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The Chrysina aurigans (left) and the C. limbata (right) beetles (Credit: Eduardo M. Libby)

Imagine you’re a conquistador in the 1500s. You’ve spent many weeks on a boat to get to Central America and many days hacking away through the jungle, dressed in hot and heavy armor, swatting at mosquitoes, desperately trying to find that fortune you were promised back home. Then you glimpse a bit of silver or gold. As you get closer, it scurries away, and you start to wonder just how crazy this trip is going to make you.

Costa Rica, rather lacking in actual gold and silver, is home to two beetle species that may have made a conquistador or two a little nuts: Chrysina aurigans, the gold variety, and C. limbata, in silver. Then again, maybe not, as the reflective surfaces likely provide good camouflage in the rainforest, where the light reflecting off them would look a lot like the light reflecting off wet leaves.

Materials scientists at the University of Costa Rica studied the light reflected off the 70 layers of chitin that form the bright forewings of these two species of beetle. (Their study appears in Optical Materials Express.) They found that a bit of light is reflected by each layer, and all those bits add up to make the reflected light brighter and brighter, giving the beetle its sheen and shine. The golden C. aurigans reflects light in wavelengths larger than 515 nm, which give it a redder color, while the silver C. limbata reflects wavelengths in the entire visible range (and as we know from elementary school, adding up all the colors of the rainbow results in a white light).

The researchers say that learning more about how the beetles mimic metallic surfaces could help create metal-like substances for jewelry and electronics.

Check out the entire collection of Surprising Science’s Pictures of the Week on our Facebook page.

A tornado in Kansas, May 23, 2008 (credit: Sean Waugh NOAA/NSSL)

UPDATE: A devastating tornado tore through Joplin, Missouri on May 22, 2011, killing at least 80 people and causing significant damage. In light of this tragedy and other storms that have hit the South this spring, we have updated parts of this post to reflect the latest news.

Communities across a wide swath of the country are cleaning up from violent storms that have been sweeping through, one after another, over the past few days. More than 200 people have been killed. This year has been unusually active for tornadoes—more than 300 have touched down so far, and we haven’t yet reached May, typically the worst month. Decades of research have made these storms more predictable, giving people more time to find shelter, but we’re sadly still vulnerable.

1 ) In order for a vortex to be classified as a tornado, the violently rotating column of air must be in contact with both the cloud above and the ground below.

2 ) Though tornadoes do occur on other continents, North America’s geography makes it more vulnerable to them. Bradley Smull, an atmospheric scientist at the National Science Foundation, explained yesterday in a Washington Post online chat: “In particular, the proximity of a major north-south mountain range…and the Gulf of Mexico…all in a latitude range frequented by strong upper-level jetstreams amounts to something of a “perfect storm” for severe (supercell-type) thunderstorm formation.”

3 ) Tornadoes are rated on the Enhanced F (EF) Scale (the old scale was called the Fujita (F) Scale), which assigns a number (0 to 5) based on estimates of 3-second wind gusts and damage. There have been more than 50 F5/EF5 tornadoes recorded in the United States since 1950.

4 ) Rain, wind, lightning and/or hail may accompany a tornado, but none of them is a reliable predictor of an oncoming tornado.

5 ) A tornado can last from a few seconds to more than an hour. On average, they persist for about 10 minutes.

6 ) It is a myth that a tornado cannot pass over features like valleys, mountains, lakes and rivers. When it passes over a lake or river, a tornado becomes a waterspout.

7 ) Tornado alley is the region in the middle of the United States where tornadoes are most frequent. However, every U.S. state and every continent (except Antarctica) has experienced a tornado.

8 ) A tornado watch means that conditions are ripe for a tornado; a warning means that a storm has been spotted on the ground or via radar (and you should take cover immediately).

9 ) Since the first tornado forecast was made in 1948, tornado warning lead times have been increasing and now average 13 minutes. However, they have a 70 percent false alarm rate, which may lead some people to take them less seriously than they should.

10 ) Mobile homes aren’t more likely to get hit by a tornado than any other type of building, but their flimsy structure provides little protection against strong winds and flying debris.

11 ) It’s also a bad idea to take shelter in a car—which can be easily tossed about—or under a bridge, where a person would be vulnerable to flying debris or a bridge collapse.

12 ) The worst tornado outbreak was on April 3 and 4, 1974, which saw 147 tornadoes across 13 states. The single deadliest tornado killed 695 people in Missouri, Illinois and Indiana on March 18, 1925.

UPDATE: The series of tornadoes that struck Tuscaloosa, Alabama and other Southern states in April 2011 set a new record. According to NOAA, there were 312 recorded tornadoes that touched down from 8 a.m. on April 27 through 8 a.m. on April 28. The death toll these storms was over 250 people, and did not break the 1925 record mentioned above.

13 ) A tornado that struck Washington, D.C. on August 25, 1814, is credited with driving the British invaders out of the city and preventing them from carrying out further destruction. They had burned the White House and much of the city the day before.

14 ) The city of Greensburg, Kansas was flattened by a tornado in 2007, but instead of abandoning the town, the people are rebuilding with an emphasis on green technology.

15 ) In 2009 and 2010, more than 100 scientists participated in VORTEX2 (funded by the National Science Foundation and National Oceanic and Atmospheric Administration), which set out to track tornadoes as they formed and moved across the landscape. The V2 researchers are trying to answer many basic questions about tornadoes, such as how, when and why they form, how strong the winds get near the ground, how they do damage, and how predictions can be improved. During the two years, they collected data from dozens of storms and tornadoes.

V2 scientists are the focus of a new IMAX movie Tornado Alley, which I watched this morning, marveling at the 50-foot-high twisters. Tornadoes are incredibly ephemeral and dangerous phenomena, and the movie drove that home, leaving little question why scientists are still struggling to answer these questions. With all of the data collected recently, warning times are sure to improve, and scientists now are able to debate how much time might be too much (that is, given enough notice, would people would fail to take shelter and instead get in their cars to drive away, potentially exposing themselves to more danger).

The destruction this week is a reminder that we need to take these storms seriously, and we might want to start by reviewing this tornado safety advice from NOAA.

Sarah Zielinski (center) with Christine Dell'Amore (left) and DCSWA board member Carolyn Gramling (right).

Congratulations to Sarah! The D.C. Science Writers Association presented her with its Newsbrief Award this weekend for her Surprising Science post “Rare Earth Elements Not Rare, Just Playing Hard to Get.”

The award is the only one of its kind for science writing. Other awards recognize long or investigative or multi-part stories. But most of what writers write—and most of what readers read, especially online—is short pieces.

The idea for the award came in part from Christine Dell’Amore, a former Smithsonian intern who now works for a publishing company called National something-or-other… Geographic, that’s it. She says Sarah “impressed the judges with her entertaining, well-researched and educational article.”

Sarah says her story started with a question: Just why does China have so much control over the world’s supply of rare earth elements? When she couldn’t find an easy answer, she answered the question herself. As in so many of her posts for Surprising Science, she took on an important, timely, complex topic and covered it with efficiency, humor, clarity and pizzazz.

The Allen Telescope Array (courtesy of flickr user brewbooks)

The SETI Institute announced this week that the Allen Telescope Array, with which the institute searches for signals of extra-terrestrials, has been temporarily taken offline due to lack of funding. Tom Pierson, the institute’s CEO, wrote in a letter to supporters (pdf):

Unfortunately, today’s government budgetary environment is very difficult, and new solutions must be found. [National Science Foundation] University Radio Observatory funding for [Hat Creek Radio Observatory, where the ATA is located] has been reduced to approximately one-tenth of its former level. This is compounded by growing State of California budget shortfalls that have severely reduced the amount of state funds available to the Radio Astronomy Lab. Combined, these factors have resulted in the current decision by [the University of California at Berkeley, which operates HCRO] to reduce operations of the Hat Creek site to a hibernation mode, pending future funding or some alternative solution. Hibernation means that, starting this week, the equipment is unavailable for normal observations and is being maintained in a safe state by a significantly reduced staff.

This doesn’t mean the search is dead. Other efforts, such as setiQuest, will continue; other telescopes can continue to search; and the ATA will come to life again once funding can be found. In addition, NASA and other space agencies will continue their searches for evidence of life on other planets. But SETI is perhaps the most famous of the ET hunters, and with the recent discovery of more than 1,200 potential planets that would make interesting listening targets for SETI, shutting down the ATA is somewhat of a disheartening development.

SETI’s scientists are used to thinking long-term, however. After decades of scanning for radio signals, they recently began to search for laser flashes, as I reported in a story for Smithsonian‘s Mysteries of the Universe special issue last year:

“We’re looking for bright flashes that last a billionth of a second or less,” says Jill Tarter, director of the Center for SETI Research and the inspiration for the Jodie Foster character in the movie Contact. “As far as we know, this is something that a laser can do but that nature can’t.” SETI scientists figure that such a pulse would represent an intentional, high-tech, long-distance message: “evidence of somebody deliberately using a laser focused into a large telescope to create a detectable signal over the many light-years between stars,” Tarter says.

The radio signal approach hasn’t turned up much so far, and Tarter admits she doesn’t know what the ideal frequencies might be. Even with the new search for laser flashes, the SETI scientists might be using incorrect technologies, but they still think the effort is worthwhile. As her colleague Seth Shostak says, “Columbus didn’t wait for a 747 to get him across the Atlantic.”

And though SETI scientists have yet to find evidence of extraterrestrials, they are well prepared for success. “Yes, we do have a plan,” Tarter says. “It starts with champagne.”

Whooping cranes at the International Crane Foundation in Wisconsin (courtesy of flickr user szatmar666)

Last year during the Gulf oil spill, as I watched reports about dead birds and talked with scientists about what might happen to the local ecosystems, I wondered how we might punish the perpetrators of such an ecological crime. BP will eventually pay some fine, based partially on the number of wildlife killed, but how do you place a value on these creatures? Does a copepod, at the base of the food chain, have more or less value than something at the top, like a whale? Does it matter if that creature is rare or endangered?

The court system might be one place to look for guidance, as people are punished there for killing endangered species. So what should we make of the recent sentencing of a young Indiana man and an unnamed juvenile for shooting and killing a whooping crane in 2009? Their sentence: probation and paying court fees of about $550.

And a one-dollar fine.

If we’re going to look for symbolism in that symbolic fine, we might conclude that the crane wasn’t worth much at all. Of course this overlooks the facts that there are fewer than 400 whooping cranes left in the wild; we spend money preserving them; and the one that was killed, seven-year-old female 17-02, had been hand-raised as part of a breeding program and was the important half of a the only successful breeding pair of cranes in that area. All the time, effort and money that went into raising her and keeping track of her and her life—that is ignored in these calculations, apparently.

We try to save species because they have value to us. Greater biodiversity and healthier ecosystems have some benefits that can be quantified, like fewer infectious diseases, but also plenty that we’ll never be able to predict. Who knows what drugs might be hiding inside some plant? Or what undiscovered microbe actually makes life on Earth possible? Or how eliminating a single bird species might affect the rest of the ecosystem, with potentially disastrous consequences for humans?

Not to mention how sad it would be for future generations to never see some of these creatures—haven’t you ever wished you could have encountered a dodo in someplace other than a dusty museum cabinet?

There is general agreement that extinctions are something to be avoided, and we invest a lot of money in trying to make that not happen. (We may not be going about it the right way, but that’s a discussion for another day.) We could try to quantify those investments in an attempt to estimate a value for the loss of a bird or turtle, but so much of the value of these creatures will remain unknowable, and it will always be difficult to place a number on such a loss.

But certainly it’s more than a single dollar.