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An overview of the Nobel Prizes 2021

The Nobel Prizes for 2021 have been announced, giving an account of some of the most influential science in living memory. Each Prize reflects important current issues and developments within their respective field.

By Sam Johnson


Photo courtesy of felixioncool from Pixabay.

Physiology/Medicine


The Prize for Physiology/Medicine was awarded jointly to David Julius and Ardem Patapoutian "for their discoveries of receptors for temperature and touch". The sensations of touch and temperature are a vital part of our perception as anyone who has recently burnt themselves on a hot stove, pan, food, or drink would attest.


One of the main methods used for this discovery was the addition or subtraction of genes. The addition process takes lab grown cells that have only the basic set of genes to allow for cell survival, then involves adding various genes in the genome to find which code for proteins and behaviours that turn the basic cell into a thermo-receptor cell. The subtraction process does the reverse, starting with a functional receptor cell and then removing genes one by one to find which genes are necessary for the cell to function as a thermo-receptor.


Another interesting finding from the understanding of this receptor is the use of capsaicin as a chemical that mediates the signalling of hot temperatures in thermo-receptors. Capsaicin is commonly found in chili peppers and is partially responsible for the sensation of spiciness. It is interesting how the popular use of these terms have cohered around a common description of heat both for spice and temperature, as we now understand the same chemical mediates the sensation of both. Due to this work, we now have a deeper understanding of perception in the realms of touch, heat, and pain. This knowledge could allow new treatments and medicines targeting these receptors, as well as broaden our understanding of how our biology perceives inputs from the external world.

Physics


The Nobel Prize in Physics was awarded "for ground-breaking contributions to our understanding of complex systems", with one half jointly to Syukuro Manabe and Klaus Hasselmann "for the physical modelling of Earth's climate, quantifying variability and reliably predicting global warming" and the other half to Giorgio Parisi "for the discovery of the interplay of disorder and fluctuations in physical systems from atomic to planetary scales".


Manabe and Hasselmann made great strides in modelling and understanding the climate and how this relates to shorter term more variable events, like weather. This obviously has particular importance at a time where we understand the existential threat caused by global warming, where these models provide much of our basic understanding and predictions of the changing climate due to human activity. Despite the initial development beginning in the 60s, these models have proved impressively accurate in predicting climate changes up to this day, and with continuous update and refinement, it should continue to be accurate and useful in predicting climate into the future. Parisi’s share of the Prize is similar but focuses more on the pure mathematics and physics than the practical applications. His work investigates hidden patterns within chaotic systems that allow better understanding, prediction, and modelling of these systems and will have many uses across various areas of application.

Chemistry


The Nobel Prize in Chemistry 2021 was awarded jointly to Benjamin List and David W.C. MacMillan "for the development of asymmetric organocatalysis".


If you have heard of thalidomide, then you already know the catastrophic changes and dangers that a mirror image of a chemical can have. Chemicals often have two possible versions, known as chirality, essentially a mirror image of the chemical structure: the right-handed version and the left-handed one. For the most part these different handed versions of a chemical behave similarly, however sometimes they can have disastrous consequences. Take the aforementioned Thalidomide: the left-handed molecule is an effective treatment for morning sickness, however the right-handed one is highly toxic. As a result of being unable to discriminate and select the left-handed version, thousands of children around the world were born with severe birth defects. Thalidomide is the most famous example, but chirality has posed a problem across chemical manufacture, particularly pharmaceuticals, with many drugs having only one chirality that is effective and a second that might add unwanted side effects or else ruin chemical manufacturing processes.


With the stakes of chemical manufacturing made clear, the Nobel Prize was given for developing a process that is able to precisely create chemicals of a single chirality and is greener than previous methods. The recipients identified a third type of catalyst (previously just metals and enzymes) called asymmetric organocatalysis and builds upon small organic molecules. This allowed for the process of organocatalysis which is a precise tool for molecular construction making research in areas such as medicine safer, more effective and chemistry greener. Organic catalysts have a stable framework of carbon atoms, to which more active chemical groups can attach. These often contain common elements such as oxygen, nitrogen, sulfur or phosphorus. This means that these catalysts are both environmentally friendly and cheap to produce. Other benefits of this process compared to previous manufacturing methods is the ability for asymmetric catalysis, that is to choose which handedness version of the chemical to produce, as chemists often only want one of these versions this prevents problems arising from the other version, such as in the case of thalidomide.

Economics


Finally, economics, and no I am not going to enter into discussions of to what extent economics is “a science”.


The Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel was divided, one half awarded to David Card "for his empirical contributions to labor economics", the other half jointly to Joshua D. Angrist and Guido W. Imbens "for their methodological contributions to the analysis of causal relationships".


In this instance, they found that increasing minimum wage did not lead to the mass layoffs expected compared to similar locations and businesses which were not subject to this increase. Another finding was that immigration also did not increase unemployment through competition for jobs; instead, the economy adapted to the demand by finding and creating jobs.

These individuals were important in key understandings of effects on economics, such as the effect of raising the minimum wage on employment and pioneering experimental methods to draw causally and empirically informed conclusions rather than rely on one of many economic theories. A/B testing is a fundamental part of scientific methodology; constructing a controlled environment; randomly dividing participants into groups; subjecting those groups to different conditions – say one gets a novel treatment and the other a placebo - then comparing results between those groups. In economics, such experiments are often unfeasible and instead the recipients developed live pseudo-experiments. Say one American state was raising the minimum wage whilst a neighboring state was not. Economists would try to find two towns that they could monitor, one in each state, which were closely matched in relation to economic factors. They would then see the impact of the minimum wage change in many metrics compared to a similar and geographically proximate town. This controls for temporal effects, such as fluctuations in market price, labor availability, or a surprise disease outbreak and allows more causal conclusions to be drawn based on empirical data. The study described above is not a hypothetical and is part of the corpus of work the Nobel Prize was awarded for. In this instance, they found that increasing minimum wage did not lead to the mass layoffs expected compared to similar locations and businesses which were not subject to this increase. Another finding was that immigration also did not increase unemployment through competition for jobs; instead, the economy adapted to the demand by finding and creating jobs. These findings and the methods used to support them are a major step forward in economics, away from subjective theorizing and towards an empirical exercise in measuring cause and effect.