Nobel Prizes 2021 announced this week

It has been happening for 120 years and this year is no exception: the 2021 winners of the world’s most prestigious science prizes were announced this week by the Nobel Foundation in Stockholm, Sweden. So, who’s won what?

The Nobel Prize for Physiology or Medicine
David Julius and Ardem Patapoutian have taken home the Nobel Prize in Physiology or Medicine. These researchers spent their careers trying to figure out how the nervous system  makes sense of, and transmits, information about temperature, pain and touch.

When we run our fingers over a rough surface or dip a tentative toe in the water at the beach, specialised structures called "receptors" on nerve endings in the skin respond by firing off electrical impulses to tell the brain what's going on. The challenge was to discover how these receptors work and to find the genes that the body uses to produce and control them. This could help unlock new ways to treat conditions like chronic pain or sensory losses.

Those who like cooking and an after-dinner mint will enjoy Julius’s and Patapoutian’s experimental strategies. Julius used chili peppers to study burning sensations, while Patapoutian used menthol to find the factors responsible for the cool sensations we feel when sucking a mint, and at the same time discovered how nerve cells respond to touch and how our bodies detect the position of our joints.

So next time you reach for the spice jar, thank Ardem Patapoutian and David Julius for explaining the science behind how our brains know we're making those movements, and how we appreciate the taste of the results.

The Nobel Prize for Physics
The Nobel Prize in Physics was all about the climate and other complex systems, like the human brain or ecosystems.

One half went to Syukuru Manabe and Klaus Hasselmann, for their contribution to the way we understand the Earth’s climate and its recent changes. We all know that the Earth is heating up because of carbon emissions, but it was thanks to Manabe’s models that we discovered the link between carbon dioxide concentration in the atmosphere and temperature. Very few people today would dispute that human activities are contributing to heating the planet’s atmosphere; Hasselmann was the first to establish that natural factors are not enough to explain global warming, and that humans are responsible, too.

The other half went to Giorgio Parisi for the theories he developed on disordered materials and random processes. Many problems in physics deal with systems made up of a lot of elements that interact with each other in random ways: the weather, for example, or the human brain, or even a flock of starlings. Parisi found a way to describe mathematically the hidden structure behind a complex system. His discoveries make it possible to understand phenomena that appear to be entirely random, not only in physics but also in other areas like  mathematics, biology, neuroscience and machine learning.

Overall, these researchers’ work helped us get a deeper insight into the properties of complex physical systems, and laid the foundations for all the models that are now helping us predict how the Earth’s climate will evolve in the next decades.

The Nobel Prize for Chemistry
Next up on the roster was the Nobel Prize for Chemistry, which was awarded for so-called “mirror-image”, or “chiral”, molecules.

A lot of molecules exist in two forms: they are almost identical, except that they appear to be face to face in a mirror when reversed. Interestingly, these similar molecules can behave in different ways. Let's take limonene as an example. This molecule, a hydrocarbon, is found in the peel of citrus fruits and is commonly used both in pharmaceuticals and for flavoring in the food industry. One version of the limonene molecule has a lemon scent, while the mirror image smells like orange. These different traits can have drastic consequences on the action of molecules, beyond just how they smell, so it’s really important that chemists are able to effectively select for the version they want - especially when making drugs.

Luckily, back in 2000, Benjamin List and David MacMillan developed a technique called asymmetric organocatalysis that makes it much easier to produce asymmetric molecules with the desired traits. The two scientists effectively developed a brand new catalyst, which is a molecule that encourages a reaction or speeds it up. This allowed them to select for the chiral version of a molecule that they wanted. Until 2000, it was generally assumed that there were only two types of catalyst: metal ones and enzymic ones. The organic catalysts developed by List and MacMillan are both more environmentally friendly and cheaper to make, and 21 years later, the award committee deemed their findings’ important implications across multiple industries worthy of a Nobel prize.

Who assigns the Nobel prizes?
It’s interesting to note that although these prizes fall under the same ‘Nobel’ umbrella term, they are assigned by different institutions. The prizes in Physics and Chemistry (as well as the Economics prize) are assigned by the Royal Swedish Academy of Sciences, which is the Swedish equivalent of the UK’s Royal Society. The prize in Physiology or Medicine, instead, is assigned by a Nobel Assembly made up of 50 professors at Karolinska Institutet, which is Sweden’s largest centre of medical academic research. In any case, congratulations to them all!