How Fake Snow Works

Last Christmas, I received a curious gift: a tiny bag of white crystals labeled Fake Snow. "Just add water," it said. So I did. And the crazy stuff puffed up unbelievably, forming a white-ish snow-like substance. Even weirder, the bag indicated that the snow could be dried out and reused (!) -- I didn't try that part.

So what is fake snow? Apparently the powder I had was primarily sodium polyacrylate, a polymer that can absorb 200-300x its own mass in water. This polymer also shows up in diapers and maxi-pads (thank you, science) and also in gardens, where it's used to hang onto water and release it over time. So indeed, if you take a batch of sodium polyacrylate, add water, then let it dry out, you can use it again. It's even "non-toxic" (though the packet, and various web resources I consulted, suggested that eating it would be a really bad idea due to its affinity for bonding with any nearby water). Apparently it should also not be poured down drains, for obvious reasons.

This video shows closeups of how sodium polyacrylate behaves when water is added. It's astounding how much water a tiny bit of this stuff can suck up. Enjoy:

And here's a slightly off-kilter ad for "Snow in Seconds™," showing how quickly the sodium polyacrylate absorbs water and puffs up, delighting kids and nerds alike. "It's even used in movies!" Note that the ad mentions how the snow "feels cold" -- this is because the substance ends up being primarily water, so handling it is like putting your hands in blobs of water. (You can also put it in a refrigerator to make it colder -- again, it's mainly water so it has similar behavior.) It takes a few days to dry out, and can be rehydrated when that occurs.

And here's a very short video showing water being added directly to a beaker of this stuff. It really is neat!

There are lots of fake snows online, though I couldn't find the sketchy dollar-store brand I used.

Have You Used Fake Snow?

I'm sure we have some fake snow experts in the audience. Can you share more about this substance? Do you save your fake snow and reuse it year after year? I'm genuinely curious how people interact with this stuff -- as I plan to turn my house into a Fake Snow Fortress this winter. (Watch out for wampas.)

You Can Sip Coffee and Play Games While This Helmet Scans Your Brain

Brain scanning is a delicate operation, one that typically involves staying very still. Researchers use imaging techniques like magnetoencephalography (MEG) and functional magnetic resonance imaging to get an idea of how the brain functions and what neurons are being activated, but it's not an easy task. Current scanners are huge, requiring patients to sit unmoving inside them, lest their head movements mess up the data. There may soon be a better way—one that would allow patients to act normally while still getting reliable data.

Researchers from the University of Nottingham in the UK report in Nature that they've developed a prototype brain scanner that can be worn like a helmet, one that can generate reliable data even if the subject moves.

It uses lightweight quantum magnetic-field sensors held against the scalp by a 3D-printed helmet that's custom-made for the patient. For the study, one of the researchers volunteered to be the patient and was fitted with a white plastic helmet that looks kind of like a cross between a Roman Centurion helmet and a Jason Voorhees Halloween mask. She was positioned between two large panels equipped with electromagnetic coils that cancel out the Earth's magnetic field so that it doesn't interfere with the magnetic data picked up from the brain. As long as the patient stayed between the panels, she was free to move—nod her head, stretch, drink coffee, and bounce a ball with a paddle—all while the scanner picked up data about on par with what a traditional scanner (seen below) might gather.

A man sits inside an MEG scanner.

The more flexible scanning system is exciting for a number of reasons, including that it would allow squirmy children to have their brains scanned easily. Since patients can move around, it could measure brain function in more natural situations, while they're moving or socializing, and allow patients with neurodegenerative or developmental disorders to get MEG scans.

The current helmet is just a prototype, and the researchers want to eventually build a more generic design that doesn't require custom fitting.

Emery Smith
Stones, Bones, and Wrecks
The 'Alien' Mummy Is of Course Human—And Yet, Still Unusual
Emery Smith
Emery Smith

Ata has never been an alien, but she's always been an enigma. Discovered in 2003 in a leather pouch near an abandoned mining town in Chile's Atacama Desert, the tiny, 6-inch mummy's unusual features—including a narrow, sloped head, angled eyes, missing ribs, and oddly dense bones—had both the “It's aliens!” crowd and paleopathologists intrigued. Now, a team of researchers from Stanford University School of Medicine and UC-San Francisco has completed a deep genomic analysis that reveals why Ata looks as she does.

As they lay out in a paper published this week in Genome Research, the researchers found a host of genetic mutations that doomed the fetus—some of which have never been seen before.

Stanford professor of microbiology and immunology Garry Nolan first analyzed Ata back in 2012; the mummy had been purchased by a Spanish businessman and studied by a doctor named Steven Greer, who made her a star of his UFO/ET conspiracy movie Sirius. Nolan was also given a sample of her bone marrow; his DNA analysis confirmed she was, of course, human. But Nolan's study, published in the journal Science, also found something very odd: Though she was just 6 inches long when she died—a typical size for a midterm fetus—her bones appeared to be 6 to 8 years old. This did not lead Nolan to hypothesize an alien origin for Ata, but to infer that she may have had a rare bone disorder.

The current analysis confirmed that interpretation. The researchers found 40 mutations in several genes that govern bone development; these mutations have been linked to "diseases of small stature, rib anomalies, cranial malformations, premature joint fusion, and osteochondrodysplasia (also known as skeletal dysplasia)," they write. The latter is commonly known as dwarfism. Some of these mutations are linked to conditions including Ehlers-Danlos syndrome, which affects connective tissue, and Kabuki syndrome, which causes a range of physical deformities and cognitive issues. Other mutations known to cause disease had never before been associated with bone growth or developmental disorders until being discovered in Ata.

scientist measures the the 6-inch-long mummy called Ata, which is not an alien
Emery Smith

"Given the size of the specimen and the severity of the mutations … it seems likely the specimen was a pre-term birth," they write. "While we can only speculate as to the cause for multiple mutations in Ata's genome, the specimen was found in La Noria, one of the Atacama Desert's many abandoned nitrate mining towns, which suggests a possible role for prenatal nitrate exposure leading to DNA damage."

Though the researchers haven't identified the exact age of Ata's remains, they're estimated to be less than 500 years old (and potentially as young as 40 years old). Genomic analysis also confirms that Ata is very much not only an Earthling, but a local; her DNA is a nearest match to three individuals from the Chilote people of Chile.

In a press statement, study co-lead Atul Butte, director of the Institute for Computational Health Sciences at UC-San Francisco, stressed the potential applications of the study to genetic disorders. "For me, what really came of this study was the idea that we shouldn't stop investigating when we find one gene that might explain a symptom. It could be multiple things going wrong, and it's worth getting a full explanation, especially as we head closer and closer to gene therapy," Butte said. "We could presumably one day fix some of these disorders."


More from mental floss studios