One small amoeba found a solution to the traveling salesman problem faster than our best algorithms. What does it know that we don’t?
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Category: computing – Page 666
These days, movies and video games render increasingly realistic 3D images on 2-D screens, giving viewers the illusion of gazing into another world. For many physicists, though, keeping things flat is far more interesting.
One reason is that flat landscapes can unlock new movement patterns in the quantum world of atoms and electrons. For instance, shedding the third dimension enables an entirely new class of particles to emerge—particles that that don’t fit neatly into the two classes, bosons and fermions, provided by nature. These new particles, known as anyons, change in novel ways when they swap places, a feat that could one day power a special breed of quantum computer.
But anyons and the conditions that produce them have been exceedingly hard to spot in experiments. In a pair of papers published this week in Physical Review Letters, JQI Fellow Alexey Gorshkov and several collaborators proposed new ways of studying this unusual flat physics, suggesting that small numbers of constrained atoms could act as stand-ins for the finicky electrons first predicted to exhibit low-dimensional quirks.
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Today, the application of engineering methodologies to the rational modification of organisms is a persistent goal of synthetic biology. Most synthetic biologists describe biological engineering as a hierarchy, wherein parts (genes, DNA) are used to build devices (many genes together), which in turn can be used to construct systems (a series of many devices). The challenge in transforming synthetic biology into a true engineering discipline is that the parts, which are the rudimentary building blocks of higher-order constructions, are fundamentally limited by the rigor of their characterization. This is really the case in all established engineering disciplines. In electrical engineering, for instance, the baseline components (transistors, resistors, wires, etc.) have been characterized so well that children can use them and the resulting circuits behave as expected. Once all ‘parts’ are standardized, it may be possible for synthetic biologists to use individual DNA building blocks to construct entirely synthetic life forms from the bottom-up.
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Researchers from the Moscow Institute of Physics and Technology, ETH Zurich, and Argonne National Laboratory, U.S, have described an extended quantum Maxwell’s demon, a device locally violating the second law of thermodynamics in a system located 1–5 meters away from the demon. The device could find applications in quantum computers and microscopic refrigerators cooling down tiny objects with pinpoint accuracy. The research was published Dec. 4 in Physical Review B.
The second law says that the entropy — that is, the degree of disorder or randomness — of an isolated system never decreases.
“Our demon causes a device called a qubit to transition into a more orderly state,” explained the study’s lead author Andrey Lebedev of MIPT and ETH Zurich. “Importantly, the demon does not alter the qubit’s energy and acts over a distance that is huge for quantum mechanics.”
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IonQ, one of many companies developing a quantum computer, has announced a new trapped ion quantum computer with 79 processing qubits. The company claims this quantum computer should beat Google’s 72-qubit quantum computer, not just in terms of number of qubits, but also in total processing performance.
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With no less than FOUR rocket launches by four different companies, today promised to be an epic one for space fans. But by mid-morning, two of the most anticipated launches, by SpaceX and Blue Origin, were scrubbed by glitches, while weather forced another launch delay in South America.
SpaceX and Blue Origin kicked off the launch attempts today (Dec. 18). A SpaceX Falcon 9 rocket was set to launch GPS III SV01, the first of an advanced new navigation satellite system for the U.S. military. At first the mission, initially scheduled for 9:11 a.m. EST (1411 GMT), slipped a few minutes to 9:34 a.m. EST as SpaceX prepared for launch at its Cape Canaveral Air Force Station pad in Florida. But seven minutes before liftoff, the Falcon 9’s onboard computer triggered an abort, forcing SpaceX to stand down for the day.
“We did have an abort,” SpaceX Firmware Engineer Tom Praderio said during live commentary. “This abort was triggered by the onboard Falcon 9 flight computer. The unfortunate part is that it has pushed us past our launch window today.” SpaceX had a 26-minute window for the launch attempt. The company will try again Wednesday (Dec. 19), with liftoff set for 9:07 a.m. EST (1407 GMT).
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Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal Small, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.
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Of course, all the algorithmic rigmarole is also causing real-world problems. Algorithms written by humans — tackling harder and harder problems, but producing code embedded with bugs and biases — are troubling enough. More worrisome, perhaps, are the algorithms that are not written by humans, algorithms written by the machine, as it learns.
Profiles in science.
Donald Knuth, master of algorithms, reflects on 50 years of his opus-in-progress, “The Art of Computer Programming.”
Donald Knuth at his home in Stanford, Calif. He is a notorious perfectionist and has offered to pay a reward to anyone who finds a mistake in any of his books. Credit Credit Brian Flaherty for The New York Times.