The West Virginia coal mining accident yesterday killed at least 25, and hope is starting to fade for finding the four missing miners alive. It’s the deadliest mining accident in the United States in more than a quarter-century.

A methane explosion appears to be the cause. Normally when DISCOVER covers methane scares, it has to do with the potent greenhouse gas leaking from permafrost or the ocean. But for coal miners, methane represents a more clear and present danger: Underground mines can fill up with the flammable gas, and a stray spark can light it and cause an explosion. As a result, mines are required to have giant fans that blow methane out of the working area.

Methane not only appears to have caused the accident, it also held up the rescue effort. Operations had to be suspended because of a build-up of methane in the mine. It’s hoped that they can resume later today — but it will require drilling about 1,000 feet, through two coal seams, to get to where the men might have been able to find shelter [NPR].

Methane is ubiquitous in coal mines. The gas, like coal, is a molecule made of hydrogen and carbon, and it is produced from the same raw material as coal, ancient piles of biological material, by the same processes. Much of the natural gas sold in the United States is drawn from coal seams. In undisturbed coal deposits, the methane is kept loosely attached to the coal molecules by compression; when the area is opened up by miners, the pressure is reduced and the methane bubbles out [The New York Times].

Coal mining is an unavoidably dangerous occupation, but it seems Massey Energy, owner of the mine, was far behind where it should have been in safety compliance. The U.S. Mine Safety and Health Administration cited the mine for 1,342 safety violations from 2005 through Monday for a total of $1.89 million in proposed fines, according to federal records. The company has contested 422 of those violations [Washington Post]. The citations at West Virginia’s Upper Big Branch mine included some for the improper ventilation of methane.

Just why Upper Big Branch suffered such a catastrophe at this particular time remains unknown. After the incident, geologists noticed that there had been two recent episodes of small seismic activities in the area—a 3.4 magnitude earthquake on Sunday and some surface blasting on Saturday that initially registered as a 2.9 quake. USGS geophysicist Julie Dutton says that the 3.4 quake could have been strong enough to dislodge methane pockets and contribute to the accident—but only if it were closer than its distance of 100 miles. “There’s the definite possibility that that’s what could have happened, but not from this earthquake,” Dutton said. “This one was too far away and days separated. That makes a big difference” [FoxNews.com].

And from the other side of the world, some slightly better news. Yesterday rescuers saved 115 people trapped underground for eight days at the Wangjialing mine in China. The rescue was rare good news for China’s mining industry, the deadliest in the world, where accidents killed 2,631 coal miners last year. That’s down from 6,995 deaths in 2002, the most dangerous year on record [AP]. However, 32 remain stuck underground, and gas buildups are hindering the operations there, too.

Related Content:
80beats: Isn’t It Ironic: Green Tech Relies on Dirty Mining in China
80beats: New EPA Rules Clamp Down on Mountaintop Removal Coal Mining
80beats: After Massive Tennessee Ash Spill, Authorities Try to Assess the Damage
80beats: Obama & Chu Push Ahead with Clean Coal Projects Despite the Cost

Image: flickr / NIOSH

Hand motion segmentation against skin colour background in breast awareness applications.

“A hand is an essential tool used in breast self-examination, which needs to be detected and analysed during the process of breast palpation. However, the background of a woman’s moving hand is her breast that has the same or similar colour as the hand. Additionally, colour images recorded by a web camera are strongly affected by the lighting or brightness conditions. Hence, it is a challenging task to segment and track the hand against the breast without utilising any artificial markers, such as coloured nail polish. In this paper, a two-dimensional Gaussian skin colour model is employed in a particular way to identify a breast but not a hand. First, an input image is transformed to YCbCr colour space, which is less sensitive to the lighting conditions and more tolerant of skin tone. The breast, thus detected by the Gaussian skin model, is used as the baseline or framework for the hand motion.”

Photo: flickr/briser50

Related content:
Discoblog: NCBI ROFL: Eye Tracking of Men’s Preferences for Female Breast Size and Areola Pigmentation.
Discoblog: NCBI ROFL: scientist…or perv?
Discoblog: NCBI ROFL: wtf?

It’s a little tardy– my first book came out in 2002, after all — but Barrel of Monkeys just reviewed Bad Astronomy.

The conclusion?

In fact, I move that Bad Astronomy be a recommended text book at secondary schools everywhere, or even primary schools, for that matter. Scratch that. Everyone in the world should read this book. Phil Plait manages to break things down to an easily understandable level, so that people without a background in physics or astronomy* can grasp the core concepts.

I agree. In fact, I’d be happy to reduce my royalty to a mere one penny per book if that would make what he wishes come true. I suspect $60M would be a sufficient and acceptable paycheck. You can start now if you’d like, and if it does sell six billion copies, I’ll send you a refund for the difference^*.

Dave Weigel is up & running at The Washington Post, covering conservative politics.

Archaeologists Uncover Land Before Wheel; Site Untouched for 6,000 Years. Of course the New World civilizations ~1492 were also pre-wheel.

Realty Check: ‘Extreme Makeover’ Downsizes Its Dream Homes. Mo money = mo problems (remember, home equal = $).

The Science of Kissing COVER! Sheril has a cover. Nice.

Today’s Social Liberal Is Tomorrow’s Social Conservative. Looking at the GSS I’ve found that conservatives of all ages tend to agree when it comes to issues like homosexuality, while liberals exhibit a split between old & young. Don’t know whether this is transitory, or a general feature of social change in the United States.

Discovery takes flight. Image credit: NASA

The crew of STS-131 have been pretty busy with the inspection of the heat shield and getting ready for docking with the ISS.  I was hoping to hear something this morning because I believe I saw a piece of ice hit the, lemme think…the lower starboard side, just after the external tank separated. The ice appeared to change directions abruptly upon impact and I don’t mean to infer damage just curious is all.

Turns out there was a Ku-band radio anomaly so the inspection results were not sent to the ground.  Instead last I heard the images will be digitized and sent to the ground after docking tomorrow and everything is set for that to happen.

NASA didn’t elaborate on the Ku-band anomaly, probably just something normal.   However there has been a uptick in solar activity since the launch took place and we’ve been in an geomagnetic storm.  While it is true a geomagnetic storm can interfere with radio signals, I tend to doubt the current storm has anything to do with the radio anomaly, the frequency is just too high.

Oh the other hand — , the aurora is back!  The Boulder K hit 7, which it hasn’t done in a long time.  The activity has been tapering off some, but there have been a few further surges.  The Boulder K was at 5 this morning, I went running outside to find clouds over the northern sky.  It appears the new solar cycle is kicking in.  Normally at a Boulder K of 5 I can see a little of the aurora  and 6 or higher is usually a pretty nice show.

The Space Weather Prediction Center has a great page on viewing the aurora and you can check a chart (and map) to see what level of Planetary K index it take to produce a visible aurora at a given latitude.  You will note I am using two scales the Boulder K (K_B) and Planetary K (K_P) indices.  I use the Boulder K because I am more used to it.

You can get a quick look at what is going on from the SWPC in a variety of scales here.

Imagine a day in the future when a soldier could just roll out of bed, pull on a cotton T-shirt, and head out into a combat zone, without worrying about taking a bullet through the chest.

An international team of scientists from Switzerland, China, and the United States have moved one step closer towards the goal of a bulletproof T-shirt by combining cotton with boron carbide–the third hardest material known on earth and the stuff used to armor battle tanks.

Chemistry World reports:

Modern military forces use plates of boron carbide (B₄C) as ceramic inserts for bulletproof clothing but these can restrict mobility, so the design of a nanocomposite — where B₄C is used to reinforce another material — could provide the perfect balance of strength and flexibility.

The scientists created the new bulletproof material by cutting squares from a pure cotton T-shirt and soaking them in a solution containing boron powder and a nickel-based catalyst. Then they heated the cloth patches to 2012 degrees Fahrenheit under a stream of argon that prevented the material from burning. In the process, the cotton fibers changed to carbon fibers, which reacted with the boron powder to form “nanowires” of boron carbide. The researchers describe their breakthrough in the journal Advanced Materials.

The cloth changed color from white to black after the reaction, but remained remarkably strong, lightweight, and flexible. But cops and soldiers won’t be sporting these bulletproof T-shirts anytime soon, Chemistry World adds:

But despite the dramatic change in their properties, this type of ‘armored cotton’ is not yet ready to replace conventional bulletproof materials, such as Kevlar.

Related Content:
80beats: New Latex & Plastic Soundproofing Could Stop Even Rumbling Bass Sound
80beats: Could a Deep-Sea Snail’s Shell Inspire Next-Gen Body-Armor?
80beats: Self-Healing Coating Could Make Scratch-Proof Cars
80beats: Super-Strong Ceramic Mimics Seashells’ Tough Mother-of-Pearl Coating

Image: Xiaoding Li. The image shows the nanowire arrays in the cotton fabric, and a cross-section diagram of the carbon microfiber coated with boron carbide nanowires.