Your House is a Fossil Museum
Or: Kitty Litter Paleontology
My watchdog never needs walking.
We usually think of fossils in the context of museums, but you might be surprised to hear that they're probably in your home without you knowing.
The first way this happens is pretty obvious: if you've got limestone as part of the construction of your house. Limestone is almost universally fossil-bearing. In fact, many types of limestone are almost entirely made up of fossils. So, if you have limestone in your house, you've probably got fossils.
Of course, fossils can be found in other rocks as well, such as certain sandstones and mudstones, though limestone is the most common fossil-bearing rock used in construction.
Next is in kitty litter. Bentonite clays are used in countless industrial settings, but they also have one extremely common use inside the home—as the main ingredient of most kitty litter products. Bentonite clay is highly absorbent, making it ideal for this purpose.
Another thing bentonite clay is famous for? Occurring near fossil formations. The Morrison Formation, the geological formation where Dinosaur National Monument is found, is also heavily mined for bentonite clay. There have also been plenty of reports of kitty litter mining companies in Canada knowingly destroying fossil beds for more profit. So... your cat might be doing its business in dinosaur bits.
Third is diatomaceous earth. This fine white powder is frequently used as a cleaning product in the home. Applications of it can kill many types of insect infestations. The actual mechanism by which it does so is a little complicated, but it essentially dehydrates the insects to death. (Sometimes it's also used in kitty litter.) Diatomaceous earth is a sedimentary rock composed entirely of fossilized diatoms, a type of ocean-going microorganism that grows a silica-based shell.
Finally, there's good old-fashioned chalk. Chalk is simply an accumulation of the shells of tiny marine microorganisms, just like diatomaceous earth. Instead of being formed of silica-shelled organisms, however, it's formed out of calcite-shelled organisms known as coccolithophores. (Interestingly, the Cretaceous is actually named after the fact that more chalk was deposited around the world than during any other geological era—not, as you might expect, due to anything to do with dinosaurs.)
So, whenever your kids are drawing on the sidewalk with chalk, they're drawing with fossils.
Finishing Corinth Canal
Or: Taking Their Time to (Not) Get it Right
That's Some Celebration
The longest construction project in history lasted almost two thousand years.
The Corinth Canal is a four-mile-long, seventy-foot-wide canal that separates the Peloponnese peninsula from mainland Greece, technically making it an island.
The Corinthian Tyrant Periander first proposed the canal in the seventh century BCE. It swiftly became too expensive, and Periander instead constructed a Diolkos, a stone road designed to use to drag (or portage) ships across the narrow isthmus. (You can still see remnants of the Diolkos alongside the canal.)
The canal idea was next resurrected in the third century BCE by Diadoch Demetrius Poliorcetes, one of the generals who warred over the remnants of Alexander the Great's empire after his death. His surveyors, however, miscalculated and feared that the canal would result in large-scale flooding, so the project was abandoned.
Roman Emperors Julius Caesar and Caligula both considered constructing the canal, but both were assassinated before they could begin. Emperor Nero became the first ruler to actually move forward with the construction of the canal—and, in fact, was the first person to labor on it, digging up the first basket of soil with a pickaxe. Construction officially began in 67 AD, after centuries of false starts.
Almost immediately afterward, of course, Nero got assassinated.
For nearly two thousand years after that, the idea never progressed farther than another proposal. Several conquerors of Greece throughout its history considered the idea, but nothing happened.
Then, in the 1830s, Greece gained its independence from the Ottoman Empire. New proposals immediately started back up, and construction finally started in the 1880s. (That’s a pretty short amount of time, as far as the Corinth Canal goes.)
Finally, on July 25, 1893, Greece completed the Corinth Canal. And, of course, it was too narrow, too windy, and had currents that were too severe for it to be of much use, except to a small number of ships a year.
Cold Welding
Or: One Advantage of Being Messy
Shut the door, please.
On June 3, 1965, a door failed to close.
In most situations, this would be a minor annoyance, but this was in the middle of the Gemini 4 space mission, and the door in question was the outer airlock door of the capsule—while they were in space.
So, yes: this was rather a big problem. In the end, the problem turned out merely to be a jammed spring; they managed to get the door shut. There were serious concerns, however, that a more severe problem might have occurred: cold welding.
Cold welding is exactly what it sounds like: Two pieces of metal welding together in cold conditions, rather than through application of heat. Specifically, it involves two clean, flat pieces of metal bonding together when they contact in a vacuum.
These need to be two exceptionally clean pieces of metal, since any contaminants can interfere with the process. Once they're welded, however, as far as the two pieces of metal are concerned, they're just one piece, not two. The process actually bonds the two together as if they'd always been one piece.
Needless to say, this is a big concern in space, where you really can't afford to have random mechanical failures due to pieces deciding they don't want to move.
Quite a few satellites have been lost through cold welding over the years, and the Galileo probe sent to Jupiter had its high-power antenna welded shut in this way.
There are a few good methods to help prevent cold welding these days—using plastic, ceramics, and coatings whenever possible, as well as making sure that any metals in or near contact with one another are different metals, to reduce risks of cold welding.
Finally, we have one more thing protecting us: our natural messiness. Skin oil, dust, and other contaminants can help prevent cold welding. And, guess what? We're really good at getting all that stuff on everything, even our super-expensive, high-tech space probes. Three cheers for being messy.
Discovering the Turkish Underground
Or: Tuff Luck
The Turkish Underground
The Cappadocia region of Anatolia, Turkey, is riddled with underground cities. In 1963, a man in the region knocked down a wall of his home (for home renovations, I hope, though maybe he was just in a particularly bad mood) and discovered a mysterious room built into the rock.
After a little more digging, he broke into a whole intricate tunnel system: the Derinkuyu underground city, carved thousands of years ago.
The Cappadocia region sits on a one kilometer (3,300-foot) tall volcanic plateau. Millions of years ago, it was covered in volcanic ash, which solidified into tuff, a type of volcanic rock.
That made for easy digging, and the inhabitants of the region some 3,000 years ago quickly took advantage of this to dig their elaborate tunnel cities. (Not all tuffs are soft and easily dug into, however; some tuffs are extremely tough.)
People developed a wide range of uses within the tunnel systems. Food storage was one of the earliest and most reliable: cave systems tend to maintain constant temperatures, often considerably cooler than the surface.
We’ve also used underground cities multiple times throughout history to hide from attack. Derinkuyu is extensive enough that it could have hidden as many as 20,000 people. They had the benefit of ample storage space, which included wine and oil presses, stables, refectories, and chapels.
The city contains five different levels, each of which could be closed off independently of the others. Not least incredibly, the Derinkuyu is also connected to the Kaymakli underground city by an 8 km (5 mile) underground tunnel.
There is some debate about who first built the cities. Some attribute them to the Hittites (between the 15th and 12th centuries BC), but most believe they were constructed by the Phrygians (between the 8th and 7th century BC), the people who supplanted the Hittites, and then themselves faded away during Roman times.
The Derinkuyu was used by the Byzantines much later to defend themselves during the Arab Byzantine wars (780-1180 AD). Even as late as the early 20th century, the tunnels were still in use by the locals to avoid Ottoman persecution, only falling into disuse in 1923. So, doing our math, the lost city had only been lost for 40 years when it was re-found.
Today, much of the Derinkuyu underground city is open for visitation by tourists. And more than 200 other underground cities with a minimum of two levels (40 have three or more) have been discovered in the region.