Eyes on the Prize

 
 

With the 2011 Nobel Prize winners announced earlier this month, Conor O’Nolan discusses this year’s scientific prizes and the importance of their work

Physics

Nobel prizes in physics are awarded to people who completely redefine our understanding of the world we live in, and the winners this year are no exception. Saul Perlmutter took half of this year’s award while Brian Schmidt and Adam Reiss received the other half for their incredible research on the expansion of our universe.

When Einstein published his theory of general relativity, he believed that the universe was static and non-expanding, which was quickly shown not to be the case a few years after publication. This would mean the gravitational force of the universe is not strong enough to stop the universe expanding. The then assumption was that the universe was continually expanding, but at a progressively decelerating rate.

In the early twentieth century, Henrietta Swan developed a technique to measure the distance of pulsing stars called cepheids by measuring their light intensity. This then became a standard way of measuring the distance of stellar objects.

Two teams, one headed by Perlmutter and the other headed by Schmidt collaborating with Reiss, raced to find the most distant supernovae (exploding stars) possible, to try and determine the current rate of expansion. What they did not expect to discover was that the universe’s expansion is in fact accelerating. These results were groundbreaking, and fundamentally changed our understanding of the universe.

The acceleration is believed to be caused by dark energy, a theoretical form of energy that is found throughout all space, making up about seventy-three per cent of the universe’s energy density (the rest is thought to be made up of about twenty per cent of the mysterious dark matter and a mere four per cent of ‘normal matter’ i.e. atoms, etc).

This research has told us much about both the evolution and the potential fates of the universe. One theory is that in billions of years the universe will become so spread out that the light of neighbouring galaxies will not be visible to each other.

Physiology or Medicine

The prize for Physiology or Medicine went to three scientists this year; Ralph M. Steinmann receiving one half and Bruce A. Beutler and Jules A. Hoffmann being awarded the other half. They received the award for their cumulative contributions to the field of immunology.

Beutler and Hoffmann were recognised for their discovery of receptor proteins. Receptor proteins are part of the body’s early immune response that recognises micro-organisms and activates innate immunity. Innate immunity is non-specific immunity, it acts very quickly, trying to stop the infection and has no memory.

Steinmann is credited for discovering dendritic cells of the immune system. These cells activate and regulate the body’s adaptive immunity, which is one of the later stages of a human’s immune response. The adaptive immune response is a bit more elaborate than the innate response. Along with fighting the target pathogens, the adaptive system has the ability to attack and remember certain pathogens, this allows the body to develop progressively more powerful immune responses each time the body is exposed to pathogens already encountered.

Together these scientists helped understand how immune responses were triggered. The components of the body’s immune response were gradually discovered in the twentieth century, but until this recent work was carried out, it was unknown how the response was triggered. If the activation level is too high, the body would respond too late (if at all), but if the activation level is too low, the body would constantly attack itself, so this work helped other scientists understand why the body responds in some situations and why it doesn’t attack itself in others.

This has meant that new methods for fighting disease, such as simple vaccines which stimulate the body’s immune response to attack tumours, have been developed and scientists also now have a better understanding of why the body attacks itself when affected by inflammatory diseases.

The award was unusual this year in that it was announced that Steinmann had won the award three days after he had died. The committee were unaware that he had died at the time of the announcement. A Nobel Prize is usually not awarded posthumously, but the committee decided that the prize would still be awarded to Steinmann.

Chemistry

The prize in Chemistry was this year awarded to Dan Shechtman, an Israeli scientist, for his work on crystals, more specifically his discovery of quasicrystals. His work completely redefined the previous definition of a crystal, which had massive implications for the field of structural chemistry as a whole.

A crystal was originally described as a regular pattern of atoms, each atom having a very fixed relationship with its neighbour and being part of a unit called the ‘unit cell’, which is repeated periodically to form the structure of the compound.

On the eighth of April 1982, Schechtman heated up a mixture of aluminium and manganese oxides until they were glowing, and then cooled it rapidly. He then looked at this material using electron microscopy (a technique which allows scientists to view materials at an almost atomic level), paying particular attention to the symmetry of the material. The results he recorded were groundbreaking. He had observed some data that made absolutely no sense whatsoever, as the symmetry of the crystals was completely impossible under the then definition of crystal.

Schechtman’s findings were initially ridiculed by the scientific community. He was asked to leave his research group and Nobel Prize-winning chemist Linus Pauling told him his results were ridiculous. It took him years to get his experimental research published, however, his “impossible” results were then proved to be correct and went on to change the definition of a crystal drastically.

When he eventually got his results published, Schechtman still had no idea what the crystals actually looked like inside, because he couldn’t find a pattern that would fit the symmetry which was given by the result. Another crystallographer who was familiar with some unusual mathematical research on patterned tiles suggested that the layout of the crystal was that of a Penrose tiling – an aperiodic pattern using only two shapes that will never repeat itself.

When this research finally got the recognition it deserved, it was hoped that it would lead to many incredible technological advances, but as it happens quasicrystals have limited practical use, but have some application in things like razorblades. However, this research is a key example of science for science’s sake; it was questioning the very fundamentals of its field. It was thought to have been ridiculous and showed that many scientists often refuse to accept what may bring their own beliefs into question.

Advertisements