More than a billion people in the developing world need glasses. But opticians aren’t exactly on every block in sub-Saharan Africa. In some places the ratio is one to one million residents. Pondering this problem, Oxford University physics professor Joshua Silver came up with a brilliantly simple solution: a pair of eyeglasses, currently costing about $19, that the wearer can adjust. Silicone oil is injected into a gap between two sheets of plastic until the lens provides sharp vision. The inventor’s field research shows the correction can be better than that of prefab glasses sold at a store.

Congratulations! The Your Shot special issue hit newsstands today (June 30). We may have done the editing, writing and design, but you took the pictures—101 of our favorite photographs submitted by readers since Your Shot debuted in March 2006.

How did we pick the pics we picked? There's no magic formula. Personally, I'm drawn to images that make me feel something, be it joy, sorrow, suprise or wonder. So that's how I structured the issue: four chapters, four emotions. The selection process took months, but for photo editor Susan Welchman and I, it was worth every moment. These two videos explain why:

1. Susan and I describe why we love editing Your Shot.

2. Susan and I share some favorite images from more than 100,000 Your Shot submissions.

—Oliver Uberti

The EPA is worried about fireworks. It’s not so much the noise and smoke—it’s the toxic chemical that provides the oxygen needed to burn the fuel.

The culprit is perchlorate, and the fear is it could seep into drinking water. Early research suggests it might hinder the thyroid’s production of growth hormones, notably in children and pregnant women. “It deserves more study,” says EPA spokesman Rick Wilkin.

When it comes to the art of egg decoration, Mother Nature is the original master. The patterns and lines that adorn many eggs—like those of murres, grackles, and jacanas—are positively calligraphic. These markings, which get their pigment from bile acids and broken-down red blood cells, are applied during the tail end of the 20 hours during which the egg is in the shell-gland region of the oviduct. A shell that emerges encircled with wispy streaks (above) means the egg rotated while the inking occurred.

In Year One, Zed (Jack Black) and Oh (Michael Cera) traipse across Biblical history after fleeing their village, narrowly escaping death, slavery, and circumcision en route to discovering their destinies.

Their final destination—where the majority of the movie takes place—is Sodom, known as the sinful city destroyed by God in “fire and brimstone.” Pop Omnivore was interested: Did Sodom really exist? To find out, we interviewed Rupert Chapman, head librarian of the Middle East department at the British Museum and co-author of the book Archaeology and the Bible, which examines how the findings of archaeology have confirmed—or refuted—the Bible.

Just north of Mexico in the Arizona desert, a crimson-hued pond is a reminder of past mining wealth and current pollution. Up to hundreds of yards long, with a service road jutting onto a promontory, it holds storm water that fell on mine tailings—crushed rock largely stripped of valuable metal. Oxidation causes the Technicolor effect. Phelps Dodge mined copper in Bisbee for decades, until profits dried up in the mid-1970s. Under state order, the company must improve contaminated groundwater caused by high sulfate levels in now flooded underground mines. It also hopes to restore the landscape to a normal tint by late 2010. —Chris Carroll

Highlights from the July issue of National Geographic: the lost city of Angkor, manta rays in the Maldives, Garrison Keillor goes to the state fair, the fire and ice of the New Zealand park where Lord of the Rings was filmed, giant telescopes; and Serbs look to the future.

Trademarks are ubiquitous—we use trademarked products every day, all day long. We use Google for Internet searches, Kleenex to blow our noses, and we wear Levis. I look up words in Merriam-Webster’s Collegiate Dictionary—itself a trademarked name—which defines trademark as “a device (as a word) pointing distinctly to the origin or ownership of merchandise to which it is applied and legally reserved to the exclusive use of the owner as maker or seller.”

There’s no question we love the Atlantic bluefin tuna (above). The problem is we love it only for its taste. Flopped out in a Japanese market, the best specimens of the sleek fish, which grow up to 15 feet long, can fetch $100,000 or more.

African frogs have taken a page right out of comic books. Like the X-Men character whose fists encase deadly blades, some frog species conceal tiny claws in their toes that cut through the animals’ own skin in order to wield them against a foe.

These amphibians have been digging into humans—and no doubt other predators—for years, but until now no one sought the cause. While collecting frogs in Cameroon, Harvard biologist David Blackburn became intrigued when one of them gave him a bloody scratch. Examining museum specimens, he’s so far found 11 species with wound-inflicting anatomy in their back feet. During stress-induced muscle contractions, he says, the sharp bony tips “pierce their way to functionality.”

Defenses that harm their user are rare, and how this one evolved isn’t yet known. But the damage done is likely minimal. “I suspect the skin heals fine,” Blackburn says. “Amphibians have remarkable regenerative capabilities.” —Jennifer S. Holland

Photo: The hairy frog is one species with bony claws that rip its own skin—a bizarre anatomical feature. Photograph by David C. Blackburn. Art: Mariel Furlong, NG staff

Luckily for us, senior graphics editor Sean McNaughton is a vector graphics wizard. In our recent Energy Special Issue, he used bright color and playful shapes to transform eye-numbing tables of carbon emissions data into eye-catching art (above). When I asked how he picked his palette, Sean said, “Honestly, I just messed around with colors I like.”

Gasp!

This was not the answer I expected. Immediately, I imagined Josef Albers, the great color theorist, tossing in his grave.

Storrs Olson, Curator of Birds at the Smithsonian National Museum of Natural History, lambasted the community of scientists and journalists investigating the connection between theropod dinosaurs and birds in an open letter he sent to the head of National Geographic's Committee for Research and Development, Peter Raven, on November 1, 1999. In that letter, he said:

"The idea of feathered dinosaurs and the theropod origin of birds is being actively promulgated by a cadre of zealous scientists acting in concert with certain editors at Nature and National Geographic who themselves have become outspoken and highly biased proselytizers of the faith. Truth and careful scientific weighing of evidence have been among the first casualties in their program, which is now fast becoming one of the grander scientific hoaxes of our age—the paleontological equivalent of cold fusion."

A scene from the documentary Act of God, part of the Silver Docs film festival this month in Silver Spring, Md.

Owlie Skywarn terrified me as a child. Mr. Skywarn was the shrieking, easily agitated, anthropormophized owl-star of Watch Out! Storms Ahead!, published by the National Oceanic and Atmospheric Administration. The alarmist owl warned of me violent weather phenomenon that was hell bent on destroying me, my family, and my pet hamsters, Fred and Ginger. Within a few weeks of getting this treatise on "Weather As A Force of Pure Evil in Your Young, Easily Extinguished Life," I was frightening my church picnic into an early departure (“Funnel cloud! I think!”) and desperately planning for Biblical floods, blinding blizzards, and Category 5 hurricanes. Hurricanes. On my family's farm. In far west Texas.

Crossword-puzzle fans probably have at least two questions about the new Geopuzzle, which makes its debut in the July issue of the magazine:

1.    Do I use ink or pencil?
2.    Who thought up all those clever clues?

For question No. 1, we’d like to hear from you. Did you try ballpoint pen (our choice) or pencil? Or did you print the puzzle out from our website and leave your magazine in pristine condition?

As for the author, she is the formidable puzzler Cathy Allis (formerly published as Millhauser), a crossword constructor for over 20 years. Her puzzles have appeared in The New York Times, The Washington Post, The Wall Street Journal, and numerous crossword collections. A book of her original puzzles, Humorous Crosswords, has been in print since 2003.

If you can’t wait until next month’s Geopuzzle, you can try a 2007 crossword created by Allis and clued by former President Bill Clinton.

And of course, we'd love to hear your reaction to our Geopuzzle!

—Marc Silver

Garrison Keillor’s mellifluous voice is practically as American as apple pie. Since 1974 he’s been telling stories from the fictional Minnesota town of Lake Wobegon every Saturday on his radio show, A Prairie Home Companion. This month Keillor chronicles the goings-on at a place that does exist, if only for a short time: the great American state fair. He hit several of these “ritual carnivals” last summer, but he remembers the day this photo was taken at the Iowa fair particularly well. It was shortly after his 66th birthday, and he’d just made a friend in the dressing room. “Senator Tom Harkin and his wife came and visited me there, and he ironed my shirt,” he says. Keillor was busy shaving when the Iowa senator explained to him that as a child he had learned to “iron a good shirt.” Keillor hosted a live performance of his radio show that evening and recalls the ideal setting: “An Iowa crowd on a warm summer night, who’ve eaten some ice cream and a pork chop on a stick—no better audience in the world. There isn’t much you can do to put a dent in their day.”

Photo: Clad in his signature red tie, socks, and sneakers, Garrison Keillor reports from a racetrack near Iowa’s State Fair grandstand. Photograph by Joel Sartore.

The presidential election isn’t the only thing being contested in Iran these days. A debate over the naming of the Persian Gulf has been simmering for some time.

Known as Persia until the name was changed in 1935, Iran has always held that the body of water extending from the Arabian Sea and separating Iran from the Arabian Peninsula is called the Persian Gulf. Saudi Arabia, however, identifies that body of water as the Arabian Gulf.

I got busted at the milk shake stand at my first state fair. My father had dropped me off along with my prize hog at the Salem fairgrounds for the Oregon State Fair’s livestock competition. He paid for a week’s food and lodging in the 4-H dorm and went to visit his parents for the day. When he returned, we went to the Dairy Bar. It came time to pay for my milk shake. I was broke. My father asked what I’d done with all the money he gave me. I confessed I’d spent it all in two hours on the bumper cars.

After Israel invaded Gaza last winter, protests sprang up in Europe. Firebombs and tear gas were part of the mix—though not in Sweden, thanks to a new kind of crowd control.

Click to expand related graphic.

Rudapithecus hungaricus, above, may be the ancestor of African great apes, including humans, but it lived in Europe. Artwork © John Gurche.

While the spotlight of the day might rest on the newly announced Miocene ape, Anoiapithecus brevirostris, another important early great ape is sitting in the shadows. It is Rudapithecus hungaricus, which, along with Dryopithecus and Anoiapithecus, is considered by some to be related to living great apes. Rudapithecus may be the closest we have yet come to finding the ancestor of African great apes and humans. All of these fossil apes were found in Europe.

The image of what appears to be a mammoth was recently discovered on a bone found in Vero Beach, Florida. The white box is approximately 3 inches wide. Florida Museum Photo by Mary Warrick.

Let's hope, hope, hope it is true—mammoth art in North America just like what they have in Europe. Now that is something I never thought I'd see. It is as if someone found American Indian arrowheads on the banks of the Seine.

A local newspaper in Vero Beach, Florida, Vero Beach 32963, has announced what will be among the most significant discoveries of prehistoric art in the New World, if it holds up. See the National Geographic news article and the Vero Beach 32963 report  for more information. The find, which is an engraved bone with what looks like a mammoth on it, is of major significance because there is simply nothing like it in the New World. Many such engravings, however, are known from European paleolithic art, which began around 35,000 years ago and continued until the end of the paleolithic around 10,000 years ago.

A diver brings up gold coins in this photograph that appeared in a 1965 National Geographic Magazine article about treasure hunting on Spanish ships that sank in 1715. Since then, concern has grown among archaeologists about what information is lost during such salvage operations. Photograph by Bruce Dale.

The search for sunken ships and underwater treasure is a standard plot line in Hollywood movies. In real life, the most successful treasure hunters aren’t a band of rough adventurers but companies, sometimes publicly traded, with smooth-talking CEOs. One such company, Odyssey Marine Exploration, is led by CEO Gregg Stemm, an individual who has earned notoriety in the underwater archaeological community by aggressively exploiting, some would say destroying, shipwrecks. Odyssey is currently embroiled in a legal dispute with the Spanish government over ownership of a sunken ship located some 180 miles west of Portugal in international waters. The discovery became public in May 2007 when Odyssey removed tons of coins from the wreck site to Florida.

In the smash-hit movie The Hangover, some guys wake up in their hotel room after a night of debauchery. One of them goes to relieve himself. He hears a roar. There’s a tiger near the toilet tank! Turns out it’s Mike Tyson’s pet.

Naturally, Pop Omnivore wondered: What should you do if there is a tiger in the room? And, on a more serious note, do people really have pet tigers?

Here is what we learned from tiger experts Philip Nyhus, assistant professor of environmental studies at Colby College and co-editor of the forthcoming book Tigers of the World, and Louis Dorfman, animal behaviorist at the International Exotic Animal Sanctuary.

Photograph of a newly discovered slate from Jamestown by Michael Lavin. The lines have been enhanced by rubbing fine chalk into them. Courtesy of Preservation Virginia.

They've done it again. The archaeological team at Jamestown has discovered a piece of slate with writing and drawings on it from a well that may be the first one that John Smith dug. There's no age on it yet, but the thought that it could have been the doodle pad of one of the earliest English colonists in Virginia is exciting.

Like most publications, large and small, National Geographic follows an in-house guide for style and word usage. Unlike most publications, however, National Geographic’s guide is free, online, and available to the public. It’s a great resource for writers, editors, and anyone else looking for guidance on matters of language style.

I try not to act like a child at the office. I wear crisp shirts, proofread emails, and treat all artists with respect even when their work makes me want to jump up and down and throw things. So it was with great chagrin that I stumbled across the blog, Tiny Art Director, which holds a funhouse mirror up to the profession and makes my efforts seem in vain.

You see, the Tiny Art Director is a four-year-old girl. In each post, she commands her artist—and father—Bill Zeman to make, revise and often scrap paintings of dinosaurs and monkeys. (That T.A.D. and National Geographic both love dinosaurs and monkeys is not lost on me.)

"I'm going to tell you what to draw," she says in one post. "Draw a dragon sneaking up on a girl." Zeman obliges (above). Her critique? "Daddy it's not supposed to be like that! He has dog legs! I'm so mad at you! I'm going to erase those legs! Daddy why did you do those legs???" Tiny Art Director then collapses into tears. "Job Status: Rejected"

Rebel angels are cast into hell but weren't cast in the movie.

To Sartre, hell was other people. To Sam Raimi, it’s the usual Christian version: fire, brimstone, anguished wails of the eternally damned—you get the picture, or will if you catch Drag Me to Hell.

Raimi’s newest feature film is a crackerjack horror/comedy, a knowingly schlocky, visually inventive movie as creepy, disgusting, goofy, and hilarious as his seminal, psychotronic Evil Dead trilogy. If you liked those flicks, you’ll probably love this one. In it, a goodhearted loan officer gets on the bad side of an elderly Hungarian woman, who proceeds to curse the poor girl. For three days she’ll be stalked, scared, and totally grossed out by a vengeful demon. On the fourth day, she’ll be—you guessed it—dragged to hell.

At least Will Ferrell is wearing the right kind of vest to be a paleontologist.

The new movie Land of the Lost stars Will Ferrell as paleontologist Rick Marshall, who invents a time machine that takes him to an alternate Earth where dinosaurs still dwell. Pop Omnivore wants to know: Does this film, based on a 1970s children’s TV show, do justice to paleontologists, not to mention dinosaurs?

For an expert opinion, we spoke with Thomas R. Holtz Jr., dinosaur paleontologist at the University of Maryland’s Department of Geology. (Warning: This interview contains spoilers—and references to poop and pee!)

If the dark seems a little darker these days—and the world a bit less wonderful—it probably is. Researchers in Asia, Europe, and North America are seeing dramatic declines in fireflies. Thailand is one place that seems to be losing the bioluminescent beetles. For centuries they blinked along Thai rivers with splendid synchronicity. Foreign visitors compared their lights to chandeliers or Christmas candles. Locals were able to fish solely by their flashes.

Did you read the previous post titled “Polar Opposites” on this blog? If so, did you notice the phrase “the Earth” was used twice? I bet you didn’t, but one reader who did notice that in the June issue of National Geographic wrote in asking us why we use the article “the” with Earth.