Recent Changes

Tuesday, February 26

Monday, November 14

  1. page B Crystal Science edited ... What is a quaiscrystal?What Is A Quasicrystal? {Zn-Mg-HoDiffraction.JPG} The defraction patte…
    ...
    What is a quaiscrystal?What Is A Quasicrystal?
    {Zn-Mg-HoDiffraction.JPG} The defraction pattern of an Icosahedral ZnMgHo Quasicrystal with 10-Fold Symmetry
    ...
    that could not be shifted
    An examination of the electron diffraction image to the right illustrates Shechtman's quasicrystal observations. This image is generated by shining a concentrated electron beam through a crystal of the test material. The electron microscope bends light in differing but predictable ways, scattered by the arrangement of atoms within lattice. This scattered light is then reflected onto an electron sensitive material (Originally a type of film, now typically a digitized photoelectric array). Scientists identify the atomic structure by examining the distribution of captured points of scattered light.
    The symmetry of the structure can be observed by drawing lines through consecutive points in the image and counting the number of resulting lines. This corresponds to the number of dots in the inner-most circle, in this case revealing 10-fold symmetry. This quantity is also observed in the dominant scatterings (the larger and brighter points) in each consecutive circle moving out from the center of the image.
    (view changes)
    4:51 am
  2. page A Introduction edited ... {http://upload.wikimedia.org/wikipedia/en/thumb/e/ed/Nobel_Prize.png/220px-Nobel_Prize.png} Th…
    ...
    {http://upload.wikimedia.org/wikipedia/en/thumb/e/ed/Nobel_Prize.png/220px-Nobel_Prize.png} The Nobel Prize.
    Daniel Shechtman's 2011 Nobel Prize in Chemistry is an inspiration for focused chemistry students. His compelling story began with a chance encounter under an electron microscope and it led to the highest honor in science. It wasn't easy. His initial exuberance turned to discouragement as his colleagues laughed in his face. But his persistence enabled him to prevail over grueling pessimism and eventually led to a Nobel Prize for the discovery of the quasicrystal.
    ...
    stated plainly: Five-sided crystalsCrystals with five fold symmetry don't exist.
    Now, many chemists and crystallographers agree on the importance of Shechtman's discovery. They include UMass-Dartmouth Assistant Professer David Manke who, in a recent interview, said it was "on the level of a Copernicus discover."
    The Nobel Prize is an international award that recognizes exceptional accomplishments in the fields of literature, peace, physics, medicine and chemistry. It was founded by scientist and innovator Alfred Nobel. Upon his death in 1895, he left most of his estate to create the prize. Since 1901, 103 Nobel Prizes in Chemistry have been awarded. Recipients of the award receive a medal, certificate and cash prize. Most importantly, winners become Nobel Laureates, distinguished forever as top echelon scientists.
    (view changes)
    4:48 am

Sunday, November 13

  1. page A Introduction edited {ENL_641_Banner_2_.png} ATTN WIKI CHEM PEOPLE: To hopefully circumvent the whole issue we're ha…
    {ENL_641_Banner_2_.png}
    ATTN WIKI CHEM PEOPLE: To hopefully circumvent the whole issue we're having, I added pages for each section that open in a new page when you click on the table of contents link. We just need the images added back into the Shechtman's Journey section, and I think we'll be ok. Add references by finding your reference in the list on the reference page, typing that number where you want the reference, and then linking it to the reference page. If you need help doing this let me know. Add additional reference to list on the reference page. I have not deleted the content on the original page yet, but plan to do so once I get the go ahead from the group. I would recommend making additional changes to the individual pages to the left which are linked to the table of contents.
    Chris has indicated that we may have more time in light of our technical issues.
    ~Jenifer
    Thanks to Jenifer for resolving this issue. The new citation method works fine. In short, cut and paste (or type in) your citations to the reference page (if they aren't already posted). Type in the applicable number in your text (for example (9)). Highlight the text and select link from the text editor>wiki link>and scroll down to the reference pages>add link. You can color the number blue by highlighting the text and selecting the text pallet. Anyone with tech issues please email me, I'll check throughout Sat and Sun.rr
    Sun am note to JE- I didn't delete the excess home page content because I didn't want to crash the whole wiki. Also, The page Undergraduate Chem Majors should be changed to Research Implications. Not sure if a rename will upset the page redirect.I'll check in later RR
    And finally-Sign-off here after you're done tweaking and editing:
    JE
    AB-Citations and edits complete
    JM- final citations complete. Read through the entire wiki and made a few small grammatical corrections. Great work everyone!
    RR-I'm all set. I'm on standby for problem resolution. Thanks group for a fine effort!
    HA-Edits complete, thanks to all
    JP I'm finished. Thanks, everyone.
    Last one out please delete everything between the Intro and the header

    Introduction
    {http://upload.wikimedia.org/wikipedia/en/thumb/e/ed/Nobel_Prize.png/220px-Nobel_Prize.png} The Nobel Prize.
    ...
    Daniel Shechtman Today
    References
    Below Here - Only Use as Reference for Other Pages
    Crystal Science
    Quasi Crystal Discovery and Revolution of the Definition of a CrystalQuasicrystals
    The Definition of a CrystalThe Definition of a Crystal
    One morning in 1982, Daniel Shechtman observed a sample mixture of Aluminum and Manganese under an Electron Microscope. Initially, he didn't believe what he saw: The scattering pattern of the x-ray crystallographic image indicated 5-fold symmetry, a crystal formation never seen before. Shechtman's skillful manipulation of the electron microscope and detailed examination of the resulting data ensured his certainty in his own work but led to persistent doubt in the scientific community for many years.
    Crystals mimic a cut-and-polished diamond with all its facets reflecting the brilliance of the world around it. A diamond is a crystal made of carbon atoms, the same carbon atoms that makeup the lead of a graphite pencil and our bodies use for fuel. Diamonds differ from pencil lead in the arrangement of their carbon atoms, packed together in what is called a crystal lattice.
    To illustrate, imagine a group of carbon atoms as connected styrofoam balls. (Need help explaining this paragraph) Connect four of them together by sticking chop sticks in them to create a cube. If you then attached many of these forms together, you would have a model resembling the arrangement of carbon atoms in a diamond. This cuboidal arrangement of atoms has symmetry in four dimensions, allowing rotation by 90 degrees 4 times before arriving back to its original orientation. However, each time {Icosahedron.gif} Icosahedron (A Platonic Solid with 2-Dimensional 5-Fold Symmetry)we rotate the grouping, it remains essentially the same. These geometric units can be stacked to infinity. Additionally, if you take any one cubic section and shift it around inside this infinite structure, it can be lined up with identical units elsewhere in the lattice. This is called Translational Symmetry.
    The historical definition of crystals comes from an examination of this type of structure. Ancient Greeks described mathematically complex 3-dimensional shapes. Philosophers such as Plato, posited that the elements of life are made up these regular geometric arrangements. The Icosahedron to the right is an example of a Platonic Solid with all of its faces being the same repeating polygon. Both these, and Archimedian Solids, are types are highly geometric structures that were (and still are) studied extensively in geometric and mathematical applications. Platonic solids are especially interesting because of the Golden Ratio a symmetric form that appears many times in nature and provides aesthetically pleasing to the human eye.
    For many years, naturally occurring crystalline solids had a narrow definition. Scientists agreed on a 3-dimensional arrangement of atoms with infinite repeating structural units that had translational symmetry in all dimensions. Constraints in 3-dimensional packing orders led to assumptions that crystalline structures could only exist with 2, 3, 4 and 6 fold symmetry. This theory was reinforced by research that proved the inability of these shapes to pack together without leaving any "void" areas, or spaces, between repeating units. Other types of symmetry would leave gaps in the structure of the crystal and these gaps were thought to lead to instability in the solid structure of the material. Observations made using X-Ray Crystallography of documented naturally occurring crystals supported this idea for many years
    What is a quaiscrystal?What Is A Quasicrystal?
    {Zn-Mg-HoDiffraction.JPG} The defraction pattern of an Icosahedral ZnMgHo Quasicrystal with 10-Fold Symmetry
    In the 1970's, crystal scientists investigated non-periodic 2-dimensional tiling patterns. Non-periodic patterns are repeating units that could be shifted within the larger pattern. These types of tilings, while displaying no unit piece or translational symmetry, seemed to follow an overarching, or long range pattern. When viewed from a distance there appeared to be some regularity to the layout of the shapes, even though it was never repeating the same pattern twice. An example of this type of tiling can be seen below in the form of a Penrose, or 2-dimensional tiling with long range 5-fold symmetry. The insights gained from 2-dimensional modeling did not begin to penetrate into examinations of 3-dimensional crystal structures until Daniel Shechtman made his unusual observation on an electron microscope in the morning of 1982. While occasional observations of such structures were in fact made before this date, due to the accepted definition of a crystal, they were not pursued.
    An examination of the electron diffraction image to the right illustrates Shechtman's quasicrystal observations. This image is generated by shining a concentrated electron beam through a crystal of the test material. The electron microscope bends light in differing but predictable ways, scattered by the arrangement of atoms within lattice. This scattered light is then reflected onto a electron sensitive material (Originally a type of film, now typically a digitized photoelectric array). Scientists identify the atomic structure by examining the distribution of captured points of scattered light.
    The symmetry of the structure can be observed by drawing lines through consecutive points in the image and counting the number of resulting lines. This corresponds to the number of dots in the inner-most circle, in this case revealing 10-fold symmetry. This quantity is also observed in the dominant scatterings (the larger and brighter points) in each consecutive circle moving out from the center of the image.
    Another type of dimensional symmetry can also be observed by examining repeating patterns in the defraction image. For example, in this image we can observe repeated pentagrams throughout the image by imagining lines between certain arrangements of the points. Since 10 is a multiple of 5, the structure of the material reveals both 5-fold and 10-fold symmetry.
    Quasicrystals typically consist of a ratio of metalic elements, frequently some sort of Aluminum alloy. They can also exist with some polymer structures. Despite being made predominately of metals (which we typically think of as conductive) quasicrystals are relatively poor conductors and only exhibit di-polar magnetic fields in certain conditions. These properties have important implications for their potential applications [1].
    Redefinition of a CrystalRedefinition of a Crystal
    Before Shechtman's discovery, 5 and 7 fold symmetries were unaccepted in {6214624380_ff0051258b_o_homepage_feature.jpg} An example of pentagonal symmetrycrystalline structures with no scientific proof to justify their existence. After many in the science community accepted Shectman's quasicrystal, the definition of a “crystal” had to be revised from the.original definition given by the International Union of Crystallography: “a substance in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating 3-dimensional pattern.”
    Now, with the concept of “quasi-crystallinity”, scientists have re-defined a crystal as “any solid having an essentially discrete diffraction diagram. 1 This is divided into two subcategories: crystallographic (those falling into the historical definition of a crystal) and non-crystallographic (aperiodic quasicrystals). So in present day the traditional definition and the quasicrystals both fall under the definition of a "crystal".
    This revised definition impacts scientists and crystallographers research. This new definition expands the “tolerance,” of the crystal community. The previous definition of crystals was as rigid as the crystals themselves, allowing no room for changes in order or symmetry – in other words, no room for growth.
    The expansion of the definition of crystals does not mean that quasicrystals have completely broken the mold. According to UMass Dartmouth researcher Siva Rasapalli, quasicrystals are still crystalline structures with some similarities to the old definition of crystals. For example, quasicrystal structure repeats inward rather than outward. So, while quasicrystals have opened up a whole new field of research for crystal science, they have only altered the landscape rather than completely changing it.
    Aside from opening the crystal community for new ideas, the revised crystal definition encouraged scientists to take action. After Shechtman’s findings, scientists increased their quasicrystal research – finding new types with decagonal, pentagonal, and octagonal symmetries.
    New or expanded scientific definition invites questions, debate, and further research. Shechtman's discovery inspired scientific quasicrystal experimentation for the past 25 years and prompted some to even take their research outside of the lab resulting in a the identification of a natural quasicrystal form.
    Icosahedrite - The Natural Quasi-CrystalIcosahedrite - The Natural Quasicrystal
    {FlorenceQCBest.jpg} The original sample of Icosahedrite (Al63Cu24Fe13) that showed natural formation
    In 2009, Daniel Shechtman’s findings resurfaced with the discovery of a naturally occurring quasicrystal called Icosahedrite. This newly approved mineral consists of the elements Al (Aluminum,) Cu (Copper,) and Fe (Iron) .
    Icosahedrite crystals have the following characteristics:
    Brittle
    Opaque
    Metallic luster
    No cleavage
    The discovery of Icosahedrite along the Khatyrka River in Chukhotka, Russia was no accident. Research teams had searched for a natural quasicrystal for over a decade.
    The Icosahedrate find changed how chemists classify minerals and the way we look at the field altogether. Eventually the teams found what they were looking for, but the results that the rock yielded were disappointing because it's still not known exactly how Icosahedrite naturally formed.
    In the laboratory, chemists can create the temperature and pressure needed to create Icosahedrite but can't explain how this natural quasicrystal forms, especially in a remote location uninterrupted by humans. Eventually, the Icosahedrite finding could lead to a new definition of minerals, the discovery of new compositions of quasicrystals, and more for you to consider in your future as chemists.
    Applications/Implications of QuasiQuasicrystal applications
    Quasicrystals display unusual hardness, low coefficients of friction (ratio of the force causing a body to slide along a plane to the normal force pressing the two surfaces together), and high thermal and electrical resistance. Proposed applications include surface treatments for ball bearings, frying pans, and other wear-resistant metals. "It's a great work of discovery, with potential applications that range from light-emitting diodes to improved diesel engines," said the president of the American Chemical Society, Nancy Jackson.
    Natural Quasicrystal Research ImpactsNatural Quasicrystal Research Impacts
    What does it mean for chemistry that quasicrystals, previously produced only in laboratories , have now been found in nature? According to UMass Dartmouth researcher David Manke, not a whole lot right now. Manke stated that the discovery of natural quasicrystals has not had any immediate impact on the science community. In fact, natural quasicrystals are far less pure than synthetic quasicrystals. In the natural samples, metals occupy a greater ratio of space. This obscures the purity and changes the diffraction pattern of the crystal, making it difficult to reproduce as a research target. This difficulty limits practical applications, meaning that it currently has little impact on the everyday work of chemists.
    However, just because this discovery has not yet had a large impact on chemistry does not mean that it is insignificant. Daniel Shechtman’s discovery fundamentally changed the way we think of crystal structures and chemistry, and his discovery eventually brought quasicrystals into the forefront of the chemistry community. This inspires us to keep looking into the mysteries that surround the formation, structure and science of crystals.
    To watch Professor Ron Lifshitz of Tel Aviv University lecture on natural quasicrystals, click here.
    Practical Quasicrystal UsesPractical Quasicrystal Uses
    Alloys and Coatings
    {alloy_wheel.jpg} David Phillips, president of the Royal Society of Chemistry, has suggested that "Quasicrystals are a fascinating aspect of chemical and material science – crystals that break all the rules of being a crystal at all. You can normally explain in simple terms where in a crystal each atom sits – they are very symmetrical. With quasicrystals, that symmetry is broken: there are regular patterns in the structure, but never repeating." He added: "They're quite beautiful, and have potential applications in protective alloys and coatings. The award of the Nobel Prize to Danny Shechtman is a celebration of fundamental research."
    'Armoring' materials - Razor blades and needles
    {razor_blade.jpg}
    Quasicrystals strengthen specialty metals. "Their closely-packed structure helps them 'armour' materials," says Phillips. Steel quasicrystals, for example, are used to imbed softer steel in razor blades and ultra-thin needles used in optical surgery."
    Cookware surfaces
    {Frying_pan.jpg}
    Quasicrystals are non-adhesive which makes them ideal non-stick surfaces for frying pans and other cooking implements.
    Insulation
    {car_engine.jpg} Quasicrystals are poor conductors of heat, making them beneficial as thermo-electrical materials, in which stored-up heat - from car engines, for instance - is converted into electricity.
    Power generation
    {lightbulb.jpg} Cesar Pay Gomez, a structural chemistry expert at Uppsala University in Sweden and an adviser to the prize committee, said research on quasicrystals is ongoing "in the field of thermal-electric applications, where waste heat can be converted to electrical currents or energy."
    Dr. Andrew Goodwin, from the department of chemistry at Oxford University, said "Shechtman's quasicrystals are now widely used to improve the mechanical properties of engineering materials and are the basis of an entirely new branch of structural science. "If there is one particular lesson we are taking from his research, it is not to underestimate the imagination of nature herself."
    x-Implications for future researchQuasicrystal Research Implications for Undergraduate Chemistry Students
    {_55836561_a1300062-quasicrystal.jpg} Need a caption
    Schechtman's resolve in the face of ridicule delivers an important lesson to chemistry students: Stand by your data,even if it contradicts accepted science. Great scientists had overcome disbelief and ridicule before Shechtman saw 10 fold crystal symmetry and credible scientific researchers continue to do the same today.
    Scientists must battle resistance from a number of opposing forces. Researchers face adversity not only from peers, as did Schechtman, but also from political leaders, the public, the media, and possibly themselves.
    Government agencies and private industry often have financial and ideological investment in the outcome of scientific research. Consequently, research can by hindered. Recent examples include stem cell research and climate change. In 2009, President Obama overturned an order that prevented the National Institutes of Health from funding research on embryonic stem cells. Such progress is encouraging, but the reality of political obstructions to unbiased science remains.
    Public distrust of scientific research is also on the rise. American citizens are well aware of government and private industry influence on science and they are naturally cautious. Web access to scientific information and science topics like disease prevention and global warming create a more educated and invested public force. When such a force leans against research findings, application of science can be slowed.
    Scientists are under a great deal of pressure to show results in a field known for incremental developments. Scientific American journalist John Ioannidis reports “false positives and exaggerated results in peer-reviewed scientific studies have reached epidemic proportions in recent years.” In a recent interview with a group of science writers, University of Massachusetts Dartmouth Assistant Professor Sivappa Rasapalli shared that overstating results has become one of the more prominent controversies in scientific research. “The two questions today are ‘Can this get published in a good journal?’ and ‘Can this get funded?’. This does not lead to good science.” warns Rasapalli.
    Chances are that most scientists will face these challenges without the prestige of a Nobel Prize and the accompanying 1.5 million dollars. Dr. Schectman advises, "The moment you are convinced of a scientific truth, 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.”
    To explain the relevance of quasicrystal research to undergraduate chemistry students we asked Sivappa Rasapalli and David Manke of the University of Massachusetts Dartmouth Chemistry department to engage in a question & answer session with Scientific Journalism students.
    x-Implications for future research-What should researchers and students do when faced with non-believers?Q: What should researchers and students do when faced with non-believers?
    Sivappa Rasapalli suggests that students and researchers "continue what you believe in. Don't give up." He recommends that if you face resistance from your peers and colleagues, you should "go to another lab" and be persistent.
    x-Implications for future research-Previous significant scientific discoveries have, at times, been "explained away" to justify the accepted theories. Why does this happen?Q: Previous significant scientific discoveries have, at times, been "explained away" to justify the accepted theories. Why does this happen?
    Sivappa Rasapalli: "Some sets of principles settle in, and people may not be ready to accept [change]." He recommends that students have a hypothesis, and be objective. "You have to rely on the data. If your data supports your hypothesis, you must decide what's next. However, if you know what you're going to expect," he says, "that's not research."
    Most importantly, he says "the science must be reproducible."
    The scientific community often gets fixated on established theories and definitions. These fixations can become like blinders, creating the equivalent of scientific tunnel vision. Scientists shouldn't dismiss controversial theories and ideas. If there is reasonable data to support a theory out of the status quo, there just might be something worth investigating further. Many scientists, including Daniel Shechtman, have faced contempt and controversy over the content and implications of their theories. Here are a few other prominent examples of theories that were initially ridiculed, only to later have their respective scientists vindicated. Many of these theories lay the foundation for modern science.
    Daniel Shechtman's Nobel Journey
    Quasicrystal Find Creates Skepticism
    Scientific discovery involves painstaking testing, accurate data compilation, and peer-reviewed publication. Daniel Shechtman's Nobel Prize began with a visual encounter under an electron microscope and only gained acceptance after he persevered through many years of aggressive rebuttal.
    As a scientist working with light aviation alloys, Shechtman studied exotic chemical compounds at the atomic level[9] One can imagine his excitement when he found a crystal form never seen before. He told his colleagues and a few laughed in disbelief. Shechtman insisted on the accuracy of his finding but his colleagues at the United States National Bureau of Standards tired of his quasicrystal theory. In a video interview posted on the right, Shechtman described the day when a fellow researcher and close friend asked him to leave the research group because of the controversy caused by his quasicrystal find. The video also describes an incident when a colleague handed him a basic chemistry book and sarcastically told him to read it closely. Others argued that his reported quasicrystals were the result of "twinning phenomenon" found when large crystal groups merge.[11] Eventually, a frustrated Shechtman joined another research group affiliated with a different institute, but they were unable to recreate his experiment. They didn't have high-powered electron microscope skills necessary and were uninterested in proving the validity of his claim.(H) Delayed Publication Fuels Controversy To gain scientist acceptance, Shechtman had to validate his findings by publishing his research in a peer-reviewed journal. Two years after his initial discovery, Ian Blech, a fellow researcher from Israel’s Technion University wrote a paper that supported Shechtman’s findings. (“PhysicsCentral: Buzz Blog,” n.d.-a) The respected Journal of Applied Physics refused to publish the paper because they felt that their publication wouldn’t provide a suitable audience. The trade publication Metallurgical Transactions accepted the article but never actually published it.[12] Desperate for publication, Shechtman condensed the paper with the assistance of John Cain, his host at the National Bureau of Standards. In 1984, Physical Review Letters published the condensed version of the paper. Shechtman described how to recreate the experiment and a few scientists duplicated the experiment. At the same time, several prominent scientists including two-time Nobel laureate Linus Pauling became vocal disbelievers.(H) Linus Pauling Leads Skeptics Pauling, probably the most famous chemist of this time, published a rebuttal article in the October 10,1985 issue of Nature magazine. The article argued that Shectman’s irregular-shaped crystals were formed by a natural process called icosahedral twinning. He argued that Shechtman actually observed a crystal formation caused by a merging of conventional crystal shapes, not the unusual “five-fold axis” Shechtman identified Reference - double click to edit. Pauling further argued against Shechtman’s findings in a letter to the editor published in the January 4,1986 issue of Science News. The letter, titled “The Nonsense about Quasicrystals”, included a complaint that many other crystallographers lost interest in disproving Shechtman. Reference - double click to edit Determined to disprove Shechtman wrong, Pauling retreated to the laboratory. In the November 15, 1988 issue of the Proceedings of the National Academy of Sciences he published a paper titled Unified Structure Theory of Icosahedral Quasicrystals. The paper began with a strong denunciation of Shechtman's work and it included data supporting Pauling’s twinning theory. Shechtman Prevails Pauling's obsession with disproving Shechtman continued at many scientific conferences. Shechtman described one conference where Pauling's opening statement included the comment: "Danny Shechtman is talking nonsense. There is no such thing as quasicrystals, only quasi-scientists." (H) Needing inspiration, Shechtman persevered by reading The Structure of Scientific Revolutions by Thomas Kuhn a book that describes how controversial science gains acceptance through a step-by-step process of refinement and persistence. (H) The unavailability of electron microscopes continued to delay peer acceptance of Shechtman's work. Crystal scientists preferred x-rays. Acceptance of quasicrystal structure began to gain momentum when Shechtman grew a crystal large enough to be seen by an x-ray beam. Shechtman's finally prevailed after his presentation at a crystallographers conference in 1987. Slowly, his colleagues accepted his findings. Linus Pauling continued to doubt Shechtman's work. However, this distrust was never at the personal level. The two often talked for hours about science, but they never agreed on the existence of the quasicrystal.(H) Daniel Shechtman Today Dr. Daniel Shechtman, 70, is a professor of materials science at Technion-Israel Institute of Technology in Haifa, Israel where he holds the Philip Tobias Chair. He is also a professor at Iowa State University and a researcher at the United States Department of Energy’s Ames Laboratory. Although the practical applications of quasicrystals are currently thought to be limited, he continues to study magnesium alloys and other materials that are strong but can also be stretched or otherwise manipulated without breaking. At Technion-Israle Institute, he leads a research group focused on the Icosahedral Phase, the first structure in the field of quasi-crystals. The group is studying the crystallography and properties of the icosahedral phase in several alloy systems. They are also researching structural defects in CVD diamond wafers and their effect on the wafer’s properties and growth. In 2004, Shechtman, who goes by “Danny,” joined the faculty of Iowa State in Ames, Iowa. He currently spends four to five months a year teaching and conducting research at the school as part of a part-time appointment. He is expected to return to the school in mid-February. He is married to Professor Zipora Shechtman, department head of Counseling and Human Development at the Univeristy of Haifa. Shechtman has compared winning the Nobel Prize to carrying his country’s flag at the Olympics. When asked about the impact the prize will have on his life, Shechtman said he would return to teach at the Technion. “Life will return relatively quickly to normal I imagine, he said.” ^ S. Jazbec, “The Properties and Applications of Quasicrystals,” University of Ljublijana Department of Mathematics and Physics Seminar II (December 2009), http://mafija.fmf.uni-lj.si/seminar/files/2009_2010/Quasicrystals.pdf. ^ Lidin S. (2011). The discovery of quasicrystals. Retrieved from The Royal Swedish Academy of Sciences website: http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2011/press.html ^ Quasicrystals. Retrieved November 1, 2011 from http://www.kri.physik.uni-muenchen.de/geo/crystal/neutronen/quasicrystals.html ^ Wang, N. Quasicrystals with 8-fold symmetry. Retrieved November 1, 2011 from http://phz389.ust.hk/lab2/index.php?option=com_content&task=view&id=45 ^ Bindi L., P. Steinhardt, N. Yao, & P. Lu (2009, June 4). Natural Quasicrystals. Science, (324), 1306-1309. Retrieved from http://unifi.it/upload/sub/notizie/naturalquasicrystals_science.pdf ^ Bindi L., P. Steinhardt, N. Yao, & P. Lu (2011). Icosahedrite, Al63Cu24Fe13, The First Natural Quasicrystal. American Mineralogist, (96). Retrieved from http://wwwphy.princeton.edu/~steinh/icosahedriteAmMin.pdf ^ Appel, Adrianne (2008, February 4). Top scientists want research free from politics. Inter Press Service. Retrieved from http://ipsnews.net/news.asp?idnews=41205 ^ Ioannidis, John P. (2011, May 31). An epidemic of false claims. Retrieved from http://www.scientificamerican.com/article.cfm?id=an-epidemic-of-false-claims ^ Clear as crystal - Haaretz Daily Newspaper | Israel News. (n.d.). Retrieved October 19, 2011, from http://www.haaretz.com/weekend/magazine/clear-as-crystal-1.353504 ^ Clear as crystal - Haaretz Daily Newspaper | Israel News. (n.d.). Retrieved October 19, 2011, from http://www.haaretz.com/weekend/magazine/clear-as-crystal-1.353504 ^ Prof. Dan Shechtman Nobel Laureate Chemistry. (2010). Retrieved from http://www.youtube.com/watch?v=EZRTzOMHQ4s&feature=youtube_gdata_player ^ PhysicsCentral: Buzz Blog. (n.d.). Retrieved October 15, 2011, from http://www.physicscentral.com/buzz/blog/index.cfm?postid=3608826130938035347 ^ S. Jazbec, “The Properties and Applications of Quasicrystals,” University of Ljublijana Department of Mathematics and Physics Seminar II (December 2009), http://mafija.fmf.uni-lj.si/seminar/files/2009_2010/Quasicrystals.pdf. ^ Lidin S. (2011). The discovery of quasicrystals. Retrieved from The Royal Swedish Academy of Sciences website: http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2011/press.html ^ Quasicrystals. Retrieved November 1, 2011 from http://www.kri.physik.uni-muenchen.de/geo/crystal/neutronen/quasicrystals.html ^ Wang, N. Quasicrystals with 8-fold symmetry. Retrieved November 1, 2011 from http://phz389.ust.hk/lab2/index.php?option=com_content&task=view&id=45 ^ Bindi L., P. Steinhardt, N. Yao, & P. Lu (2009, June 4). Natural Quasicrystals. Science, (324), 1306-1309. Retrieved from http://unifi.it/upload/sub/notizie/naturalquasicrystals_science.pdf ^ Bindi L., P. Steinhardt, N. Yao, & P. Lu (2011). Icosahedrite, Al63Cu24Fe13, The First Natural Quasicrystal. American Mineralogist, (96). Retrieved from http://wwwphy.princeton.edu/~steinh/icosahedriteAmMin.pdf ^ Appel, Adrianne (2008, February 4). Top scientists want research free from politics. Inter Press Service. Retrieved from http://ipsnews.net/news.asp?idnews=41205 ^ Ioannidis, John P. (2011, May 31). An epidemic of false claims. Retrieved from http://www.scientificamerican.com/article.cfm?id=an-epidemic-of-false-claims ^ Clear as crystal - Haaretz Daily Newspaper | Israel News. (n.d.). Retrieved October 19, 2011, from http://www.haaretz.com/weekend/magazine/clear-as-crystal-1.353504 ^ Clear as crystal - Haaretz Daily Newspaper | Israel News. (n.d.). Retrieved October 19, 2011, from http://www.haaretz.com/weekend/magazine/clear-as-crystal-1.353504 ^ Prof. Dan Shechtman Nobel Laureate Chemistry. (2010). Retrieved from http://www.youtube.com/watch?v=EZRTzOMHQ4s&feature=youtube_gdata_player ^ S. Jazbec, “The Properties and Applications of Quasicrystals,” University of Ljublijana Department of Mathematics and Physics Seminar II (December 2009), http://mafija.fmf.uni-lj.si/seminar/files/2009_2010/Quasicrystals.pdf. ^ Quasicrystals. Retrieved November 1, 2011 from http://www.kri.physik.uni-muenchen.de/geo/crystal/neutronen/quasicrystals.html ^ Wang, N. Quasicrystals with 8-fold symmetry. Retrieved November 1, 2011 from http://phz389.ust.hk/lab2/index.php?option=com_content&task=view&id=45 ^ Bindi L., P. Steinhardt, N. Yao, & P. Lu (2009, June 4). Natural Quasicrystals. Science, (324), 1306-1309. Retrieved from http://unifi.it/upload/sub/notizie/naturalquasicrystals_science.pdf ^ Bindi L., P. Steinhardt, N. Yao, & P. Lu (2011). Icosahedrite, Al63Cu24Fe13, The First Natural Quasicrystal. American Mineralogist, (96). Retrieved from http://wwwphy.princeton.edu/~steinh/icosahedriteAmMin.pdf ^ Appel, Adrianne (2008, February 4). Top scientists want research free from politics. Inter Press Service. Retrieved from http://ipsnews.net/news.asp?idnews=41205 ^ Ioannidis, John P. (2011, May 31). An epidemic of false claims. Retrieved from http://www.scientificamerican.com/article.cfm?id=an-epidemic-of-false-claims ^ Clear as crystal - Haaretz Daily Newspaper | Israel News. (n.d.). Retrieved October 19, 2011, from http://www.haaretz.com/weekend/magazine/clear-as-crystal-1.353504 ^ Clear as crystal - Haaretz Daily Newspaper | Israel News. (n.d.). Retrieved October 19, 2011, from http://www.haaretz.com/weekend/magazine/clear-as-crystal-1.353504
    S. Jazbec, “The Properties and Applications of Quasicrystals,” University of Ljublijana Department of Mathematics and Physics Seminar II (December 2009), http://mafija.fmf.uni-lj.si/seminar/files/2009_2010/Quasicrystals.pdf.
    Quasicrystals. Retrieved November 1, 2011 from http://www.kri.physik.uni-muenchen.de/geo/crystal/neutronen/quasicrystals.html
    Wang, N. Quasicrystals with 8-fold symmetry. Retrieved November 1, 2011 from http://phz389.ust.hk/lab2/index.php?option=com_content&task=view&id=45
    Bindi L., P. Steinhardt, N. Yao, & P. Lu (2009, June 4). Natural Quasicrystals. Science, (324), 1306-1309. Retrieved from http://unifi.it/upload/sub/notizie/naturalquasicrystals_science.pdf
    Bindi L., P. Steinhardt, N. Yao, & P. Lu (2011). Icosahedrite, Al63Cu24Fe13, The First Natural Quasicrystal. American Mineralogist, (96). Retrieved from http://wwwphy.princeton.edu/~steinh/icosahedriteAmMin.pdf
    Appel, Adrianne (2008, February 4). Top scientists want research free from politics. Inter Press Service. Retrieved from http://ipsnews.net/news.asp?idnews=41205
    Ioannidis, John P. (2011, May 31). An epidemic of false claims. Retrieved from http://www.scientificamerican.com/article.cfm?id=an-epidemic-of-false-claims
    Clear as crystal - Haaretz Daily Newspaper | Israel News. (n.d.). Retrieved October 19, 2011, from http://www.haaretz.com/weekend/magazine/clear-as-crystal-1.353504

    (view changes)
    9:52 pm
  2. page A Introduction edited ... JE AB-Citations and edits complete JM JM- final citations complete. Read through the entir…
    ...
    JE
    AB-Citations and edits complete
    JMJM- final citations complete. Read through the entire wiki and made a few small grammatical corrections. Great work everyone!
    RR-I'm all set. I'm on standby for problem resolution. Thanks group for a fine effort!
    HA-Edits complete, thanks to all
    (view changes)
    9:02 am
  3. page B Crystal Science edited ... {Zn-Mg-HoDiffraction.JPG} The defraction pattern of an Icosahedral ZnMgHo Quasicrystal with 10…
    ...
    {Zn-Mg-HoDiffraction.JPG} The defraction pattern of an Icosahedral ZnMgHo Quasicrystal with 10-Fold Symmetry
    In the 1970s, crystal scientists investigated non-periodic 2-dimensional tiling patterns. Non-periodic patterns are repeating units that could be shifted within the larger pattern. These types of tilings, while displaying no unit piece or translational symmetry, seemed to follow an overarching, or long range pattern. When viewed from a distance there appeared to be some regularity to the layout of the shapes, even though it was never repeating the same pattern twice. An example of this type of tiling can be seen below in the form of a Penrose, or 2-dimensional tiling with long range 5-fold symmetry. The insights gained from 2-dimensional modeling did not begin to penetrate into examinations of 3-dimensional crystal structures until Daniel Shechtman made his unusual observation on an electron microscope in the morning of 1982. While occasional observations of such structures were in fact made prior to Shechtman's observations, due to the accepted definition of a crystal at the time, they were not pursued.
    ...
    reflected onto aan electron sensitive
    The symmetry of the structure can be observed by drawing lines through consecutive points in the image and counting the number of resulting lines. This corresponds to the number of dots in the inner-most circle, in this case revealing 10-fold symmetry. This quantity is also observed in the dominant scatterings (the larger and brighter points) in each consecutive circle moving out from the center of the image.
    Another type of dimensional symmetry can also be observed by examining repeating patterns in the defraction image. For example, in this image we can observe repeated pentagrams throughout the image by imagining lines between certain arrangements of the points. Since 10 is a multiple of 5, the structure of the material reveals both 5-fold and 10-fold symmetry.
    ...
    Before Shechtman's discovery, 5 and 7 fold symmetries were unaccepted in {6214624380_ff0051258b_o_homepage_feature.jpg} An example of pentagonal symmetrycrystalline structures with no scientific proof to justify their existence. After many in the science community accepted Shectman's quasicrystal, the definition of a “crystal” had to be revised from the.original definition given by the International Union of Crystallography: “a substance in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating 3-dimensional pattern.”[2]
    Now, with the concept of “quasi-crystallinity”, scientists have re-defined a crystal as “any solid having an essentially discrete diffraction diagram. This is divided into two subcategories: crystallographic (those falling into the historical definition of a crystal) and non-crystallographic (aperiodic quasicrystals). So in present day, both crystals falling under the traditional definition and the new quasicrystal structures fall under the definition of a "crystal" [1].
    ...
    and crystallographers research. This new definitionresearch because it expands the
    The expansion of the definition of crystals does not mean that quasicrystals have completely broken the mold. According to UMass Dartmouth researcher Siva Rasapalli, quasicrystals are still crystalline structures with some similarities to the old definition of crystals. For example, quasicrystal structure repeats inward rather than outward. So, while quasicrystals have opened up a whole new field of research for crystal science, they have only altered the landscape rather than completely changing it.
    Aside from opening the crystal community for new ideas, the revised crystal definition encouraged scientists to take action. After Shechtman’s findings, scientists increased their quasicrystal research – finding new types with decagonal, pentagonal, and octagonal symmetries [3][4].
    (view changes)
    8:58 am
  4. page A Introduction edited ... Daniel Shechtman's 2011 Nobel Prize in Chemistry is an inspiration for focused chemistry stude…
    ...
    Daniel Shechtman's 2011 Nobel Prize in Chemistry is an inspiration for focused chemistry students. His compelling story began with a chance encounter under an electron microscope and it led to the highest honor in science. It wasn't easy. His initial exuberance turned to discouragement as his colleagues laughed in his face. But his persistence enabled him to prevail over grueling pessimism and eventually led to a Nobel Prize for the discovery of the quasicrystal.
    Shechtman's findings contradicted longstanding crystal theory and conclusions about the nature of matter. Before Shechtman's discovery, science texts stated plainly: Five-sided crystals don't exist. His discovery in 1982 fueled a decade of crystal science controversy.
    ...
    Professer David Mankewho,Manke who, in a
    The Nobel Prize is an international award that recognizes exceptional accomplishments in the fields of literature, peace, physics, medicine and chemistry. It was founded by scientist and innovator Alfred Nobel. Upon his death in 1895, he left most of his estate to create the prize. Since 1901, 103 Nobel Prizes in Chemistry have been awarded. Recipients of the award receive a medal, certificate and cash prize. Most importantly, winners become Nobel Laureates, distinguished forever as top echelon scientists.
    In this wiki, we will first explain basic crystal science and then discuss the practical applications of quasicrystals. We will conclude by describing Daniel Shechtman's Nobel journey.
    (view changes)
    8:48 am
  5. page B Crystal Science edited ... Quasicrystals exhibit long range order that appears similar to the tiling patterns mentioned e…
    ...
    Quasicrystals exhibit long range order that appears similar to the tiling patterns mentioned earlier, but in three dimensions. This long range order follows strict mathematical regularity, even without translational symmetry. The golden ratio is involved in the shape of the atoms occurring in the "void" areas [12]. Just as in non-periodic tiling patterns, these gaps are filled by an atom of a complementary shape. Depending on how a quasicrystal is made, these in-between portions are able to stabilize the structure of the quasicrystal to different degrees. Initial quasicrystal structures were metastable, and degraded with time [1]. This contributed to doubt about Shectman's work since he was initially unable to produce the sample used to produce his electron diffraction patterns.
    Redefinition of a CrystalRedefinition of a Crystal
    ...
    repeating 3-dimensional pattern.”pattern.”[2]
    Now, with the concept of “quasi-crystallinity”, scientists have re-defined a crystal as “any solid having an essentially discrete diffraction diagram. This is divided into two subcategories: crystallographic (those falling into the historical definition of a crystal) and non-crystallographic (aperiodic quasicrystals). So in present day, both crystals falling under the traditional definition and the new quasicrystal structures fall under the definition of a "crystal" [1].
    This revised definition impacts scientists and crystallographers research. This new definition expands the “tolerance,” of the crystal community. The previous definition of crystals was as rigid as the crystals themselves, allowing no room for changes in order or symmetry – in other words, no room for growth.
    (view changes)
    8:38 am
  6. page C Applications edited ... Quasicrystals display unusual hardness, low coefficients of friction (ratio of the force causi…
    ...
    Quasicrystals display unusual hardness, low coefficients of friction (ratio of the force causing a body to slide along a plane to the normal force pressing the two surfaces together) and high thermal and electrical resistance. Proposed applications include surface treatments for ball bearings, frying pans and other wear-resistant metals. "It's a great work of discovery, with potential applications that range from light-emitting diodes to improved diesel engines," said Nancy Jackson, president of the American Chemical Society.
    Natural Quasicrystal Research ImpactsNatural Quasicrystal Research Impacts
    ...
    in laboratories [5][6] -- have
    However, just because this discovery has not yet had a large impact on chemistry does not mean that it is insignificant. Daniel Shechtman’s discovery fundamentally changed the way we think of crystal structures and chemistry, and his discovery eventually brought quasicrystals into the forefront of the chemistry community. This inspires us to keep looking into the mysteries that surround the formation, structure and science of crystals.
    To watch Professor Ron Lifshitz of Tel Aviv University lecture on natural quasicrystals, click here.
    (view changes)
    8:35 am
  7. page B Crystal Science edited ... This revised definition impacts scientists and crystallographers research. This new definition…
    ...
    This revised definition impacts scientists and crystallographers research. This new definition expands the “tolerance,” of the crystal community. The previous definition of crystals was as rigid as the crystals themselves, allowing no room for changes in order or symmetry – in other words, no room for growth.
    The expansion of the definition of crystals does not mean that quasicrystals have completely broken the mold. According to UMass Dartmouth researcher Siva Rasapalli, quasicrystals are still crystalline structures with some similarities to the old definition of crystals. For example, quasicrystal structure repeats inward rather than outward. So, while quasicrystals have opened up a whole new field of research for crystal science, they have only altered the landscape rather than completely changing it.
    ...
    octagonal symmetries [3].[3][4].
    New or expanded scientific definition invites questions, debate, and further research. Shechtman's discovery inspired scientific quasicrystal experimentation for the past 25 years and prompted some to even take their research outside of the lab resulting in a the identification of a natural quasicrystal form.
    Icosahedrite - The Natural Quasi-CrystalIcosahedrite - The Natural Quasicrystal
    {FlorenceQCBest.jpg} The original sample of Icosahedrite (Al63Cu24Fe13) that showed natural formation
    In 2009, Daniel Shechtman’s findings resurfaced with the discovery of a naturally occurring quasicrystal called Icosahedrite. This newly approved mineral consists of the elements Al (Aluminum,) Cu (Copper,) and Fe (Iron).
    ...
    following characteristics [4]:[5]:
    Brittle
    Opaque
    (view changes)
    8:35 am

More