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When Can We Have A Space Elevator?

The space shuttle's retirement has prompted me to think a bit harder about the future of the American space program. I always took the space shuttle, and the giant rockets that propelled it, for granted, assuming they were the best and only method of launching things into space. It turns out, however, that somebody thought of making a space elevator way back in the 19th century, and we've had the technology to create one in a lower-gravity environment like the moon or Mars since the 70s.
So what would a space elevator be, theoretically? It's a fairly simple concept, actually -- it would be a giant cable, one end tethered to the ground (or possibly to a mobile platform in the ocean) at the equator, the other end towed past geostationary orbit and attached to a big artificial counterweight in space. I'm notoriously bad at grasping concepts that involve math or physics, but the idea seems designed to place the system's center of mass exactly at geostationary orbit over the equatorial spot where the base of the cable is anchored, thus keeping the whole thing more or less upright (with maybe one degree of bend at certain spots along the cable). Then a cable car of sorts -- or multiple cars -- could climb and descend the "beanstalk," as some call it, at will. The cost and energy savings of transporting materials to space in this manner is potentially huge; currently, it costs around $11,000 to blast a pound of payload into space. With a space elevator, it'd be more like $100 -- just slightly more expensive than overnight FedEx, in other words.

Of course, there are challenges, primary among them developing a cable from material that's both extremely light and extremely strong. Carbon nanotube technology seems to be promising, but despite a number of X-prize-type contests over the past five years or so, we haven't quite clinched it yet. Japan seems especially excited about the prospect of a space elevator -- in fact, an American-penned book called "Leaving the Planet by Space Elevator" was a best-seller there in 2008. From Wikipedia:

This has led to a Japanese announcement of intent to build a Space Elevator at a projected price tag of £5 billion. In a report by Leo Lewis, Tokyo correspondent of The Times newspaper in England, plans by Shuichi Ono, chairman of the Japan Space Elevator Association, are unveiled. Lewis says: "Japan is increasingly confident that its sprawling academic and industrial base can solve those [construction] issues, and has even put the astonishingly low price tag of a trillion yen (£5 billion/ $8 billion) on building the elevator. Japan is renowned as a global leader in the precision engineering and high-quality material production without which the idea could never be possible."

That was a few years ago, though, and Japan surely has other things on its collective mind right now. All things considered, however, this really does seem like a great -- and much more efficient -- way to get ourselves and our stuff into space. I wouldn't be surprised at all if space elevators became a reality in my lifetime.

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History
The Secret World War II History Hidden in London's Fences

In South London, the remains of the UK’s World War II history are visible in an unlikely place—one that you might pass by regularly and never take a second look at. In a significant number of housing estates, the fences around the perimeter are actually upcycled medical stretchers from the war, as the design podcast 99% Invisible reports.

During the Blitz of 1940 and 1941, the UK’s Air Raid Precautions department worked to protect civilians from the bombings. The organization built 60,000 steel stretchers to carry injured people during attacks. The metal structures were designed to be easy to disinfect in case of a gas attack, but that design ended up making them perfect for reuse after the war.

Many London housing developments at the time had to remove their fences so that the metal could be used in the war effort, and once the war was over, they were looking to replace them. The London County Council came up with a solution that would benefit everyone: They repurposed the excess stretchers that the city no longer needed into residential railings.

You can tell a stretcher railing from a regular fence because of the curves in the poles at the top and bottom of the fence. They’re hand-holds, designed to make it easier to carry it.

Unfortunately, decades of being exposed to the elements have left some of these historic artifacts in poor shape, and some housing estates have removed them due to high levels of degradation. The Stretcher Railing Society is currently working to preserve these heritage pieces of London infrastructure.

As of right now, though, there are plenty of stretchers you can still find on the streets. If you're in the London area, this handy Google map shows where you can find the historic fencing.

[h/t 99% Invisible]

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holidays
Custom-Design the Ugly Christmas Sweater of Your Dreams (or Nightmares)
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For those of you aspiring to be the worst dressed person at your family's holiday dinner, UglyChristmasSweater.com sells—you guessed it—ugly Christmas sweaters to seasonal revelers possessing a sense of irony. But the Michigan-based online retailer has elevated kitsch to new heights by offering a create-your-own-sweater tool on its website.

Simply visit the site's homepage, and click on the Sweater Customizer link. There, you'll be provided with a basic sweater template, which you can decorate with festive snowflakes, reindeer, and other designs in five different colors. If you're feeling really creative, you can even upload photos, logos, hand-drawn pictures, and/or text. After you approve and purchase a mock-up of the final design, you can purchase the final result (prices start at under $70). But you'd better act quickly: due to high demand, orders will take about two weeks plus shipping time to arrive.

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