Thursday, October 20, 2011

Prof. Balaram's Editorial on This Year's Chemistry Nobel

The latest issue of Current Science features this editorial: Seeing is Believing: Quasicrystals and the Demise of Perfect Order. [More on the "demise of perfect order" below].

In his editorial, Prof. P. Balaram summarizes the history of the discovery of quasicrystals and its aftermath, interleaving them with musings on two other high profile discoveries from the 1980s -- high Tc superconductivity and Fullerenes.

Towards the end, he gets to the Linus Pauling's intense -- and intensely misguided -- opposition to the idea of quasicrystals ("there are no quasicrystals, only quasi-scientists," he quipped), and concludes that the "duel over the nature of quasicrystals seems mild" when one actually considers some of the "past battles in science" that have been far more vicious. How vicious? He quotes from Jacob Bronowski's Ascent of Man:

Who would think that only in 1900, people were battling, one might say to the death, over the issue whether atoms are real or not. The great philosopher Ernst Mach in Vienna said, No. The great chemist Wilhelm Ostwald said, No. And yet one man, at the critical turn of the century, stood up for the reality of atoms on fundamental grounds of theory. He was Ludwig Boltzmann…. Did Boltzmann just argue? No. He lived and died that passion. In 1906, at the age of sixty two, feeling isolated and defeated, at the very moment when atomic doctrine was going to win, he thought all was lost, and he committed suicide.

Balaram has produced an engrossing essay, but he gets one thing wrong -- that quasicrystals, somehow, imply a "demise of order." As my colleague Prof. S. Ranganathan said in an e-mail conversation (excerpted here with his permission):

... To echo Mark Twain, Perfect Order might as well say "The report of my death was an exaggeration," ... Quasicrystals are as highly ordered as crystals. What they lack is strict translational periodicity, but they sport "forbidden "rotational symmetries -- they are quasiperiodic. ... The divorce between order and periodicity is the beauty of Shechtman's discovery. [bold emphasis added]

* * *

Update: Here's another another great quote I received from Prof. Ranganathan; I'm reproducing his e-mail in its entirety:

From Mark Twain to G K Chesterton via Martin Gardner:

A sort of secret treason in the Universe

G. K. Chesterton once suggested that an extraterrestrial being, observing how many features of a human body are duplicated on the left and the right, would reasonably deduce that we have a heart on each side. The world, he said, "looks just a little more mathematical and regular than it is; its exactitude is obvious, but its inexactitude is hidden; its wildness lies in wait." Everywhere there is a "silent swerving from accuracy by an inch that is the uncanny element in everything . . . a sort of secret treason in the universe."

The passage is a nice description of Penrose's planar worlds.


  1. Anonymous said...

    Hi all,

    Are there any mathematical measures to adequately capture the entire spectrum of orderliness, from full order to full disorder: i.e. the spectrum from materials of highest order (e.g. an FCC/HCP metal) through various materials of intermediate order (quasicrystals, polymers of varying degrees of crystallinity, liquid crystals), through any possible order present in liquids, and so on, on to the greatest disorder (gases)?

    Any measure other than the broadening of the essentially discrete diffraction spots (or the softening of their otherwise sharp boundaries)? (BTW, has any one at all used such broadening/softening, as a serious quantitative measure of the order/disorder?)

    If yes, how do the proposed measures factor in, or deal with, the issue of the scale (i.e. the resolution), and the periodicity or otherwise of the reference volume itself?

    Thanks in advance for any links/thoughts.

    PS: Another related question: What about discrete spots that are not very well ordered in the Fourier space (i.e. in the diffraction pattern)? How do they deal with that, in the theory---if they at all do?


  2. Wavefunction said...

    Another chemical controversy worth mentioning is the non-classical ion debate waged principally by H C Brown and Saul Winstein in the 60s and 70s. Some say Winstein died early partly because of the stress.

    Ajit: I don't know about crystals but here's a recent attempt trying to mathematically capture the order-disorder continuum in case of proteins.

    Protein structure along the order-disorder continuum.
    Fisher CK, Stultz CM.
    J Am Chem Soc. 2011 Jul 6;133(26):10022-5. Epub 2011 Jun 13.