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.
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.
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.
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. In particular, you need a space that's airtight. This means that you can't just pump air into the sort of cave you've toured while on vacation. Instead, you have to find a hollowed-out space underground that used to hold something naturally-such as a natural gas reservoir that's had all of the gas pumped out of it.
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.