'Quantum Cheshire Cat' becomes reality

Scientists have for the first time separated a particle from one of its physical properties - creating a “quantum Cheshire Cat”.

The phenomenon is named after the curious feline in Alice in Wonderland, who vanishes leaving only its grin.

Researchers took a beam of neutrons and separated them from their magnetic moment, like passengers and their baggage at airport security.

They describe their feat in Nature Communications.”

Read more at bbcnews

spring-of-mathematics:

Mathematically Correct Breakfast - How to Slice a Bagel into Two Linked Halves. If a torus is cut by a Möbius strip it will split up into to interlocking rings.

It is not hard to cut a bagel into two equal halves which are linked like two links of a chain. Figure 1:

  1. To start, you must visualize four key points.  Center the bagel at the origin, circling the Z axis. A is the highest point above the +X axis.  B is where the +Y axis enters the bagel. C is the lowest point below the -X axis.  D is where the -Y axis exits the bagel.
  2. These sharpie markings on the bagel are just to help visualize the geometry and the points.  You don’t need to actually write on the bagel to cut it properly.
  3. The line ABCDA, which goes smoothly through all four key points, is the cut line.  As it goes 360 degrees around the Z axis, it also goes 360 degrees around the bagel.
  4. The red line is like the black line but is rotated 180 degrees (around Z or through the hole). An ideal knife could enter on the black line and come out exactly opposite, on the red line. But in practice, it is easier to cut in halfway on both the black line and the red line. The cutting surface is a two-twist Mobius strip; it has two sides, one for each half.
  5. After being cut, the two halves can be moved but are still linked together, each passing through the hole of the other.

It is much more fun to put cream cheese on these bagels than on an ordinary bagel. In additional to the intellectual stimulation, you get more cream cheese, because there is slightly more surface area.
Topology problem: Modify the cut so the cutting surface is a one-twist Mobius strip. (You can still get cream cheese into the cut, but it doesn’t separate into two parts). See more at: Mathematically Correct Breakfast: How to Slice a Bagel into Two Linked Halves by George W. Hart.

Images: How to Slice a Bagel into Two Linked Halves by George W. Hart - Cutting bagels into linked halves on Mathematica. - Interlocking Bagel Rings

Maybe, that’s one of the reasons why I love bagel :)

Fist Bumps Pass Along Fewer Germs Than Handshakes

A few weeks ago, we took a look at nonverbal greetings around the world. In Japan, they bow. Ethiopian men touch shoulders. And some in the Democratic Republic of the Congo do a type of head knock.

But the American fist bump stood apart from the rest.

Knocking knuckles was the only greeting we could find that signaled both victory and equality; neither bumper has the upper hand, so to speak.

But of many of our readers pointed out that bumping fists may have another superior quality: it’s cleaner than a traditional handshake.

Now scientists in Wales have confirmed what these astute reader’s already knew. You’re much less likely to pass along bacteria when you bump fists than shake hands or high-five, biologists reportedMonday in the American Journal of Infection Control.”

Learn more from NPR.

Noctilucent Clouds … Frooooom Spaaaaaace!

"I recently wrote an article talking about noctilucent clouds—relatively rare high-altitude clouds usually seen just after sunset and before sunrise. They have a milky, silvery appearance, and are usually pretty hard to capture on photos.

It can be even harder from space, where lighting conditions are harsher and getting the right exposure balance is difficult. But astronaut Reid Wiseman got it just right recently, snagging a photo of the odd clouds from the International Space Station.”

Find out more from astronomer Phil Plait.

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