A comprehensive look at the Nobel prizes for Physics and Chemistry, 2021
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Nobel 2021 for Physics and Chemistry - An analysis
- The story: The 2021 Nobel for Physics was given to climatologists Syukuro Manabe (US), Klaus Hasselmann (Germany) and physicist Giorgio Parisi (Italy). Why? They helped everyone understand complex physical systems.
- Who did what: Manabe and Hasselmann did physical modelling of Earth's climate, and predicted global warming. Parisi studied disorder in physical systems, from atoms to planets.
- Both the works fall uner "complex systems", ranging from climate to spin liquids
- A Nobel being given to climatologists is a message that climate science is solid science
- Syukuro Manabe: He started modelling atmospheric warming due to rising CO2 concentrations, starting 1950s and 60s.
- Greenhouse effect on earth keeps it warm and makes life possible (first identified by mathematician Joseph Fourier). Sun's incoming short wavelength radiation is absorbed by Earth, and re-emitted outwards as long wavelength radiation. Atmosphere absorbs some, and warms up (greenhouse effect). The greenhouse gases that aid it are CO2, H2O, methane etc. But beyond a level, it can be dangerous for life.
- Manabe estimated that doubling of CO2 may lead to warming of excess 2 degree C. He proved that rising temperatures were due to rising CO2 levels. Temperatures close to surface were higher, and reduced with altitude. Had he been wrong (and warming would be due to sun's radiation only), then uniform warming would happen.
- Klaus Hasselmann: Weather is the daily variation in temperature and rainfall, and climate is the long-term trend. Hasselmann was able to create links between the two, using a stochastic climate model in 1980s. He also worked on human impact on climate.
- Giorgio Parisi: There are four concepts - spins, frustration, spin glasses, replica symmetry. These are used to describe magnetic lines like systems, and how various components align or not align with each other in it. Parisi in 1979 was able to mathematically solve the problem of "spin glasses" by using "a replica trick". That method was then used for mathematics, biology and neuroscience.
- Summary: These three Nobel laureates worked in fields that seemed incredibly complex at that time, but successfully put mathematical modelling at the core of understanding. Their work is being used across fields now.
- The Chemistry story: The 2021 Nobel for Chemistry was given to Benjamin List (Germany) and David WC MacMillan (US). Why? They helped develop asymmetric organocatalysis, a cheapr, fast and environmentally better method.
- Catalysis: It is a process where a catalyst controls the rate and outcome of a reaction. Catalyst doesn't change in it, and can be removed finally. In cars, catalysts transform toxic substances in exhaust into harmless molecules. Silver in hydrogen peroxide helps produce water and oxygen. All this was first observed in 1835 by Swedish chemist Jacob Berzelius.
- Before asymmetric organocatalysis arrived: Metals and enzymes were used for catalysis. Metal catalysts use heavy metals, expensive and environmentally dangerous. They are also sensitive to presence of oxygen and moisture. Enzyme catalysts are huge molecules, and take time to make. They exist in mirror images - left-handed and right-handed. The one of interest will be only one of these two. Enzymes are proteins in nature, and human bodies have many such. They help build complicated molecules with precision.
- After asymmetric organocatalysis (AO): These AOs are made of a single amino acid, which are environmentally friendly, speed up reactions and are cheaper. They allow only one mirror image of the molecule to form as catalysts are made from a single, circular amino acid.
- Organic catalysts have a stable carbon framework, to which more active chemicals can attach.
- These can be oxygen, nitrogen, sulphur and phosphorus.
- They help in cascade reactions, where the first reaction step product becomes the starting material for next sequence, thereby avoiding purification between steps. (that reduces waste hugely)
- Flourishing field: What the two Nobel winners did, was picked up by other well since 2000. Many stable and cheap organocatalysts are now available, a gold rush. They help build many substances that crores of people use in daily life - pharma, platics, food flavourings and perfumes.
- Summary: Estimates suggest that more than 35% of world's GDP is linked with chemical catalysis in some or the other way.
- EXAM QUESTIONS: (1) Explain the basic working of asymmetric organocatalysis. How does it help? (2) Which five products underpin most of the world GDP today? List and explain. (3) What is the general thrust of the Nobel Committee's criteria for selection? Explain. (4) Explain how climate systems were modelled by the Nobel winners. (5) What are the practical ways anthropogenic changes can be understood, in climate context? Explain. (6) Climate science is not a precise science, but yet is a reliable science. Comment analytically.
#Nobel #Physics #Chemistry
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