Earth Art

You’re Gonna Need a Bigger Boat

I am not a well educated man when it comes to art. Give me a ten-dollar painting of a sailing ship from a yard sale or thrift store and I'll be perfectly happy with it. Every once in a while, though, I find something that makes me take notice—in this case, it's a fella named Michael Heizer.

Heizer is known as what we call a land or earth artist—someone who builds immense outdoor pieces designed around and for their specific locations. These pieces are left out in the open to age and erode naturally. (Kinda like me.) Many of the earliest pieces from the 1960s don't exist anymore. If nothing else, Heizer's pieces are particularly notable for their sheer size.

dubnegOne of his best known pieces is a work called Double Negative, a pair of massive trenches cut into the edge of Mormon Mesa in Nevada. Each is 50 feet wide and 30 feet deep, and they have a combined length of 1,500 feet. The project involved moving 244,000 tons of rock.

Another project, Levitated Mass, involved the suspension of a massive, 21-foot tall, 340-ton boulder above a concrete trench that you can walk through. Moving the boulder itself was a massive feat of engineering. It only had 60 miles to travel, as the bird flies, but in order to get there they took it on a tangled 106-mile route through 22 cities in order to find bridges strong enough and streets wide enough.

The colossal custom transport could only move at seven miles an hour, and so they needed 11 days to get there, traveling only at night. Along the way, they had to cut down trees, temporarily remove traffic lights, and tow cars. The whole route turned into a series of parties at the transport's daytime resting places.

(The event was so cool that our other Yard Ramp Guy has blogged about it.)

Heizer’s current project, in the works for 20 years now, is by far his most impressive. Not yet open to the public, it is an enormous, mile-long monolithic structure known only as City, with two smaller complexes nearby.

To give you a comparison, it's about the size of the National Mall in DC. It's located in the brand new Basin and Range National Monument. As soon as it opens to the public, you can bet I'll be visiting.

City

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Clf23 at English Wikipedia [GFDL, CC-BY-SA-3.0], via Wikimedia Commons

Now Dig This

One Way to Save on Airfare to China

Little kids try to dig to China all the time—regardless what’s actually on the other side of the world from them—and, well, they never get very far—because…

It’s dinnertime, or they bust a pipe and flood the basement, or mom comes out and tells them they can’t go because your passport is outdated and you’ll get tossed in jail and just wait till your father gets home, and when dad gets home he stares at them with a look that’ll keep‘em local for at least 12 more years.

And now that I’ve covered parenting tips and travails for the moment, what's the actual deepest hole ever dug?

The Kola Superdeep Borehole, on the Kola Peninsula in northern Russia, reaches a depth of 40,230 feet. That’s more than seven and a half miles, far deeper than even the deepest point in any ocean. Started by the Soviet Union in 1970, it held the record for deepest borehole for decades.

Though longer boreholes have since been drilled, largely for oil related purposes, the Kola Superdeep Borehole remains the deepest point on Earth. During its lifespan it contributed immensely to scientific understanding.

Work on the borehole shut down in 2005, due to lack of funding. Oh, and though the hole is still there, you can't fall into it: along with being sealed with a thick metal cap, it's too thin to accommodate a human.

Even though that project has ended, it's not the only one of its type.

The Chikyū, a Japanese scientific vessel, is a drilling ship designed to drill miles below the seafloor. While that won't likely ever reach the extreme depths of the Kola Superdeep Borehole, its data is much more scientifically interesting, through drilling into more seismically active regions where the crust is much thinner. The Chikyū might actually be able to reach the upper layers of the mantle.

(Fun fact: the boundary between the crust and the mantle is known as the Mohorovičić Discontinuity, though most geologists just call it the Moho.)

Why is it important to dig all of these holes? Well, apart from giving us a richer understanding of the Earth’s history, (which should be important enough on its own), we also gain more knowledge of continental drift, volcanism, rock formations, and mineral deposit locations.

That’s why we can thank all those who started digging those holes to China as kids, got interrupted by their meddling parents, and then returned to the dig after college. The way I see it: if the parents had only let their kids have at it, they would’ve saved a fortune on tuition.

On Living Bridges

I've blogged a lot about bridges, I know (Sir Bridges Blog-a-Lot, eh?) but I haven't yet explored living bridges.

Meghalaya, a state in north-eastern India, is one of the wettest places in the world, getting close to 500 inches of rainfall a year. Almost three-quarters of the state is forested. One of the indigenous tribes living there, the War-Khasi, build living foot bridges from the roots of the Ficus elastica — a variety of rubber tree.

thebridgePhoto by Arshiya Urveeja Bose [CC BY 2.0], via Wikimedia Commons

To grow the bridges, the Khasis create root guidance systems out of halved and hollowed betel nut trunks. The roots are channeled to the other side of the river, where they are allowed to bury themselves in the soil on that side.

The bridges take 10 to 15 years to grow strong enough for regular use; once they do, they last incredible amounts of time with no maintenance: since they're still growing, they actually continue to grow stronger and stronger over time. Some of the older bridges are five centuries old. Many of the older, stronger bridges can support 50 or more people at once.

mfthoughtThe most famous of the bridges, the Umshiang Double-Decker Root Bridge, is actually two of those bridges, with one stacked directly over the other. Local dedication to the art has kept the bridges alive and prevented them from being replaced with steel. (Steel, frankly—and with all respect to those dealing with, ahem, yard ramps—don't have anything near the lifespan of the root bridges and aren't nearly as sturdy.)

The root bridges aren't the only living bridges around. In the Iya Valley in Japan, there are bridges woven out of living wisteria vines. They're much less common, and only three remain. They're built by growing immense lengths of wisteria on each side of the river before weaving them together—a process that must be repeated once every three years.

These wisteria bridges are much less sturdy than the Khasi root bridges, with wooden planks spaced over seven inches apart, and they apparently shake wildly while you're on them. By all accounts, these things are terrifying to cross, which makes sense: they’re widely thought to have been designed originally for defense. The original bridges didn't even have railings.

Grading Kinds of Grating

Everyone knows what bridge grating looks like. It’s seemingly part of everything—from stairs to ladders to ramps to fire escapes to flooring. You know this: the stuff that comes in four-foot by eight-foot panels.

Grating is easy to clean (it doesn't get dirty, really), allows light to permeate a space easily, makes a fantastic drain cover, and weighs relatively little for its strength. It's a pretty basic and essential part of construction.

aluminum

What most people don't consider, though, is its composition. Not all gratings are made of the usual, default-mode steel. Like all matters involving construction, there are very specific trade-offs that need to be made in choosing your material.

Yes, steel gratings are easily the most common: strong, not too heavy, and not too expensive. There's a lot to be said for sticking to the old classics. You know what you're dealing with.

Aluminum is the next most-common material and is usually present in structures that need to minimize weight. These gratings tend to show up in ships and, on occasion, airplanes.

One of the less common materials for grating is fiberglass. (Actually, fiberglass is reinforced plastic, but let’s not get too picky.) Made through a pultrusion process, fiberglass-reinforced plastic grating (or FRP grating) is non-corrodible, unlike steel or aluminum gratings.

weldedThis makes the fiberglass type ideal for environments filled with corrosive chemicals or gases; chemical plants are one obvious setting for them, depending on the plant. Another is geothermal generating stations, which tend to have sulfur and other chemical deposits accumulating on everything.

Material isn't everything, either. You need to choose the joints in the grating with care. Welded joints, the most popular, provide both strength and lightness and are good enough for most projects.

Also to consider: the size of the gaps in the grating. If your inventory features lots of small objects, it might make sense to use a heavier grate with much closer meshing. Tends to keep things from falling through.

(I need to invent a personal, portable grating system that I can use whenever I take my house keys and car keys somewhere. Maggie, of course, would just hand me the colander she uses to drain pasta.)

Kiva Robots: A Bit Like Forklifts

Amazon is the biggest online retailer in existence. On some of their busier days, they've been known to receive more than 400 orders per second. Anyone who has ever worked in a warehouse can tell you that this is an absolutely astounding number. Even with warehouses all over, this would be a huge challenge for human workers. So, in 2012 Amazon purchased an army of robots for three quarters of a billion dollars.

The Kiva robots are like big, square Roomba robot vacuum cleaners, though they function more like forklifts. They're about 16 inches tall and weigh 320 pounds When a customer orders something on Amazon, a robot is dispatched with orders to retrieve the tall, thin square shelf that the item is on.

robotsThe Kivas roll through the Amazon warehouses, carefully guided and controlled by a central computer to avoid collisions. They scoot under shelves, stopping when they reach the programmed location and spin in place to lift the shelf. Then they pilot the whole shelf to a station where a human employee grabs the customer's order. The order then travels through an array of other steps to get to the customer.

Amazon has more than 15,000 of these robots in their warehouses right now, processing a majority of the orders. Establishing a testing a system for a warehouse can take quite a while, sometimes months. Amazon's engineers have to assure that the army of robots on the warehouse floor can move about without running into one another and toppling shelves over left and right, which is no easy task.

They also have to set the system up for prioritizing where to set shelves, in order to minimize retrieval times for the robots.

Surprisingly enough, the Kiva robots haven't resulted in job losses. Instead, the workers move from the picking-and-sorting jobs to train in other positions. In this scenario, when more robots are added, more work is created for the human workers. Seemingly: everybody wins. Plus, as anyone who has ever worked in a warehouse can easily attest, picking is a job tailor-made for robots.