The original version of This story appeared in How many magazine.
Since their discovery in 1982, exotic materials known under the name of quasicrystats have had physicists and chemists Bedevitald. Their atoms are organized in pentagonous chains, decagons and other forms to form patterns that never repeat themselves. These models seem to challenge physical laws and intuition. How can atoms “know” how to train non-repetitive arrangements elaborated without an advanced sub-demand of mathematics?
“The quasi-cristals are one of those things that as a scientist of the materials, when you learn them for the first time, you say to yourself:” It’s crazy “,” said Wenhao sunto a scientist of materials at the University of Michigan.
Recently, however, a wave of results supported some of their secrets. In A studyThe sun and the collaborators have adapted a method to study the crystals to determine that at least some quasi -cristals are thermodynamically stable – their atoms will not be intra an arrangement of lower energy. This observation helps to explain how and why the quasi-cristals are formed. HAS Second study Gave a new way of quasi-cristals engineering and to observe them in the training process. And a third research group has recorded Previous unknown properties of these unusual materials.
Historically, the quasi-cristals have been a challenge to create and characterize.
“There is no doubt that they have interesting properties,” said Sharon GlotzerTo the IT physicist who is also based at the University of Michigan but which was not an involution in this work. “But being able to do them in bulk, to make them evolve, at the industrial level -[that] Did not seem possible, but I think it will start to show us how to do it in a reproducible way. “”
Symmetries `prohibited ”
Almost a decade before the Israeli physicist Dan Shechtman I discovered the first examples of quasicristales in the laboratory, the British mathematical physicist Roger Penrose thought that the motifs “almost periodic” – almost but not quite – models that would manifest in these materials.
Leaning Sets of developed tiles This neck covers the anal plane without gaps or rides, in models that do not and cannot repeat. Unlike triangles, rectangles and hexagons testellations – in two, three, four or six axes symmetrical forms, and what a tile space in periodic models – Penrose stories have a “prohibited” five -time symmetry. The tiles form pentagonal arrangements, but the pentagons cannot adapt perfectly side by side to tile the plane. I know, where the tiles align along five axes and the endless pepper, different sections of the pattern are only similar; The exact repetition is impossible. The almost periodic fishermen of penrose made the cover of American scientist In 1977, five years before spending pure mathematics in the real world.
