How 2026 Nobel Prize-winning Research in Science Benefits Humanity

The Nobel Assembly at the Karolinska Institute has decided to award the Nobel Prize in Physiology or Medicine 2026 jointly to Karl Deisseroth of the Howard Hughes Medical Institute and Stanford University, Peter Hegemann of Humboldt University of Berlin and Georg Nagel of the University of Würzburg, Germany, ‘for their discoveries concerning light-gated ion channels and optogenetics.’ Peter Hegemann and Georg Nagel were born in 1954 and 1953, respectively, and are German citizens, whereas Karl Deisseroth was born in 1971 and is a citizen of the United States. The laureates will share twelve million Swedish kronor equally.
To understand the discovery of Deisseroth, Hegemann, and Nagel, we first need to know what optogenetics is and what a light-gated ion channel means. Optogenetics is a biological technique used to characterise and manipulate the activity of neurones or other cell types with light. A neurone is a cell that is excitable, firing electrical signals. Per Svenningsson, Chair of the Nobel Committee, mentioned, “Optogenetics provides opportunities for mapping the brain in a way that we could once only dream of.” In fact, this method controls our nerve signals with light.

Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore. Their functions include gating the flow of ions across the cell membrane. It is to note that the term ‘gating’ refers to the opening or closing of ion channels. When ion channels are in a ‘closed’ state, they are impermeable to ions and do not conduct electrical current. When ion channels are in their open state, they conduct electrical current by allowing specific types of ions to pass through them and thus across the plasma membrane of the cell. Gating is the process by which an ion channel transitions between its open and closed states. Ion channels are present in the membranes of all cells. Light-gated ion channels are a family of ion channels regulated by electromagnetic radiation.
Over 300 types of ion channels exist in the cells of the inner ear alone. Most light-gated ion channels have been synthesised in the laboratory for study, although two naturally occurring examples, channelrhodopsin and anion-conducting channelrhodopsin, are currently known. Channelrhodopsins are a sub-family of retinylidene proteins that function as light-gated ion channels. Retinylidene proteins use the retinal as a chromophore for light reception. In the 1990s, Hegemann at the Max Planck Institute for Biochemistry started his research with a question: how can the unicellular alga Chlamydomonas react so rapidly to light? These are green algae and are able to swim towards light. The fast light reaction in algae ignites Hegemann’s curiosity. He teamed up with Nagel, who was working at the Max Planck Institute for Biophysics in Frankfurt. They discovered a protein named channelrhodopsin in a single-celled alga, which could be used as a powerful tool to generate electrical impulses in cells using light. They also noticed that regardless of which cell they put the protein in, those cells became light-sensitive.
Karl Deisseroth at Stanford University introduced the gene for channelrhodopsin into nerve cells from rats. By illuminating the cells with blue light, he was able to trigger a nerve signal. Later, he made this light-controlled switch for nerve cells to work in the brains of living mice. The implication of their discovery is tremendous. Their method makes it possible to show how nerve cells shape memories, feelings and behaviours in the living brain. The Nobel Assembly, in their press release, mentioned that in clinical medicine, researchers are using the method in attempts to restore sight in people with visual impairment.
The Royal Swedish Academy of Sciences (RSAS) has decided to award the Nobel Prize in Physics 2026 to Francis Halzen of the University of Wisconsin-Madison, USA ‘for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin’. Halzen was born in 1944, a Belgian-American citizen. Halzen will receive twelve million Swedish kronor.
This year’s Nobel Prize in Physics recognised two issues. One is Hazen’s contribution to the IceCube Neutrino Observatory, and another is the discovery of high-energy neutrinos of astrophysical origin. A neutrino is an elementary sub-atomic particle. They are electrically neutral, meaning they do not feel the electromagnetic force. They have a very small rest mass, millions of times lighter than an electron. They only interact via gravity and the weak nuclear force, earning them the nickname “ghost particles”. Trillions pass through our body every second without us feeling them. They come in three forms: electron neutrino, muon neutrino, and tau neutrino and can change between these types as they travel, a process called neutrino oscillation. Francis Halzen in the 1980s realised that ice at the South Pole could be used to track this particle. He made a fundamental contribution to the development of the IceCube Neutrino Observatory in the South Pole. IceCube is a cubic-kilometre particle detector made of Antarctic ice and located near the Amundsen-Scott South Pole Station. It is buried beneath the surface, extending to a depth of about 2,500 metres. Halzen mentioned that after decades of planning and construction, ‘there was no guarantee we would ever see anything.’ But it took only two years for the collaboration to detect particles from outside our Solar System, establishing the new field of neutrino astronomy. In a nutshell, how does it work? As a neutrino from space interacts with atomic nuclei in water or ice, the shower of particles given off emits blue light. The light can be tracked with detectors, which are a string of buried sensors that track blue light from the particles as they move through the array and reveal the neutrino’s energy and the direction the particle came from.
However, this is not a one-man’s lonely journey; though Halzen was a theorist in this process, he mentioned in his interview with Swedish Television that there were many collaborators involved, who made the project a success. Halzen mentioned that ‘Theorists write two kinds of papers: one kind to explore the physics they really believe in, and another kind just to show how smart they are. And my initial neutrino papers were certainly in the second category. I never had any intention of ending up doing this, but then things got out of hand.’
It is to be noted here that Francis Halzen is a good science writer. His essay ‘Antarctic Dreams’ was featured in The Best American Science Writing 2000. In it, he wrote that, as a ‘superfluous theorist’, he has never made the journey to see his project in person. ‘But even now, on the nights when drilling goes on there, I can never sleep,’ he wrote. ‘To have your career on the line half a world away is hard enough. But to know that you have embroiled so many others in the same improbable adventure, that your funders and colleagues expect results, and that you are totally powerless to affect the outcome, is a form of exquisite torture.’
The RSAS has decided to award the Nobel Prize in Chemistry 2026 to Henri B. Kagan of Université Paris-Sud, France and Kenso Soai of Tokyo University of Science, Japan, ‘for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis’. Kagan was born in France in 1930, and Soai was born in Hiroshima in 1950. The laureates will share twelve million Swedish kronor equally. To understand Kagan and Soai’s research, we first need to know the chiral behaviour of molecules. Chirality is a geometric property where an object or molecule cannot be placed on top of its own mirror image. Just as our left hand cannot fit comfortably into a right-handed glove, chiral shapes have distinct “left-handed” and “right-handed” forms.  The two mirror-image versions of a chiral molecule are called enantiomers. Homochiral means a group of molecules that all share the same “handedness”. For example, amino acids in the human body are homochiral, because they are all ‘left-handed’. Chemists long ago wondered how homochirality emerges in natural systems, whereas in a test tube they get equal proportions of left- and right-handed molecules. Another point to know here is an asymmetric reaction, which is a chemical reaction that creates unequal amounts of enantiomers.
Kagan began to wonder what would happen if he combined left and right enantiomers in the catalyst. This was how he realised that he could enhance the reaction’s asymmetry. In practice, he had found a method for enhancing the formation of one of the enantiomers in the product using a metal catalyst. In 1986, he described three different asymmetric reactions that displayed what chemists call non-linear effects. Kenso Soai explored Kagan’s idea further and tried to design a reaction in which the catalyst formed itself in an autocatalytic process. Soai developed a reaction which is now known as the Soai reaction. His reaction starts with a non-chiral solution. Chiral catalysts are formed from the reaction. When the substrate and reagent have been used up, more are added, and this process can be repeated. Interestingly, life on earth uses only one “hand” of molecules, such as left-handed amino acids and right-handed sugars. The Soai reaction shows how a tiny physical trigger could create this single-handedness naturally.
 In short, this year’s Nobel Prize-winning research in Physiology or Medicine has transformed neuroscience and tells humanity how the brain works. In the past, we mapped an atom and called it an atomic map, but now we can map a function and call it a functional map using optogenetics.  
This year’s Nobel Prize-winning research in physics provided researchers with novel knowledge about the universe’s natural particle accelerators. High-energy neutrinos provide information about extreme processes in distant regions of space. Their observation therefore opens up entirely new possibilities in astrophysics. This year’s Nobel Prize-winning research in chemistry gave us a tool for designing new reactions and the technique of autocatalysis that solves the mysteries of homochirality-like that found in all living beings that can be created in the laboratory. All these discoveries are bringing the greatest benefit to humanity.
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The writer is a UK-based academic who writes on science, philosophy and education