உங்களுக்கு மூளை இருக்கிறதா?

இதுபோன்ற ஒரு கேள்வி உங்களின் முன் கொஞ்ச காலத்தில் நிச்சயமாய் வைக்கப்படலாம். அதற்கான தேவை இப்பொழுது இருப்பதை விடவும் பிற்காலத்தில் நிச்சயமாய் வரும் என்பதாலேயே தான். ஏன் என்றால் இப்பொழுது கூகுள் மூளையால் செலுத்தப்படும் அலைகளால் கம்ப்யூட்டரை இயக்குவதற்கான ஆராய்ச்சிகளில் இறங்கியுள்ளது.

SAN FRANCISCO (Business 2.0 Magazine) – Two years ago, a quadriplegic man started playing video games using his brain as a controller. That may just sound like fun and games for the unfortunate, but really, it spells the beginning of a radical change in how we interact with computers – and business will never be the same.

Someday, keyboards and computer mice will be remembered only as medieval-style torture devices for the wrists. All work – emails, spreadsheets, and Google searches – will be performed by mind control.

If you think that’s mind-blowing, try to wrap your head around the sensational research that’s been done on the brain of one Matthew Nagle by scientists at Brown University and three other institutions, in collaboration with Foxborough, Mass.-based company Cyberkinetics Neurotechnology Systems. The research was published for the first time last week in the British science journal Nature.

Nagle, a 26-year-old quadriplegic, was hooked up to a computer via an implant smaller than an aspirin that sits on top of his brain and reads electrical patterns. Using that technology, he learned how to move a cursor around a screen, play simple games, control a robotic arm, and even – couch potatoes, prepare to gasp in awe – turn his brain into a TV remote control. All while chatting amiably with the researchers. He even learned how to perform these tasks in less time than the average PC owner spends installing Microsoft (Charts) Windows.
Decoding the brain

Nagle was able to accomplish all this because the brain has been greatly demystified in laboratories over the last decade or so. Researchers unlocked the brain patterns for thoughts that represent letters of the alphabet as early as 1999.

Now, Cyberkinetics and a host of other companies are working on turning those discoveries into real products. Neurodevices – medical devices that compensate for damage to the brain, nerves, and spinal column – are a $3.4 billion business that grew 21 percent last year, according to NeuroInsights, a research and advisory company. There are currently some 300 companies working in the field.

But Cyberkinetics is trying to do more than just repair neural damage: It’s working on an implantable chip that Nagle and patients in two other cities are using to control electronic devices with their minds. (Check out this demonstration video).

Already, the Brown researchers say, this kind of technology can enable a hooked-up human to write at 15 words a minute – half as fast as the average person writes by hand. Remember, though, that silicon-based technology typically doubles in capacity every two years.

So if improved hardware is all it takes to speed up the device, Cyberkinetics’ chip could be able to process thoughts as fast as speech – 110 to 170 words per minute – by 2012. Imagine issuing commands to a computer as quickly as you could talk.

But who would want to get a brain implant if they haven’t been struck by a drastic case of paralysis? Leaving aside the fact that there is a lucrative market for providing such profoundly life-enhancing products for millions of paralyzed patients, it may soon not even be necessary to stick a chip inside your skull to take advantage of this technology.
What a tale your thoughts could tell

Brain-reading technology is improving rapidly. Last year, Sony (Charts) took out a patent on a game system that beams data directly into the mind without implants. It uses a pulsed ultrasonic signal that induces sensory experiences such as smells, sounds and images.

And Niels Birbaumer, a neuroscientist at the University of Tuebingen in Germany, has developed a device that enables disabled people to communicate by reading their brain waves through the skin, also without implants.

Stu Wolf, one of the top scientists at Darpa, the Pentagon’s scientific research agency which gave birth to the Internet, seriously believes we’ll all be wearing computers in headbands within 20 years.

By that time, we’ll have super fast, super tiny computers that make today’s machines look like typewriters. The desktop will be dead, says Wolf, and the headband will dominate.

“We already know we can trigger neurons mechanically,” he says. “You can interact directly with the brain without implanted electrodes. Then the next step is being able to think something and have it happen: Flying a plane, driving a car, operating household machinery.”

Controlling devices with the mind is just the beginning. Next, Wolf believes, is what he calls “network-enabled telepathy” – instant thought transfer. In other words, your thoughts will flow from your brain over the network right into someone else’s brain. If you think instant messaging is addictive, just wait for instant thinking.

The only issue, Wolf says, is making sure it’s consensual; that’s a problem likely to tax the minds of security experts.

But just think of the advantages. In the office of the future, the conference call, too, will be remembered as a medieval form of torture.

Found 20 light years away: the New Earth

இருபது ஒளி ஆண்டுகள் தொலைவில் நம்முடைய பூமியைப் போலவே தட்பவெட்ப சூழ்நிலை, தண்ணீர், புவியீர்ப்பு விசை உட்பட அனைத்திலும் நம்மை ஒத்த கிரகம் ஒன்றைக் கண்டுபிடித்திருக்கிறார்கள். நம்முடைய சூரியனைப் போலவே இந்த புதிய பூமியும் Gliese 581 என்ற நட்சத்திரத்தைச் சுற்றி வருவதாகச் சொல்கிறார்கள்.

மேல் விவரங்களுக்கு
இங்கே கிளிக்கவும்

Quantum Secrets Of Photosynthesis Revealed

இன்னும் ஒரு பதிவு குவாண்டம் பற்றி. எனக்கு இதைப் பற்றிய ஆர்வம் ஒவ்வொரு முறையும் அதிகரித்துக் கொண்டே வருகிறது.

Science Daily — Through photosynthesis, green plants and cyanobacteria are able to transfer sunlight energy to molecular reaction centers for conversion into chemical energy with nearly 100-percent efficiency. Speed is the key – the transfer of the solar energy takes place almost instantaneously so little energy is wasted as heat. How photosynthesis achieves this near instantaneous energy transfer is a long-standing mystery that may have finally been solved.


Sunlight absorbed by bacteriochlorophyll (green) within the FMO protein (gray) generates a wavelike motion of excitation energy whose quantum mechanical properties can be mapped through the use of two-dimensional electronic spectroscopy. (Credit: Greg Engel, Lawrence Berkeley National Laboratory, Physical Biociences Division)

A study led by researchers with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) at Berkeley reports that the answer lies in quantum mechanical effects. Results of the study are presented in the April 12, 2007 issue of the journal Nature.

“We have obtained the first direct evidence that remarkably long-lived wavelike electronic quantum coherence plays an important part in energy transfer processes during photosynthesis,” said Graham Fleming, the principal investigator for the study. “This wavelike characteristic can explain the extreme efficiency of the energy transfer because it enables the system to simultaneously sample all the potential energy pathways and choose the most efficient one.”

Fleming is the Deputy Director of Berkeley Lab, a professor of chemistry at UC Berkeley, and an internationally acclaimed leader in spectroscopic studies of the photosynthetic process. In a paper entitled, Evidence for wavelike energy transfer through quantum coherence in photosynthetic systems, he and his collaborators report the detection of “quantum beating” signals, coherent electronic oscillations in both donor and acceptor molecules, generated by light-induced energy excitations, like the ripples formed when stones are tossed into a pond.

Electronic spectroscopy measurements made on a femtosecond (millionths of a billionth of a second) time-scale showed these oscillations meeting and interfering constructively, forming wavelike motions of energy (superposition states) that can explore all potential energy pathways simultaneously and reversibly, meaning they can retreat from wrong pathways with no penalty. This finding contradicts the classical description of the photosynthetic energy transfer process as one in which excitation energy hops from light-capturing pigment molecules to reaction center molecules step-by-step down the molecular energy ladder.

“The classical hopping description of the energy transfer process is both inadequate and inaccurate,” said Fleming. “It gives the wrong picture of how the process actually works, and misses a crucial aspect of the reason for the wonderful efficiency.”

Co-authoring the Nature paper with Fleming were Gregory Engel, who was first author, Tessa Calhoun, Elizabeth Read, Tae-Kyu Ahn, Tomáš Man al and Yuan-Chung Cheng, all of whom held joint appointments with Berkeley Lab’s Physical Biosciences Division and the UC Berkeley Chemistry Department at the time of the study, plus Robert Blankenship, from the Washington University in St. Louis.

The photosynthetic technique for transferring energy from one molecular system to another should make any short-list of Mother Nature’s spectacular accomplishments. If we can learn enough to emulate this process, we might be able to create artificial versions of photosynthesis that would help us effectively tap into the sun as a clean, efficient, sustainable and carbon-neutral source of energy.

Towards this end, Fleming and his research group have developed a technique called two-dimensional electronic spectroscopy that enables them to follow the flow of light-induced excitation energy through molecular complexes with femtosecond temporal resolution. The technique involves sequentially flashing a sample with femtosecond pulses of light from three laser beams. A fourth beam is used as a local oscillator to amplify and detect the resulting spectroscopic signals as the excitation energy from the laser lights is transferred from one molecule to the next. (The excitation energy changes the way each molecule absorbs and emits light.)

Fleming has compared 2-D electronic spectroscopy to the technique used in the early super-heterodyne radios, where an incoming high frequency radio signal was converted by an oscillator to a lower frequency for more controllable amplification and better reception. In the case of 2-D electronic spectroscopy, scientists can track the transfer of energy between molecules that are coupled (connected) through their electronic and vibrational states in any photoactive system, macromolecular assembly or nanostructure.

Fleming and his group first described 2-D electronic spectroscopy in a 2005 Nature paper, when they used the technique to observe electronic couplings in the Fenna-Matthews-Olson (FMO) photosynthetic light-harvesting protein, a molecular complex in green sulphur bacteria.

Said Engel, “The 2005 paper was the first biological application of this technique, now we have used 2-D electronic spectroscopy to discover a new phenomenon in photosynthetic systems. While the possibility that photosynthetic energy transfer might involve quantum oscillations was first suggested more than 70 years ago, the wavelike motion of excitation energy had never been observed until now.”

As in the 2005 paper, the FMO protein was again the target. FMO is considered a model system for studying photosynthetic energy transfer because it consists of only seven pigment molecules and its chemistry has been well characterized.

“To observe the quantum beats, 2-D spectra were taken at 33 population times, ranging from 0 to 660 femtoseconds,” said Engel. “In these spectra, the lowest-energy exciton (a bound electron-hole pair formed when an incoming photon boosts an electron out of the valence energy band into the conduction band) gives rise to a diagonal peak near 825 nanometers that clearly oscillates. The associated cross-peak amplitude also appears to oscillate. Surprisingly, this quantum beating lasted the entire 660 femtoseconds.”

Engel said the duration of the quantum beating signals was unexpected because the general scientific assumption had been that the electronic coherences responsible for such oscillations are rapidly destroyed.

“For this reason, the transfer of electronic coherence between excitons during relaxation has usually been ignored,” Engel said. “By demonstrating that the energy transfer process does involve electronic coherence and that this coherence is much stronger than we would ever have expected, we have shown that the process can be much more efficient than the classical view could explain. However, we still don’t know to what degree photosynthesis benefits from these quantum effects.”

Engel said one of the next steps for the Fleming group in this line of research will be to look at the effects of temperature changes on the photosynthetic energy transfer process. The results for this latest paper in Nature were obtained from FMO complexes kept at 77 Kelvin. The group will also be looking at broader bandwidths of energy using different colors of light pulses to map out everything that is going on, not just energy transfer. Ultimately, the idea is to gain a much better understanding how Nature not only transfers energy from one molecular system to another, but is also able to convert it into useful forms.

“Nature has had about 2.7 billion years to perfect photosynthesis, so there are huge lessons that remain for us to learn,” Engel said. “The results we’re reporting in this latest paper, however, at least give us a new way to think about the design of future artificial photosynthesis systems.”

This research was funded by the U.S. Department of Energy and by the Miller Institute for Basic Research in Sciences.

Note: This story has been adapted from a news release issued by DOE/Lawrence Berkeley National Laboratory.

Nano-generator could power tiny devices

ஆச்சர்யங்கள் மட்டுமே சாத்தியம் இந்த நானோ டெக்னாலஜியில். இன்னும் காத்துக்கொண்டேதான் இருக்கிறோம் என்றாலும், வெற்றி இன்னும் அதிக தொலைவில் இல்லை என்பதே உண்மை.

The day when you can charge your cell phone or iPod just by going for a stroll around the block could be a step closer, thanks to a “nano-generator”.

About a year ago, Zhong Lin Wang of Georgia Tech in the US discovered that, when he disturbed zinc oxide nanowires, they gave off a tiny electrical current, a phenomenon called piezoelectricity. At the time, he had to use the tip of an atomic force microscope – a $250,000 instrument – to create about one-billionth of a watt of power. Not exactly energy efficiency.

But with his latest experiment, Wang has improved his design at least a thousand-fold. Using gold nanoparticle as seeds, he grew a small forest of 1-micron-high zinc oxide wires on a conductive substrate 2 millimetres square. Then he placed a saw-toothed electrode on top, which is designed to make contact with as many nanowires as possible. Finally, by rattling the whole thing with ultrasound, he found that he could generate a few microwatts of electricity.

That is still only a few millionths of a watt. But, by using ultrasound, the team demonstrated that they can activate the generator using any form of vibration. The movement of the top electrode disturbs the nanowires, providing a potential power source for anything that moves.

Furthermore, nanowires can be chemically grown on virtually any substrate, including metals, polymers, and anything else that could double as an electrode. The wires also precipitate from solution at 70°C, making them easy to grow under normal laboratory conditions.

Human implants

The generator suffers from a few key limitations, however. First, growing uniform nanowires is difficult – they are usually of slightly different height or diameter. As a result, in a generator containing many thousands of nanowires, only a few hundred or so successfully generate electricity when shaken, as they do not all make contact with the electrode. That hurdle must be overcome in order to charge large, power-hungry devices.

But Wang believes the nano-generator could be ideal for powering tiny devices, including those that may be implanted inside the human body. “Imagine self-powered force-sensors implanted in blood vessel walls, taking your blood pressure. Or generators in your shoes that can charge devices while you walk,” he says.

Almost any device that could use a wireless, mobile power source could potentially use the nanogenerator, Wang says: “I have full confidence that within three years we will have something that is useful commercially.”

The Valiant Swabian – Albert Einstein

எனக்கு ரிலேட்டிவிட்டி தியரி பிரகாசமாய்த் தெரியும் என்றெல்லாம் ஒன்றும் கிடையாது. ஆனால் அது எதைப் பற்றியதாயிருக்கும் என்பதைப் பற்றித் தெரியும், ஒரு முறை என் சித்தப்பா(என்று நினைக்கிறேன்), ரிலேட்டிவிட்டி தியரியை ஒரு ‘ஈ’யைக் கொண்டு விளக்கினார். எப்படியென்றால்,

நாம் ஒரு காரில் பயணம் செய்கிறோம், 60km வேகத்தில், ஆனால் நாம் பயணம் செய்யத் தொடங்கிய அதே சமயத்தில் அந்தக் காரினுள் புகுந்த ‘ஈ’ ஒன்று நம்முடைன் பயணம் செய்கிறது, எப்படியென்றால் காரின் எந்த ஒரு பகுதியையும் தொடாமல் – காருக்குள் பறந்துகொண்டேயிருக்கிறது. ‘ஈ’ காருக்குள் பயணம்(பறந்து) செய்து கொண்டுதானே இருக்கிறது.

இதன் காரணமாகயெல்லாம் ‘ஈ’யும் 60km வேகத்தில் பயணம் செய்ததாகக் கொள்ள முடியுமா? இப்படித்தான் வேகம் என்பது வேறுபடுவதாய் இருக்கிறது. இந்த சூழ்நிலையில் காரில் பயணம் செய்த நம்முடைய வேகத்தையும், நம்முடை பயணம் செய்த ‘ஈ’யினுடைய வேகத்தையும் ஒரு சமன்பாட்டிற்குள் கொண்டுவருவது தான் ரிலேட்டிவிட்டி என்றார் அவர். இது உண்மையா எனக்குத் தெரியாது.

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The Valiant Swabian – A new biography of Albert Einstein.

When youthful and frisky, Albert Einstein would refer to himself as “the valiant Swabian,” quoting the poem by Ludwig Uhland: “But the valiant Swabian is not afraid.” Albert—the name Abraham had been considered by his unreligious parents but was rejected as “too Jewish”—was born in Ulm, in March of 1879, not long after Swabia joined the new German Reich; he was the first child and only son of a mathematics-minded but financially inept father and a strong-willed, musically gifted woman of some inherited means. A daughter, Maria, was born to the couple two and a half years later; when shown his infant sister, Albert took a look and said, “Yes, but where are the wheels?” Though this showed an investigative turn of mind, the boy was slow to talk, and the family maid dubbed him der Depperte—“the dopey one.”

As the boy progressed through the schools of Munich, where his father had found employment in his brother Jakob’s gas-and-electrical-supply company, Albert’s teachers, though giving him generally high marks, noted his resistance to authority and Germanic discipline, even in its milder Bavarian form. As early as the age of four or five, while sick in bed, he had had a revelatory encounter with the invisible forces of nature: his father brought him a compass, and, as he later remembered it, he was so excited as he examined it that he trembled and grew cold. The child drew the momentous conclusion that “something deeply hidden had to be behind things.” That intimation was to carry him to some of the greatest scientific discoveries of the twentieth century, and to a subsequent persistent but unsuccessful search for a theory that would unite all the known laws of nature, and to a global fame impossible to imagine befalling any mere intellectual now.

Walter Isaacson’s thorough, comprehensive, affectionate new biography, “Einstein: His Life and Universe” (Simon & Schuster; $32), relates how, in 1931, during the fifty-one-year-old scientist’s second visit to America, he and his second wife, Elsa, attended, in California, a séance at the home of Mr. and Mrs. Upton Sinclair. He must have allowed a little skepticism to creep into his polite conversation, for “Mrs. Sinclair challenged his views on science and spirituality.” His own wife overheard and indignantly intervened, telling their hostess, “You know, my husband has the greatest mind in the world.” Mrs. Sinclair didn’t dispute the assertion, replying, “Yes, I know, but surely he doesn’t know everything.” On the same excursion, Einstein, at his own request, met Charlie Chaplin, who, as they arrived at the première of “City Lights,” said, of the applauding public, “They cheer me because they all understand me, and they cheer you because no one understands you.”

In 1905, Einstein, a twenty-six-year-old patent clerk in Bern, Switzerland, had produced in rapid succession five scientific papers that (a) proposed that light came not just in waves but in indivisible, discrete packets of energy or particles called, after Max Planck’s discovery, quanta; (b) calculated how many water molecules existed in 22.4 litres (a number so vast that, Isaacson tells us, “that many unpopped popcorn kernels when spread across the United States would cover the country nine miles deep”); (c) explained Brownian motion as the jostling of motes of matter by invisible molecules; (d) expounded the special theory of relativity, holding that all measurable motion is relative to some other object and that no universal coördinates, and no hypothetical ubiquitous ether, exist; and (e) asserted that mass and energy were different manifestations of the same thing and that their relation could be tidily expressed in the equation E=mc², where c is the speed of light, a constant. Only a few friends and theoretical physicists took notice.

from the issuecartoon banke-mail thisIn 1903, Einstein had married a woman three years older than he, Mileva Marić, a lame, homely Serbian he had met when both were students at the Zurich Polytechnic. It emerged only in 1986 that before their marriage the couple became parents of a girl, Lieserl, whom Einstein probably never saw and whose fate is unknown. A legitimate son, Hans Albert, was born in 1904. Einstein had not been able to secure any teaching job; his cavalier and even defiant attitude toward academic authority worked against his early signs of promise. He had left Germany and renounced his citizenship at the age of sixteen, and for four years was too poor to buy Swiss citizenship, depending for sustenance on a monthly stipend from his mother’s family and some fees from private tutorials. In the pinch, Marcel Grossmann, a brilliant math student whose meticulous lecture notes helped Einstein get high grades at the Zurich Polytechnic, managed to secure him a job at the Swiss Patent Office, in Bern. His long stint there figures, in the conventional Einstein mythology, as the absurd ordeal of a neglected genius, but Isaacson thinks it might have been a good thing:

So it was that Albert Einstein would end up spending the most creative seven years of his life—even after he had written the papers that reoriented physics—arriving at work at 8 A.M., six days a week, and examining patent applications.…Yet it would be wrong to think that poring over applications for patents was drudgery.…Every day, he would do thought experiments based on theoretical premises, sniffing out the underlying realities. Focusing on real-life questions, he later said, “stimulated me to see the physical ramifications of theoretical concepts.”

“Had he been consigned instead to the job of an assistant to a professor,” Isaacson points out, “he might have felt compelled to churn out safe publications and be overly cautious in challenging accepted notions.” Special relativity has a flavor of the patent office; one of the theory’s charms for the fascinated public was the practical apparatus of its exposition, involving down-to-earth images like passing trains equipped with reflecting mirrors on their ceilings, and measuring rods that magically shrink with speed from the standpoint of a stationary observer, and clocks that slow as they accelerate—counterintuitive effects graspable with little more math than plane geometry.

The general theory of relativity took longer, from 1907 to 1915, and came harder. Generalizing from the special theory’s assumption of uniform velocity to cases of accelerated motion, and incorporating Newton’s laws of gravity into a field theory that corrected his assumption of instant gravitational effect across any distance, led Einstein into advanced areas of mathematics where he felt at sea. He turned to his invaluable friend Marcel Grossmann, now chairman of the math department at the Zurich Polytechnic; Isaacson quotes him as saying, “Grossmann, you’ve got to help me or I will go crazy.” After consulting the literature, Grossmann “recommended the non-Euclidean geometry that had been devised by Bernhard Riemann.” Einstein, beginning with the insight that acceleration and gravity exert an equivalent force, worked for years to find the equations that would describe

1. How a gravitational field acts on matter, telling it how to move.

2. And in turn, how matter generates gravitational fields in spacetime, telling it how to curve.

“I have gained enormous respect for mathematics,” he wrote a friend, “whose more subtle parts I considered until now, in my ignorance, as pure luxury!” For a time, he discarded Riemannian tensors, but eventually returned to them, and, to quote Isaacson, “in the throes of one of the most concentrated frenzies of scientific creativity in history,” he felt close enough to the solution to schedule four Thursday lectures at the Prussian Academy, in Berlin, which would unveil his “triumphant revision of Newton’s universe.” Then, heightening the suspense, another player entered the game. Einstein, still a little short of the full solution and beset with nervous stomach pains, showed one of his lectures to David Hilbert, “who was not only a better pure mathematician than Einstein, he also had the advantage of not being as good a physicist.” Hilbert told Einstein that he was ready to lay out his own “axiomatic solution to your great problem,” and the physicist battled to establish the priority of his theory even as he was putting the last, perfecting touches into his fourth and final lecture. It all came down to:

Rµν—½gµνR = 8πTµν

The other giants of physics in the first half of the twentieth century applauded. Paul Dirac called general relativity “probably the greatest scientific discovery ever made,” and Max Born termed it “the greatest feat of human thinking about nature, the most amazing combination of philosophical penetration, physical intuition and mathematical skill.” In 1919, the discovery was given empirical proof when Arthur Eddington, the director of the Cambridge Observatory, led an expedition to equatorial realms to observe a solar eclipse and see if, as Einstein’s field equations predicted, stars near the sun’s rim would be apparently displaced 1.7 arc seconds. With a little massaging from Eddington, they were. Einstein, asked what his reaction would have been if the experiment had showed his theory to be wrong, serenely replied, “Then I would have been sorry for the dear Lord; the theory is correct.”

from the issuecartoon banke-mail thisThough Einstein was to reap many honors (including the 1921 Nobel, belatedly, for his early work on the photoelectrical effect) and was to serve humanity as a genial icon and fount of humanist wisdom for three more decades, he never again made a significant contribution to the ongoing life of the physical sciences. Beginning around 1918, he devoted himself to a quest even more solitary and visionary than his relativity triumphs. “We seek,” he said in his Nobel Prize lecture, “a mathematically unified field theory in which the gravitational field and the electromagnetic field are interpreted only as different components or manifestations of the same uniform field.” Quantum theory, with its built-in uncertainties and paradoxes, struck him as a spooky violation of physical realism. “The more successes the quantum theory enjoys,” he lamented to a friend in 1912, “the sillier it looks.” In an autobiographical sketch published in 1949, he described his frustrated attempts “to adapt the theoretical foundation of physics” to quantum science: “It was as if the ground had been pulled out from under one, with no firm foundation to be seen anywhere upon which one could have built,” leaving “an intermediate state of physics without a uniform basis for the whole, a state that—although unsatisfactory—is far from having been overcome.”

His faith that a unified theory of all the fields exists went back to his childhood sense that “something deeply hidden had to be behind things,” a something that would evince itself in an encompassing theory of elegant simplicity. Isaacson tells us: “On one of the many occasions when Einstein declared that God would not play dice, it was Bohr”—the physicist Niels Bohr—“who countered with the famous rejoinder: Einstein, stop telling God what to do!” God, sometimes identified as “the Almighty” or “the Old One” (der Alte) frequently cropped up in Einstein’s utterances, although, after a brief period of “deep religiousness” at the age of twelve, he firmly distanced himself from organized religion. In a collection of statements published in English as “The World As I See It,” there is this on “The Religiousness of Science”:

The scientist is possessed by the sense of universal causation.…His religious feeling takes the form of a rapturous amazement at the harmony of natural law, which reveals an intelligence of such superiority that, compared with it, all the systematic thinking and acting of human beings is an utterly insignificant reflection. This feeling is the guiding principle

The apparition of a superior intelligence behind the impassive arrangements of nature was more than a playful metaphor for Einstein, and the escape from selfishness through scientific thought was a principle he lived. In composing, at the request of an editor, his “Autobiographical Notes,” he concentrated almost exclusively on his thought processes, complete with equations.

Yet things happened to him; he had a life. In 1909, the University of Zurich upped an initial offer, and Einstein, “four years after he had revolutionized physics,” resigned from the patent office and accepted his first professorship. “So, now I too am an official member of the guild of whores,” he told a colleague. In 1910, Mileva gave birth to a second son, Eduard, who as he grew older developed mental illness and was to end up in a Swiss asylum. In 1911, the Einsteins moved to Prague, where Einstein accepted a full professorship at the German part of the University of Prague. Offers kept coming; in 1912 he returned to the Zurich Polytechnic, which had become a full university, the Eidgenössische Technische Hochschule. Mileva should have been happy back in Zurich, among old friends, but her health was uncertain, carrying with it depression, and continued to decline. In 1913, an invitation was personally delivered by two pillars of Berlin’s academic establishment, Max Planck and Walther Hermann Nernst, to come to Berlin as a university professor and the director of a new physics institute, and to become, at the age of thirty-four, the youngest member of the Prussian Academy. Einstein stayed in Berlin until 1932, when the combination of rising Nazism and tempting offers from America impelled him to leave Germany, never to return.

In America, Robert A. Millikan, a physicist whose experiments had verified Einstein’s photoelectrical equation, was now the president of Caltech, and he aggressively courted Einstein to come to Pasadena. However, the educator Abraham Flexner, a former officer of the Rockefeller Foundation, was in the process of establishing, with funds from the Bamberger department-store fortune, a haven for scholars named the Institute for Advanced Study, to be situated in New Jersey, next to but not affiliated with Princeton University. Einstein, intending to split his time between Europe and America, accepted the Princeton proposal. He and Elsa moved there, and in 1935, after renting for a few years, they bought a modest frame house at 112 Mercer Street, where Einstein lived until his death, in 1955.

He and Mileva had divorced, after many difficulties, in March, 1919. One of the attractions of Berlin in 1913 had been the presence of his divorced cousin Elsa Einstein. During the First World War, while Mileva stayed in Zurich with the two boys, Elsa and Einstein shared a life in Berlin—in his divorce deposition he gave the period of “intimate relations” as “about four and a half years.” After some friction (Einstein wasn’t sure that he wanted to be married at all, after the mental exertions of general relativity, but Elsa’s respectable family wanted her reputation salvaged), he and Elsa married, in June, 1919. In their “spacious and somberly furnished apartment near the center of Berlin,” with her two daughters, he seemed, a colleague remarked, “a Bohemian as a guest in a bourgeois home.” Elsa was shrewd but, unlike Mileva Marić, not scientific, which at his stage of life and eminence may have been a blessing. Einstein and women are a complicated story, and Isaacson doesn’t attempt to tell it all. There were a number of extramarital relationships; how many of them tipped from companionship into sex is, like the electron, difficult to measure. (One startling fact, according to Isaacson: beginning in 1941, Einstein was sleeping with an alleged Soviet spy, the multilingual Margarita Konenkova, though the F.B.I., which was keeping close tabs on him, never twigged.) Isaacson, a former managing editor of Time, whose previous biographies dealt with Benjamin Franklin and Henry Kissinger, writes in short paragraphs; taking up in rotation science and politics and personal developments, he has much material to compress. He notes that at Elsa’s untimely death, in 1936, “Einstein was hit harder than he might have expected,” and pronounces on their marriage:

Beneath the surface of many romances that evolve into partnerships, there is a depth not visible to outside observers. Elsa and Albert Einstein liked each other, understood each other, and perhaps most important (for she, too, was actually quite clever in her own way) were amused by each other. So even if it was not the stuff of poetry, the bond between them was a solid one.

Yet when Michele Besso, an old friend from his youth in Zurich, died, not long before Einstein’s own death, he wrote to Besso’s family that the deceased’s most admirable trait had been to live harmoniously with a woman, “an undertaking in which I twice failed rather miserably.” He was married to the universe, and gave back to people less love than he attracted. Max Born said, “For all his kindness, sociability and love of humanity, he was nevertheless totally detached from his environment and the human beings in it.”

But he loved America, and America reciprocated. Its informality, optimism, and emphasis on free speech delighted him: “From what I have seen of Americans, I think that life would not be worth living to them without this freedom of self expression.” Except for a brief trip to Bermuda as part of his application for citizenship, he never left; he never returned to Europe, let alone to Germany, whose crimes, he wrote the chemist Otto Hahn, “are really the most abominable ever to be recorded in the history of the so-called civilized nations.” To America, Isaacson says, he projected a “rumpled-genius image as famous as Chaplin[’s] little tramp.” As famous as Chaplin, he appeared, to Americans of my age, as saintly as Gandhi. Einstein’s public political life—his initially reluctant but eventually committed Zionism, his initially militant but eventually modified pacifism, his wartime patriotism (including a sponsoring role in the creation of the atomic bomb), his scorn of McCarthyism, and his good humor and amiable wit in shouldering all the causes and interviews he was asked to shoulder—contributed to American morale in the challenging years between 1933 and 1955. Having the greatest mind in the world on the premises lifted American spirits. In his own freedom of thought, the valiant Swabian demonstrated how to be free.

The Enduring Mystery of Light

The electromagnetic spectrum: Light is much more than what meets the eye. Credit: George Frederick for LiveScience

It goes through walls, but slows to a standstill in ultra-cold gases. It carries electronic information for radios and TVs, but destroys genetic information in cells. It bends around buildings and squeezes through pinholes, but ricochets off tiny electrons.

It’s light. And although we know it primarily as the opposite of darkness, most of light is not visible to our eyes. From low energy radio waves to high energy gamma rays, light zips around us, bounces off us, and sometimes goes through us.

Electromagnetic Radiation

The Whole Spectrum

Because it is so many things, defining light is a bit of a philosophical quandary. It doesn’t help that light continue to surprise us, with novel materials that alter light’s speed and trajectory in unexpected ways.

Is it a wave?

What ties together microwaves, X-rays and the colors of the rainbow is that they are all waves—electromagnetic waves to be exact. The substance that sloshes back and forth isn’t water or air, but a combination of electric and magnetic fields.

These fluctuating fields exert forces on charged particles—sometimes causing them to bob up and down like buoys in the ocean.

What separates all the various forms of light is wavelength. Our eyes are sensitive to light with wavelengths between 750 nanometers (red) and 380 nanometers (violet), where a nanometer is one billionth of a meter, or about the size of a single molecule.

But the visible spectrum—seen through a prism—is only a small chunk of the entire electromagnetic spectrum. The wavelength of light ranges from hundreds of miles for long radio waves to one millionth of a nanometer for gamma rays [graphic].

The energy of light is inversely proportional to the wavelength, such that gamma rays are a billion billion times more energetic than radio waves.

Or is it a particle?

But waves are not the whole story. Light is composed of particles called photons. This is most obvious with higher energy light, like X-rays and gamma rays, but it is true all the way down to radio waves.

The classic example of particleness is the photoelectric effect, in which light hitting a metal sheet causes electrons to fly out of the surface. Surprisingly, light longer than a certain wavelength cannot liberate electrons, no matter how bright the source is.

How Light Works?

A strict wave theory of light cannot explain this wavelength threshold, since many long waves should pack the same total energy as a few short waves.

Albert Einstein deciphered the mystery in 1905 by assuming that particles of light smacked into the electrons, like colliding billiard balls. Only particles from short wavelength light can give a hard enough kick.

Despite this success, the particle theory never replaced the wave theory, since only waves can describe how light interferes with itself when it passes through two slits. We therefore have to live with light being both a particle and a wave—sometimes acting as hard as a rock, sometimes as soft as a ripple.

Physicists rectify light’s split personality by thinking in terms of wave packets, which one can imagine as a group of light waves traveling together in a tight, particle-like bundle.

Making a spectacle

Instead of worrying about what light is, it might be better to concentrate on what light does. Light shakes, twists and shoves the charged particles (like electrons) that reside in all materials.

These light actions are wavelength-specific. Or to say it another way, each material responds only to a particular set of wavelengths.

Take an apple, for instance. Radio waves and X-rays go essentially straight through it, whereas visible light is stopped by various apple molecules that either absorb the light as heat or reflect it back out.

If the reflected light enters our eyes, it will stimulate color receptors (cones) that are specifically “tuned” to either long, medium or short wavelengths. The brain compares the different cone responses to determine that the apple reflects “red” light [graphic].

Here are some other examples of light’s specific activities.

  • Radio waves from a local station cause the free electrons in a radio’s antenna to oscillate. Electronics tuned to the station’s frequency (or wavelength) can decode the oscillating signal into music or words.
  • A microwave oven heats food from the inside out because microwaves penetrate the surface to rotate water molecules contained in the food. This molecular shuffling generates heat.
  • Standing next to a camp fire, infrared light vibrates molecules in our skin to make us warm. Conversely, we constantly lose heat when these same molecules emit infrared light.
  • In sunlight, several visible and ultraviolet wavelengths are missing, or dark. These “shadows” are due to the capture of photons by atoms, like hydrogen and helium, that make up the sun. The captured photon energy is used to boost the atoms’ electrons from one energy level to another.
  • An X-ray image of a skeleton is due to the fact that X-rays pass through soft tissue but are blocked by dense bone. However, even when just passing through, X-rays and gamma rays ionize molecules along their path, meaning they strip electrons from the molecules. The ionized molecules can directly or indirectly damage DNA in a cell. Some of these genetic alterations may lead to cancer.
  • All this shows that light wears many different hats in its manipulation of matter. It is perhaps fitting then that light’s true identity—wave or particle—is unanswerable.
  • Physicists Find Way To ‘See’ Extra Dimensions

    ஒவ்வொரு முறையும் எனக்கு இது போன்ற விஷயங்கள் கண்ணில் பட்டு விடுகின்றன ஹிஹி ஆச்சர்யம் தான். முன்பே என் பதிவுகளில் சொல்லியிருந்தது போல் நாம் பார்க்கும் அல்லது நம்மால் பார்க்கயியலும் முப்பரிமாணங்களுக்கும் மேலாக பரிமாணங்கள் இருக்கும் சாத்தியக்கூறுகளை அறிவியல் அடித்துக்கூறுகிறது. ஸ்ட்ரிங் தியரிப்படி இது நிச்சயமாகச் சாத்தியமே. இப்பொழுது அண்டசராசரத்தின் நாம் பார்க்காத பகுதிகளையும் “பார்க்க” ஒரு வழி கண்டுபிடித்திருப்பதாக சொல்கிறார்கள்.

    உடனே ஸ்ட்ரிங் தியரி, பிக் பேங்க் என்று ஜல்லியடிப்பதாக நண்பர்கள் புலம்பவேண்டாம். வேண்டியவர்கள் படிக்கலாம், வேண்டாதவர்கள் குப்பையில் போடலாம். எல்லாப் புகழும் பார்வேர்ட் பண்ணியவனுக்கே.

    Science Daily — Peering backward in time to an instant after the big bang, physicists at the University of Wisconsin-Madison have devised an approach that may help unlock the hidden shapes of alternate dimensions of the universe.


    A computer-generated rendering of a possible six-dimensional geometry similar to those studied by UW-Madison physicist Gary Shiu. (Image: courtesy Andrew J. Hanson, Indiana University)Ads by Google Advertise on this site

    A new study demonstrates that the shapes of extra dimensions can be “seen” by deciphering their influence on cosmic energy released by the violent birth of the universe 13 billion years ago. The method, published today (Feb. 2) in Physical Review Letters, provides evidence that physicists can use experimental data to discern the nature of these elusive dimensions – the existence of which is a critical but as yet unproven element of string theory, the leading contender for a unified “theory of everything.”

    Scientists developed string theory, which proposes that everything in the universe is made of tiny, vibrating strings of energy, to encompass the physical principles of all objects from immense galaxies to subatomic particles. Though currently the front-runner to explain the framework of the cosmos, the theory remains, to date, untested.

    The mathematics of string theory suggests that the world we know is not complete. In addition to our four familiar dimensions – three-dimensional space and time – string theory predicts the existence of six extra spatial dimensions, “hidden” dimensions curled in tiny geometric shapes at every single point in our universe.

    Don’t worry if you can’t picture a 10-dimensional world. Our minds are accustomed to only three spatial dimensions and lack a frame of reference for the other six, says UW-Madison physicist Gary Shiu, who led the new study. Though scientists use computers to visualize what these six-dimensional geometries could look like (see image), no one really knows for sure what shape they take.

    The new Wisconsin work may provide a long-sought foundation for measuring this previously immeasurable aspect of string theory.

    According to string theory mathematics, the extra dimensions could adopt any of tens of thousands of possible shapes, each shape theoretically corresponding to its own universe with its own set of physical laws.

    For our universe, “Nature picked one – and we want to know what that one looks like,” explains Henry Tye, a physicist at Cornell University who was not involved in the new research.

    Shiu says the many-dimensional shapes are far too small to see or measure through any usual means of observation, which makes testing this crucial aspect of string theory very difficult. “You can theorize anything, but you have to be able to show it with experiments,” he says. “Now the problem is, how do we test it?”

    He and graduate student Bret Underwood turned to the sky for inspiration.

    Their approach is based on the idea that the six tiny dimensions had their strongest influence on the universe when it itself was a tiny speck of highly compressed matter and energy – that is, in the instant just after the big bang.

    “Our idea was to go back in time and see what happened back then,” says Shiu. “Of course, we couldn’t really go back in time.”

    Lacking the requisite time machine, they used the next-best thing: a map of cosmic energy released from the big bang. The energy, captured by satellites such as NASA’s Wilkinson Microwave Anisotropy Probe (WMAP), has persisted virtually unchanged for the last 13 billion years, making the energy map basically “a snapshot of the baby universe,” Shiu says. The WMAP experiment is the successor to NASA’s Cosmic Background Explorer (COBE) project, which garnered the 2006 Nobel Prize in physics.

    Just as a shadow can give an idea of the shape of an object, the pattern of cosmic energy in the sky can give an indication of the shape of the other six dimensions present, Shiu explains.

    To learn how to read telltale signs of the six-dimensional geometry from the cosmic map, they worked backward. Starting with two different types of mathematically simple geometries, called warped throats, they calculated the predicted energy map that would be seen in the universe described by each shape. When they compared the two maps, they found small but significant differences between them.

    Their results show that specific patterns of cosmic energy can hold clues to the geometry of the six-dimensional shape – the first type of observable data to demonstrate such promise, says Tye.

    Though the current data are not precise enough to compare their findings to our universe, upcoming experiments such as the European Space Agency’s Planck satellite should have the sensitivity to detect subtle variations between different geometries, Shiu says.

    “Our results with simple, well-understood shapes give proof of concept that the geometry of hidden dimensions can be deciphered from the pattern of cosmic energy,” he says. “This provides a rare opportunity in which string theory can be tested.”

    Technological improvements to capture more detailed cosmic maps should help narrow down the possibilities and may allow scientists to crack the code of the cosmic energy map – and inch closer to identifying the single geometry that fits our universe.

    The implications of such a possibility are profound, says Tye. “If this shape can be measured, it would also tell us that string theory is correct.”

    The new work was funded by grants from the National Science Foundation, the U.S. Department of Energy, and the Research Corp.

    Note: This story has been adapted from a news release issued by University of Wisconsin-Madison.