and future, but your entire family.
Click to expand...
@Loerwyn just ignore Tim his is a fake from SoCal that will take your money and provide no assuarnces that he has actually performed as required. I will however mail you a full color certificate of authenticity (suitable for framing) confirming that you have gotten everything you paid for and more. Our program offers lots of extras that are only available through our exclusive offers and divine connections. Accept no substitutes.

For just pennies a day
We wash your sins away!
And for a few dollars more
We'll cover the future and what's in store!
 
hobbsyoyo said:
TIL about the Ewing amputation.

Basically, doctors have found a way to amputate below the knee and leave the nerves intact to interface with prosthetics. People are moving mechanical feet with their thoughts alone and getting semi-elective surgery to amputate their messed up feet and replace them with bionic prosthetics.

The future is effing lit fam

https://journals.lww.com/prsgo/Fulltext/2018/11000/The_Ewing_Amputation___The_First_Human.22.aspx
Spoiler :
4-Figure4-1.png
Click to expand...

Still not as lit as chinese farming of organs on one's face :)
 
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