The Hindu : 'Femtochemistry' could open up new possibilities

Online edition of India's National Newspaper
Wednesday, Oct 23, 2002

National

National

'Femtochemistry' could open up new possibilities

By K. Kannan

Ahmed H. Zewail

NEW DELHI OCT. 22 . Microscopic measurements of time have opened up immense possibilities for the future of science, including the hope of curing killer diseases such as cancer and AIDS by controlling and manipulating genes at their sub-atomic level. Other possibilities include the artificial creation of photosynthesis and manipulating the dynamics of vision.

"If you study the molecular dynamics of vision, you will realise that the entire process of seeing depends upon a photon hitting the eye and this first step takes 200 femtoseconds (10 to the power of minus 15 seconds). The total physiological eye response takes 0.2 seconds. This study at the femtoscopic level opens up immense possibilities,'' said Ahmed H. Zewail, who won the 1999 Nobel Prize for Chemistry, here today.

Delivering the Albert Einstein Lecture on "Time's Mysteries and Miracles'' here this evening, Prof. Zewail, who occupies the Linus Pauling Chair of Professor of Chemistry and Physics at the California Institute of Technology, said the classical paradigm had returned to science but in the weirdest manner. The lecture was organised by the Centre for Philosophy and Foundations of Science. Describing the experiments carried out by them at the femtoscopic level by setting up what he called the phenomenon of atomic coherence, Prof. Zewail said this had given rise to the belief that "new material can be created by manipulating matter on the femtoscopic scale''.

Time, said Prof. Zewail, was incredibly diverse, and from the big bang to the atom it covered 30 orders of magnitude.

While experiments conducted in the 19th century such as the "galloping horse'' experiment and the "cat in motion'' experiment were early pointers to the study of time at the microscopic level, the real problem came when it was realised that atoms behaved like waves at this level.

Measuring the time-scale at the femtoscopic level further becomes difficult because of two uncertainties — uncertainties in the simultaneous mapping of position and distance and in energy and time. "It is like driving in New Delhi and Cairo. Each one has its own time and there is no coherence between them,'' he said.

The measurements became possible, added Prof. Zewail, when all the uncertain factors were cleverly adjusted in such a manner that a coherence was set up. The entire localised atom then becomes a representation of the one at the femtoscopic level.

"These experiments have proven that it is a classical atom after all.''

Other developments that are possible in science include evolving artificial systems to convert solar energy into useful energy.

"However, the arrow of time has always traversed in one direction and despite all these efforts to understand time, we still do not understand it,'' he concluded.

Welcoming Prof. Zewail, Ranjit Nair of the Centre for Philosophy and Foundations of Science, said that the Nobel Laureate was the first person to observe the formation and dissolution of atomic bonds by using laser flashes of some tens of femtoseconds.

He described him as the founder of a new discipline — `Femtochemistry'.

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