Tag: chemistry

The Smells of Space: Burned Steak, Gunpowder, Raspberries

By Veronique Greenwood | July 19, 2012 12:09 pm

space
Space!

You’ll never get to take a deep breath and smell the roses in Earth’s orbit. The distinct lack of air there means you’d die a gruesome death sans space helmet, probably without smelling a thing.

Ah, but what about once you get back in your ship? As many places around the Web have been discussing recently, astronauts have said that upon coming back from space walks and taking off their gear, a certain specific scent seems to hang in the air…some think it smells like charred steak, or maybe like something metallic.

Here’s how astronaut Don Pettit put it nearly ten years ago:

Each time, when I repressed the airlock, opened the hatch and welcomed two tired workers inside, a peculiar odor tickled my olfactory senses. At first I couldn’t quite place it. It must have come from the air ducts that re-pressed the compartment. Then I noticed that this smell was on their suit, helmet, gloves, and tools. It was more pronounced on fabrics than on metal or plastic surfaces. It is hard to describe this smell; it is definitely not the olfactory equivalent to describing the palette sensations of some new food as “tastes like chicken.” The best description I can come up with is metallic; a rather pleasant sweet metallic sensation. It reminded me of my college summers where I labored for many hours with an arc welding torch repairing heavy equipment for a small logging outfit. It reminded me of pleasant sweet smelling welding fumes. That is the smell of space.

What sounds like a similar smell—astronauts describe it as something like gunpowder—also emanates from moondust.

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CATEGORIZED UNDER: Living World, Space

Flaming Rocks That Ignited in Woman's Pocket Were Coated in Phosphorus

By Veronique Greenwood | May 21, 2012 1:11 pm

phosphorus
Flares have been washing up on beaches for a long time:
an AP news item from February 23, 1993

Last week, several small stones in the pocket of a California woman’s shorts exploded into flame, leaving her with third-degree burns. The stones came from a beach at San Onofre State Beach in San Diego, which she’d visited earlier in the day.

The story caused a sensation, as media discussed what could make rocks catch on fire. By Friday, California environmental health officials had an answer, or at least part of one: two of the rocks were covered in phosphorus, an element that’s known for igniting into a fierce white flame when it’s exposed to air. Near as they can tell, as long as the rocks were wet with seawater, the phosphorus didn’t ignite, but after they’d dried out in the woman’s pockets over the course of the day, the phosphorus reacted explosively.

But how did the rocks get covered with phosphorus? Though the substance is mined and used in fertilizers, it isn’t very common in in the natural world in its explosive form, called white phosphorus. White phosphorous does, however, have a long history of production by militaries, who use it in flares. Unexploded military flares, presumably dropped by aircraft, have been known to wash up on beaches: Just last year flares washed up on a beach a half-hour’s drive from San Onofre. NBC reported that those flares were from military exercises going on off the coast.

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CATEGORIZED UNDER: Health & Medicine

What's in Spam with Bacon? Tasty, Tasty Chemistry

By Veronique Greenwood | May 15, 2012 12:26 pm

spam

You’d be surprised what’s in your lunch. When you look closer at what makes your American cheese melt well and your hotdog so delicious, you might cringe for a few minutes, but hopefully you also get curious about what other characteristics we like in our food and how food manufacturers have, for better or for worse, given our taste buds what they want.

Over at Wired, they’ve dissected Spam with Bacon, and what they find runs the gammut from “Hey, it’s cool that science can do that!” to “Maybe canned meat was a really bad idea.”

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CATEGORIZED UNDER: Health & Medicine

The Superabsorbent Nanosponge That Only Soaks Up Oil (100x Its Own Weight!)

By Sarah Zhang | April 18, 2012 7:37 am

Using carbon nanotubes and a dash of boron, scientists at Rice University have created a sponge that only absorbs oil. The superabsorbent sponge may not be of much use in the kitchen, but selective sucking of oil could be very helpful in cleaning up oil spills in the ocean. Other perks: the nanosponge is attracted to magnets, so that’s they’re easily controlled, and they’re reusable. At the end of this video, grad student Daniel Hashim shows how to extract energy from the oil-soaked nanosponge by burning it. Then you’re left with just the nanosponge, all ready to absorb oil again.

[via SciAm]

CATEGORIZED UNDER: Technology

With a New Chip, Scientists Use Chemistry to Identify Fluids (And Write Secret Messages)

By Veronique Greenwood | August 4, 2011 1:38 pm

wink
Each fluid reveals a different letter.

What’s the News: Scientists have developed a chip that can instantaneously identify fluids applied to it, just from their unique surface tension. In a handheld device, it could help toxic site remediators figure out what that ominous clear liquid is. And there’s a bonus for the kids-in-the-treehouse user demographic: different secret messages can appear on the chip depending on what fluid is applied.

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CATEGORIZED UNDER: Technology, Top Posts

Ingenious Geological Sleuthing Reveals the Shapes of Ancient Mountains

By Valerie Ross | April 2, 2011 11:46 am

Fiordland National Park
Fiordland National Park in New Zealand, the location of the study

What’s the News: Researchers have mapped out the detailed geological history of a 300-square-mile chunk of New Zealand, from 2.5 million years ago to the present day. The study showed how glaciers carved out the area’s distinctive valleys using a little-known technique called thermochronometry, which involves shooting proton beams onto rocks and making note of what happens—along with some impressive analytical skills.

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CATEGORIZED UNDER: Environment, Physics & Math

Faded Sunflowers: Why Van Gogh's Yellows Are Turning Brown

By Andrew Moseman | February 15, 2011 12:04 pm


Walking the halls of one of the world’s great art museums, it’s easy to regard familiar classic paintings as eternal and unchanging. But this is not the case. Paintings are a mix not only of color but of chemistry—and chemistry changes. In some of Vincent van Gogh’s works, the striking, sunny yellows have faded and turned brownish, robbing the Dutch master’s art of some of its trademark intensity. So a European team of scientists decided to find out exactly what was happening on those canvases.

Using sophisticated X-ray machines, they discovered the chemical reaction to blame — one never before observed in paint. Ironically, van Gogh’s decision to use a lighter shade of yellow paint mixed with white is responsible for the unintended darkening, according to a study published online Monday in the journal Analytical Chemistry. [Los Angeles Times]

Vincent loved yellow. In particular, he loved chrome yellow, a 19th century invention that shone brighter than previously available hues of paint. Art preservationists have known that the lead-based paint fades under intense sunlight, so they’ve done what they can to keep van Goghs and similar works out of intense light. What’s curious about his paintings, however, is that some yellows have faded while others have not.

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CATEGORIZED UNDER: Physics & Math, Technology, Top Posts

To Find the Future of Biofuels, Punch a Hole in a Cow

By Andrew Moseman | January 27, 2011 6:36 pm

We humans are great at making ethanol from grains. We’ve been doing it for thousands of years to make beer and liquor, and our expertise is one reason that corn ethanol has been the biofuel of choice so far. But the biofuels of the future, experts say, will come not from the starch in corn but from the cellulose in grasses and other abundant green plants. There’s just one problem: We’re not good at breaking down the tough structure of cellulose to get at the sugars inside.

But cows are.

Cows, like termites and leafcutter ants, love to eat tough plant material, and host bacteria with the molecular machinery to do so in their guts. Scientists, in their attempts to get better at breaking down cellulose, have tried to copy nature by studying the enzymes that allow those grass-eating animals to do their thing. And now researchers say they have found a treasure trove of new microbe-produced enzymes inside a cow that could help them in their quest.

In a study published Thursday in the peer-reviewed journal Science, researchers described how they incubated bags of switchgrass inside cow rumens and from that found 27,755 “candidate genes” with the potential for efficiently breaking down plant cellulose into usable sugar that can then become ethanol. [MSNBC]

Eddy Rubin and his team executed this chemical excursion by surgically opening a hole into the first of the cow’s four stomachs.

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CATEGORIZED UNDER: Living World, Technology

Ten Tricky Elements Force a Periodic Table Upgrade

By Andrew Moseman | December 17, 2010 5:22 pm

Periodic_TableThe weights, they are a-changin’.

What we’re taught in school science classes is a streamlined version of a muddier and more complicated reality, and it’s no different with something as iconic as the periodic table of elements. This week the venerable chart’s overseers decided to fiddle with the atomic weights of 10 elements, changing their values from a single set number to a range of numbers, which is messier but more accurately resembles the messy real world.

The reason for the change is that atomic weights are not always as concrete as most general-chemistry students are taught, according to the University of Calgary, which made the announcement, and the snappily named International Union of Pure and Applied Chemistry‘s Commission on Isotopic Abundances and Atomic Weights, which oversees such weighty matters. [CNET]

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CATEGORIZED UNDER: Physics & Math

Nobel Week Continues With the Chemistry Prize, Awarded To…

By Andrew Moseman | October 6, 2010 10:36 am

NobelChemistryAkira Suzuki, Ei-ichi Negishi, and Richard Heck.

These three scientists won the Nobel Prize for Chemistry this morning for their discoveries that made it easier and cheaper to build long carbon chains in the lab, and use those chains to develop new drugs, build electronics, and more.

Despite the ubiquity of carbon chains in nature, they’re hard to make in the lab at room temperature. The three chemists independently created essentially the same way to skirt this problem, using palladium to link carbon atoms through a process called palladium-catalyzed cross coupling. The palladium is a go-between, bonding to carbon to bring its atoms closer to one another than they could go on their own. The carbons then break their attachment to palladium and bond together in chains.

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CATEGORIZED UNDER: Health & Medicine
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