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Screenshot from YouTube

Researchers Discover a New Type of Fire Called "Blue Whirl"

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Screenshot from YouTube

Scientists at the University of Maryland’s A. James Clark School of Engineering say they’ve discovered a new type of fire whirl that could make handling oil spills a lot cleaner. As Gizmodo reports, the so-called “blue whirl” burns while leaving behind little to no soot.

A fire whirl (otherwise known as a fire tornado, firenado, or fire devil) occurs when hot air rises quickly from the ground during a wildfire. The awe-inspiring event can be extremely dangerous in nature, but the University of Maryland researchers believe the power of this new type of fire whirl can be harnessed for good.

In their paper published last week in the journal Proceedings of the National Academy of Sciences (PNAS) [PDF], the authors describe how the blue whirl’s mesmerizing color makes it notable. “The yellow color [in conventional fire whirls] is due to radiating soot particles, which form when there is not enough oxygen to burn the fuel completely,” paper co-author Elaine Oran said in a press statement. “Blue in the whirl indicates there is enough oxygen for complete combustion, which means less or no soot, and is therefore a cleaner burn.” This cleaner burn could have significant applications outside the lab. 

The researchers initially wanted to see how regular fire whirls behave on water. Their suspicion was that fire whirls would be better at burning oil spilled on the ocean’s surface than traditional flames were. Their findings backed them up: Fire whirls burn hotter while sucking up fuel away from the surface. If they could find a way to produce a blue whirl on a larger scale, it would clean up spills more efficiently while leaving behind less airborne pollutants. What's even more promising is that blue whirls burn without the chaotic turbulence of yellow flame tornadoes—at least in the lab. You can watch the blue fire ignite in the video below.

[h/t Gizmodo]

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Live Smarter
Not Sure About Your Tap Water? Here's How to Test for Contaminants
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In the wake of Flint, Michigan's water crisis, you may have begun to wonder: Is my tap water safe? How would I know? To put your mind at ease—or just to satisfy your scientific curiosity—you can find out exactly what's in your municipal water pretty easily, as Popular Science reports. Depending on where you live, it might even be free.

A new water quality test called Tap Score, launched on Kickstarter in June 2017, helps you test for the most common household water contaminants for $120 per kit. You just need to take a few samples, mail them to the lab, and you'll get the results back in 10 days, telling you about lead levels, copper and cadmium content, arsenic, and other common hazardous materials that can make their way into water via pipes or wells. If you're mostly worried about lead, you can get a $40 test that only tells you about the lead and copper content of your water.

In New York State, a free lead-testing program will send you a test kit on request that allows you to send off samples of your water to a state-certified lab for processing, no purchase required. A few weeks later, you'll get a letter with the results, telling you what kind of lead levels were found in your water. This option is great if you live in New York, but if your state doesn't offer free testing (or only offers it to specific locations, like schools), there are other budget-friendly ways to test, too.

While mailing samples of your water off to a certified lab is the most accurate way to test your water, you can do it entirely at home with inexpensive strip tests that will only set you back $10 to $15. These tests aren't as sensitive as lab versions, and they don't test for as many contaminants, but they can tell you roughly whether you should be concerned about high levels of toxic metals like lead. The strip tests will only give you positive or negative readings, though, whereas the EPA and other official agencies test for the concentration of contaminants (the parts-per-billion) to determine the safety of a water source. If you're truly concerned with what's in your water, you should probably stick to sending your samples off to a professional, since you'll get a more detailed report of the results from a lab than from a colored strip.

In the future, there will likely be an even quicker way to test for lead and other metals—one that hooks up to your smartphone. Gitanjali Rao, an 11-year-old from Colorado, won the 2017 Young Scientist Challenge by inventing Tethys, a faster lead-testing device than what's currently on the market. With Tethys, instead of waiting for a lab, you can get results instantly. It's not commercially available yet, though, so for now, we'll have to stick with mail-away options.

[h/t Popular Science]

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Attila Kisbenedek/AFP/Getty Images
The Elements
8 Essential Facts About Uranium
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Uranium glass vessels.
Attila Kisbenedek/AFP/Getty Images

How well do you know the periodic table? Our series The Elements explores the fundamental building blocks of the observable universe—and their relevance to your life—one by one.

Uranium took some time asserting itself. For centuries, heaps of it languished in waste rock piles near European mines. After formal discovery of the element in the late 18th century, it found a useful niche coloring glass and dinner plates. In the first half of the 20th century, scientists began investigating uranium's innate potential as an energy source, and it has earned its place among the substances that define the "Atomic Age," the era in which we still live. Here are some essential facts about U92.


With a nucleus packed with 92 protons, uranium is the heaviest of the elements. That weight once compelled shipbuilders to use spent uranium as ballast in ship keels. Were it employed that way now, sailing into port could set off defense systems.

Uranium was first found in silver mines in the 1500s in what's now the Czech Republic. It generally appeared where the silver vein ran out, earning it the nickname pechblende, meaning "bad luck rock." In 1789, Martin Klaproth, a German chemist analyzing mineral samples from the mines, heated it and isolated a "strange kind of half-metal"—uranium dioxide. He named it after the recently discovered planet Uranus.

French physicist Henri Becquerel discovered uranium's radioactive properties—and radioactivity itself—in 1896. He left uranyl potassium sulfate, a type of salt, on a photographic plate in a drawer, and found the uranium had fogged the glass like exposure to sunlight would have. It had emitted its own rays.


Uranium decays into other elements, shedding protons to become protactinium, radium, radon, polonium, and on for a total of 14 transitions, all of them radioactive, until it finds a resting point as lead. Before Ernest Rutherford and Frederick Soddy discovered this trait around 1901, the notion of transforming one element into another was thought to be solely the territory of alchemists.


Uranium's size creates instability. As Tom Zoellner writes in Uranium: War, Energy, and the Rock That Shaped the World, "A uranium atom is so overloaded that it has begun to cast off pieces of itself, as a deluded man might tear off his clothes. In a frenzy to achieve a state of rest, it slings off a missile of two protons and two neutrons at a velocity fast enough to whip around the circumference of the earth in roughly two seconds."


Traces of uranium appear in rock, soil, and water, and can be ingested in root vegetables and seafood. Kidneys take the burden of removing it from the bloodstream, and at high enough levels, that process can damage cells, according to the Argonne National Laboratory. But here's the good news: After short-term, low-level exposures, kidneys can repair themselves.


Before we recognized uranium's potential for energy—and bombs—most of its uses revolved around color. Photographers washed platinotype prints in uranium salts to tone otherwise black and white images reddish-brown. Added to glass, uranium gave beads and goblets a canary hue. Perhaps most disconcertingly, uranium makes Fiesta Ware's red-orange glaze—a.k.a. "radioactive red"—as hot as it looks; plates made before 1973 still send Geiger counters into a frenzy.


Uranium occurs naturally in three isotopes (forms with different masses): 234, 235, and 238. Only uranium-235—which constitutes a mere 0.72 percent of an average uranium ore sample—can trigger a nuclear chain reaction. In that process, a neutron bombards a uranium nucleus, causing it to split, shedding neutrons that go on to divide more nuclei.

In the 1940s, a team of scientists began experimenting in the then-secret city of Los Alamos, New Mexico, with how to harness that power. They called it "tickling the dragon's tail." The uranium bomb their work built, Little Boy, detonated over the Japanese city of Hiroshima on August 6, 1945. Estimates vary, but the detonation is thought to have killed 70,000 people in the initial blast and at least another 130,000 more from radiation poisoning over the following five years.

The same property that powered bombs is what now makes uranium useful for electricity. "It's very energy dense, so the amount of energy you can get out of one gram of uranium is exponentially more than you can get out of a gram of coal or a gram of oil," Denise Lee, research and development staff member at Oak Ridge National Laboratory, tells Mental Floss. A uranium fuel pellet the size of a fingertip boasts the same energy potential as 17,000 cubic feet of natural gas, 1780 pounds of coal, or 149 gallons of oil, according to the Nuclear Energy Institute, an industry group.


In the 1970s, ore samples from a mine in what is now Gabon came up short on uranium-235, finding it at 0.717 percent instead of the expected 0.72 percent. In part of the mine, about 200 kilograms were mysteriously absent—enough to have fueled a half-dozen nuclear bombs. At the time, the possibility of nuclear fission reactors spontaneously occurring was just a theory. The conditions for it required a certain deposit size, a higher concentration of uranium-235, and a surrounding environment that encouraged nuclei to continue splitting. Based on uranium-235's half-life, researchers determined that about 2 billion years ago, uranium occurred as about 3 percent of the ore. It was enough to set off nuclear fission reactions in at least 16 places, which flickered on and off for hundreds of thousands of years. As impressive as that sounds, the average output was likely less than 100 kilowatts—enough to run a few dozen toasters, as physicist Alex Meshik explained in Scientific American.


A 2010 study from MIT found the world had enough uranium reserves to supply power for decades to come. At present, all commercial nuclear power plants use at least some uranium, though plutonium is in the mix as well. One run through the reactors consumes only about 3 percent of the enriched uranium. "If you could reprocess it multiple times, it can be practically infinite," Stephanie Bruffey, a research and development staff member for Oak Ridge National Laboratory, tells Mental Floss. Tons of depleted uranium or its radioactive waste byproducts sit on concrete platforms at nuclear power plants and in vaults at historic weapons facilities around the country; these once temporary storage systems have become a permanent home. 


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