Crystal Ships

Fivefold 2d aperiodic pattern

“The main lesson that I have learned over time is that a good scientist is a humble and listening scientist and not one that is sure 100 percent in what he reads in the textbooks.”
Dan Shechtman


The neatest story I read today was about recent Israeli Nobel Prize winner Dan Shechtman. Apparently Shechtman noticed some crystal formations that weren't exactly behaving correctly, at least according to all the academic experts. He brought it to the attention of his colleagues at the university and he was vilified for it, even told that he was a humiliation to the whole department.

In 1982 Shechtman discovered a new class of solid matter called quasicrystals, with atoms so densely packed that their patterns would not repeat, as so called "normal" crystal forms are supposed to be constructed. Crystals are said to be periodic at the molecular level.

His discovery was not well received and he was forced to leave his research group, his hypothesis thought by skeptical scientists to be both preposterous and embarrassing and he was told that he "brought disgrace" to the group.

Shechtman's discovery dates to April 8, 1982, while on a sabbatical at the US National Institute of Standards and Technology, he was studying an alloy of aluminium and manganese at the time.

Shechtman was looking at a section of chilled molten metal with an electron microscope when he realized that the atomic structure appeared in a pattern that was not known to comport with any known laws of crystal structure. The pattern of dots had a tenfold symmetric pattern, while only three, four or six were thought possible. He could turn the structure and view it from ten vantages that all looked identical. He noted the discovery in his notebook that day.

Shechtman was vilified by his peers, told that his research was contrary to the laws of nature itself but he kept battling for his beliefs and finally forced fellow scientists to reconsider the nature of crystal forms. One colleague initially said, “Go away, Danny.”

Linus Pauling, a double Nobel Laureate, for chemistry and for peace, once declared publicly that 'Danny Shechtman is talking nonsense. There is no such thing as quasicrystals, only quasi-scientists.'  Paulson believed that the base five structure was the result of a combinative event called twinning. When Pauling died in the early 1990's, people started looking at Shechtman's work with fresh eyes and opposition finally vanished.

The definition of crystal had to be changed. Previously, a crystal had been defined as having “a regularly ordered, repeating three-dimensional pattern,” according to the International Union of Crystallography. The new definition, adopted in 1992, states that a crystal is simply a solid with a “discrete diffraction diagram.”

The Tel Aviv born scientist teaches at the prestigious Technion University in Haifa and is the 10th Israeli to win the nobel and the fourth to win it in Chemistry. You have to love a guy who has made an empirical discovery, gets vilified and slandered and yet has enough faith and endurance to stick to his guns, gain acceptance and shut up his detractors.

I read an interesting article about his discovery today by Richard Allen Greene of CNN of which I excerpt:

Interestingly, the structure of quasicrystals seems to have been foreshadowed in medieval Islamic art that contradicts what Western geometry had always taught."If you want to tile a bathroom floor with squares, you can do it out to infinity," said Peter J. Lu, a Harvard University professor who has studied Islamic tile work."If you want to do it with five-sides figures, there are gaps," he explained.


But Islamic artists figured out how to do it without leaving gaps by making the pattern irregular rather than repeating -- the same thing that happens in quasicrystals, he said."Aperiodic mosaics, such as those found in the medieval Islamic mosaics of the Alhambra Palace in Spain and the Darb-i Imam Shrine in Iran, have helped scientists understand what quasicrystals look like at the atomic level," the Swedish academy said.

Islamic tile patterns dating back to the early 1400s were put together in ways not understood in the West until 1973, Lu and Paul Steinhardt of Princeton University argued in a paper in 2007 in the journal Science. The Muslim artists discovered ways to tile shapes with five, 10 or 12 shapes without leaving gaps between them -- a structure thought by standard geometry to be impossible.


British mathematician and physicist Roger Penrose explained in 1973 how it was done, and just over a decade later the same pattern was found at the molecular level in quasicrystals, according to a report in Lu and Steinhardt's work in the journal Nature in 2007.


Mueller, a principle research scientist at MIT, said he was "fascinated" by the structure of quasicrystals, even as he admitted he would not have the knowledge to analyze them himself. But specialists in quasicrystals will eventually "gain knowledge of some structures which we cannot analyze with conventional methods," he predicted. The academy that awards the Nobel Prize in Chemistry said quasicrystals have a "unique atomic structure" which makes them "bad conductors of heat and electricity, and (they) have nonstick surfaces."