Devangshu Datta: Nobel efforts

Last Updated: Thu, Oct 18, 2012 19:21 hrs

In contrast to the awards for literature, peace and economics, controversy rarely follows in the wake of the science Nobels. They have never been awarded for dubious research. The award committees are stubborn about demanding irrefutable practical demonstrations of theory.

But there are often rumblings because decades often separate research from recognition. Sometimes major contributors are also omitted from citations because science Nobels can only be shared by a maximum of three individuals.

The 2012 physics prize was preceded by speculation about honouring the discovery of the Higgs Boson. In 1964, six physicists, including Peter Higgs, presented papers postulating its existence and in 2012, CERN’s Large Hadron Collider team found it.

The Royal Swedish Academy postponed assigning responsibility for this collaborative effort. Instead, the 2012 award went to Serge Haroche and David Wineland, two great pioneers of quantum experimentation.

Their work demonstrates superposition and entanglement. Superposition was the paradox explored in Schrodinger’s thought experiment about a mysterious feline, which is both alive and dead. Entanglement occurs when two physically distant particles affect each other.

Wineland’s speciality is trapping ions (electrically charged particles) inside “cages” formed by electrical fields and zapping them with lasers. The energy levels of subatomic particles are separated by discrete (quantum) amounts of energy. Superposition is achieved by the laser-bombardment manipulating energy levels to force ions to exist in two energy states at the same time.

The Paris-based Haroche traps photons (light particles). He’s found ingenious methods to use entanglement to observe photons without destroying them. His apparatus consists of a pair of super-cooled, super-conducting, super-reflective mirrors facing each other with a gap three centimetres in-between.

Microwaved photons are pushed into the gap and reflect off the mirrors. The photons may bounce around for about a tenth of a second — given light speeds, they cover 40,000-odd kms paths in that time. By pumping large atoms into the gap, Haroche observes photon behaviour — direct interaction would destroy the particles. Entanglement occurs between the atoms and photons and the state of the photon is deduced from observing the state of the atom.

The potential applications of this work include quantum computing. A “quantum bit” or Qbit can hold both the values, 0, 1, at the same time, whereas a normal binary bit is either 1 or 0. If this difference in information storage can be exploited, computing could be hugely enhanced.

Wineland’s team at Colorado University have also built optical clocks, using ions. These are at least a hundred times more precise than standard Caesium atomic clocks. They allow relativistic effects to be measured even when caused by tiny changes in speed (variations of 10 metres/ second) or gravity (30 metres difference in distance).

The 2012 Chemistry Nobel went to American professors, Robert J Lefkowitz of Duke University, and Brian K Kobilka of Stanford, for work on G-protein coupled receptors (GPCRs). This is recognition for 45-year worth of ongoing research.

In the late 1960s, Lefkowitz started researching hormonal receptors. Receptors are on the outside of a cell. They sense adrenalin, serotonin, histamine, etc, and transmit the information into the cell by binding with G-proteins, thus triggering the cell’s reaction to hormones.

Lefkowitz’s big insight came when he tagged hormones with radioactive iodine to trace their paths. But though he found receptors, he despaired of figuring out how they functioned.

The 1994 Nobel for medicine went to Alfred Gilman and Martin Rodbell for work done in the 1980s, when they discovered the role of G-proteins in signal transmission. Around that time, Lefkowitz hired Kobilka, a cardiologist, to investigate hormonal effects on heart cells.

Kobilka isolated a gene for hormonal heart receptors and found it was similar to another gene, which controlled light receptors in the eye. He realised all receptors are related. The mapping of the human genome has since identified a thousand-odd genes involved in coding GPCRs, which work in sensing images, tastes, odours and hormones.

In 2011, Kobilka’s team at Stanford used X-ray crystallography to grab an image of a receptor as it transferred signals into the cell. Most modern medicines exploit GPCRs.

The 2012 Nobel Prize in medicine went to Sir John Gurdon and Shinya Yamanaka for discovering “mature cells can be reprogrammed to become pluripotent”. Pluripotent means capable of developing in multiple ways.

Immature cell are pluripotent and can grow into any type of cell. Gurdon and Shimanaka showed that mature cells can become pluripotent. This is yet another story of research that began 50 years ago and continues to this day.

John Gurdon was famously bottom of his class in Eton and advised to avoid science as a career. In 1962, he disproved the belief that specialised mature cells (skin cells, heart, liver, etc) are irreversibly programmed. He replaced the immature nucleus in an frog-egg cell with the mature nucleus from the intestinal cell of a full-grown frog. The modified egg hatched into a tadpole and then, a normal frog. Advances on Gurdon’s work led to the cloning of mammals like Dolly.

In 2006, Shinya Yamanaka went further. Gurdon, Wilmut and co had inserted nuclei into immature cells. Yamanaka reprogrammed intact, mature mouse-cells and turned them into immature stem cells, by introducing a few genes. The implications of reversing cell growth and maturity are staggering.

Despite the fuddy-duddy reputation of the science Nobels and the understandable disappointment about the Higgs, the 2012 awards honour great research, which is still ongoing. There could be a vast number of potential new applications and insights arising from these areas in the near future.

More from Sify: