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But what exactly makes one knot more stable than another has not been well-understood, until now. MIT mathematicians and engineers have developed a mathematical model that predicts how stable a knot is, based on several key properties, including the number of crossings involved and the direction in which the rope segments twist as the knot is pulled tight. With confidence in their model, Patil then simulated more complicated knots, taking note of which knots experienced more pressure and were therefore stronger than other knots. Once they categorized knots based on their relative strength, Patil and Dunkel looked for an explanation...

“Harnessing the mysterious property that Albert Einstein called ‘spooky action at a distance’ is a crucial step toward exploiting quantum quirks for technology such as new kinds of sensors or computers,” the physicists said. “Entanglement is not just some academic curiosity; it’s also something you can harness as a basis for doing useful things with quantum mechanics,” Professor Clerk added. Entangled states are typically extremely fragile — especially so when they involve large objects. So Professor Clerk and his colleague, Dr. Matt Woolley from the University of New South Wales, developed a theoretical proposal for how to keep the motion...

The knots in question, the researchers wrote in their paper, were visible enough in images of the light wave data for them to identify the figure eights and toruses. ... To create the knots, the researchers carefully tuned the up-and-down and side-to-side wave motion (the polarization) of two beams of light, partly using technology not unlike that found in polarized sunglasses. The knots formed around "polarization singularities" where the beams intersected, places where the side-to-side and up-and-down wavelengths were exactly equal, and a number of other wavelengths of light looped around them. At those points, light bent in the way...

If i was blocked behind anti-trumpers at a rally...Would you get me out of jail if i knock some noggins with slap jacks? Not deadly...just painful

With just four minutes and a series of well-tied knots, Michael McDonnell saved himself and his Belle Harbor neighbors the night Hurricane Sandy hit. The experienced fisherman and surfer from the Rockaways fashioned a lifeline from electrical wire and twine to ferry a half-dozen people to safety from raging waters and fire. “You are only as good as the knots you make,” he said. Now McDonnell is hoping to take his experience to youngsters and others to help them figure out what to do if they have only minutes to evacuate their home — as he and others in the...

Tangled telephone cords and electronic cables that come to resemble bird nests can frazzle even the most stoic person. Now researchers have unraveled the mystery behind how such knots form. Two physicists used string-tumbling experiments and mathematical models to create a step-by-step recipe for knot formation and determined which factors cause the knottiest knots. Their research, published online this week by the Proceedings of the National Academy of Sciences, sheds light on an everyday phenomenon about which little was known beyond the madness it incites.

Source: University At Buffalo Date: 2004-01-05 Professor Works To Unravel Mysteries Of Khipu: Colored, Knotted Strings Used By The Ancient Incas BUFFALO, N.Y. -- Although the ancient Inca are renowned for their highly organized society and extraordinary skill in working with gold, stone and pottery, few are familiar with the khipu -- an elaborate system of colored, knotted strings that many researchers believe to be primarily mnemonic in nature, like a rosary -- that was used by the ancient conquerors to record census, tribute, genealogies and calendrical information. Because the Inca didn't employ a recognizable system of writing, researchers like...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 May 12 At the Edge of the Helix Nebula Credit: R. O'Dell and K. Handron (Rice University), NASA Explanation: While exploring the inner edge of the Helix Nebula with the Hubble Space Telescope's Wide Field Planetary Camera 2, astronomers were able to produce this striking image - rich in details of an exotic environment. This planetary nebula, created near the final phase of a sun-like star's life,...