Speaker 1: Welcome to Brainstuff, a production of iHeartRadio, Hey brain Stuff.
Speaker 1: Lauren vogelbam here on January twenty ninth of nineteen ninety two,
Speaker 1: A cargo ships build a portion of its contents into
Speaker 1: the Pacific Ocean, thus releasing some twenty eight thousand little
Speaker 1: yellow rubber ducks and other bathtub toys to journey around
Speaker 1: the globe. Beachcombers and other amateur and professional ocean enthusiasts
Speaker 1: logged findings of them for at least twenty years. The
Speaker 1: last report I know of is from August of twenty thirteen.
Speaker 1: They've ridden ocean currents up the eastern coast of the
Speaker 1: United States, along the shores of Greenland, and through the
Speaker 1: ice pack in the Arctic Ocean. Some two thousand are
Speaker 1: still unaccounted for. How these simple bathtub toys remained afloat
Speaker 1: for so long isn't much of a mystery. After all,
Speaker 1: they're made of lightweight rubber and filled with air. It's
Speaker 1: no wonder the dense sea water holds them up. But
Speaker 1: how do their flesh and blood brethren accomplish the same task.
Speaker 1: Real ducks aren't made of plastic, and they contain more
Speaker 1: than just air. Today, let's talk about how ducks float.
Speaker 1: To understand this, you first have to understand why anything floats.
Speaker 1: Objects either float or sink in water because of what's
Speaker 1: called buoyancy. When an object placed in water weighs less
Speaker 1: than the amount of water that it displaces, the object floats.
Speaker 1: If it weighs more, the object sinks. If that cargo
Speaker 1: ship had been transporting bowling balls, you can bet they
Speaker 1: wouldn't be cruising the high seas. Rubber ducks, however, are
Speaker 1: a different story. They typically weigh no more than say,
Speaker 1: zero point two ounces, but they take up about four
Speaker 1: point five cubic inches of space. For our metric friends,
Speaker 1: that's about five grams and seventy five cubic centimeters. So
Speaker 1: that means that the water that they displace weighs over
Speaker 1: two and a half ounces or seventy five grams, so
Speaker 1: that water significantly outweighs them. Therefore, the heavier sea water
Speaker 1: will keep them afloat. Real ducks are also lighter than
Speaker 1: the water they displace, but it takes several things working
Speaker 1: in tandem to achieve that lightness. First up, ducks have
Speaker 1: a special gland called the europhygeal gland, or the prene gland.
Speaker 1: This gland, located at the base of their tail, produces
Speaker 1: an oil that the ducks spread over their bodies to
Speaker 1: make their feathers water repellent. If you've ever seen ducks
Speaker 1: preening themselves and seeming to pay special attention to their
Speaker 1: tail feathers, that's why they keep going back to that
Speaker 1: gland for more oil. Because the oil treated feathers resist
Speaker 1: getting saturated with water, the birds weigh less than they
Speaker 1: would if their feathers absorbed that water. This is also
Speaker 1: how the phrase like water off a duck came about.
Speaker 1: In addition to their water proofing abilities, duck feathers possess
Speaker 1: another quality that helps them to float. They trap air.
Speaker 1: The bird's feathers are tightly interlocked with a system of
Speaker 1: bendy barbs that hold air in. You know those little
Speaker 1: wings that kids wear on their arms in the pool
Speaker 1: to help them swim. Ducks practically have those built into
Speaker 1: their feathers. If they need to dive under water for
Speaker 1: a quick snack, they just squeeze the air out by
Speaker 1: pressing their feathers in. The feathers will trap air again
Speaker 1: soon after the duck resurfaces and shakes any beads of
Speaker 1: water off of its oil treated feathers. Ducks further have
Speaker 1: a system of internal air sacks that helps to keep
Speaker 1: them buoyant. These sects, which include the duck's lungs and
Speaker 1: are located along the length of the duck's body, are
Speaker 1: the equivalent of having miniature helium balloons inside of them.
Speaker 1: The secs stay filled with air unless the duck wants
Speaker 1: to dive underwater, at which point it squeezes the air out. However,
Speaker 1: one feature that does not help ducks float is the
Speaker 1: weight of their hollow bones. Most birds that fly and
Speaker 1: some that don't, and some dinosaurs have a bone structure
Speaker 1: that's webbed through with pockets on the inside instead of
Speaker 1: being relatively solid, which most human bones are. If you
Speaker 1: think of it in terms of candy, the cross section
Speaker 1: of hollow bird bones is sort of like honeycombed toffee,
Speaker 1: and many human bones are more like a chocolate bar
Speaker 1: with a few crunchies in it and some kind of
Speaker 1: chewy center, sort of. People used to think that the
Speaker 1: air pockets in birds hollow bones made them lighter, but
Speaker 1: it turns out that it doesn't because of that webbed
Speaker 1: or honeycomb structure. Birds bones are actually more dense than
Speaker 1: mammal bones. They have to be because they have to
Speaker 1: be stiffer and stronger so that they don't break the
Speaker 1: real benefit of these hollow bones is that they're essentially
Speaker 1: part of the bird's lung system. Air sacks from a
Speaker 1: bird's lungs form and attached to the hollows in its
Speaker 1: bones as the bird grows, so when the bird flies,
Speaker 1: it has extra space to take in oxygen. That means
Speaker 1: extra oxygen will find its way into the bird's blood,
Speaker 1: which will give it extra energy for flight. I guess
Speaker 1: it's possible that when a bird with lots of hollow
Speaker 1: bones really breeds in it might give them an edge
Speaker 1: in floating, but it would only be for as long
Speaker 1: as the breath lasts, so not really useful overall, and
Speaker 1: ducks don't have that many hollow bones to begin with.
Speaker 1: Not all birds have the same number. Birds that spend
Speaker 1: a lot of time gliding or soaring have more, and
Speaker 1: birds like ducks that spend a lot of time diving
Speaker 1: have fewer. Some diving birds like penguins, puffins, and loons,
Speaker 1: don't have any hollow bones at all, which indeed places
Speaker 1: them at odds with the rubber duckies that we discussed early,
Speaker 1: which are entirely hollow, by the way, if you would
Speaker 1: like to learn more about their journey. There's been a
Speaker 1: bunch of research published about these rubber ducks and what
Speaker 1: they mean for our oceans and the plastics that wind
Speaker 1: up there. This includes at least two books. A one
Speaker 1: is called This Is a Long One Moby Duck, The
Speaker 1: True story of twenty eight eight hundred bath Toys lost
Speaker 1: at sea and of the Beachcomber's oceanographers, environmentalists and fools,
Speaker 1: including the author who went in search of them, and
Speaker 1: another called slightly more simply Flotsymmetrics and the Floating World.
Speaker 1: How one man's obsession with runaway sneakers and rubber ducks
Speaker 1: revolutionized ocean science. Today's episode is based on the article
Speaker 1: how do Ducks Float? On HowStuffWorks dot Com written by
Speaker 1: Jennifer Horton. Brain Stuff is production of by Heart Radio
Speaker 1: in partnership with how Stuffworks dot Com and is produced
Speaker 1: by Tyler Klais. Four more podcasts my Heart Radio, visit
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