No ordinary math

Harvard applied mathematics professor Lakshminarayan Mahadevan likes to solve problems from how skin wrinkles to how a sheet can be made to stay afloat

Two years ago,he famously dusted the magic carpet out of Arabian Nights and gave it a dreamy scientific possibility. When Lakshminarayan Mahadevan,professor of applied mathematics and physics at Harvard University in Cambridge,Massachusetts,and his associates concluded in December 2007 that a sheet rippling through a fluid a medium in which molecules move freely,such as in air could be made to stay afloat,it seemed to matter little to the media that their DIY guide to making a flying carpet 10 cm long and 0.1 mm thickvibrating at 10 Hz with an amplitude of 0.25 mmcould never carry an Aladdin,or his pet monkey for that matter. Mahadevan insists the study was a precise mathematical treatment,and not driven by fantasy,inspired as it was by a sheet of paper sliding effortlessly on a table top.

All the hype belies the essential simplicity that drives Mahadevans research,which ranges from predicting wrinkles mathematically and developing a theory of draping cloth to studying Miura-oria folded origami structure developed by Japanese aeronautics engineer Koryo Miura,it is a periodic array of geometrically and elastically coupled mountain and valley folds that allows the entire structure to be folded or unfolded simultaneouslyto find that hornbeam leaves follow the pattern,allowing them to open and close with ease.

The IIT-Madras and Stanford University alumnus has bagged the MacArthur fellowshipwhich comes with a grant of 500,000 over five yearsthis year for his extraordinary and eclectic work.

How do snakes propel themselves on land? What determines the waves a flag makes when aflutter? How does the venus fly-trap shut fast enough to trap an insect? Non-linear and non-equilibrium behaviour interests Mahadevan,who admits his curiosity is a double-edged sword,in turns inspiring and frustrating,since he cannot find enough time to pursue all the things that I would like to.

Mahadevans equations may be complex,but they seek to underline and explain ubiquitous,convergent patterns in nature and everyday objects. In an age of super-specialisation,the diversity of his research is brave and charming. Scientists have always been generalists and specialistswe like to solve specific problems and also generalise from them towards broader perspectives, he says.

While his mathematical models cannot always account for all the non-linear forces at work,they do provide insights on how things are ordered in space and time. Which is why structureand how it changesis essential to his research. Playing with folds and flutters has led him to study wrinkles on skin,and by extensionapplied math,by definition,is full of far-reaching analogiesthose on the earths crust. Mahadevan and his colleagues found in 2003 that the wavelength and amplitude of wrinkles could be predicted through a single quantitative framework based on the idea that the outer layer of skin,which is a thin surface,prefers one large fold rather than several small ones,while the layer underneath is stiffer and tends to form smaller waves.

Born in Delhi,Mahadevan visits India once a year. My fondest memories are of spending my holidays at my grandparents large home in Palakkad with my cousins and auntsplaying all day and being completely carefree, he says,with characteristic simplicity.