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Pythagoras Solar turns windows into panels of energy

Pythagoras Solar

Pythagoras Solar's "solar window" technology (credit: Pythagoras Solar)

Pythagoras Solar, a start-up based in San Mateo, California, is working on creating “solar windows” that could generate power for office buildings and shield offices from sunlight, thus reducing air conditioning costs, according to the San Francisco Chronicle.

Thin horizontal rows of silicon cells embedded between dual panes of glass catch light from above. And through a trick of optics, the window blocks direct sunlight from entering the building. The Pythagoras window belongs to a class of solar equipment known as BIPVbuilding-integrated photovoltaics.

Pythagoras already installed some of the windows at Chicago’s Willis Tower, formerly known as the Sears Tower.


Subatomic quantum memory in diamond demonstrated

Physicists at the University of California, Santa Barbara and the University of Konstanz in Germany have developed a breakthrough in the use of diamond in quantum physics, marking an important step toward quantum computing.

The physicists were able to coax the quantum information contained within a single electron in diamond to move into an adjacent single nitrogen nucleus and then back again, using on-chip wiring.

The researchers said the discovery shows the high-fidelity operation of a quantum mechanical gate at the atomic level, enabling the transfer of full quantum information to and from one electron spin and a single nuclear spin at room temperature. The process is scalable, and opens the door to new solid-state quantum device development.

Ref.: D. D. Awschalom, et al., A quantum memory intrinsic to single nitrogen–vacancy centres in diamond, Nature Physics, 2011; [DOI: 10.1038/nphys2026]

Hippie days

Charter members of the 'Fundamental Fysiks Group,' circa 1975. Standing, left to right: Jack Sarfatti, Saul-Paul Sirag, Nick Herbert; bottom corner: Fred Alan Wolf. (Credit: Fred Alan Wolf)

Every Friday afternoon for several years in the 1970s, a group of underemployed quantum physicists met at Lawrence Berkeley Laboratory, in Northern California, to talk about a subject so peculiar it was rarely discussed in mainstream science: entanglement. Did subatomic particles influence each other from a distance? What were the implications?

Many of these scientists, who dubbed themselves the “Fundamental Fysiks Group,” were fascinated by the paranormal and thought quantum physics might reveal “the possibility of psycho-kinetic and telepathic effects,” as one put it. Some of the physicists cultivated flamboyant countercultural personas. In lieu of solid academic jobs, a few of them received funding from the leaders of the “human potential” movement that was a staple of 1970s self-help culture.

In short, the Fundamental Fysiks Group appeared to be just a bunch of eccentric, obscure physicists whiling away the Me Decade in the Berkeley Hills. But as MIT historian of science David Kaiser asserts in his new book, How the Hippies Saved Physics, published this month by W.W. Norton, the group’s members actually helped to steer physics in a new direction: They revived scientific interest in the puzzling foundations of quantum mechanics, provided new insights about entanglement, and laid the intellectual groundwork for the field of quantum information science, which today produces cutting-edge computing and encryption research.

“That’s a pretty good track record for a few years of zany, fun-loving, free-spirited and yet devoted research,” says Kaiser, head of MIT’s Program in Science, Technology, and Society, and a senior lecturer in the Department of Physics.

For whom Bell toiled

The intellectual beacon guiding the Fundamental Fysiks Group was a 1964 insight by Irish physicist John Bell, which strongly suggested that entanglement was real: Measuring the properties of one particle could influence the properties of another, distant particle. “This group was obsessed with Bell’s Theorem and wanted to wring out its implications,” Kaiser says.

In so doing, the group was returning to the physics tradition of inquiry about the structure of the universe. Famous prewar quantum theorists such as Erwin Schrödinger regularly tackled questions about subatomic strangeness, like the apparent particle-wave duality of matter. But after World War II, Kaiser notes, quantum physics became a much more pragmatic field, developing technologies such as the transistor; a popular mantra was “shut up and calculate.”

The few physicists left pondering the nature of reality were doomed in the sour academic job market of the 1970s, after Sputnik-driven education funding had dried up. “No field grew faster than physics after World War II, and no field crashed harder in the 1970s,” Kaiser says.

Still, one physicist in the Fundamental Fysiks Group, John Clauser, rigged an apparatus at Lawrence Berkeley Laboratory and conducted the first experiment testing Bell’s Theorem; it suggested entanglement was real. In 2010, this earned Clauser a share of the Wolf Prize, physics’ leading award after the Nobel Prize; back then, the experiment merely earned Clauser a little recognition.

“I think the field had gotten out of balance,” says Kaiser, who has PhDs in both physics and the history of science from Harvard.

Another mainstay of the group, Nick Herbert, concocted influential thought experiments about the uses of entanglement. One paper Herbert circulated, on something he called the FLASH scheme, described a possible way that entangled particles could influence each other faster than the speed of light — violating Einstein’s theory of special relativity. If proven true, Herbert thought, information could be transmitted instantaneously. Eventually other scientists concluded that the concept would not work, since devices cannot copy unknown properties of particles. This “no-cloning theorem” is the basis of quantum encryption: Codes based on quantum information cannot be replicated and thus cracked.

“The no-cloning theorem was discovered by three groups in response to Nick Herbert’s FLASH scheme,” Kaiser says. “It’s a new insight into the structure and meaning of quantum theory. That’s page one of our quantum information science textbooks today.”

The Tao of Physics makes waves

According to Kaiser, the Fundamental Fysiks Group also contributed to science education, by helping to renew interest in the philosophical dimension of physics. Largely ignored by academia, group members began writing for popular publication.

One physicist at large associated with the group, Frijtof Capra, wrote a quirky book in 1975 drawing links between quantum phenomena and Eastern religions. Surprisingly, The Tao of Physics became an international bestseller with millions of copies in print. Equally surprisingly, after decades spent ignoring quantum weirdness, professors began assigning Capra’s book, to draw students back into the physics classroom.

Herbert and others in the group would also write successful texts on quantum physics that were assimilated into the physics curriculum. “Today’s undergraduates at MIT learn about Bell’s Theorem in the first semester of quantum mechanics,” Kaiser says. “That simply wasn’t true for a long time. Questions about what it all means now have a place in the curriculum.”

‘These folks had to show people the goods’

Not every scientist in the Fundamental Fysiks Group could write a best-seller, of course. To gain attention, the group circulated mimeographed working papers, sent letters to prominent physicists such as John Wheeler, and sought coverage in alternative newspapers, as Kaiser documents.

“The book captures something that seems quite ephemeral, a moment in the history of physics when a lot of thinking was not recorded in traditional publications,” says Ken Alder, a professor of history and founder of the Science in Human Culture Program at Northwestern University. “David has done an amazing job of piecing together what was going on at the time.”

Though many of the physicists were attracted to entanglement because it suggested that the paranormal might be possible, Kaiser is careful to distinguish between their personal interests and the value of their technical work. “Virtually every member of the group had PhDs from very elite programs,” Kaiser says. “They weren’t just leaning back and saying, ‘Hey man, can you dig it?’” Instead, he says, “These folks had to show people the goods, pages of calculations in papers they submitted to peer-reviewed journals.”

The hippie physicists also represent a larger point about American history, Kaiser believes: The counterculture movement was not primarily an anti-scientific phenomenon, as many commentators have described it. “There was a rejection of a certain kind of militarized Cold War science, not a general rejection of science or technology,” Kaiser says.

Today, new technologies based on entanglement seem plausible; banks have demonstrated money transfers using entangled photons, and research into quantum computing is expanding. As much as the Fundamental Fysiks Group wanted to move away from applied physics and return to foundational questions, the two things are very much entangled.

Written by Peter Dizikes, MIT News Office

‘Orca ears’ inspire researchers to develop ultrasensitive undersea microphone

A miniature underwater microphone (credit: L.A. Cicero)

Imagine a miniature microphone that responds to ocean sounds from 1 to 100kHz (a deep inaudible rumble to ultrasonic sounds) with a dynamic range of 160 dB (a whisper in a quiet library to the sound from 1 ton of TNT exploding 60 feet away) and operates at any depth.

An amazing microphone that does all that — modeled after the extraordinarily acute hearing of orcas — has been developed by Onur Kilic and other researchers at Stanford University.

At the core of the microphone, the researchers fabricated a silicon chip with a thin membrane (diaphragm) about 500 nanometers thick and drilled a grid of tiny holes (about 100 nanometers) in it, to allow water flow into the microphone, keeping the water pressure on each side of the membrane equal, no matter how deep.

They ran a fiberoptic cable into the water-filled microphone, with the end of the cable positioned near the inside surface of the diaphragm. They then shot light from a laser out the end of the cable onto the diaphragm. When the diaphragm was deformed ever so slightly by a sound wave, the intensity of the light reflected back into the cable was altered, which was measured with an optical detector.

Exploded view of the sensor structure showing (a) the silicon-based sensor chip, (b) the brass backchamber, and (c) the fiber bundle, each fiber with a mirror at its tip (credit: Onur Kilic et al./Acoustical Society of America)

The result was a hydrophone that would function at any depth and could detect and measure sound with extreme accuracy. But to be able to capture the full range of volumes they were after (a spread of 160 decibels), they needed not just one diaphragm, but three.

By giving each diaphragm a different diameter, they were able to “tune” each one to maximize its sensitivity to a different part of the range of volumes they wanted to detect.

One was tuned to measure quiet sounds on the library-whisper end of the spectrum, one was attuned more to the loud, TNT explosion end of the range, and the third was tuned to the mid-range volumes.

Since they all measured the exact same signal — just with different degrees of responsiveness — they worked like a single sensor.

Kilic said the uses for this would include ocean surveys and using the ocean as a giant neutrino detection system. He also told me the microphone fibers could be made into an array, which would allow for even greater sensitivity as well as localization. One could create a system that would operate very much like whale’s hearing (ranging over thousands of miles) and even do 3-D imaging.

He couldn’t comment on it, but this technology was funded by Litton Systems Inc., a subsidiary of Northrop-Grumman Northrup-Grumman, and would clearly be perfect for long-distance submarine detection and for communicating signals via sound in the ocean, perhaps covertly over long distances.

I could say more, but I’d have to kill all our readers. Not a good editorial strategy.

Ref.: Olav Solgaard, et al., Miniature photonic-crystal hydrophone optimized for ocean acoustics, The Journal of the Acoustical Society of America, 2011; 129 (4): 1837 [DOI: 10.1121/1.3543949]

ocean surveys and neutrino detection

Stealth mold genes take over human genome, jump to databases and chips!

“Earlier this year, molecular biologists announced that 20 per cent of nonhuman genome databases are contaminated with human DNA, probably from the researchers who sequenced the samples,” Technology Review‘s The Physics ArXiv blog said on Thursday.

“Now, the human genome itself has become contaminated. Bill Langdon at University College London and Matthew Arno at Kings College London say they’ve found sequences from mycoplasma bacteria in the human genome database.”

Holy Zuul, Batman! These are stealth pathogens unaffected by many common antibiotics and can cause serious diseases — autodialing CDC!

“These mycoplasma genes are clearly successful in reproducing themselves in silico,” the post further warned. “One possibility is that we’re seeing the beginnings of an entirely new kind of landscape of infection. Here, genes that can masquerade as human (or indeed as other organisms) can successfully transmit themselves from one database to another.”

Huh? I decided to reality-check this with Arno and Langdon, co-authors of More Mouldy Data: Virtual Infection of the Human Genome.

“Some people have totally misunderstood the blog, and are thinking that we meant human genomes (i.e. DNA in living human cells, in humans) are becoming infected with mycoplasma and this will take over the world,” said Arno reassuringly in an email. “This is not what we meant! I think this was caused by the less than scientific language used in that blog, and a few of the more ‘creative’ assertions there — nothing wrong with a few hypotheses, though.”

“The gene sequences chosen when they were designed are built into them and cannot be changed,” Langdon added. “The results of thousands of such gene chips are widely disseminated via the Internet. Once a tissue sample is contaminated, routines are used to destroy it immediately in the hope of preventing the mold spreading to other samples. Some laboratories routinely sterilise all their experimental glassware every 6 weeks. They do not ‘disinfect’ their computer databases.”

There’s actually a potential benefit, though, Langdon said: “If a sample is contaminated with mycoplasma, there is probably no point to using the data collected from it. [But] if the gene chip design measures the presence of the mold gene, it gives a cheap automatic way of detecting mycoplasma contamination.”

Hmm… maybe there’s a germ (pun intended) of an idea here for a new kind of multipathogen detector?

Biologists discover how yeast cells reverse aging

Yeast Cell

A whole yeast (Saccharomyces cerevisiae) cell viewed by X-ray microscopy. Inside, the nucleus and a large vacuole (red) are visible (credit: NIH)

Researchers at MIT have discovered a gene called NDT80 that can double yeast lifespan when turned on late in life.

The gene is activated when yeast cell rejuvenation occurs. When they turned on this gene in aged cells that were not reproducing, the cells lived twice as long as normal.

The MIT team found that the signs of cellular aging disappear at the very end of meiosis (which produces spores). “There’s a true rejuvenation going on,” said professor Angelika Amon.

In aged cells with activated NDT80, the nucleolar damage was the only age-related change that disappeared. That suggests that nucleolar changes are the primary force behind the aging process, Amon said.

If the human cell lifespan is controlled in a similar way, it could offer a new approach to rejuvenating human cells or creating pluripotent stem cells, Amon said.

Ref.: Amon, et al., Gametogenesis Eliminates Age-Induced Cellular Damage and Resets Life Span in Yeast, Science, June 2011, [DOI: 10.1126/science.1204349]

How to make a clock run for 10,000 years

Clock Design

Clock design model (credit: Long Now Foundation)

Billionaire founder Jeff Bezos has a long-term plan: to build a clock that runs for 10,000 years.

The idea for the clock has been around since Danny Hillis first proposed it in WIRED magazine in 1995. Since then, Hillis and others have built prototypes and created a nonprofit, the Long Now Foundation, to work on the clock and promote long-term thinking.

But nobody actually started building a full-scale 10,000-year clock until Bezos put up a small portion — $42 million, he says — of his fortune.