Ahmed Zewail

Ahmed Zewail
Portrait of Ahmed Zewail
Born	Ahmed Hassan Zewail (1946-02-26) February 26, 1946 Damanhour, Kingdom of Egypt
Nationality	Egyptian
Fields	Chemistry, physics
Institutions	California Institute of Technology
Alma mater	University of Alexandria, University of Pennsylvania
Known for	Femtochemistry
Notable awards	Nobel Prize for Chemistry (1999) The Franklin Medal (USA) (1998) Wolf Prize (Israel) (1993) Priestley Medal (USA) (2011) Davy Medal (2011)
Website
http://www.its.caltech.edu/~femto/

Ahmed Hassan Zewail (Arabic: أحمد حسن زويل‎, IPA: [ˈæħmæd ˈħæsæn zeˈweːl]; born February 26, 1946) is an Egyptian scientist, known as the "father of femtochemistry", he won the 1999 Nobel Prize in Chemistry for his work on femtochemistry. He is the Linus Pauling Chair Professor Chemistry and Professor of Physics at the California Institute of Technology.

Birth and education

Ahmed Hassan Zewail, was born on February 26, 1946 in Damanhour, Egypt and was raised in Alexandria. His father Hassan assembled bicycles and motorcycles and later became a government official. His parents remained married for 50 years, until Hassan died on October 22, 1992.

He received a bachelor's and an MS degree from the University of Alexandria before moving from Egypt to the United States to complete his PhD at the University of Pennsylvania with advisor Robin Hochstrasser. While at the University of Alexandria he met his wife, Mervat. She accompanied him to the University of Pennsylvania. At the university, Ahmed completed his Ph.D. and they had their first child. He completed a post-doctoral fellowship at the University of California, Berkeley with advisor Charles B. Harris.

Academic career

After some post doctorate work at UC-Berkeley, he was awarded a faculty appointment at Caltech in 1976, where he has remained since, and in 1990, he was made the first Linus Pauling Chair in Chemical Physics. He became a naturalized citizen of the United States in 1982.

Zewail has been nominated and will participate in President Barack Obama's Presidential Council of Advisors on Science and Technology (PCAST), an advisory group of the nation's leading scientists and engineers to advise the President and Vice President and formulate policy in the areas of science, technology, and innovation.

Research

Zewail's key work has been as a pioneer of femtochemistry—i.e. the study of chemical reactions across femtoseconds. Using a rapid ultrafast laser technique (consisting of ultrashort laser flashes), the technique allows the description of reactions on very short time scales - short enough to analyse transition states in selected chemical reactions.

His work started with the question, how fast did the energy within and isolated large molecule like naphthalene redistribute among all the atomic motions? They had to build an apparatus with a vacuum chamber for molecules coming out of the source as a collimated beam at supersonic speed. The challenge was to build an ultrafast laser to be used with the molecular beam. The beam and the picosecond laser system were interfaced. The goal of the project began as wanting to directly measure the rate of vibrational-energy redistribution for an isolated molecule using the picosecond laser.

They wanted to see the process from birth to death of a molecule. In this experiment the isolated anthracene molecule was unexpected and contrary to popular wisdom. During redistribution the population was oscillating coherently back and forth. There was no decay, but there was rebirth and all molecules moved coherently in a phase. In a large molecule, each vibrational motion is like a pendulum, but there are many motions because a molecules has many atoms. If the motions were not coherent, the observation would have been much different.

The results of this experiment revealed the significance of coherence and its existence in complex molecular systems. The finding of coherence were significant because it showed that through the expected chaotic motions in molecules, ordered motion can be found, despite the presence of a "heat sink", which can destroy coherence and drain energy. Coherence in molecules had not been observed before not because of a lack of coherence, but because of a lack of proper probes. In the anthracene experiments, time and energy resolutions were introduced and correlated.

Though Zewail continued studies on vibrational-energy redistributions, he started new studies on shorter time resolutions for molecules showing different chemical processes and rotational motions.

In 1999, Zewail became the third ethnic Egyptian to receive the Nobel Prize, following Egyptian president Anwar Al-Sadat (1978 in Peace), Naguib Mahfouz (1988 in Literature). Mohamed ElBaradei followed him (2005 in peace). Other international awards include the Wolf Prize in Chemistry (1993) awarded to him by the Wolf Foundation, the Tolman Medal (1997), the Robert A. Welch Award (1997), the Priestley Medal from the American Chemical Society and Davy Medal from the Royal Society in 2011. In 1999, he received Egypt's highest state honor, the Grand Collar of the Nile.

Zewail was awarded an honorary doctorate by Lund University in Sweden in May 2003 and is a member of the Royal Swedish Academy of Sciences. Cambridge University awarded him an honorary Doctor of Science in 2006. In May 2008, Zewail received an honorary doctorate from Complutense University of Madrid. In February, 2009, Zewail was awarded an honorary doctorate in arts and sciences by the University of Jordan. In May 2010, he received a Doctor of Humane Letters from Southwestern University. in October/2011 he was awarded an honorary doctorate in science from the University of Glasgow, UK His students include scientists like Martin Gruebele

Zewail is married, and has four children. He also has won the King Faisal award in 1989.

Political work

In June 4, 2009 speech at Cairo University, US President Barack Obama announced a new Science Envoy program as part of a "new beginning between the United States and Muslims around the world." In January 2010, Ahmed Zewail, Elias Zerhouni, and Bruce Alberts became the first US science envoys to Islam, visiting Muslim-majority countries from North Africa to Southeast Asia.

When asked about rumors that he might contest the 2011 Egyptian presidential election, Ahmed Zewail said: "I am a frank man... I have no political ambition, as I have stressed repeatedly that I only want to serve Egypt in the field of science and die as a scientist."

During the 2011 Egyptian protests he announced his return to the country. Zewail said that he would join a committee for constitutional reform alongside Ayman Nour, Mubarak's rival at the 2005 presidential elections and a leading lawyer. Zewail was later mentioned as a respected figure working as an intermediary between the military regime ruling after Mubarak's resignation, and revolutionary youth groups such as the April 6 Youth Movement and young supporters of Mohamed ElBaradei.

Publications

• Advances in Laser Spectroscopy I, ed. A. H. Zewail, SPIE, Bellingham, 1977
• Advances in Laser Chemistry, ed. A. H. Zewail, Springer-Verlag, Berlin-Heidelberg, 1978
• Photochemistry and Photobiology, Vols. 1 and 2, ed. A. H. Zewail, Harwood Academic, London, 1983
• Ultrafast Phenomena VII, eds. C. B. Harris, E. P. Ippen, G. A. Mourou and A. H. Zewail, Springer-Verlag, Berlin-Heidelberg, 1990
• The Chemical Bond: Structure and Dynamics, ed. A. H. Zewail, Academic Press, Boston, 1992
• Ultrafast Phenomena VIII, eds. J.-L. Martin, A. Migus, G. A. Mourou, and A. H. Zewail, Springer-Verlag, Berlin-Heidelberg, 1993
• Ultrafast Phenomena IX, eds.
• Age of Science (autobiography)
• Physical Biology: From Atoms to Medicine, ed. A. H. Zewail, Imperial College Press, London, 2008
• 4D Electron Microscopy, ed. A. H. Zewail, Imperial College Press, London, 2009
• Encyclopedia of Analytical Chemistry (editor)
• Voyage Through Time, ed. Ahmed Zewail, 2002

See also

List of Muslim Nobel Laureates

External links

• Ahmed Zewail on Twitter
• Ahmad Zewail's Caltech website
• Zewail Nobel Prize lecture
• Article about Zewail