Wednesday, April 13, 2011

World's longest Yo-Yo

The Technion “Technobrain” Competition Opens 
The world’s longest yo-yo will be released from a 30 m high crane

As part of Technion’s traditional “Technbrain” competition, students will compete against each other by releasing the world’s longest yo-yo from a 30 meter high crane. The yo-yo will have to run back up a 20 meter long rope, to its maximum height and then drop down again and run up a number of times to a minimum of over 5 meters. A team of judges will measure the maximum height the yo-yo reaches on its first ascent after release from the crane and the number of times it loops up and down.

The crane will have a compartment in which the yo-yo will be placed. The compartment’s floor will open and the yo-yo will be released downward. Competitors are not allowed to use an external energy source and the dynamic rope will be supplied to them by the competition organizers. Winners will receive 10,000 ₪, 5,000 ₪, and 3,000 ₪ (1st, 2nd and 3rd places, respectively).

The “Technbrain” competition is held at the Technion in memory of Neev-Ya Durban, who first envisioned and thereafter established the competition, and was a student and outstanding Technion graduate. Neev-Ya was an officer in the IDF when he was murdered during a mugging on a quiet street in Tel Aviv in March 2003. The competition and the prizes are funded by Dr. Robert Shillman (who everyone knows as “Dr. Bob”), who did his graduate work at the Technion.

Tuesday, April 5, 2011

Is Smart being Greedy? Tomorrow's Internet.

Prof. Seffi Naor found a way to improve online advertising sales using the auction sales method and achieve impressive results of 75% of the maximum income

Prof. Seffi Naor.
By: Yisrael Benyamini, From the main Technion website.

In the strange world of online sales, it doesn’t always pay to sell at the highest price. In order to understand why, let’s imagine a wine merchant who gets two orders: Customer A is interested in purchasing 10 bottles, at most, of Merlot or Cabernet wine and is prepared to pay $100 per bottle. Customer B would like to buy ten bottles, at most, of Merlot wine and is prepared to pay $99 per bottle. The seller checks with his suppliers and finds a bottle of Merlot. He decides to send the bottle to Customer A, who offered the higher price. Later on he finds an additional nine bottles of Merlot and sends them all to Customer A. Only towards the end of the day does the seller find ten bottles of Cabernet – except that now he does not have a customer for them and he ends his day making only $1000 in sales. If he would have sold the Merlot to Customer B and the Cabernet to Customer A, he would have made $1990 that day.

When he made his decision, the merchant could not have known that at the end of the day he would find ten additional bottles. Only after making the sale was it possible to know what decision would have generated the maximum income. Issues about which decisions to make before getting all the information are called online decision problems. In these problems every decision is liable to end up as not optimal in light of information that will be received after making the decision. Regardless of this, according to Prof. Seffi Naor of the Computer Science Department at the Technion, there is a way for the merchant to always achieve an income that is at least 63% (more exactly, 1-1/e »0.632) of the maximum income that he would have been able to get had he had all the information from the start. This number is called the competitive ratio of this method: the ratio between the results of the online method and the best results that in hindsight could have been achieved. Our merchant’s greedy method enabled him to earn $1000 instead of $1990 – in other words, a 50% competitive ratio.

Can’t wait

Some readers may perhaps suggest to the merchant not to immediately give the bottles to the customer and rather wait till the end of the day in order to decide how best to divide the bottles between his customers. This possibility does not exist in the area studied by Prof. Naor: advertising on the Internet through “Public Auction of Search Words”. In this time of advertising situation there is an Internet site on which there are ads (e.g., Google) and a large number of advertisers who want their ad on the site. Every advertiser tells the site which search words he is interested in “purchasing”, what his daily budget is, and how much he is willing to pay per search word. When a web surfer keys in one of these search words, the site presents, alongside the search results, ads that have been chosen from among the advertisers interested in the keyed-in search words: this is why this process is called a public auction.

This type of advertising presents the same dilemma that the wine merchant faced: sometimes it pays to choose the advertiser who offered a slightly lower price, so that at the end of the day, you can exploit as much as possible the budget allocated by all the advertisers.

Naor (52) completed his undergraduate studies in computer science at the Technion and his graduate and doctoral studies at Hebrew University of Jerusalem. He thereafter did a post-doctoral fellowship at the University of Southern California and Stanford University and since 1991 has been a faculty member of the Technion’s Computer Science Department. Here he focuses on the field of algorithmic theory, and specifically, on online algorithms, approximation algorithms and algorithmic game theory. Naor worked on the online advertising problem with a former student of his, Dr. Niv Buchbiner, and Dr. Kamal Jain, while on sabbatical in Microsoft’s Research Lab in Redmond, USA. Two years earlier a solution that arrived at the same ratio had already been presented but the new solution is far simpler and can be expanded to additional cases, among which advertisers also compete for the position of their ads on the page.

Good balance

In order to reach a new solution, the researchers used techniques drawn from linear programming. The principle is easy to describe: instead of the greedy method in which every time an ad is supposed to be shown, one looks for the maximum profit that can be made off of it, research showed that it is preferable to choose the advertiser who has the best balance between his remaining budget and the price he is ready to pay for the search word.

If the wine merchant had used this method, he would also have sold the first bottle of Merlot to Customer A, which would have reduced Customer A’s available budget so that the second bottle would have been sold to Customer B, who had a higher available budget. True, in this way the merchant would not have reached the amount that, in retrospect, he could have, but certainly more than he made using his greedy method. If he would have sold five bottles of Merlot to Customer A and five to Customer B, and then found the bottles of Cabernet, he would have been able to sell these to Customer B and his income would have reached $1495: a competitive ratio of 75%. There are cases in which the competitive ratio drops to 63% but never below this.

 “The algorithm presented in this research is based on a general method that I developed together with my research student Niv Buchbinder as part of his doctoral research, for a large group of online decision problems with common features,” says Naor. “The method uses techniques from the field of linear programming in order to create a formula for developing suitable algorithms. The strength of the general method proved itself when we used it to solve problems that had already been studied in the past and we obtained simpler and more efficient algorithms than the ones previously known.”

The frequency capping problem

Lately, Buchbinder and Naor used this method to solve the problem of frequency capping. This is another online decision problem from the field of Internet advertising, which was previously researched together with Moran Feldman, a doctoral student at the Technion, and Dr. Arpita Ghosh, from Yahoo!’s Research Center. In this problem, too, an ad has to be chosen such that the income for the website presenting the ad will be as high as possible. The requirement here is more typical of a content website such as a news site.

Content websites show identical pages to a large number of surfers, some of whom visit the site many times throughout the day. Research has shown that after a surfer sees a particular ad a number of times in a short period, he stops paying any attention to it – a phenomenon dubbed “ad blindness”. Consequently, many advertisers prefer to limit the number of times their ad is shown to the same surfer.

It turns out that frequency capping creates situations in which greediness does not pay off. For example, ten advertisers are prepared to pay $1 each time their ad is shown, but their budget is only enough to show one ad each day. Let’s call this group of advertisers “Group A”. Another advertiser is ready to pay $0.99 each time his ad is shown and his budget is large enough to show ten ads per day. However, he demands that if the ad is shown to a certain surfer, it must not be shown to that same surfer again the same day. Let’s call this advertiser “Advertiser B”.

Assume that initially ten different surfers arrive at the site. The greedy method would choose to show all of them one of the ads from the Group A advertisers, given that this group is ready to pay one cent more than Advertiser B. Now assume that at this point a new surfer visits the same page ten times. The first time he visits the page he is shown Advertiser B’s ad, and then the next nine times he will not be shown any ads, given that he has already seen Advertiser B’s ad (and can’t be shown it again on that day) and Group A has already used up its budget. Accordingly, the income on this day is $10.99. If we would have known ahead of time the order in which surfers would visit the page, we would have been able to show Advertiser B’s ad to the first visitors and Group A’s ads to the last ten visitors and earn $19.90 for the day – almost twice as much as the greedy method.

A greedy but smart algorithm

Of course, no site knows ahead of time in what order surfers will arrive at the site: this is an online decision problem that requires site managers to make a decision the moment the surfer arrives at the site. Buchbinder, Feldman, Ghosh and Naor’s paper presented a greedy but smarter algorithm that achieves a ¾ competitive ratio, when all the advertisers are ready to pay the same amount for an ad presentation, and proves that this result is the best possible one. For the general case, using the general method explained above, the researchers developed an algorithm that reaches a 0.63 competitive ratio, and they hypothesize that it is possible to obtain an even better ratio.

To what extent are mathematical theories such as these appropriate for real life situations? “A mathematical solution is the starting point, not the end point,” says Naor. “The real world is more complex that the assumptions on which a mathematical model is based, but algorithms can be expanded to cope with the complexity required for practical use.”

Prize-winning Mathematics

Erdos Award

Assoc. Prof. Tamar Ziegler from the Faculty of Mathematics was elected by the Israeli Mathematical Union to receive the 2011 Erdos AwardShe is the first Technion faculty member to win this award. This is the highest award for Israeli mathematician and is awarded to a person not older than 40 years old who made outstanding contributions in pure or applied mathematics. 

Assoc. Prof. Tammy Ziegler
Mathematics in its prime!

Work recently completed by Dr. Tammy Ziegler of the Department of Mathematics together with colleagues from the U.S. and Britain presents a major advance in Number Theory

Dr. Tammy Ziegler

By Noam Bercovitz;

The conversation with Dr. Tammy Ziegler of the Department of Mathematics took place, by pure chance, on the same day that it was announced that Prof. Elon Lindenstrauss of the Hebrew University was the recipient of the Fields Medal – the most prestigious mathematics prize in the world, which is, for mathematicians, the equivalent of the Nobel Prize. Dr. Ziegler, who got her degrees at the Hebrew University, knows Prof. Lindenstrauss and his work well, and was excited and happy for him and the mathematics community in Israel. This feeling  was also reflected in the Israeli media, which proudly reported the achievement, while being somewhat surprised to note that high-level research in mathematics was actually taking place, and that Israel, as it became clear, was a major player in the field.
Dr. Ziegler has been in the Technion’s Department of Mathematics for three years. Work that she and her two colleagues, Professor Tao from UCLA and Professor Green of Cambridge University, have recently completed, has aroused much interest among mathematicians since it solves basic problems in the field of prime numbers – a mathematical field that has lately become a center of attention, after a period of slumber. The results delineate methods for finding asymptotics for arithmetic patterns of prime numbers. The solution combines methods from two seemingly unrelated fields – dynamics and number theory.

The problem of prime number pairs (twins)

The next step, according to Ziegler, involved finding arithmetic patterns in the sequence of prime numbers. The question is interesting because of the inherent difficulty in understanding the additive behavior of prime numbers. For example, many prime number pairs that differ from each other by two (called "twin primes") are known. It is tempting to conjecture that there might be an infinite number of such pairs, but to-date the answer to this question has eluded mathematicians; it remains an open problem.
A related question that has interested mathematicians concerns the existence of arithmetic progressions in the sequence of primes. Only in 2004 did Green and Tao achieve a breakthrough by showing that the set of prime numbers contains arbitrarily long arithmetic progressions. The two researchers approached the problem from a different and surprising direction, using ideas from Ergodic theory, which is a branch of mathematics that deals with the study of dynamic systems. Green and Tao proved the existence of arithmetic progressions  of prime numbers, but their methods did not provide estimates of the number of k-term arithmetic progressions of prime numbers, all of  whose elements are smaller than N.
Dr. Ziegler’s doctorate focused on the connection between the arithmetic progressions and nilpotent dynamic systems. Prof .Tao's interest in this work led to their collaboration. About three years ago Ziegler started working with both Green and Tao and the collaboration resulted in finding the important estimates that have aroused so much interest.

When things get complicated

Trying to explain her unique contribution to the solution of the problem, Dr. Ziegler finds it is too complicated to do in simple terms. The explanation would involve sophisticated concepts and require the reader to possess advanced knowledge of Mathematics; thus, it is beyond the scope of this interview.
In mathematical language, one of the conclusions of the work of Green, Tao and Ziegler is that each system of equations of finite complexity, or in other words, a system that is not hiding within it a problem similar to prime twins, has prime solutions unless there are “local obstructions”, and thereby corroborates a multidimensional generalization for Hardy and Littlewood’s conjectures of the early twentieth century.

With paper and pencil

It is intriguing to find out how mathematicians work, and Dr. Ziegler explains with a smile: a lot of work and not being afraid to try new ideas. Dr. Ziegler relates that her office in the department provides a pleasant and quiet environment, and sometimes in the evenings she goes to a café with a notepad and a pencil.
Her work involves thinking hard, discussions with colleagues both here and overseas in order to analyze the problem and come up with new ideas. Finally, once you get an idea for a solution, you have to try and write it out in full detail. In most cases, though, you reach a dead end, which means that a significant part of your work ends up with tossing away ideas that at first looked promising. There is also no guarantee at the start of the road that a solution will be found at its end, therefore, when you do reach a solution, such as Ziegler and her colleagues did, there is a sense of accomplishment.

Monday, April 4, 2011

Raising Chutzpah

Israeli Professor Peretz Lavie says one of the secrets to success in innovation is to not give up on the young.

Jameson Berkow, Financial Post · Apr. 4, 2011 | Last Updated: Apr. 4, 2011 8:36 AM ET
Professor Peretz Lavie is a serial entrepreneur and president of The Technion: Israel Institute of Technology. He was in Toronto last week to speak to the Economic Club of Canada about Israel's thriving high-tech startup economy. Financial Post technology reporter Jameson Berkow had a chance to sit down with Prof. Lavie to discuss the origins of that booming industry and how Canada might be able to replicate some of that success. The following is an edited transcription of their conversation.
Q Your institution notes that Israel is home to about 4,000 high-tech startups, the equivalent to the entire European continent in absolute numbers. What do you believe accounts for that?
There is something about Israel, the combination of excellent education plus some attributes that are unique to Israel that make it such an innovative society.
Q What are some examples of those attributes?
A There are Israeli characteristics. If you are [here] and you give a talk to students and you ask questions, the fear of the hierarchy is so embedded in the culture that the fear of being embarrassed in public is a major issue. For Israelis, the hierarchy is very weak. They challenge you whether you are a professor, whether you are a CEO, whether you are a politician, they constantly challenge you so there is no fear of failure, we call it chutzpah. It is part of the spirit and I think the characteristic of the Israeli culture; the ability to find solutions where everybody says there is no solution; the resilience, you fail? that is part of the game, we'll do it again.
Is it Israeli chutzpah that has attracted large technology firms such as Intel Corp. and Microsoft Corp. to open research centres in Israel?
Microsoft, Google, Yahoo, every major company has an R&D centre in Israel. Many of the microchips for [Intel Corp.] were developed in Haifa. I was in the U.S. and I visited several of these companies in Silicon Valley three weeks ago and I asked them what brought you to Israel? They said if we have a problem that cannot be solved, we know that the centre that will do it is in Israel. It is like the elite troops that [Israel] has and they have 30 centres all over the world. But if they need something that is tough where there is no other solution, they know the only place where it can be done is in Israel.
Canadians are not exactly known for their chutzpah. Quite the opposite in fact, we are known for being shy and non-confrontational. Do those characteristics represent a barrier to fostering the same entrepreneurial drive and passion?
I believe so. I think that to really invest in innovative technologies you must take risks, you must have this chutzpah. In the book Startup Nation the authors describe a scenario in which somebody is buying an Israeli company and when he met the employees for one second he wasn't so sure who was buying who because of the way they asked him questions and talked about the company. So I think you need a society that encourages shorter distances between different hierarchies.
Q You mentioned that Israel went from being a Jaffaoranges economy to one based on semi-conductors in recent decades. What else might account for that transformation?
We had an influx of one million people from the former Soviet Union. They were highly educated, highly talented, with an inclination toward the natural sciences. So the number of engineers and scientists in Israel, mostly because of the Russian immigration, is the largest in the world per capita. I also should credit the government. It is interesting and very few people know that during the 1960s when Levi Eshkol was prime minister, he established in every ministry a chief scientist position and the chief scientist was given a budget for research and development. It helped to generate some of these companies, and then there was a community of venture capitalists that developed and continued to fuel this trend.
That is a stark contrast to Canada, which is currently facing a serious labour shortage for technology-related positions. Do you have any advice for how Canada can encourage more students to study math and science?
A The philosophy is you have to encourage these children at the age of 8 or 9, otherwise don't invest. That is wrong, it can be done and it is incredible. We have something called the 'pre-academic centre' in which we take 700 youth a year after their army service and they come to the centre for six to 18 months depending on how much they need to complete the course. Out of this 700, two thirds are accepted to the Technion. So one of the keys is not to give up on the young people who drop out and facilitate some education that will allow them to catch up and join university and professional schools. I see it as a national mission.

Sunday, April 3, 2011

Top 100 in Materials Science

World-class Matters
Prof. Yeshayahu Lifshitz
Prof. Yeshayahu Lifshitz from the Technion's Department of Materials Engineering has been included in Thomson Reuters list (based on Essential Science Indicators) of the top 100 materials scientists in the world of the past decade (the only one from Israel) which according to them represents the top 0.02 of 1 percent in the field.
Thomson Reuters Logo
On March 2, 2011, Thomson Reuters released the data that identifies the world’s top 100 materials scientists who achieved the highest citation impact scores for their papers (articles and reviews) published since January 2000.
Lifshitz is an active member of Technion's Russell Berrie Nanotechnology Institute (RBNI)
Image: Dept. of Materials Engineering Homepage.

Happy Passover from Technion President Peretz Lavie.


Passover 2011 Message from Technion President Prof. Peretz Lavie.

“Only when we have the courage to regard ourselves as a nation, only when we respect ourselves, can we win the respect of others; or rather, the respect of others will then come of itself.”
Technion founding father Albert Einstein, 1931.
Welcome to the April 2011 Passover issue of TechnionLIVE. At Technion, we are deeply aware of the central themes of freedom and national realization embedded within the Passover story. We were slaves in Egypt. We could have continued that way for generations, but there was a critical shift in attitude. We stopped seeing ourselves as the “problem”, and we became the solution. We took responsibility for our position, individually and as a whole, and we took an unconditional movement into our own integrity. Together, the entire Jewish workforce of Egypt got up and left. The reward for this act of responsibility and unity was great: it initiated a process in which we were to receive the land of Israel.

At the opening of the last century, we were again scattered around the planet, enduring antisemitism, persecution, and exclusion. We could complain and mourn injustice, or we could take responsibility. Embedded in the vision of Theodore Herzl was a movement into vision, responsibility and application in which freedom will always be the outcome.

The inspired question then, as ever, was: “How do we do it?” How do we build a nation from nothing? Jews were barred from technical universities and professions, and there just wasn’t the skilled manpower to begin laying the foundations of an independent state. Back then, we took responsibility, and the answer was a technical university in Haifa. 99 years ago, in 1912, the first cornerstone was laid. Nearly 100 years later, millions of people in Israel and across the world feel the reward of this freedom.
Gathering to lay the 1st cornerstone of the Technion, 1912.
This is the spirit of Technion. We don’t see problems, we see opportunities. We take responsibility for real concerns, and stone by stone, we build the basis of our freedom. 
One person who for many of us, really embodied this wisdom, was the great philanthropist and unshakeable friend of the State of Israel and the Technion Henry Taub, who sadly passed away on April 1st, 2011. A giant of his generation, Henry left his imprint on every aspect of Technion life and shaped the building of its campus. We have lost a true and beloved friend.
The past month has revealed many global challenges. In Japan, nature has shown us how truly powerful it is, unfortunately, with devastating effects. One of our former students of physics from Japan, Shumon Mor, wrote to us of the "nightmare" happening in his country.  We send our sincere hopes that recovery will come swiftly and as painlessly as possible. We also thoroughly believe and trust in the ability of our Japanese colleagues to find even smarter ways to rebuild their nation, and to meet the challenge of finding ways to heal the wounds, creating a Japan that will be stronger than ever before.

Events in Japan highlight the energy choices facing nations today. The depletion of fossil fuels brings a serious risk of war, terrorism and poverty. Events in Japan have shown that the nuclear power alternative has grave drawbacks. New energy sources - such as wind, solar, hydrogen and biofuels - need researching, improving and developing in order to power tomorrow’s world. We also need to research smarter, cleaner and more efficient ways to use conventional energy sources, including oil, coal, and Israel's newfound gas resources. Also here, in the establishment of the multidisciplinary Grand Technion Energy Program (GTEP)  we took a critical step of responsibility and vision, through which we will gain our freedom in the future.

Following events in Japan, an understandable response is to ask: "Could it happen in Israel?" The answer, unfortunately, from a top Technion disaster expert Prof. Avi Kirshenbaum, is: "Yes, it could." It is our task as scientists to come with the simulations, crisis research, building codes, sensors, and systems that will make the difference should Israel ever face a similar challenge as its friend, Japan.

Across Technion, spring is in the air and the green spaces have become a forest of spring flowers. The Zielony Graduate Student Village is getting its final touches, as it will soon become a thriving community of top graduate researchers, their partners and young children. Some of them will be pursuing advanced multidisciplinary degrees in Nanotechnology or Energy Science. These are the graduates with the spirit of responsibility and freedom that have made Israel great, some of whom you can read about at TechnionLIVE.
We sincerely wish you all a Happy Passover, and that you will feel your strength and unity with the whole Technion Family. Together, we take responsibility for our shared future, and together, we celebrate in freedom.

Henry Taub: a Giant of his Generation

Technion Family Mourns the Loss of Henry Taub, Great Friend of Israel and the Technion

“The Technion has lost a beloved friend, a visionary technology pioneer – a giant of his generation. My profound condolences to Marilyn and the family.”

Technion President, Prof. Peretz Lavie.
Henry Taub: 1927-2011.

The worldwide Technion family deeply mourns the loss of Henry Taub, who passed away in New Jersey on March 31, 2011, at the age of 83.

Henry Taub was one of the Technion’s greatest and most revered friends. His four decades of devoted service included numerous key leadership roles, including President of the American Technion Society (1974 – 1976) and Chairman of the International Board of Governors (1990 – 2003). The Technion honored him with it highest tributes: Honorary Doctor (1983) and the Technion Medal (1998).
A man of great vision and generosity, Henry Taub left his imprint on every aspect of life at the Technion and on the development of the campus. Among the projects he and his wife Marilyn promoted were the Henry and Marilyn Taub and Family Science and Technology Center, a Technion campus landmark and home to its Faculty of Computer Science, considered one of the best in the world; the Leaders in Science and Technology Faculty Recruitment Program; and the Henry and Marilyn Taub Fund for the Future.
Chairman of the Technion Board of Governors, Lawrence S. Jackier, and Chairman of the Technion Council, Yoram Alster, said “the State of Israel has lost a true friend, who understood that the future of Israel depends on the quality of its higher education and advanced technology, and strongly supported young scientists.”
Henry Taub was a visionary businessman and technology pioneer. In 1949, at the age of 22, he founded Automatic Payrolls Inc., now known as Automatic Data Processing, the leading provider of computerized payroll and benefits management services to employers in the U.S.
In addition to his decades of devoted service to the Technion, Henry Taub held active leadership roles in a variety of charitable, educational and cultural organizations such as the American Joint Distribution Committee, the United Israel Appeal, New York and Columbia universities, Interfaith Hunger Appeal and the New York Shakespeare Festival/Public Theater.
The Technion sends its most heartfelt condolences to his beloved wife Marilyn Taub, his children Ira Taub, Judith Gold and Steven Taub, his grandchildren and the entire Taub family.

Friday, April 1, 2011

A Serious Matter - Dan Shechtman and a revolution in basic science.

Clear as crystal

Three decades ago, Prof. Dan Shechtman looked into an electron microscope and couldn't believe what he saw. His discovery led to a new field of study and an ongoing candidacy for a Nobel Prize

By Asaf Shtull-Trauring Reproduced from Haaretz.

On a cool, clear Thursday morning in April 1982, Prof. Dan Shechtman was alone in the laboratory of the National Bureau of Standards in Gaithersburg, a handsome suburb of Washington D.C., where he was spending a sabbatical. At about 10 o'clock, he examined through an electron microscope a new crystal he had produced in his laboratory. The electron beam passed through the crystal and left a diffraction pattern of points of light on the screen of the microscope.

Shechtman counted the points: 10 points, arranged in a circle around a central point. He counted again and got the same result: 10 points. He had never before seen a pattern like this. Moreover, he realized immediately that the pattern he was looking at was impossible under the laws of crystallography, the science of crystals. He went out into the long corridor outside the lab, looking for someone with whom to share this strange finding. The corridor was empty. Returning to the lab, he looked again at the peculiar pattern of dots of light.

"I told myself that there is no such thing," he recalls. Since the birth of modern crystallography in 1912, when x-rays were diffracted from a crystal for the first time, until that moment 70 years later, this branch of science had relied on an unchallengeable basic tenet: the atoms in crystalline solids - such as metals, rocks or ceramic materials - are arranged in periodic order. The periodic pattern repeats itself throughout the crystal, as in a chessboard or a honeycomb hexagon. The regularity of the pattern dictates another important quality: crystals are composed of "tiles" possessing rotational symmetry. In other words, if the basic form that makes up the crystal is rotated, it will look exactly the same. A chessboard can be rotated four times, a quarter of a rotation each time, and it will look the same; the hexagon of a honeycomb can be rotated six times.

Crystallographers determined that there were only five possible rotational symmetries: single symmetry (there is only one way to rotate the tile so it will look the same ), double (two stages of rotation ), triangular, quadruple and hexagonal. The scientists concluded that there can be no pentagonal symmetry in crystals, since they cannot create periodic order - as anyone who has tried to cover a bathroom floor with five-sided tiles knows. In countless observations over many decades, crystallographers indeed saw only geometric crystals, all of them possessing rotational symmetry.

But on that April day in 1982, when Shechtman looked at the pattern of points created by the crystal of the alloy he had prepared in the lab from aluminum and manganese, he saw a structure that contradicted both rules: the 10 points that appeared through the microscope attested to the existence of pentagonal symmetry; and the immediate conclusion was that the crystal did not possess a periodic structure. Shechtman had discovered a new world, in which there are solid crystals, but the known order was gone.

"On that day the realization that this was something new trickled in, but I didn't yet know what it was," he relates.

From that very moment, when he hunched over an electron microscope and then went out to look for someone to join him in counting the 10 points, his conclusions sounded utterly baseless. Moreover, he had not come to the laboratory on the East Coast of the United States to produce far-reaching theoretical developments in the study of crystals, a field that in many ways had itself crystallized and solidified. Shechtman had been invited to the institute to do research on light alloys for the aircraft industry. Within days, his peculiar ideas generated suspicion and ridicule, to which he would be subjected for some time. Until he succeeded in convincing everyone.

Looking for a partner

"I told everyone who was ready to listen that I had material with pentagonal symmetry. People just laughed at me," Shechtman says in his office at the Technion, in Haifa. On one wall hang a row of certificates testifying that something major happened that day: the Rothschild Prize in Engineering, 1990; the Israel Prize in physics, 1998; the Wolf Prize in physics, 1999; the EMET Prize in chemistry, 2002. Amid the prize certificates Shechtman has hung Hieronymus Bosch's triptych "The Garden of Earthly Delights."

His colleagues, he says, attributed the discovery to the "twinning phenomenon," a convergence of crystals that can create a semblance of pentagonal symmetry. But Shechtman, who was familiar with the phenomenon from previous research, had already contemplated that possibility. Following a series of tests with the electron microscope on the day of the discovery, he ruled out the twinning phenomenon as a possible explanation.

In the months that followed, he tried to persuade his colleagues in the lab that what they were looking at was a previously unknown crystal. But in vain. "I knew my observations were in order. I couldn't explain the phenomenon, but I knew it was material that no one had seen before me, impossible material according to the laws of crystallography," he says. The incessant criticism sent him back to the microscope repeatedly in order to reexamine the alloy, but his initial insight remained intact.

One day, the administrative director of his research group approached him. "He gave a sheepish smile, placed a textbook on my desk and said, 'Please read what's written here.' I told him that I taught my students from the book, but that I also knew that we're dealing with something that exceeded the book's understanding," Shechtman says. The director returned 24 hours later and asked him to leave the research group, because he was "bringing disgrace" on the members.

"I felt rejected," Shechtman says. "As I see it, the head of the group expressed the view of many. He would not have reached that conclusion unless he heard from others that someone in his group was fiddling with nonsense."

Shechtman moved to another group and continued his research. However, the researchers at the institute were not able to check the discovery for themselves. Many of them did not know how to work with an electron microscope, which is the most appropriate tool for identifying rotational symmetries in small crystals. Moreover, he notes, "They were not really interested in dealing with it."

Shechtman also forwarded the findings to a friend, who was about to go on a scientific tour. When the friend returned, Shechtman relates, he brought an array of off-the-wall explanations for the 10 microscopic points, gleaned from colleagues. None of them took seriously the possibility that it was a case of pentagonal symmetry.

At the end of 1983, following the conclusion of his sabbatical, Shechtman returned to the Technion. He continued to share his discovery in Israel. But only one person was ready to listen in earnest: Prof. Ilan Blech, from the Technion's Faculty of Materials Science. He suggested that the two of them work together on the discovery. Within a short time he developed a model that derives the phenomenon from a pentagonal symmetry, which is one of the rotational symmetries of a three-dimensional body called an icosahedron - an entity composed of 20 identical equilateral triangular faces. Shechtman now felt sufficiently confident to publish an article on the subject.

Until then, he says, "I was afraid to publish alone, in case it turned out to be nonsense."

He returned to the National Bureau of Standards in Maryland in the summer of 1984, where he wrote the article together with Blech and send it to the Journal of Applied Physics. Within a short while a reply arrived from the editor, rejecting the article as not being of interest to physicists. "The editor later deeply regretted his decision," Shechtman says. Disappointed, Shechtman turned to the senior scientist John Cahn, who had invited him to work in the institute. Cahn initially had reservations, but afterward worked with Shechtman and proposed that they co-author an article. For the mathematical aspects he added a French crystallographer, Denis Gratias, and the three wrote an article that was a concise, refined version of the first article. They added Ilan Blech's name as a fourth author and sent the article to Physical Review Letters, which also deals with physics. The addition of Cahn's name turned out to be a winning move: the article appeared in November 1984, within a few weeks of its submission.

Fear and compliments

Publication of the article provoked a brouhaha in the scientific community. The discovery of a crystalline structure possessing pentagonal rotational symmetry and overall icosahedral symmetry - a concept that until then had been confined largely to the realm of mathematical amusements - demanded a fundamental change in all the textbooks on the subject. To get researchers to believe him, Shechtman described exactly how to prepare the alloy.

"There are people who keep the mode of preparation secret, but I wanted every researcher who had an appropriate laboratory to be able to prepare the material and examine it under an electron microscope within a few days," he says. "Telephone calls started coming in very soon from scientists around the world. 'I have it,' they told me."

However, despite the success in repeating the experiment in several labs, only a few scientists accepted the thesis of pentagonal symmetry. Leading scientists rejected Shechtman's conclusions, and towering above all of them was Linus Pauling, the only person ever to have been awarded the Nobel Prize twice on his own, once for chemistry and once for peace, and considered one of the most important chemists of the 20th century. The issue of quasiperiodic crystals continued to exercise him from the moment the article was published in 1984 until his death a decade later.

"There are tens of thousands of chemists in the United States, and Pauling was their star," Shechtman notes. "He would open the conferences of the American Chemical Society, and quasiperiodic crystals were always his topic. I attended one of the conferences, at Stanford. Thousands of people were there, and he attacked me. He would stand on those platforms and declare, 'Danny Shechtman is talking nonsense. There is no such thing as quasicrystals, only quasi-scientists.'

"At first, being the target of this crusade was scary at an existential level," Shechtman admits. One day, he relates, his daughter came back from school and told him she had learned about Linus Pauling. "She asked me if this was the same Linus Pauling who was against me; because if so, she said, he must be right."

Shechtman was concerned that his promotion would be impeded. "I knew that if it turned out to be a flop, it would be a major flop." Nevertheless, he says, he was very confident about the findings. Not long after the article's publication, Shechtman received a copy of "The Structure of Scientific Revolutions," by the philosopher of science Thomas Kuhn. That iconic book deals with the process by which scientific paradigms are produced and replaced. "I went through stage after stage, just as Kuhn describes. I told myself I have gone through chapter one, I have gone through chapter two, and I know what lies ahead."

In the first years following the discovery, Shechtman's support came primarily from physicists and mathematicians. But crystallographers had a serious problem with the findings: Shechtman had used an electron microscope, whereas their main tool was the x-ray. "It's as though a mechanical engineer were to explain to a heart surgeon how to perform an operation," Shechtman says. "From their point of view, I was not a crystallographer, because I had used a tool they considered imprecise and illegitimate."

It was not easy to repeat the successful experiment with the use of x-rays, which produce more accurate results than a microscope but demand larger single quasi-periodic crystals. However, in 1987, friends of Shechtman's from France and Japan succeeded in growing quasi-periodic crystals large enough for x-rays to repeat and verify what he had discovered with the electron microscope: the existence of pentagonal symmetry.

"In the forefront of science there is not much difference between religion and science People harbor beliefs. The argument with Linus Pauling was almost theological."

That summer of 1987, Shechtman presented the photographs at a large conference of crystallographers in Perth, Australia. This brought about the turning point he had been anticipating for the past five years. "Suddenly people told me, 'Now you're talking,'" he recalls. After the Perth conference, recognition of Shechtman's achievement began to trickle down into the ranks of the scientists. Linus Pauling, however, persisted in his opposition until his final day.

"In the forefront of science there is not much difference between religion and science," Shechtman says. "People harbor beliefs. That's what happens when people believe something religiously. The argument with Linus Pauling was almost theological." Still, their disagreements never deteriorated to the personal level. "At conferences people would wait for fights to break out between us over dinner. But Pauling was always cordial. He was a New Yorker with southern manners. We would sit and talk for hours about things we agreed on. For example, he was a big advocate of vitamin C, and so am I. We agreed about everything, but not about quasicrystals."

Nobel Laureate and top Materials Scientist Linus Pauling.

As his fear of not finding employment faded, Pauling's assaults became a compliment for Shechtman. "I realized that if it's Pauling against Shechtman, then at some level we are equals. From a situation in which I was on the floor and he was on the ceiling, I saw that very slowly, over a period of 10 years, the balance was shifting," he says. At the beginning of the 1990s, with Pauling also in his nineties, he made a gesture to Shechtman, inviting him to write a joint article, "Shechtman-Pauling," on quasiperiodic crystals. Shechtman replied that he would be delighted to co-author the article with him, but that Pauling first had to agree that quasi-periodic crystals in fact exist. Pauling's rejoinder was that it was apparently still too soon for a joint article. A year later, he died. With his death, the opposition to Shechtman in the scientific community vanished.

Music of chance

Like many scientific revolutions in the past, Shechtman's discovery involved luck, professionalism and determination. Indeed, Shechtman describes his whole scientific path as an interplay of those qualities. "I always say that people are like peanut shells on the ocean: the waves will take them everywhere."

Dan Shechtman was born 70 years ago in Tel Aviv and grew up in Ramat Gan and Petah Tikva. He may well have inherited his industriousness from his grandparents, who arrived in the Second Aliya (wave of Jewish immigration to Palestine, 1904-1914 ) and founded a well-known printing press. But Jules Verne was responsible for the young Shechtman's scientific aspirations. "My childhood dream was to study mechanical engineering," Shechtman says. "After reading 'The Mysterious Island' - which I read 25 times as a boy - I thought that was the best thing a person could do. The engineer in the book knows mechanics and physics, and he creates a whole way of life on the island out of nothing. I wanted to be like that."

He obtained his first degree from the Technion in 1966, but the best job he was able to find during that recession period was as an official in charge of road signs. He quickly went on to a master's degree in materials engineering, a field he came to by chance. In the senior year of his undergraduate degree, a friend told him about a nice project they could do in metallurgy. "It was quite random; if that guy hadn't approached me, I would be in a different place," he says. A year later he found himself a graduate student of metallurgy.

After obtaining his doctorate, in 1972, Shechtman did post-doctoral work for the U.S. Air Force, at the conclusion of which he was offered what he describes as a "marvelous position." Shechtman continues: "I was already married and we had three daughters. We sat down and drew up a list of reasons to stay in the United States and reasons to return to Israel. The first list was about a meter long, the second maybe a centimeter." But on the day he was supposed to sign the contract, he received a message from the Technion that he had a position there if he wanted it. "I am a Zionist and I try to do many things for Israel's good," he says. "I went to my boss and told him I was going back to Israel. He was a Jew and he understood." After six years at the Technion came a sabbatical. And during the sabbatical came that moment of discovery.

That major discovery has long since taken on a life of its own, independent of Shechtman. For more than a decade he has not been working on quasiperiodic crystals but on developing new magnesium alloys for various industrial applications, materials that can be used for implants and be absorbed by the body afterward. However, the field he founded has become a scientific branch of its own.

Prof. Shlomo Ben-Abraham, one of the first Israeli scientists to support the discovery, says, "Until Danny's discovery, we thought the subject of crystal structure was completely closed. Today, nearly 30 years later, we know we have not even scratched the surface. There is a great deal of activity, things are getting interesting and there are constant surprises and many questions to which we do not yet have an answer."

Another researcher, who took part in an international conference held in January of this year to mark Shechtman's 70th birthday, Prof. Ron Lifshitz, a physicist from Tel Aviv University, describes Shechtman's discovery as "a scientific revolution that is still in going on." Science, he says, must now answer questions that were once thought to be basic and closed, such as what a crystal is, alongside new questions, such as how the nonperiodic structure influences the qualities of those materials.

"In addition," says Lifshitz, "we need to find substitutes for the experimental and theoretical tools that were developed during many decades and are not applicable to nonperiodic crystals. Hundreds of scientists around the world are dealing with these questions. We can look forward to many years of intensive and fascinating research until we reach a point where we again think we understand everything there is to understand about crystals. At that stage, we will be ready for the next scientific revolution."

Regular candidate

Shechtman is not prone to revolutionary fervor. He prefers to view his exploits through a prism of pure professionalism, as one who simultaneously exposed the weakness of science but also its strength. For decades, crystallography clung to a mistaken description of the physical world, which was presented as a solid, total truth. On the other hand, that same science was able to acknowledge its mistake and refute long-held basic assumptions within a relatively short time, once the theory was shown to be inconsistent with reality. Still, it was necessary to have someone who is capable of shouldering the revolution.

Prof. Ben-Abraham explains Shechtman's strength: "The greatness of a discoverer lies in knowing what he has discovered. People encounter things and ignore them for one reason or another. I know of four documented cases in which people found this before Danny." However, he notes, because all the books state that pentagonal symmetry is inconsistent with periodicity of crystals, the researchers ignored what they saw.

Science truly needs to examine itself. How is it possible that in the course of investigating about a quarter of a million crystals during 70 years, scientists did not discover a single quasiperiodic crystal? It's now known that such crystals are not rare. There are hundreds of them, they are made of commonplace materials such as aluminum or iron and it is not difficult to create them. Last year such crystals were even discovered in nature. So, what was going on for 70 years?

Shechtman thinks that one of the reasons for this state of affairs is that the discovery demanded the use of non-applied materials, such as alloys with non-appliable concentrations of magnesium, and expertise in the use of an electron microscope, in which Shechtman was a professional. Those two requirements, he explains, significantly reduced the community of scientists who could have discovered quasicrystals.

At the same time, he adds: "When you see pentagonal symmetry, you have to know that it is impossible - and not everyone knows that. You have to be very professional, consistent and thorough. I repeated the investigation of the new structure several times. I wanted to check that it was not a case of flaws of periodic crystal. After I convinced myself, I was ready to fight for my opinion, and with the aid of observations to persuade colleagues of the truth of what I had found."

Since publication of the discovery, Shechtman's name has been submitted regularly as a candidate for a Nobel Prize in physics or chemistry. There appears to be broad agreement that he merits the prize. In 2008, Thomson Reuters cited his name in its annual forecast of Nobel laureates, along with Andre Geim and Konstantin Novoselov, who were in fact awarded the 2010 prize for physics.

Shechtman believes that the major obstacle standing between him and the prize is that quasiperiodic crystals have no significant applications. But Ben-Abraham is optimistic precisely in regard to the discovery's potential applications.

"Semiconductors were known for 150 years, since the middle of the 19th century, but it was only after the invention of the transistor that this field exploded. I believe the day will come when a use will also be found for quasiperiodic crystals." In the meantime, Shechtman has an important lesson to share with the select few holding a contested scientific discovery in their hands these days. "The moment you are convinced of a scientific truth," he says, "it doesn't matter what people say. But for that you have to be a professional. You have to be good at what you are doing, and when someone argues with you about the data you have collected, you have to be certain yourself that you did it right. If you are sure that you're right, don't budge until others explain to you, citing chapter and verse, that you are wrong. Those are exactly the stages I went through."

Haaretz reports on 'Shechtmanite'

In the months after the publication of Prof. Shechtman's first article, the discovery drew the attention of the world's media - but in Israel no one seemed to have heard of him, or the breakthrough. That all changed after a short random conversation between Shechtman and the physicist Prof. Benjamin Gal-Or in the Technion's faculty restaurant. "He asked me, coincidentally, what was happening, and I told him. He asked, 'How come I never heard about it?' I told him no one had heard about it, because in Israel no one was aware of what was happening in the world."

That same day, Gal-Or told the science affairs correspondent of Haaretz, Yerah Tal, about the future Nobel laureate who was wandering around the Technion campus. The next day, March 19, 1985, Shechtman's story got big play on the paper's front page, with a large photograph of the 10 points illustrating pentagonal symmetry. The headline was, "Technion scientist discovers material of new crystalline structure: Shechtmanite." From there, the rumor spread even into the Israeli academic world.