Nobel month is coming to an end. Each field’s prominent science journals are recognizing their winners. As the new resident chemist here at Skepchick, I wanted to recognize Daniel Shechtman of Technion-Israel Institute of Technology in Haifa as this years winner of the chemistry Nobel Prize. His once ridiculed discovery of “quasicrystals” received the ultimate justification when a phone call from Sweden came earlier this month.
Crystals had been traditionally defined as a material where atoms are arranged in a regular, repeating pattern. This limits crystals to particular shapes such as triangles, squares, and hexagons with three, four, and six fold symmetry, respectively. However, shapes in crystals such as pentagons with five fold symmetry are impossible because the material will always exhibit gaps. In 1982, Shechtman saw something that contradicted popular science.
While working at the National Institute of Standards and Technology, he viewed experimental evidence indicating 10 fold symmetry. Shechtman was convinced of the seemingly impossible results the first day. Over the next several weeks, he checked and rechecked his work each time confirming his conclusions. Once he told his colleagues about the evidence he received taunting and ridicule. Later his boss asked him to leave the research group because the embarrassment associated with the discovery was too great. In 1984, he published his work in Physical Review Letters and that is when “all hell broke loose” according to Shechtman.
The simple experiment could easily be repeated by other research groups confirming what Shechtman saw, however the arrangement of the atoms remained a mystery. The answer was gleaned from mathematicians who were examing tile patterns. Penrose elucidated the pattern in the 1970’s. Patterns such as this were created by Arabic artists as early as the 13th century and can still be seen at the Alhambra Palace in Granada, Spain. I had the opportunity to visit the Alhambra this summer and the symmetry of the art creates a unique beauty.
Shechtman showed his colleague, Steinhardt, a pre-print copy of the 1984 paper. Steinhardt and his student, Dov Levine, had been designing chemical structures based on Penrose tiling. They published a paper shortly after Shechtmans detailing their structures and named them “quasicrystals.” Despite the evidence by multiple research groups, not all members of the chemical community were convinced. It wasn’t until three years later when a quasicrystal was grown large enough for experimental X-ray diffraction that the mockery decreased. Shechtman labeled that as “the turning point” and in 1992 the International Union of Crystallography changed the definition of a crystal to “any solid having an essentially discrete diffraction pattern.”
Quasicrystals have been found to exist nature. The first example discovered in the Koryak Mountains in eastern Russia was published in Science on June 5, 2009. They have also been found in one of the world’s most durable steels used for razors by a company in Sweden. Many other industrial applications are being explored including nonstick coating in pans and thermoelectric materials.
Fascinating narratives often accompany research and this is another case. It is an almost movie-esque overcoming of the odds, from embarassment to Nobel. I also appreciate the elegant research that further explains beauty in nature and art. Ultimately, I applaud Shechtman for sticking to his guns and dealing with the heat associated with his discovery.
Science 14 October 2011:
Vol. 334 no. 6053 p. 165