Time Marches On

Even Nobel Prize winners do not fully understand the concept of time.

In a series of presentations for the 2010 West Texas Medical Associates Distinguished Lectureship in Science Honoring Dr. Roy E. Moon, Dr. Ahmed Zewail attempted to explain what is known about the concept of time and why it is so important in all aspects of life.
�Perhaps the best thing we know about time is that we can measure it,� Zewail said.� �But, the most significant thing about it is that life would not exist without the concept of time.� Time is change.� If you are static, sitting in the same chair and not moving, there is no need for time.� Time tells us how things change.�

�Time also has a direction,� he added.� �We all like to look at our watch and not have to think about it, but time has a direction, a past and a future, and it moves for all of us in one direction.� It also can be stopped, or resolved.�

A professor of chemistry and physics at the California Institute of Technology, Zewail won the 1999 Nobel Prize in Chemistry for his work in �stopping� time.� He developed a technique to observe chemical reactions and other movement at the sub-atomic level on a femtosecond (one million-billionth of a second) scale by taking what amounts to stop-action photos and then piecing them together.

Dubbed �femtoscience,� Zewail�s work goes a step further than regular three-dimensional imaging by adding the fourth dimension of time.� It has practical applications in chemistry, physics and physical biology, and has also helped lead to medical breakthroughs like magnetic resonance imaging (MRI) machines.

�We came up with the new idea of microscopy,� Zewail said.� �We wanted to see inside cells and all of their functions in space and time.�
By allowing scientists to see the smallest building blocks of the human body, Zewail�s method could also be used to observe the causes of various ailments, including why proteins mis-fold and cause maladies like Alzheimer�s and Parkinson�s diseases, and help lead to cures.

During his public presentation, Zewail also used a couple of basic props to illustrate the concept of entropy, of moving from an ordered system to a disordered system, and explained how the constant movement of time affects all life.

�It is much easier to take something in a highly ordered state, or low entropy, and send it to a high-entropy state, like spraying perfume into space, rather than doing the reverse,� Zewail said.� �That is why we are born, we live and we disintegrate.�

�The only way that life can exist and the only way that you can function is because of the arrow of time,� he added.� �We are in a non-equilibrium state.� We are in a state where things are constantly changing as a function of time.�

While he and other researchers have mastered several aspects of measuring and using time, Zewail admitted that there are other facets of time that still elude them, including why some things move faster than others, why different things happen on different time scales, going back in time and predicting the future.

Fueled by the curiosity of current and future scientists, he hopes the search for clues to address those and many other concepts continues, specifically at American universities, which are in the midst of what he calls a �golden age� of research.

�Nobody knows when they start to do curiosity-driven research what is going to be the ultimate impact on our society,� Zewail said.� �But, good societies, enlightened societies, will invest in the seeking of new knowledge.�