He calls it YouTube's most unusual bicycle commute. It's a fair claim, too, what with pedaling daily through cavernous limestone mines repurposed as The Springfield Underground, a secure business park in Missouri.

2.5m square feet of warehouses, and who knows how many millions more yet to be developed. The caverns down here are just incredible. THE CAVES.

Here's a slideshow history of the facility, from mining to meat storage.

Vacancies are rare, according to the Springfield News-Leader. Kraft is the largest tenant. Most use it as warehousing and distribution for products that must stay cool; it is always 58° in the caves.

With about a dozen facilities, Missouri is one of the leading states in the underground real estate industry, largely thanks to its mining history and geological makeup — limestone deposits are often covered with a layer of shale, which prevents runoff water from entering old mines. In addition to Springfield Underground, local facilities include The Mountain Complex in Branson and an Americold Logistics facility in Carthage. SubTropolis, a facility in Kansas City which bills itself as "the world's largest underground business complex," has nearly 6 million square feet of space rented.

Here's a video taken coming into a different entrance:

The bike-commute video could be the intro sequence to a video game where the lights suddenly go off and you have to escape the facility, suddenly overrun by ████████, but not before you've found out what that creepy new tenant was up to and ███████████ the █████. Read the rest

In Bermuda, the enchanting Crystal Caves attract tourists with their huge stalactites and stalagmites above the clear water pools. As a child, Michael K. Frith frequently visited the caves and never forgot their weird, otherworldly beauty. Those caves would eventually inspire Frith, working with puppeteer Jim Henson, to co-create Fraggle Rock, a beloved muppet TV series that premiered in 1983. From Jennifer Nalewicki's lovely piece about Frith and the Crystal Caves in Smithsonian:

...It wasn’t simply the caves themselves that inspired Frith; it was also the way they were discovered. During the last Ice Age, roughly 1.6 million years ago, the Crystal Caves formed as a result of rainwater eroding the surrounding limestone, but they remained unknown to Bermudians up until 1907, when Carl Gibbons and Edgar Hollis, two local boys, accidentally discovered them. As the story goes, during a game of cricket their ball rolled next to a small crevice that was emitting warm gusts of air. Curious, the duo began digging with their hands, dropping a rock through the narrow opening to see how far down the hole went. Hearing a "plink," Gibbons ran the short distance home and grabbed a crowbar and a kerosene lamp, and they continued digging only to find a subterranean world beneath them....

“The thing that got me about the story [of their discovery] is the idea that these kids were suddenly in a place where no human being had ever been before,” says Frith, who is now retired. “I always felt that must have been an astonishing thing to be standing there with a flashlight and tracing its beam and hitting the stalactites, stalagmites and the glitter of the water running down them.

The BBC reports that the last of the boys trapped deep in a flooded Thai cave is out, along with their coach.

• All 12 members of a Thai youth football team and their coach have been brought safely out of the cave in northern Thailand

• Eight boys rescued on Sunday and Monday are in hospital but have not been named and are being kept in quarantine

• Each person was pulled through the cave by expert divers

• A rescue doctor and three Navy Seals who stayed with the group are still to emerge

• The 12 boys and their coach were trapped by floods more than two weeks ago

Before China came under the sway of Communist rule, many of the impoverished people of the country's southwestern Guizhou province opted to live in caves rather than face the frequent assaults by the region's criminal element. The cave complexes in Guizhou are massive, and until recently, were unknown to those who hailed from outside of the province. Its connection to the outside world is a small one. In order to enter Guizhou, visitors to the region need to navigate a narrow mountain footpath. The difficulties that getting to Guizhou poses has gifted its people with a rare commodity in our increasingly connected world: seclusion.

But of late, the region's cave dwellers have become less cloistered. Tourists eager to see cave dwellers' way of life have been making the trek to Guizhou. This is good news for Guizhou's cave dwellers: The tourists have proven happy to pay for the privilege of renting space in the caves. It's also bad news: the Chinese government has noted that some of its citizens are hiding out in caves. Because of the optics this presents, they've been encouraging the cave dwellers to move onto farm properties, complete with modest houses and a relocation payment – let's call it a bribe – of $9,500. Five of the cave dwelling families were totally into the deal. The other 18? Not so much.

From The Globe & Mail:

The remaining 18 families have held on stubbornly to their homes inside the cave. They say that the new homes are too small, that they fear losing access to their land, and that they alone, because of their historical connection to the cave, should have the right to independently control its small tourism economy.

New Zealand's Waitomo Glowworm Caves shimmer with a constellation of glow worms, and Jordan and Jenna from Stoked for Saturday got this gorgeous footage after a lot of trial and error. Read the rest

Geoff from BLDGBLOG sez,

I thought I'd send a link to a new and very long post I just put up, describing a visit last month to Nottingham, England, where we explored nearly a dozen artificial cave systems, carved directly from the sandstone, with archaeologist David Strange-Walker.

Nottingham, as few people seem to know, is a bit like a sandstone Cappadocia, in the sense that there are at least 450 caves--and quite possibly more than a thousand--that have been cut into the earth, serving as everything from malting kilns to private basements, from jails to "gentlemen's lounges" for underground sessions of cigar-smoking.

We spent literally all day down there, moving from one cave system to another, from pubs to graveyards, and we saw barely a fraction of what's actually under the city.

The post includes some animations, tons of photos, and some laser scans produced by David's organization, the Nottingham Caves Survey. At the very least, their work is well worth checking out, as many of the scans (and the resulting videos) are incredible.

Caves of Nottingham

(Thanks, Geoff!) Read the rest

The Eisriesenwelt—the "World of the Ice Giants"—is an Austrian cave that stays cold enough year-round to freeze any water that gets into it. As a result, the cave is full of massive ice formations. On April 28th, it was also full of people like physicist Daniel Schildhammer (seen above) who came to the cave to test out a wide array of space technologies, from protective suits to roving robots. It's all part of an international effort to prepare for a mission to Mars. Caves on Mars are likely place where bacteria and other forms of microbial life might be hiding out—the temperatures stay steady underground and the cave would protect those microbes from cosmic rays. Below: Another scientist tests out a rover meant to scale cliffs.

Images: REUTERS/Lisi Niesner

Read the rest

How many batteries have you used today?

Energy storage devices have become an integral part of our lives, but they still aren't really a part of our electric grid. There are some good reasons for that—at that scale of storage, batteries become gigantic and extremely expensive. But the lack of storage on the grid has some distinct drawbacks, putting the stability of our electric system at risk and making it harder to add in lots of renewable energy generation.

Because of that, researchers are looking for ways to get the benefits of batteries without some of the detriments. There are lots of different ways to do this, but one solution is particularly awesome to describe. Hint: It involves caves.

Last Friday, I had a guest post on i09 explaining Compressed Air Energy Storage, an old technology that could be one of the most cost-effective ways to store energy at a grid scale.

At any given moment, there must be almost exactly the same amount of electricity being produced as there is being consumed. If the balance tilts either way-even by a fraction of a percent-it could lead to a blackout. To simply keep the lights on, the grid has to be constantly monitored, with controllers predicting demand and making small adjustments, minute-by-minute, to supply. This happens 24 hours a day, 7 days a week.

... That's where CAES comes in. CAES systems store energy underground in the form of compressed air, but to make it work you have to start with the right kind of geology.

Last year, when I posted here about the history of the lighthouse at Devil's Island, Wisconsin, several of you noticed the island's extensive network of sea caves, carved into the sandstone cliffs by splashing waves and moving water. This year, when some friends and I went on a little paddle through the caves, I took along a video camera. It doesn't quite capture the eerie awesomeness of floating into the dark with Lake Superior behind you, but it's still pretty neat.

Apologies in advance for the occasional sudden jerky movements and possible audible swearing. Devil's Island is also home to a large population of biting flies and my ankles are, apparently, quite tasty.

Video Link Read the rest