Ohm’s Law Survives at the Atomic Scale

Ohm’s Law is extended to the atomic level, and Moore’s Law may get a reprieve

By Saswato R. Das  /  January 2012

Image: Bent Weber

Atomic Bridge: The template for a 1.5-nanometer-wide nanowire was made by pushing atoms around using a scanning tunneling microscope. The resulting nanowire showed that Ohm's Law works even for wires just 4 atoms thick. Click on image to enlarge.

5 January 2012—Moore’s Law, the cornerstone rule of the semiconductor industry, may get a reprieve from its predicted demise, according to a group of scientists in Australia and the United States. Their unexpected findings show that a well-understood law of classical physics—and a pillar of electrical engineering—holds for some objects that are just four atoms wide, a size where quantum effects should rule instead.

Michelle Simmons and her colleagues at the University of New South Wales, in Australia, together with collaborators at the University of Melbourne and Purdue University, in Indiana, have built low-resistance silicon wires that show that Ohm’s Law works at the atomic level. Ohm’s Law, an empirical rule discovered by the German physicist Georg Ohm in 1827, says that the current through a conductor is directly proportional to the potential difference across the conductor. Introducing the concept of resistance, the law is a mainstay of circuit theory and is taught to high school and college students in physics and engineering classes.

In an accompanying commentary in Science, where the research is being reported Friday, Arizona State University’s David Ferry called the finding "surprising." Scientists expected that classical behavior like Ohm’s Law would break down at the atomic level. "The pointlike electron motion of the classical world would be replaced by the spread-out quantum waves. These quantum waves would lead to very different behavior," the IEEE Fellow adds.

Simmons and her collaborators built fine nanowires out of silicon that were just one atom tall, four atoms wide (about 1.5 nanometers), and 106 nm long. They used scanning tunnel microscopy to pattern the wires on a silicon surface and then silicon crystal growth to bury the wires and protect them from surfaces and interfaces that could suck up any free electrons and interfere with Ohm’s Law–like behavior, Simmons says.

Previous experiments had shown that at widths less than 10 nm, the resistivity of silicon nanowires increased exponentially (Ohm’s Law, by contrast, is linear). The researchers were able to get around this exponential increase and follow Ohm’s Law, in effect, by heavily doping the silicon nanowires with phosphorus.

"The phosphorus atoms have one more electron than silicon, and these extra electrons allow the nanowire to conduct," Simmons explains. "Within the wires we place the phosphorous atoms less than 1 nm apart so that the wave functions of the electron overlap to form a metallic-like state, and that gives us this low resistivity."

Electrical engineer John Kymissis of Columbia University was impressed with the experiments. "It avoids all of the interfaces, surface scattering, and grain boundaries" that hampered other approaches, he says. Researchers say that the finding should make it easier for Moore’s Law to maintain its momentum. Today’s high-end chips already mustfend off some esoteric quantum effects, and more are expected as engineers continue to shrink IC components. A major challenge to scaling down silicon chips is "the power dissipation from parasitic resistances that cannot be eliminated from current designs and materials," says Dick Slusher, head of the Georgia Tech Quantum Institute. An atomic wire that follows Ohm’s Law could help.

Simmons says that the work grew out of efforts to develop a scalable quantum computer in silicon. Her group and others have been working on quantum computers, whose quantum bits, or qubits, are the spin states of electrons in individual phosphorus atoms. "In Sydney, we have recently demonstrated that single-phosphorus-atom electron-spin qubits have very long lifetimes—several seconds," she says. "We are on the edge of being able to make truly single-atom devices with precision control electrodes to manipulate and couple the spin state of these qubits."

Physicist Steven Simon of Oxford University calls the nanowire "an impressive piece of technology" but says making multiple wires with identical resistivity could get tricky. "Unless one can control exactly where the [phosphorus] impurities are, there may always be outlier samples that don’t conduct at all."

Of course, the experiments by Simmons and colleagues were not done using standard silicon processing techniques, but eventually they might be made to conform to them.

"Fundamentally, we have shown that we can maintain low resistivities in doped silicon wires down to the atomic scale," Simmons says. It may not be ready for production now, but, she says, "who knows 20 years from now?"

About the Author

Saswato R. Das, a New York City–based writer, contributes frequently to IEEE Spectrum. In September 2011 he reported on advances that could bring us closer to practical quantum computing.

Bedside Cancer Detector

2 March 2011—A handheld device that detects proteins produced by tumor cellscould give doctors a fast, accurate way to diagnose and monitor cancer. Tumor-marker testing usually requires pea-size tissue samples and can take days in a laboratory to yield results. The new detector, by contrast, requires a tiny speck of tissue, takes less than an hour to process samples, and could be used in a doctor’s office instead of a hospital.

The device, which was developed by researchers at Harvard Medical School, attaches to a smartphone, providing a user-friendly interface for doctors to view results. In tests on patient tissue samples, the researchers accurately detected cancer 96 percent of the time. They reported the results last week in the journal Science Translational Medicine.

Doctors typically use tumor-marker testing together with a biopsy to diagnose cancer. Marker levels can help them choose the appropriate therapy and later check to see if it is working. To get the tissue samples, they typically use 2-millimeter hollow-core needles, which carry a risk of bleeding and infection. Pathologists then examine the sample under a microscope.

The new tool can detect standard tumor markers and their concentrations in samples taken with a fine needle—a 0.5-mm core. It gives results in as little as a half hour. ”We think the device could support big medical decisions like whether to do surgery on a patient to look at the malignancy or refer them to more intensive CT or MRI scans,” says Hakho Lee, a biomedical engineering professor at Harvard who developed the technology. ”If a patient is already getting chemotherapy, the doctor could quickly tell whether a treatment is working.”

The detector is a miniature nuclear magnetic resonance (NMR) machine. NMR is used to determine the chemical structure of organic molecules. It involves aligning atoms in a strong magnetic field and making them vibrate under the influence of a radio-frequency signal. Conventional machines use huge magnets in order to make the atoms vibrate strongly enough to measure their natural oscillation frequency.

The new detector’s magnet can be smaller because the sample volume is also smaller and because the system measures only how quickly the atoms’ vibrations decay over time rather than measuring the frequency, as a conventional NMR does. The test sample goes on a thumb-size probe, which also contains the chips that process the data and communicate with the smartphone.

The researchers used the device to analyze abnormal stomach tissue samples from 50 patients who were suspected to have malignant tumors. They detected NMR signals for nine different cancer protein markers and identified a group of four markers as the best tumor indicators. Then, looking only for NMR signatures of these four markers, they correctly identified cancer in 96 percent of the cases. They managed to improve accuracy to 100 percent in a later set of 20 patients. Standard pathology testing on a larger biopsy specimen from the same tumors was only 84 percent accurate.

”It’s an exciting technology and could be used for cancer prescreening at a patient’s bedside,” says Shan Wang, an electrical engineering professor at Stanford University who is developing magnetic nanoparticle-based sensors for tumor-marker detection that rely on detecting a small electrical resistance change. He points out, however, that while the device is very sensitive, it also gave false positives, identifying some healthy people as having cancer.

Andrew Seidman, a clinical oncologist at Memorial Sloan-Kettering Cancer Center, says that the detector’s appeal lies in being less invasive than core-needle biopsies. He believes it would be most helpful for guiding cancer therapy. ”Tumors evolve during treatment,” Seidman says. ”I can see this as a safer way to do serial biopsy—to reassess the biology of a patient’s tumor and adjust treatment as the cancer progresses.”

In the future, the technology could replace core-needle biopsies for cancer diagnosis, Seidman says, but right now, ”it’s not ready for prime time. It’s a promising technology but needs to be further refined and validated in larger cohorts.”

About the Author

Prachi Patel is a contributing editor to IEEE Spectrum and a freelance journalist in Pittsburgh. In the February 2011 issue, she wrote about the benefits and choices that engineers have in business school.

Designing For Start-Ups: How To Deliver The Message Across

Why is this one here ?

My room-mate happens to be a design major, and he is gonna join a start up or maybe have one himself someday. So I got intrigued by it and started reading about how design and startups come together and this is what I found. It is a lovely article, truly inspiring but less technoramical :) 

In my opinion design permeates almost every decision, in some other words you are designing your life or your future with every decision and it influences everyone around you. Not only that such a design is user centric, you are its very user. This is just another way of looking at it. Enjoy !! 

<-------- Article starts here ------>

Start-up organizations provide an extraordinary example of chaos organized into manageable chunks. Perhaps more than anyone else, the individuals who comprise a start-up team are required to understand their team’s goals across a variety of disciplines — research, marketing, design, development, architecture, etc. — as well as their own responsibility to move the company’s overarching objective forward. Entrepreneurs must choose the direction, designers must think through the options, and developers must cull a functional product or service, all while giving feedback to and receiving it from their colleagues.

At least, that’s the idea. Most start-ups tend to take liberties somewhere along the way. Some start-ups begin with a novel business model, whereas others begin with a beautiful design. Still others try to test things out first with a functional prototype, even if it is a bit ugly. All of them — regardless of their initial approach — adapt their process over time in order to create a well-rounded product or service. And for this reason, most of today’s start-ups describe themselves as “agile.”

Agile start-ups, as the name implies, should be capable of changing their design, development and/or business objectives on a dime. This is much easier said than done — especially for today’s user experience designers. The user experience (UX) designers who work at agile start-ups are required to do two things exceptionally well: (1) grasp the intent of the product or service being developed, and (2) effectively communicate those good intentions to end users in a language they’ll understand. Neither of these is as straightforward as it might sound.

Ideally, designers will jumpstart their design process by carefully selecting well-reasoned entrepreneurs to work with; but what happens when the designer is altogether alien to the community he is designing for? The breakneck speed of agile start-ups makes it incredibly difficult for designers to craft appropriate messages to their audience at large. Only by understanding the processes and opinions that dominate start-ups can designers begin to reach out and make a difference for the end users of their product or service.

User-Centered Design, Sans User

Designing with a clear idea of who the users are has never been simple. Most designers who have experience with the trial by fire known as a “lean start-up” will almost vehemently agree: because there are more than a few fires to fight, adopting a big-d Design process at start-up organizations is, simply put, exceedingly difficult. Invariably, this means that most start-up organizations devolve to the point that salability reigns supreme, or form trumps function. But whereas flexible, agile environments are very good for getting those things done, good design takes time, which makes the design process of start-ups almost universally hamstrung.

Keep the levels of UX in mind. (Image: Jon and Barb)

In short, agile, user-centered design tends to ignore the aesthetic, intangible, ambient qualities that good experiences are all about. As a consequence, budding artistic directors, brand ninjas and interaction designers have been apt to worry. Without the ability to intimately understand the audience for whom they’re designing, these team members can’t do their jobs. The logical question becomes, how canthey? How can designers effectively communicate with an audience they’ve yet to meet?

The textbook definition(s) of UX design yields some clue. User-centered designers are encouraged to performdesign research and then create personas as well as other deliverables. Certainly those would spotlight the factors that affect a company’s relationship with its users… right? Perhaps. While research is undoubtedly necessary to the design process, its deliverables are not.

I’ve written before that designers should bootstrap their own culture of UX within an organization. In this article, I’ll take that idea one step further: in order for a start-up to effectively communicate with its target audience, a spirit of empathy must pervade its every design decision — empathy cultivated by engaging in an ongoing, outward, user-centered conversation.

Where Has All The Empathy Gone?

The task of any designer who works in a start-up environment requires empathy. The designer, perhaps more than any other team member, must empathize with stakeholders (to understand the project’s business objectives), developers (to understand its technical requirements) and, of course, users (to understand the nature of the problem they’re solving), all at once. Designing with consideration for all three parties effectively frames their strife.

Valuable though it may be, however, most start-up environments discourage empathy. Consider the number of times you’ve heard something like, “We’re targeting wealthy single males, ages 45 to 55,” or “We’re just like Amazon, but for baby boomers.” Well, that’s just great. A product description like that might initially help a team grok (a word that, ironically, means “understand by empathy”) an idea, but as far as rhetoric goes, merely saying that you know what segment you’re targeting isn’t enough.

Every e-commerce company sells products. Newcomers to the space can, and often do, learn a lot by studying the desire paths paved by industry notables (indeed, entire books are written on the subject). But let’s be clear: “I want to be Amazon” doesn’t imbue the designer with empathy. Creating something that looks and feels like Amazon will, of course, look and feel like Amazon. If that website is then marketed to a wholly different crowd, then the resulting outfit will be disingenuous — the polar opposite of empathetic.

In order to create something real, unique, of lasting value and with a look and feel of its own, members of start-up teams must vacate their cubicles.

One… Erm, Three Processes

Adding to this perceived resistance are the various processes that drive start-up organizations at any given time. A recent blog post by Whitney Hess contrasts three specific types. It’s worth noting that all of the approaches detailed below show the exact same verbs in the exact same sequence. What’s different in each is the primary action that drives change along the way.

To cite Hess:

I see a lot of products developed using the Reactive Procedure:

1. I’m scratching my itch.
2. Should I keep scratching this itch?
3. I’ll scratch this other itch.

As a designer who frequently consults with agile start-ups, I concur with Whitney’s sentiments: the reactive approach (“build it and they will come”) is far and away the most common. There is, of course, a good reason for all that action: development drives change. Start-ups act in order to build an initial prototype. Prototypes, in turn, move the company — indeed, the user feedback loop — forward.

Unfortunately, the prototypes developed by most start-ups exhibit a keen lack of consideration. Who is the prototype targeted at? 40 to 50 somethings? There are certainly a lot of them. Will those 40 to 50 somethings be able to grok it? That is, will users be able to tell what it’s “all about” from the design? Because this kind of subjectivity is incredibly nebulous, prudent start-ups rely on experienced UX designers to help them uncover the answers. It’s no wonder that Whitney and I see this in our line of work.

As a user experience designer, consultant and member of the New York tech community, I instead advocate for using the Preactive Procedure:

1. Who’s itchy?
2. That itch isn’t being scratched.
3. This is how to scratch that itch.

I believe that most UX designers would agree — dare I say, empathize — with Whitney’s prescribed preactive approach. Beginning with thinking — with research — is in a user-centered designer’s blood; it helps them understand their audience and voice their messages appropriately. Further still, “preactivity” appears to be the only real way for designers to gain empathy. But most start-up environments run counter to this approach. Acting and then thinking usually leaves little room for the voice of research. Has Whitney encountered a start-up that tries to reconcile the two?

As luck would have it, she has. Whitney recently worked with an entrepreneur who marches to a different beat:

Campbell McKellar, founder of Loosecubes, is the first person to make me realize that there’s something even better than the Preactive Procedure — the Proactive Procedure.

By acting sooner, you are actually achieving more. You are creating the future instead of just predicting and accommodating for it. You are inventing a new reality, based half in what people need, and half in what you want them to have. You can observe behavior sooner and course-correct. It is the most transformative of all three procedures for both the subject and the object.

An entrepreneur at heart, I want to agree here, too. The proactive process appears to be a viable alternative to the unenviable tension between designers and developers at start-ups. But just because a group is humming along with a decision-based proactive process doesn’t mean that the organization’s designerunderstands its users any better. By UX standards, this process almost seems to disenfranchise them: it moves “thinking” — and here, I presume, research — all the way to the back of the bus.

In sum, it’s easy to envision scenarios at a start-up in which a given development process proves more valuable, more productive, than its alternative. Should the team think, act or decide? It depends. Regardless, as designers join start-ups, they’re very likely to find that design is secondary to the process unless, of course, their organization follows a preactive process. But for most start-ups, that’s simply not the case.

In order for an organization to learn more about its users, the design-minded members must advocate to that effect, changing the way that design is approached. Designers must stand up for their part of the process. As UX designer Joshua Porter attests, “The further a designer is from the people they’re designing for, the harder it is to design for them.”

Start-ups — or more specifically, the designers at start-ups — need to get as close to users as they can. Product development can’t rest in the entrepreneurs’ and/or the developers’ hands alone.

Why Design Fails

When asked, most designers don’t take long to provide honest, valid reasons why the design process is important to developers and entrepreneurs alike. There is firm precedent to that end, and they are designers by choice, after all. But just because the truth and beauty of good design is evident to most designers doesn’t exactly mean that their colleagues share their sentiments.

If it isn’t making Dollars… (Image: Kristian Bjornard)

Start-ups — and more importantly, the individuals who comprise them — have a great number of mental hurdles standing in the way of their empathy with end users. The aforementioned quickened pace and changing processes aside, here are those hurdles:

• Start-up teams have strong convictions.
  Anyone who believes strongly in a cause (be it an idea or a Web application… or both) will identify with it. If a designer questions the validity of an idea, then they are questioning the team. This is a difficult, integral part of the design process.
• Research doesn’t (immediately) sell.
  It doesn’t take weeks of research to sell a product to someone, and given enough time a good marketer can sell anyone almost anything — especially something beautiful. As a consequence, team members are likely to judge the design book by its cover. Research rarely affects their notion of beauty.
• Start-ups trust results they can measure (preferably in dollars).
  Web metrics are currently the bread and butter of today’s Web-savvy marketers. Saying that a design is good is one thing. Saying that a design has increased conversions by 200% is another. Attaching a number to something makes entrepreneurs (and, yes, designers, too) feel better about the problem being addressed. If the current process is measurable, should an up-front design process be allowed to slow that down?

In sum, short-term, yes-or-no, go-or-no-go (Decide! Act!) thinking pervades the start-up space. The reality is that most agile start-ups favor a “design-less” process. While UX designers might trust that empathy (or understanding) is tantamount to a start-up’s success, their teammates won’t necessarily believe so. In order to effect change, designers must fight for the integrity of their design from the inside out.

Leading The Way With Empathy

To be clear, good design doesn’t come about at start-ups just by studying the metrics generated from a prototype or by talking to users through a proxy — say, support emails. That isn’t to say that these things aren’t valuable — they certainly can (and often do) point to the consequences of prior decisions. But feedback, by definition, cannot determine the company’s next — or, more importantly, first — steps. There’s the rub. Unfortunately, that is the problem routinely faced by start-up designers.

Create Empathy and Inclusion. (Image: Kristian Bjornard)

No one would argue that determining what’s “good” for a Web design is subjective, which makes it a frightening prospect. As D. Keith Robinson wrote on A List Apart all the way back in 2005:

Knowing what people want on the Web can be hard. You either need to have incredible empathy or have done fairly extensive research. This empathy I’m talking about, in my opinion, can really only be built up over time observing all kinds of people doing all kinds of things on all kinds of websites and applications. Even then, as you move from project to project, the people, problems and needs change.

With every new project comes a new target user, a new person to empathize with. And just as with meeting a new person, understanding what they like and don’t like takes time. If designers are to appeal to this new person, they first have to get to know them. As both Whitney Hess and Cennydd Bowles have asserted, focusing on a rapid proactive process — decide, act, think — gives most start-ups a solid plan of attack. Not only do teams get to test market viability first, they can then think about how they’ll differentiate the product shortly thereafter.

Yes, this process makes brand-conscious designers uneasy, and understandably so. In the beginning, though, without the context that a prototype creates, designers must lean towards the relatively “safe” side, where all interaction design begins: buttons look like buttons, drop-downs look like drop-downs and perhaps even the names of start-ups sound like start-ups. Robert Hoekman, Jr. calls this Designing the Obvious. I call it designing the boring bits.

Because what this approach makes up for in usability, it certainly lacks in propriety. To determine what’s appropriate (which is subjective), designers must conduct field research.

Hold Your Own Convictions

Plenty of UX designers preach preactivity; they are the ones who want to understand — to empathize with — their audience and build something tailored to them. Moreover, these designers have the relative luxury of working within organizations. For them, Cennydd Bowles and James Box have written a lovely book,Undercover User Experience Design. If you’re at a company where design is ailing and you want to fix it, I suggest picking up a copy right away.

If you’re an independent consultant or a designer working with a start-up that’s out to craft the best possible experience, then I would suggest a couple of things, all centered on the same concept, which is to make listening a part of the company’s design process:

1. Create a design strategy.
   Articulate who you’ll be designing for (even if they’re only make-believe) and how they’ll use the website. I’ve written before how I do this. Regardless of how you do it, know who you’re trying to know.
2. Have a solution.
   Work with a development team to generate a quick prototype that demonstrates your best (albeit uninformed) solution. Have at least two people use the prototype the way it is intended to be used. Befriend them, and see if they’ll contribute feedback as you refine your vision.
3. See for yourself.
   Finally, and most importantly, see for yourself. Visit your users in their natural environment, and make sure their concerns are addressed. If you’re in a position to do this, ask them questions related to the problem your start-up addresses.

In all cases, start-up designers should center their design process on listening to users. Instead of speakingto users by way of the design, converse with users to inform the design. Empathy, the human connection, makes or breaks an informed experience.

Because most of us work behind computers for hours, days or weeks at a time, gaining empathy is obviously easier said than done. However, empathy is the only way to turn a good business idea into a well-articulated design conversation. Respect is earned, a brand is born, when every interaction that an organization has with its users is open, earnest, honest and, most of all, appropriate.

BBC News: Microscope with 50-nanometre resolution demonstrated

UK researchers have demonstrated the highest-resolution optical microscope ever - aided by tiny glass beads.

The microscope imaged objects down to just 50 billionths of a metre to yield a never-before-seen, direct glimpse into the "nanoscopic" world.

The team says the method could even be used to view individual viruses.

Their technique, reported in Nature Communications, makes use of "evanescent waves", emitted very near an object and usually lost altogether.

Instead, the beads gather the light and re-focus it, channelling it into a standard microscope.

This allowed researchers to see with their own eyes a level of detail that is normally restricted to indirect methods such as atomic force microscopy or scanning electron microscopy.

Some of these indirect methods have imaged to a resolution of one billionth of a metre (nanometre), and even given a glimpse of a single molecule - but none is the same as simply looking down a microscope directly at details this tiny.

Using the full spectrum of visible light - the kind that we can see - to look at objects of this size is, in a sense, breaking light's rules.

Normally, the smallest object that can be seen is set by a physical property known as the diffraction limit; for visible light, that limits resolution to about 200 nanometres.

Light waves naturally and inevitably "spread out" in such a way as to limit the degree to which they can be focused - or, equivalently, the size of the object that can be imaged.

At the surfaces of objects, these evanescent waves are also produced.

As the name implies, evanescent waves fade quickly with distance. But crucially, they are not subject to the diffraction limit - so if they can be captured, they hold promise for far higher resolution than standard imaging methods can provide.

How this works read here.

Watch the video at the bottom to know what a nanometer is !!

©BBC News
Thanks Karthik for the contribution.

Scientists create tornadoes to test homes in Japan

I have always heard of cool buildings in games like RA3 (named as weather storm generator) but this is reality and Japan strikes back again.

From Times of India:

In fact , a team from four Japanese organisations — National Institute for Land and Infrastructure Management , the Building Research Institute , the University of Tokyo and the Disaster Prevention Research Institute at Kyoto University — has been developing a tornado simulator .

"We're doing this because there's been many more reports of serious structural damages in recent years compared to before ," the New Scientist quoted Hitomitsu Kikitsu at NILIM in Tsukuba , Ibaraki , as saying .

The simulator is 1.5 metres in diameter and is mounted on a frame that is 2.3 metres tall and 5 metres wide. It can generate maximum wind velocity of 15 to 20 metres per second , enough to simulate an F3-size storm .

On Japan's Fujita scale for measuring tornadoes , an F3 storm is one powerful enough to uproot large trees , lift and hurl cars , knock down walls and destroy steel-frame structures .

Read More
Journal

Now that is what I call a life changing invention.

Amazing Science Quotes

Most of us know Louis Pasteur as a great microbiologist, more popularly by his invention of pasteurization used so commonly today.

Wikipedia quotes:

Louis Pasteur (27 December 1822 – 28 September 1895) French microbiologist, chemist, pioneer of the "Germ theory of disease", and inventor of the process of Pasteurization.

Amongst the more interesting things you can read about him on Wiki are the science quotes that have been related to him. The complete article can be found here.

A few quotes that I really liked were :

"Chance favors the prepared mind."

"The universe is asymmetric. "

"Happy is he who bears a God within." 

"I am on the edge of mysteries and the veil is getting thinner and thinner." 

Enjoy !!!

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Computer Math Proof Shows Reasoning Power

A computer program written by researchers at Argonne National Laboratory in Illinois has come up with a major mathematical proof that would have been called creative if a human had thought of it. In doing so, the computer has, for the first time, got a toehold into pure mathematics, a field described by its practitioners as more of an art form than a science. And the implications, some say, are profound, showing just how powerful computers can be at reasoning itself, at mimicking the flashes of logical insight or even genius that have characterized the best human minds.

Computers have found proofs of mathematical conjectures before, of course, but those conjectures were easy to prove. The difference this time is that the computer has solved a conjecture that stumped some of the best mathematicians for 60 years. And it did so with a program that was designed to reason, not to solve a specific problem. In that sense, the program is very different from chess-playing computer programs, for example, which are intended to solve just one problem: the moves of a chess game.
"It's a sign of power, of reasoning power," said Dr. Larry Wos, the supervisor of the computer reasoning project at Argonne. And with this result, obtained by a colleague, Dr. William McCune, he said, "We've taken a quantum leap forward."

Complete article here.

Contributed by: Paritosh Karnatak, IIT, Kanpur

©NY Times