Joshua Foer is a guest blogger on Boing Boing. Joshua is a freelance science journalist and the co-founder of the Atlas Obscura: A Compendium of the World's Wonders, Curiosities, and Esoterica, with Dylan Thuras.

Graham Burnett wrote a fascinating essay in Cabinet recently about otolithic organs, the pair of sensors in the inner ear that help us stay balanced and maintain inertia. "Grossly speaking," writes Burnett, the otolithic organs consist of "a bunch of tiny pebbles (of the white rock known as calcium carbonate) embedded in a gooey wad that sits atop a carpet of delicate hairs." In humans, those "pebbles" are practically microscopic, but in fish, they can be as large as marbles:

There are several thousand researchers around the world who spend their whole working day looking at fish otoliths. This has nothing to do with their physiological functions, however, and everything to do with their structure and the staggering amount of information they contain. In the first place, each species of fish has a unique otolith shape. Couple this with the fact that they are stone (and therefore comparatively resistant to decomposition), and their utility as a biological marker becomes clear. Interested in the food habits of bottlenose whales? Pump their stomachs and you will end up with relatively few bones but lots of otoliths. Find an otolith expert and he or she will be able to give you a menu…

But the true wonder of these peculiar pearls lies within. Should you have occasion to tonsure a snapper or sea-bass, slicing off the top of its skull just above the eyes, you might take a moment to remove the two largest otoliths (there are, as a rule, six in all, three on each side) from their velvet seats to the right and left of the brain stem. With the heel of a knife you should be able to snap one of them in two, and then, holding it to the light, you will discern a set of concentric bands. These are growth rings–annuli–which, properly counted, will give the age of your fish in years.

Joshua Foer is a guest blogger on Boing Boing. Joshua is a freelance science journalist and the co-founder of the Atlas Obscura: A Compendium of the World's Wonders, Curiosities, and Esoterica, with Dylan Thuras.

Following up on Dylan's post about the Electrum, the world's largest Tesla Coil, I'd like to mention my own favorite super-sized scientific instrument: the Jantar Mantar astronomical complex in Jaipur, India. Constructed almost three centuries ago, its 73-foot-tall sundial is the largest in the world:

In 1728, Sawai Jai Singh II, rajah of Jaipur, dispatched his emissaries across the globe to gather the most accurate astronomical data possible. When they returned, Jai Singh ordered the construction of the Jantar Mantar complex, a monumental astronomical observatory constructed entirely out of stone and based on the astronomical tables of the French mathematician Phillipe de la Hire. Among the stone instruments Jai Singh constructed was the Samrat Yantra, a 73-foot tall sundial which remains the largest ever built. Though indistinguishable in design from other dials of the day, it was far and away the most accurate. Its two-second interval markings are more precise than even la Hire's table.

UPDATE: Uh oh. The picture above is of the Jantar Mantar complex in Delhi. Here's a photo of the one in Jaipur:

UPDATE TO THE UPDATE: Oy. That second picture, which I nabbed off Wikipedia, may still not be the right Jantar Mantar. This one, I am confident, is definitely the Jantar Mantar in Jaipur. Sorry for the confusion.

Joshua Foer is a guest blogger on Boing Boing. Joshua is a freelance science journalist and the co-founder of the Atlas Obscura: A Compendium of the World's Wonders, Curiosities, and Esoterica, with Dylan Thuras.

My wife and I are in the process of relocating from Brooklyn to New Haven. So far, the most tedious part of the move has been packing up the collection of death masks we acquired once upon a time in a fortuitous eBay bonanza:

The majority of these heads are gazillionth-order plaster cast reproductions (knock-offs of knock-offs of knock-offs) of originals held in the Laurence Hutton Collection at Princeton. Several are actually life masks, originally cast by sculptors.

In roughly bottom-to-top, left-to-right order, the faces in this photo belong to:

On the ledge: Abraham Lincoln, Laurence Barrett, Sir Richard Owen, Robert E. Lee, John C. Calhoun, William Tecumseh Sherman

The bottom six hanging on the wall: Ludwig van Beethoven, Antonio Canova, John Keats, Hyrum Smith, Joseph Smith, Jean-Paul Marat

The next highest six: Franz Liszt, Napoleon Bonaparte (well, maybe), Frederick the Great, George Washington, William Blake, Oliver Cromwell

The next highest five: Jeremy Bentham, Aaron Burr, Friedrich Nietzsche, Edward Kean, Ulysses S. Grant

And the top row: Jonathan Swift, Maria Malibran, David Garrick, Thomas Paine, and Thomas Moore.

On another wall not pictured we've got: Robespierre, another Abe Lincoln, Frederic Chopin, Pope Pius IX, Benjamin Disraeli, Benjamin Franklin, and John Dilinger. Plus there are a few more whose names I've forgotten in storage.

If there's one death mask I wish we had, it would be the Inconnue de la Seine.

Joshua Foer is a guest blogger on Boing Boing. Joshua is a freelance science journalist and the co-founder of the Atlas Obscura: A Compendium of the World's Wonders, Curiosities, and Esoterica, with Dylan Thuras.

I'm awed and wowed by the huge number of incredible places that people have been adding to the Atlas Obscura over the last couple days. It's especially neat to see folks contributing the sorts of local curiosities that are not only not listed in conventional travel guides, but are barely mentioned anywhere else on the web. Like this odd tree in Grana, Italy, submitted by a user named Alpha:

A very unusual tree grows in the town of Grana, Italy–or rather, an unusual pair of trees. It consists of a fruit tree growing on top of a common willow tree, creating a kind of two-tiered, two-species hybrid duplex. While it's not uncommon for a small tree to grow on a larger one, it is rare to see two fully grown trees in such an unusual configuration. Nonetheless, the arrangement appears to be working well for both individuals, as the fruit tree on top bears lovely white flowers.

Joshua Foer is a guest blogger on Boing Boing. Joshua is a freelance science journalist and the co-founder of the Atlas Obscura: A Compendium of the World's Wonders, Curiosities, and Esoterica, with Dylan Thuras.

A couple years ago, I came across the incredible story of the 19th-century Japanese sculptor Hananuma Masakichi in Umberto Eco's essay collection Travels in Hyperreality. After being diagnosed with tuberculosis, Masakichi decided that his last great project would be to carve a perfectly life-like portrait of himself out of wood, to leave behind for the woman he loved. The hair, fingernails, teeth, and toenails of the sculpture were all pulled directly from his own body. The above image is from an old postcard of the statue, which has the following caption:

The statue is composed of over 2000 separate pieces being hollow with the exception of the feet. The head, thighs, calves, and every member of the anatomy was carved separately and the whole put together. The joints were perfectly made, dovetailed, and glued together — no metal nails, only wooden pegs or pins beings used to fasten where necessary. After putting all the members together and finishing as far as the woodwork was concerned, he painted and lacquered the statue to give it the flesh and blood appearance; The hairs which adorn the figure belong to himself. He used clippings of his head and ears and each and every hair is bored for and put in one by one. The body hairs were actually pulled from his own body and put in exactly the same position as they occupied on himself. The eyes were also made by the artist and are the wonder of the oculist and optical precision.

And just in case this story wasn't poetic enough already, Ripley's Believe It Or Not!, which owns the statue, holds that Masakichi "later regained his health but lost his lover."

When I originally wrote about Masakichi in the Proceedings of the Athanasius Kircher Society, the only information I could find about the sculpture's present whereabouts was a notice saying that it had once been on display in a Ripley's museum, but was put in storage after being badly damaged in an earthquake.

I called up Ripley's the other day to find out about the fate of the sculpture, and was connected to their archivist, Ed Meyer. He informed me that it got banged up pretty badly in the 1989 San Francisco earthquake. "It was on a rotating platform, and it spun right off the rotator," he said. It took four months for a professional restorer to get Hananuma back into shape, however, "the hair still looks a little funny." The self-portrait is now back on display in Ripley's Wisconsin Dells location.

None of the Ripley's museums have yet been entered into the Atlas Obscura. But surely they all will be soon!

UPDATE: I found this picture at Sideshow World. Man or Image?! I guess that's the real Masakichi on the right.

Joshua Foer is a guest blogger on Boing Boing. Joshua is a freelance science journalist and the co-founder of the Atlas Obscura: A Compendium of the World's Wonders, Curiosities, and Esoterica, with Dylan Thuras.

One of the areas of the Atlas Obscura that I hope will get filled out as people continue to contribute content to the site is our "Purveyors of Curiosities" category. Right now it's got a measly six places in it. We're looking to find all those cool stores around the world that share the "wunderkammer sensibility"–places like Deyrolle in Paris (shown above), Evolution and Obscura Antiques in New York City, and Paxton Gate in San Francisco, just to name a few of the more famous and fabulous ones.

Whenever I travel, I always seek these sorts of shops out, but they can be awfully hard to find (there's no page in the phone book for "odd stores"). If we could put together a good list of the world's "purveyors of curiosities," I think it would go a long way to making the Atlas Obscura into a really useful resource for curious travelers. So, please tell us: what are the most "wondrous, curious, and esoteric" stores in the world? (And if you have a few minutes to spare, would you consider writing up a brief description and adding them to the Atlas?)

Joshua Foer is a guest blogger on Boing Boing. Joshua is a freelance science journalist and the co-founder of the Atlas Obscura: A Compendium of the World's Wonders, Curiosities, and Esoterica, with Dylan Thuras.

Speaking of giant holes in the ground, let me pass along one more that happens to be one of today's featured places on the Atlas Obscura home page. The Mirny diamond mine in Siberia is the biggest man-made ditch in the world:

The largest man-made hole in the world is a diamond mine located on the outskirts of Mirny, a small town in eastern Siberia. Begun in 1955, the pit is now 525 meters deep and 1.25 kilometers across. The massive 20-foot tall rock-hauling trucks that service the mine travel along a road that spirals down from the lip of the hole to its basin. Round-trip travel time: two hours. Airspace above the mine is off-limits to helicopters, after "a few accidents when they were 'sucked in' by downward air flow…"

Joshua Foer is a guest blogger on Boing Boing. Joshua is a freelance science journalist and the co-founder of the Atlas Obscura: A Compendium of the World's Wonders, Curiosities, and Esoterica, with Dylan Thuras.

Spotty (now hopefully fixed) server aside, it's been fun watching new entries pour into the Atlas Obscura from people we've never met. I want to share a place that recently caught my eye, posted the other day by a user named Dave. It's a massive underground coal fire that's been smoldering beneath the town of Centralia, Pennsylvania ever since 1962:

The town sits on top of a rich vein of coal, and the fire has defied every attempt to extinguish it. National awareness of Centralia's unending environmental catastrophe came in 1981 when a 12-year-old boy fell into a 150-foot hole that suddenly appeared in his back yard. Most residents were relocated in 1984, and in 1992 the entire town was condemned. Most buildings were torn down, creating the Centralia that can still be seen today: a network of streets running through empty fields and, increasingly, new growth forest. As of 2007, Centralia had nine residents.

Then Dylan told me about a similar, and even more dramatic, subterranean fire that's been burning for almost as long under the Karakum desert of Turkmenistan (pictured above). Locals call it the "Gates of Hell":

The hole is the outcome not of nature but of an industrial accident. In 1971 a Soviet drilling rig accidentally punched into a massive underground natural gas cavern, causing the ground to collapse and the entire drilling rig to fall in. Having punctured a pocket of gas, poisonous fumes began leaking from the hole at an alarming rate. To head off a potential environmental catastrophe, the Soviets set the hole alight. The crater hasn't stopped burning since.

Turns out, these sorts of mine fires can stay lit for a very long time. One burned in the city of Zwickau, Germany from 1476 to 1860. Another coal fire in Germany, at a place called Brennender Berg (Burning Mountain), has been smoking continually since 1688!

Joshua Foer is a guest blogger on Boing Boing. Joshua is a freelance science journalist and the co-founder of the Atlas Obscura: A Compendium of the World's Wonders, Curiosities, and Esoterica, with Dylan Thuras.

Thanks so much, Mark, for that introduction. We're thrilled that you guys have lent us the keys to Boing Boing for the next few days.

I'd like to tell Boing Boing's readers a little bit about the new web site that Dylan and I have launched, the Atlas Obscura.

The Atlas is a collaborative project whose purpose is to catalog all of the "wondrous, curious, and esoteric places" that get left out of traditional travel guidebooks and are ignored by the average tourist.

Anyone can enter new places into the Atlas Obscura, or edit content that someone else has already contributed. We're counting on you, Boing Boing readers, to help us fill out the map and document all of the world's wonders and curiosities!

What kind of places are we talking about? Here are a few that were recently added to the Atlas:

– A hidden spot in the Smoky Mountains where you can find fireflies that blink in unison

-A 70-year-old house made entirely out of paper

– A giant hole in the middle of the Turkmenistan desert that's been burning for four decades

– A Czech church built of bones

– The world's largest Tesla coil

– A museum filled with the genitals of every known mammal in Iceland

– Enormous concrete sound mirrors once used to detect aircraft off the English coast

– The self-built cathedral of an eccentric Spanish ex-monk

– A museum of Victorian hair art in Independence, Missiouri

– An underwater sculpture garden off the coast of Grenada

– Galileo's amputated middle finger

– An island in the Canaries where people communicate by whistling

– The corpse of a 14th-cenutry Japanese monk who mummified himself while he was still alive

Dylan and I are hopeful that we if can get a bunch of like-minded travelers (and armchair travelers) to share their obscure knowledge, we can build a truly awesome resource for everyone. So, please check the site out! Explore! Get involved! Add a curious place!

First, though, a quick caveat: The site is still very much in beta. We're still adding features, making improvements, and sussing out bugs. So please let us know what works and what doesn't.

Now, before handing the mic over to Dylan, I'd like to take a moment to abuse this very big soapbox by giving a quick shout out to the Atlas Obscura's amazing developer Adam Varga of Sawhorse Media, our genius fix-it guru Boaz Sender, and our slick designer Aaron Taylor Waldman. Thanks gentlemen!