2019 Nobel Prizes:
- The Nobel Prize in Physics 2019:
Awarded “for contributions to our understanding of the evolution of the universe and Earth’s place in the cosmos”. Winners are:
- James Peebles “for theoretical discoveries in physical cosmology”.
- Michel Mayor and Didier Queloz “for the discovery of an exoplanet orbiting a solar-type star”.
- The Nobel Prize in Chemistry 2019:
John B. Goodenough, M. Stanley Whittingham and Akira Yoshino “for the development of lithium-ion batteries”
What are lithium-ion batteries?
Lithium is the lightest of all metals, has the greatest electrochemical potential and provides the largest energy density for weight.
Although slightly lower in energy density than lithium metal, lithium-ion is safe, provided certain precautions are met when charging and discharging.
In 1991, the Sony Corporation commercialized the first lithium-ion battery. Other manufacturers followed suit.
Why are they important?
- The energy density of lithium-ion is typically twice that of the standard nickel-cadmium.
- There is potential for higher energy densities.
- The load characteristics are reasonably good and behave similarly to nickel-cadmium in terms of discharge.
- The high cell voltage of 3.6 volts allows battery pack designs with only one cell.
- Lithium-ion is a low maintenance battery, an advantage that most other chemistries cannot claim.
- There is no memory and no scheduled cycling is required to prolong the battery’s life.
- In addition, the self-discharge is less than half compared to nickel-cadmium, making lithium-ion well suited for modern fuel gauge applications.
- lithium-ion cells cause little harm when disposed.
- It is fragile and requires a protection circuit to maintain safe operation.
- Aging is a concern with most lithium-ion batteries.
- Some capacity deterioration is noticeable after one year, whether the battery is in use or not.
- Expensive to manufacture – about 40 percent higher in cost than nickel-cadmium.
- Not fully mature – metals and chemicals are changing on a continuing basis.
- The Nobel Prize in Physiology or Medicine 2019:
William G. Kaelin Jr, Sir Peter J. Ratcliffe and Gregg L. Semenza “for their discoveries of how cells sense and adapt to oxygen availability”
What we knew so far?
The rate at which we respire depends on the amount of oxygen being carried in the blood.
Specialised cells present next to large blood vessels in the neck sense the blood oxygen level and alert the brain to increase the rate of respiration when the oxygen level in the blood goes down. This discovery won a Nobel Prize in 1938.
- At the beginning of the last century, scientists knew that specialised cells present in the kidneys make and release a hormone called erythropoietin. When oxygen level is low, as in high altitudes, more of this hormone is produced and released, leading to increased production of red blood cells in the bone marrow — helping the body adapt to high altitudes.
- Besides increasing red blood cells, the body also grows new blood vessels to increase blood supply.
What are the main contributions of 2019’s winners?
- Both Prof. Semenza and Sir Ratcliffe independently studied how the erythropoietin gene is regulated by varying oxygen levels.
- Both researchers found that the oxygen-sensing mechanism is not restricted to kidneys where the erythropoietin is produced but by diverse cells in tissues other than the kidney.
- Semenza identified a pair of genes that express two proteins. When the oxygen level is low, one of the proteins (HIF-1alpha) turns on certain genes, including the erythropoietin gene, to increase the production of erythropoietin. The hormone, in turn, increases the oxygen availability by boosting the production of red blood cells.
- Kaelin Jr. found the VHL gene seemed to be involved in how cells respond to oxygen.
- The function of the HIF-1alpha protein, which turns on the genes to produce more erythropoietin, is blocked and is rapidly degraded when the oxygen level is normal but remains intact when oxygen level is low.
- Sir Ratcliffe found that VHL interacts with the HIF-1alpha protein and degrades it when the oxygen level is normal. This ensures that excess red blood cells are not produced when the oxygen level is normal.
Significance of the discovery:
- Oxygen is essential for animal life: it is used by the mitochondria present in virtually all animal cells in order to convert food into useful energy.
- While oxygen is essential for the survival of cells, excess or too little oxygen can lead to adverse health consequences.
- Oxygen supply temporarily reduces in muscles during intense exercise and under such conditions the cells adapt their metabolism to low oxygen levels.
- Proper growth of the foetus and placenta depends on the ability of the cells to sense oxygen.
- Many diseases can be treated by increasing the function of a particular pathway of the oxygen-sensing machinery.
- The Nobel Prize in Literature 2019:
Polish author Olga Tokarczuk and Austrian novelist Peter Handke would receive 2018 and 2019 Nobel Prize for Literature. The prize was postponed in 2018 after the academy was hit by a sexual assault scandal.
Peter Handke “for an influential work that with linguistic ingenuity has explored the periphery and the specificity of human experience”
- The Nobel Peace Prize 2019:
Abiy Ahmed Ali (PM of Ethiopia) “for his efforts to achieve peace and international cooperation, and in particular for his decisive initiative to resolve the border conflict with neighbouring Eritrea”
History of the Ethiopia-Eritrea conflict:
- In April 1993, Eritrea broke from its federation with Ethiopia, becoming an independent country that was located strategically at the mouth of the Red Sea on the Horn of Africa, in close proximity to one of the world’s most crucial shipping lanes. Independence was the outcome of a 30-year war by Eritrean liberation fighters against Ethiopia, which had annexed the small multiethnic territory to its north in 1962.
- Just over five years after Independence, however, war broke out between the two countries over the control of Badme — a border town of no apparent significance, but which both Addis Ababa and Asmara coveted.
- The Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel 2019:
Abhijit Banerjee, Esther Duflo and Michael Kremer “for their experimental approach to alleviating global poverty”.
Esther Duflo has become the second woman to win prize after Elinor Ostrom (2009) of US.
This year’s Laureates have introduced a new approach to obtaining reliable answers about the best ways to fight global poverty.
In brief, it involves dividing this issue into smaller, more manageable, questions – for example, the most effective interventions for improving educational outcomes or child health.
They have shown that these smaller, more precise, questions are often best answered via carefully designed experiments among the people who are most affected.