descend-wow.com

Wednesday, February 4, 2009

A new historic physics record has been set by scientists for exceedingly small writing, opening a new door to computing‘s future. Stanford University physicists have claimed to have written the letters “SU” at sub-atomic size.

Graduate students Christopher Moon, Laila Mattos, Brian Foster and Gabriel Zeltzer, under the direction of assistant professor of physics Hari Manoharan, have produced the world’s smallest lettering, which is approximately 1.5 nanometres tall, using a molecular projector, called Scanning Tunneling Microscope (STM) to push individual carbon monoxide molecules on a copper or silver sheet surface, based on interference of electron energy states.

A nanometre (Greek: ?????, nanos, dwarf; ?????, metr?, count) is a unit of length in the metric system, equal to one billionth of a metre (i.e., 10^-9 m or one millionth of a millimetre), and also equals ten Ångström, an internationally recognized non-SI unit of length. It is often associated with the field of nanotechnology.

“We miniaturised their size so drastically that we ended up with the smallest writing in history,” said Manoharan. “S” and “U,” the two letters in honor of their employer have been reduced so tiny in nanoimprint that if used to print out 32 volumes of an Encyclopedia, 2,000 times, the contents would easily fit on a pinhead.

In the world of downsizing, nanoscribes Manoharan and Moon have proven that information, if reduced in size smaller than an atom, can be stored in more compact form than previously thought. In computing jargon, small sizing results to greater speed and better computer data storage.

“Writing really small has a long history. We wondered: What are the limits? How far can you go? Because materials are made of atoms, it was always believed that if you continue scaling down, you’d end up at that fundamental limit. You’d hit a wall,” said Manoharan.

In writing the letters, the Stanford team utilized an electron‘s unique feature of “pinball table for electrons” — its ability to bounce between different quantum states. In the vibration-proof basement lab of Stanford’s Varian Physics Building, the physicists used a Scanning tunneling microscope in encoding the “S” and “U” within the patterns formed by the electron’s activity, called wave function, arranging carbon monoxide molecules in a very specific pattern on a copper or silver sheet surface.

“Imagine [the copper as] a very shallow pool of water into which we put some rocks [the carbon monoxide molecules]. The water waves scatter and interfere off the rocks, making well defined standing wave patterns,” Manoharan noted. If the “rocks” are placed just right, then the shapes of the waves will form any letters in the alphabet, the researchers said. They used the quantum properties of electrons, rather than photons, as their source of illumination.

According to the study, the atoms were ordered in a circular fashion, with a hole in the middle. A flow of electrons was thereafter fired at the copper support, which resulted into a ripple effect in between the existing atoms. These were pushed aside, and a holographic projection of the letters “SU” became visible in the space between them. “What we did is show that the atom is not the limit — that you can go below that,” Manoharan said.

“It’s difficult to properly express the size of their stacked S and U, but the equivalent would be 0.3 nanometres. This is sufficiently small that you could copy out the Encyclopaedia Britannica on the head of a pin not just once, but thousands of times over,” Manoharan and his nanohologram collaborator Christopher Moon explained.

The team has also shown the salient features of the holographic principle, a property of quantum gravity theories which resolves the black hole information paradox within string theory. They stacked “S” and the “U” – two layers, or pages, of information — within the hologram.

The team stressed their discovery was concentrating electrons in space, in essence, a wire, hoping such a structure could be used to wire together a super-fast quantum computer in the future. In essence, “these electron patterns can act as holograms, that pack information into subatomic spaces, which could one day lead to unlimited information storage,” the study states.

The “Conclusion” of the Stanford article goes as follows:

The team is not the first to design or print small letters, as attempts have been made since as early as 1960. In December 1959, Nobel Prize-winning physicist Richard Feynman, who delivered his now-legendary lecture entitled “There’s Plenty of Room at the Bottom,” promised new opportunities for those who “thought small.”

Feynman was an American physicist known for the path integral formulation of quantum mechanics, the theory of quantum electrodynamics and the physics of the superfluidity of supercooled liquid helium, as well as work in particle physics (he proposed the parton model).

Feynman offered two challenges at the annual meeting of the American Physical Society, held that year in Caltech, offering a $1000 prize to the first person to solve each of them. Both challenges involved nanotechnology, and the first prize was won by William McLellan, who solved the first. The first problem required someone to build a working electric motor that would fit inside a cube ¹/₆₄ inches on each side. McLellan achieved this feat by November 1960 with his 250-microgram 2000-rpm motor consisting of 13 separate parts.

In 1985, the prize for the second challenge was claimed by Stanford Tom Newman, who, working with electrical engineering professor Fabian Pease, used electron lithography. He wrote or engraved the first page of Charles Dickens’ A Tale of Two Cities, at the required scale, on the head of a pin, with a beam of electrons. The main problem he had before he could claim the prize was finding the text after he had written it; the head of the pin was a huge empty space compared with the text inscribed on it. Such small print could only be read with an electron microscope.

In 1989, however, Stanford lost its record, when Donald Eigler and Erhard Schweizer, scientists at IBM’s Almaden Research Center in San Jose were the first to position or manipulate 35 individual atoms of xenon one at a time to form the letters I, B and M using a STM. The atoms were pushed on the surface of the nickel to create letters 5nm tall.

In 1991, Japanese researchers managed to chisel 1.5 nm-tall characters onto a molybdenum disulphide crystal, using the same STM method. Hitachi, at that time, set the record for the smallest microscopic calligraphy ever designed. The Stanford effort failed to surpass the feat, but it, however, introduced a novel technique. Having equaled Hitachi’s record, the Stanford team went a step further. They used a holographic variation on the IBM technique, for instead of fixing the letters onto a support, the new method created them holographically.

In the scientific breakthrough, the Stanford team has now claimed they have written the smallest letters ever – assembled from subatomic-sized bits as small as 0.3 nanometers, or roughly one third of a billionth of a meter. The new super-mini letters created are 40 times smaller than the original effort and more than four times smaller than the IBM initials, states the paper Quantum holographic encoding in a two-dimensional electron gas, published online in the journal Nature Nanotechnology. The new sub-atomic size letters are around a third of the size of the atomic ones created by Eigler and Schweizer at IBM.

A subatomic particle is an elementary or composite particle smaller than an atom. Particle physics and nuclear physics are concerned with the study of these particles, their interactions, and non-atomic matter. Subatomic particles include the atomic constituents electrons, protons, and neutrons. Protons and neutrons are composite particles, consisting of quarks.

“Everyone can look around and see the growing amount of information we deal with on a daily basis. All that knowledge is out there. For society to move forward, we need a better way to process it, and store it more densely,” Manoharan said. “Although these projections are stable — they’ll last as long as none of the carbon dioxide molecules move — this technique is unlikely to revolutionize storage, as it’s currently a bit too challenging to determine and create the appropriate pattern of molecules to create a desired hologram,” the authors cautioned. Nevertheless, they suggest that “the practical limits of both the technique and the data density it enables merit further research.”

In 2000, it was Hari Manoharan, Christopher Lutz and Donald Eigler who first experimentally observed quantum mirage at the IBM Almaden Research Center in San Jose, California. In physics, a quantum mirage is a peculiar result in quantum chaos. Their study in a paper published in Nature, states they demonstrated that the Kondo resonance signature of a magnetic adatom located at one focus of an elliptically shaped quantum corral could be projected to, and made large at the other focus of the corral.

Wednesday, March 5, 2008

The implosion of a relationship between Wikipedia founder Jimmy Wales and journalist Rachel Marsden has resulted in controversy and international headlines. Associated Press and ABC News have also reported on questionable activity by Wales involving Wikimedia Foundation expenses. The Wikimedia Foundation is a donor-supported non-profit organization which runs Wikipedia.

Marsden had contacted Wales two years ago about concerns she had over the article about her on Wikipedia, and Wales determined the article was not compliant with Wikipedia’s standards. The tech blog Valleywag revealed Wales had a personal relationship with Marsden, and posted supposed transcripts of their instant message conversations on its site, www.valleywag.com. Wales and Marsden met in February, and The Times reported that “An apparent transcript of their conversations before that meeting suggests that, although Mr Wales had withdrawn from the editing process, he was still influencing the editors.” The Times quoted Wales from the chat logs as having stated to Marsden “The truth is of course a much worse conflict of interest than that; but that will do.” — in reference to his conflict of interest regarding Marsden’s article on Wikipedia.

Wales posted a public statement on Saturday on Wikipedia addressing the matter, and stated that his relationship with Marsden was over: “First, while I find it hard to imagine that anyone really cares about my sex life, the facts are: I am separated from my wife. I considered myself single at the time of my one meeting with Rachel Marsden on Feb. 9, 2008 … I am no longer involved with Rachel Marsden. Gossipy stories suggesting that I have been in a relationship with her ‘since last fall’ are completely false … I care deeply about the integrity of Wikipedia, and take very seriously my responsibilities as a member of the board and as a member of the Wikipedia community. I would never knowingly do anything to compromise that trust.” With regard to the conflict of interest in Marsden’s article, Wales had acknowledged to a team of Wikipedia editors in February 2008 that he and Marsden “became friends … and that we would be meeting about that,” and stated “I recused myself from any further official action with respect to her biography.”

On Sunday, The Canadian Press reported that Marsden had posted photos of herself on Ebay, and was selling items that Wales had left at her New York City apartment. In her Ebay posting, Marsden stated: “Hi, my name is Rachel and my (now ex-) boyfriend, Wikipedia founder Jimmy Wales, just broke up with me via an announcement on Wikipedia … It was such a classy move that I was inspired to do something equally classy myself, so I’m selling a couple of items of clothing he left behind, here in my NYC apartment, on eBay. Jimbo was supposed to come visit me in a couple of weeks and pick up some of his stuff, but obviously that won’t be happening now.” Marsden told The Canadian Press “It didn’t really help matters that Jimmy chose to announce the breakup to the entire world via Wikipedia (which apparently now is an online encyclopedia that doubles as a personal soapbox?) rather than to me directly (which he did much later, in an instant message discussion).”

Marsden placed a t-shirt and sweater which she said were left at her apartment by Wales up on Ebay, and started the bidding for each at ninety-nine cents, with the auctions set to end on March 12. By Monday, bidding on the t-shirt had reached US$300, and by Tuesday the highest bid had reached $12,200. In an email to The Globe and Mail, Marsden stated “My only focus right now, to be really honest, is on my career and finding a way to get back into print, TV, or radio here in NYC,” she wrote. “All of this other personal stuff is just an unfortunate distraction.”

Jay Walsh, the Wikimedia Foundation’s head of communications, told the San Jose Mercury News that Wales’ actions in relaying Marsden’s concerns about her Wikipedia article to a team of trusted editors was within his “routine” role. When asked by the San Jose Mercury News if Wales’ actions regarding the Marsden article could compromise his role with the Wikimedia Foundation and Wikipedia, Walsh responded “No, absolutely not.”

On Tuesday, ABC News carried a story by Wired News reporter Megan McCarthy regarding allegations of “excessive spending” by Wales, and Associated Press also reported on questions involving Wikimedia Foundation expenses. McCarthy reported that former Wikimedia executive Danny Wool, who had left the foundation last year, criticized Wales’ use of Wikimedia Foundation expenses in a blog post. Wool stated that Wales had tried to expense $300 bottles of wine, a $1,300 dinner for four at a Florida steakhouse, and visits to Moscow massage parlors to the foundation, and that the foundation rescinded Wales’ corporate credit card in 2006. Wool also stated that Wales paid the foundation $7,000, after being short $30,000 on receipts for expenses.

Wool told EPICENTER that “There were occasions where he used [the Wikimedia Foundation] for personal advancement under the guide [sic] of the mission. And, as someone who was in there for the mission part of it, I found that rather distressful.” Wool commented in an interview with the San Francisco Chronicle: “Originally, it was carelessness … But as things developed, it became more apparent and obvious that he was taking advantage of the foundation credit card. It was almost like his personal piggy bank.”

In an instant message exchange with Associated Press, Wales denied that the Wikimedia Foundation had taken away his corporate credit card, and asserted that he had made the decision to stop expensing business travel for the foundation. Wales highlighted a statement by the foundation’s executive director Sue Gardner: “Jimmy has never used Wikimedia money to subsidize his personal expenditures. Indeed, he has consistently put the foundation’s interests ahead of his own.” In an email to Associated Press, Brad Patrick, a former attorney for the Wikimedia Foundation, stated “Danny seems interested in blogging his way straight to a lawsuit”.

Florence Devouard, who chairs the Wikimedia Foundation, told Associated Press that Wales had been “slow in submitting receipts,” and that the foundation had rejected Wales’ expense at the Florida steakhouse. Devouard told fellow foundation board members in a private email that she had convinced Associated Press that “the money story was a no story,” and told Wales “I find (it) tiring to see how you are constantly trying to rewrite the past. Get a grip!” Wales told Associated Press: “The board, the current executive director, the previous executive director, and independent auditors have reviewed our books and publicly agree that all of my expenses were appropriate and fully accounted for.”

Media reports speculated on how the controversy would end up being represented in Wikipedia itself. On Wednesday, the St. Petersburg Times wrote: “Wales’ Wikipedia page said only this about Marsden: ‘Wales had a brief relationship with Canadian journalist Rachel Marsden.'” An article in The Australian surmised: “History will decide whether Mr Wales broke his own principles, but before that happens there may well be a Wikipedia page devoted to the controversy.”