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May 8, 2019

How the Slinky buckles — A series of experiments shed light on "overcurvature"

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As opposed to haute couture.

But I digress.

Below, excerpts from Evelyn Lamb's March 2013 Scientific American article.

Camping enthusiasts and aspiring modern sculptors take heed: researchers have achieved a breakthrough in understanding and controlling overcurvature, which is found in such disparate settings as pop-up tents, DNA plasmids and curved origami. Overcurvature occurs when a ring is too curved to lie flat in a plane the way a normal circle does. For example, if you detached a segment of a Slinky and connected its ends to make a closed loop, you would have a hard time getting the whole thing to lie flat on the floor. The intrinsic curvature of the Slinky would cause the ring to buckle and assume a three-dimensional saddle shape.

In fact, the Slinky played a major role in this research project, the results of which were published in the journal Nature Communications last December. After observing overcurved rings of various sizes and materials, the researchers found a family of curves with fairly simple mathematical descriptions that they believed would model the shapes these overcurved rings take in space. They used loops made from portions of plastic Slinkys as the setting for precise measurements and found that their predicted curves were indeed what they observed in the Slinkys. "It was really surprising to us," says Alain Jonas, a materials scientist at the Catholic University of Leuven in Belgium, who led the research. "It was this experience where you find something and it actually fits!"

The paper includes an efficient pathway for folding pop-up tents and other overcurved rings, as shown in the illustration above. To fold a ring into three loops, place your hands on opposite sides of the ring. As you lift up, bring your hands together and grab the opposite sides in one hand. Use your free hand to coax the two opposite sides down and toward each other to form a saddle shape. At both the top and the bottom, push one side over the other and collapse the loops together.

The proposal differs from the approach that people usually take. It requires more energy initially but uses less overall. "It's not very intuitive when you do it," Jonas says, "but that's what the physics of the problem wants." After performing the research, he borrowed a friend's tent to practice the technique and his colleagues had developed. It was a success.

May 8, 2019 at 04:01 PM | Permalink | Comments (1)

Same pictures. Same places. 68 years apart.


From the New York Times:


"In iconic locations, we recreated


New York Times photos from 1951."

May 8, 2019 at 02:01 PM | Permalink | Comments (0)

Car models most likely not to start

Car models most likely not to start

Way better to find out here than on your own.

[via Your Mechanic]

May 8, 2019 at 12:01 PM | Permalink | Comments (0)

"Confessions of a Memory Eater" — Pagan Kennedy


I just finished this remarkable, under the radar 2006 novel about time travel, told in the form of a story about a man who learns of a drug that gives the user the ability to travel back in time to any point in the their own past and then experience things exactly as they were then.

Who wouldn't pay plenty for that?

As I think about it, this is actually science fiction, though I've never seen it mentioned in lists of sci-fi books about time travel.

Ken Grimwood's nonpareil 1986 "Replay" is perhaps the closest thing I can think of.

Both books are tours de force if you like this sort of thing (I do). 

May 8, 2019 at 10:01 AM | Permalink | Comments (0)

Perriand Mini Bag

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From websites:


Métier's coquettish Perriand Mini is supple yet strong, and the slouchy silhouette conceals a structured yet remarkably lightweight linen interior with four symmetrical pockets.

Features and Details:

• Weight: 1.1 lbs.

• Hand made in Italy

• Magnet tab closure

• Hand-braided handles

• 12.2"H x 7.5"W x 5.9"D; handle drop 5.1"

• Shoulder strap adjusts from 33.9"-42" and is detachable



May 8, 2019 at 08:01 AM | Permalink | Comments (0)

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