Watch a Former NASA Engineer Turn Sand Into Liquid—Then Take a Dip

iStock
iStock

NASA engineer-turned-YouTube host Mark Rober is known for regularly conducting zany science experiments in his own backyard and filming the results. More than a year after he went swimming in a sea of Orbeez, Rober's latest stunt features him taking a dip in a hot tub filled with liquid sand.

But wait: Wouldn't bathing in liquid sand be akin to taking a really grainy mud bath (albeit with great exfoliation potential)? Rober isn't technically wetting down the granular material, as he explains in the video below—he's making the sand sift, blow, and bubble using nothing but a nitrogen tank and some PVC pipe.

“If you take a tub of sand ... and then add air in just the right way, it basically becomes a liquefied soup,” Rober explains of the seemingly magical process. “In science this is known as a fluidized bed," or a bed of small, solid particles that are suspended and galvanized by an upward flow of gas.

The upwards-blowing air is equal to the downward force of gravity. This causes the sand to hover in equilibrium, and allows the grains to slide around like water. The top surface of the mix "is nearly frictionless," Rober says. "It's like an air hockey table. And then when you cut off the air, it freezes everything exactly where it's at," prompting the tub's ingredients to transform back into ordinary, heavy sand.

[h/t Twisted Sifter]

21 Widespread Myths About Animals, Debunked

YouTube
YouTube

No, that nasty-looking wart on your finger didn't come from a toad. And yes, giraffes really do need more than 30 minutes of shut-eye in a day. Chances are that one of the "facts" you've come to know about your favorite animal isn't a fact at all. (Cats can swim and dogs do see colors—though in a different way than you probably do.)

Since our fuzzy, furry, finned, and winged friends can't always speak for themselves, Mental Floss Editor-in-Chief Erin McCarthy is here to clear up 21 widespread animal myths. So gather up your pets and check out this week's all-new edition of the Mental Floss List Show. You can watch the full episode below.

For more episodes like this one, be sure to subscribe here.

17 Signs That You’d Qualify as a Witch in the 1600s

YouTube
YouTube

Are you a woman? Do you have a birthmark? Do you enjoy spending quality time with friends without a chaperone? You might just be a witch! At least that's how the thinking went in the 1600s, when now completely normal behaviors could have seen you accused of witchcraft.

Grab your broom and the pointiest black hat you can find, and join Mental Floss editor-in-chief Erin McCarthy as she shares 17 signs that might have branded you a witch during the 17th century in this week's all-new edition of the Mental Floss List Show. You can check out the full episode below:

For more episodes like this one, be sure to subscribe here!

SECTIONS

arrow
LIVE SMARTER