🗞️ Why in News The Royal Swedish Academy of Sciences on 6 October 2026 awarded the 2026 Nobel Prize in Physics 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, born in 1944 in Tienen, Belgium, first proposed in 1988 that the ice at the South Pole could be used to catch neutrinos from the distant universe.
The Prize in One Minute
The universe contains natural particle accelerators, far more powerful than any machine on Earth, and for over a century nobody has been able to say exactly where they are. They fire particles across space, but most of those particles are electrically charged, so magnetic fields bend their paths and scramble the trail back to the source.
Halzen’s answer was to look for a different particle that is made in the same places but travels in a dead straight line: the neutrino. The catch is that neutrinos almost never interact with anything, so catching even a few needs an enormous detector. He proposed using a cubic kilometre of Antarctic ice as that detector, then led the decades of work that built it. The result, IceCube, caught the first high-energy neutrinos from beyond the solar system and opened neutrino astronomy: watching the universe through a particle instead of through light.
If you remember only three things: neutrinos are ghost-like particles that point straight back to where they were made; IceCube catches them by seeing the faint blue glow they leave in deep, clear ice; and it has now shown that such neutrinos arrive from distant galaxies and from our own Milky Way.
The Laureate at a Glance
| Laureate | Francis Halzen (sole winner) |
| Born | 1944, Tienen, Belgium |
| PhD | 1969, KU Leuven, Belgium |
| Affiliation | Professor, University of Wisconsin-Madison, USA |
| Citation | “for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin” |
| Role | Principal Investigator of IceCube, from the idea and design through construction to science operations |
| Awarded by | Royal Swedish Academy of Sciences |
| Prize amount | 12 million Swedish kronor |
Start Here: The Science, Step by Step
You need five ideas to follow this prize. None of them needs mathematics.
1. What Is a Neutrino?
Everything around us is built from a small set of elementary particles, pieces of matter that cannot be split further. The electron is the best-known one. A neutrino is another: an elementary particle with no electric charge and almost no mass. It interacts so weakly with matter that it passes straight through the Earth and through our bodies. The Nobel committee notes that about 65 billion neutrinos from the Sun pass through a fingernail every second, harmlessly and unnoticed.
How we know they exist. The physicist Wolfgang Pauli proposed the neutrino in 1930 to explain energy that seemed to go missing in a type of radioactive decay. The particle was so elusive that it was first caught only in 1956, by Clyde Cowan and Frederick Reines, using a nuclear reactor as a powerful source. Reines received the Nobel Prize for it in 1995.
Three kinds, and they change. Neutrinos come in three types, called flavours: the electron neutrino, the muon neutrino and the tau neutrino. A neutrino born as one flavour can arrive at a detector as another. This shape-shifting, called neutrino oscillation, is possible only if neutrinos have some mass; its discovery won the 2015 Nobel Prize. It also solved an old puzzle: early experiments caught only about one-third of the neutrinos expected from the Sun, because many had changed flavour on the way.
Where neutrinos come from:
- The Sun, from the nuclear reactions in its core (low energy, very many)
- Radioactive decay on Earth
- The atmosphere, when cosmic rays smash into air molecules
- Exploding stars (supernovae)
- Distant cosmic accelerators: the rare, very high-energy neutrinos IceCube was built to catch
The last group is what the 2026 prize is about. A neutrino carrying a huge amount of energy cannot have come from the Sun or from radioactivity; it must have come from somewhere far away and violent.
2. Cosmic Rays: A Puzzle Since 1912
Space is constantly crossed by fast particles called cosmic rays. They were discovered in 1912 by Victor Hess, who carried instruments up in balloons and found that radiation grew stronger with height, so it had to be coming from space. He received the Nobel Prize in 1936.
Cosmic rays are mostly protons (the nuclei of hydrogen atoms) and helium nuclei. Some arrive with astonishing energy: up to about 1020 electronvolts, millions of times the 7 TeV beam energy of CERN’s Large Hadron Collider, the most powerful machine humans have built. The most energetic are extremely rare: of those above about 1018 electronvolts, roughly one particle per square kilometre per year reaches the Earth, and far fewer at the very top of the range.
The mystery. What accelerates them? Scientists believe the lower-energy ones come from inside our own galaxy, pushed by the shock waves of exploding stars, and the highest-energy ones from other galaxies. But proving this is hard, because a cosmic ray is electrically charged. On its journey it passes through magnetic fields that bend its path, like a ball that keeps getting deflected. By the time it reaches us, the direction it arrives from says nothing about where it started.
3. Why Neutrinos Make Perfect Messengers
Physics says that wherever protons are accelerated to very high energies and collide with matter or light, neutrinos are made too. So the neutrinos are a by-product of exactly the places we want to find. And unlike the protons, they keep a clean record of the journey:
| Messenger | What happens to it on the way | Can it point back to its source? |
|---|---|---|
| Light (radio to gamma rays) | Blocked by dust and gas; the highest-energy gamma rays are absorbed when they meet light and matter over long distances | Yes, if it gets through |
| Cosmic rays (charged particles) | Bent by magnetic fields | No |
| Neutrinos | Pass through dust, gas, stars and magnetic fields untouched, without losing energy | Yes, in a straight line |
That shyness is exactly what makes neutrinos valuable to astronomers. A neutrino arriving at Earth points back to its source, even if that source is hidden behind thick clouds of dust or so far away that its light has faded. The press release describes cosmic accelerators that fire out particles with energies up to a million times what laboratories on Earth can achieve; neutrinos can carry news of these places that no other messenger can.
An analogy. Think of a crime scene where the only witnesses are people who got pushed around in the crowd on their way out (cosmic rays) and a few who walked out in a straight line but almost never stop to talk (neutrinos). The straight walkers are the reliable witnesses; the hard part is getting them to stop.
The flip side. The same quality that makes neutrinos honest messengers makes them almost impossible to catch. Nearly all of them pass through the whole Earth without touching a single atom. The only way to catch a meaningful number is to watch an enormous amount of matter and wait for the rare collision.
4. Measuring Energy: The Electronvolt
Particle physicists measure energy in electronvolts (eV): the energy an electron gains when it moves through a voltage of one volt. It is a tiny unit, so big numbers need prefixes.
| Unit | Value | Where it shows up in this story |
|---|---|---|
| TeV (teraelectronvolt) | 1012 eV, a million million eV | The Large Hadron Collider accelerates protons to 7 TeV |
| PeV (petaelectronvolt) | 1015 eV, a thousand TeV | IceCube’s first two cosmic neutrinos, about 1 PeV each |
| EeV (exaelectronvolt) | 1018 eV, a thousand PeV | The most extreme cosmic rays, which come from beyond our galaxy |
So a single neutrino of 1 PeV carries more than a hundred times the energy of a proton in the world’s biggest accelerator.
5. Seeing the Invisible: Cherenkov Light
A neutrino leaves no trace on its own. IceCube sees it only on the rare occasion that it hits an atomic nucleus in the ice. That collision produces charged particles (for example a muon, a heavier cousin of the electron) that carry on in almost the same direction as the neutrino.
Here is the key. Nothing can travel faster than light in a vacuum. But light slows down inside a material: in ice it moves at roughly three-quarters of its vacuum speed. A very fast charged particle can therefore outrun light inside the ice. When it does, it gives off a faint cone of bluish light called Cherenkov light, named after the Soviet physicist Pavel Cherenkov.
An analogy. A jet flying faster than sound creates a sonic boom; a boat moving faster than the waves it makes leaves a V-shaped wake. Cherenkov light is the light version of that wake. Because the cone points along the particle’s path, the light tells you which way the particle, and so the neutrino, was going.
How IceCube Catches Them
1. The idea (1988). Very rarely, a neutrino hits an atomic nucleus. The collision produces a charged particle that moves through the medium faster than light does in that medium, and it emits a faint blue glow called Cherenkov light. Physicists had suggested around 1960 that a large volume of water could catch neutrinos this way, and a project called DUMAND tried it in the deep ocean off Hawaii. Halzen realised that the clear, deep glacial ice of Antarctica could serve as both target and detector. With John G. Learned of DUMAND, he first presented the concept at a conference in Poland in 1988.
2. The trials (1992 to 2000). Researchers began lowering light sensors into the South Pole ice in 1992. The upper ice was full of bubbles that scattered the light, but below about 1,400 metres the ice turned out to be extremely pure: light could travel about 300 metres before being absorbed. The pilot detector, AMANDA, was completed in January 2000. It worked, but it was too small to catch the rare cosmic neutrinos.
3. IceCube (full size in 2011). IceCube instruments one cubic kilometre of ice with 5,160 light sensors on 86 cables, placed between 1,450 and 2,450 metres below the surface. The South Pole was chosen because its ice is free of many kinds of interference and the area is geologically stable, with no earthquakes.
4. Finding the needle. Every day IceCube registers over a hundred million particles from cosmic rays in the atmosphere, and a few hundred atmospheric neutrinos that have passed through the Earth from the northern hemisphere. The cosmic neutrinos have to be picked out statistically from this background.
Inside the Detector
| Feature | Detail | Why it matters |
|---|---|---|
| Holes | Melted with a hot-water drill that works like a giant shower head | A drill bit cannot cut kilometre-deep holes in ice; hot water can |
| Strings | 86 cables, each carrying 60 sensors spaced every 17 metres | Sensors spread through the whole cubic kilometre |
| Sensors | Each holds a light detector (a photomultiplier tube, 25.4 cm across) facing downwards, with its own electronics | Halzen calls them “a lightbulb in reverse”: they turn light into an electrical signal |
| Layout | A hexagonal grid with strings 125 metres apart | Even coverage, so a passing particle crosses many sensors |
| Depth | 1,450 to 2,450 metres | Total darkness, and below the bubbly upper ice |
| Target mass | About one billion tonnes of ice | The bigger the target, the more rare collisions are caught |
| Construction | Strings lowered from 2005 to 2010; full size in 2011 | Work is possible only in the Antarctic summer, November to February |
| IceTop | Surface detectors above the strings | Spot cosmic-ray showers in the air, so their particles can be ruled out below |
Why ice, and why the South Pole? At depth the ice is permanently dark. Unlike the ocean, it has no glowing sea creatures and very little natural radioactivity to cause false flashes. It is a solid, stable platform, and the Amundsen-Scott South Pole Station already provided transport and support.
Looking Down, Not Up: The Earth as a Filter
The biggest problem is noise. Cosmic rays hitting the atmosphere above Antarctica create muons that rain down into the ice from above, thousands of them every second. To a sensor, a muon from the sky looks much like a muon made by a neutrino.
The trick is to look down. Only a neutrino can pass through the entire planet, so a particle track coming up from below the horizon must have been made by a neutrino. The Earth acts as a giant shield. This one choice cuts the muon background from thousands per second to around one per second. It also means that IceCube’s clearest view, through the Earth, is of the northern sky.
The second sorting step separates cosmic neutrinos from the much more common atmospheric ones. IceCube records about 100,000 neutrinos a year above 0.1 TeV, almost all made in the atmosphere. Only about 100 a year are expected to come from space. The cosmic ones stand out at high energy: above a few tens of TeV, atmospheric neutrinos fall away fast and the cosmic ones remain.
Two Shapes of Light: Tracks and Cascades
The sensors record how much light arrives (which gives the energy) and when it reaches each sensor (which gives the direction). Neutrino collisions leave two main patterns:
| Track | Cascade | |
|---|---|---|
| Looks like | A long straight streak of light across the detector | A roughly round burst of light |
| Made by | A muon neutrino that produces a muon, which can travel kilometres | Electron and tau neutrinos, and some collisions of any flavour |
| Direction | Very precise: about 0.3 degrees at 100 TeV | Rough: about 5 degrees |
| Energy | Rough: only within a factor of about two | Precise: about 8 per cent at 100 TeV |
| Best for | Pointing to a source in the sky | Measuring energy, and seeing the whole sky |
| Analogy | A shooting star’s streak | A firework burst |
A tau neutrino can leave a rare “double bang”: two bursts a short distance apart. IceCube reported seven high-energy tau neutrinos in 2024. They matter because above a certain energy the atmosphere cannot make tau neutrinos, so they must come from space.
What It Found
| When | Result | What it means |
|---|---|---|
| 2013 | Two neutrinos of about 1 PeV each (1.04 and 1.14 PeV), found by chance during a search for even higher energies; soon after, 28 high-energy neutrinos in the same data (21 cascades, 7 tracks) | First evidence of high-energy neutrinos from beyond the solar system |
| 2014 | A purely atmospheric explanation of the 2010 to 2013 data rejected at 5.7 sigma | Within a couple of years the data were strong enough to make the discovery certain |
| 22 September 2017 | A neutrino of about 290 TeV arrived from within 0.06 degrees of the blazar TXS 0506+056, which was flaring in gamma rays; an alert went out to telescopes worldwide within a minute | The first time a single high-energy neutrino was tied to a known object. The collaboration reported it in 2018; a search of older data found a burst of neutrinos from the same direction in 2014 and 2015 (3.5 sigma) |
| 2022 | 79 neutrinos traced to the direction of the active galaxy NGC 1068 (M77), 46 million light-years away (4.2 sigma) | A likely source, whose central black hole is wrapped in gas and dust that block light but not neutrinos. The Nobel committee notes this is not yet conclusive proof |
| 2023 | High-energy neutrinos from the plane of our own galaxy, the Milky Way (4.5 sigma) | Neutrinos made when cosmic rays strike the thin gas between the stars |
| 2024 | Seven high-energy tau neutrinos | Independent confirmation of neutrinos from space |
| 2026 | The Milky Way signal confirmed at 5.7 sigma with 12 years of data | The first source of high-energy neutrinos above the 5-sigma discovery threshold; no single point source within it yet |
| Highest energy | IceCube’s most energetic neutrino published so far, recorded on 31 March 2019: about 11 PeV | Published in March 2026 |
What is a blazar? At the centre of many galaxies sits a supermassive black hole. When it swallows gas and dust, it can launch two narrow jets of particles moving at nearly the speed of light, stretching up to several hundred thousand light-years. When one of those jets happens to point almost straight at Earth, astronomers call the galaxy a blazar. Such jets are prime suspects for the cosmic accelerators.
The big picture. The results show that most high-energy cosmic neutrinos come from outside our galaxy, from many sources spread across the sky, with a smaller contribution from the Milky Way. Identifying the individual sources is the work that remains.
How Sure Is Sure? The Sigma Scale
Physicists report certainty in sigma (σ), a measure of how unlikely a result would be if nothing but random background were at work.
| Level | Convention | Chance that background alone would give a signal this strong |
|---|---|---|
| 3 sigma | “Evidence” | about 1 in 740 |
| 5 sigma | “Discovery” | about 1 in 3.5 million |
Read the table above with this in mind: the Milky Way signal (5.7 sigma) and the existence of cosmic neutrinos as a whole (5.7 sigma) are discoveries; NGC 1068 (4.2 sigma) and the 2014 to 2015 TXS 0506+056 burst (3.5 sigma) are strong evidence that is not yet conclusive.
Multi-Messenger Astronomy, Simply
The committee’s chair, Mark Pearce, said Halzen’s “tenacity and scientific vision has paved the way for a new kind of astronomy”. Neutrino astronomy now joins light, cosmic rays and gravitational waves as a way of observing the universe: so-called multi-messenger astronomy.
The idea is simple: study the same cosmic event with every kind of signal it gives off. Each messenger shows something the others cannot.
| Messenger | Since | What it reveals |
|---|---|---|
| Light (all wavelengths) | Antiquity (radio, X-ray and gamma-ray telescopes in the 20th century) | Shape, temperature and make-up of objects, unless dust hides them |
| Cosmic rays | 1912 (Hess) | That cosmic accelerators exist, but not where |
| Neutrinos | Sun in the 1960s; a supernova in 1987; high-energy cosmic neutrinos 2013 (IceCube) | The insides of stars and the hidden engines of galaxies |
| Gravitational waves | First detected 2015 | Ripples in space-time from colliding black holes and neutron stars |
The 2017 blazar was a textbook case. IceCube’s alert sent telescopes around the world to the same patch of sky, and the gamma-ray telescopes found the blazar flaring at that moment. Two messengers, one event.
Earlier neutrino astronomy. Raymond Davis Jr caught neutrinos from the Sun in the 1960s, and Japan’s Kamiokande detector, led by Masatoshi Koshiba, caught a burst of neutrinos from a supernova in the Large Magellanic Cloud in 1987. Both shared the 2002 Nobel Prize. IceCube takes the field to energies millions of times higher and to sources far beyond our galaxy.
Why It Took a Quarter Century
| Year | Step |
|---|---|
| About 1960 | Physicists propose large volumes of water as neutrino detectors |
| 1980s | Halzen hears of a Soviet plan to catch neutrinos in Antarctica with radio antennas, and thinks of light sensors instead |
| 1988 | Halzen and John Learned present the South Pole ice concept at a conference in Poland |
| 1992 | First attempts to lower light sensors into the South Pole ice, after tests in Greenland |
| 1993 | Halzen spends Christmas Eve at the dinner table waiting for word that the first cable of sensors is in the ice |
| January 2000 | AMANDA, the pilot detector, completed |
| 1999 to 2004 | IceCube proposal to the US National Science Foundation (1999), funding approved (2002), construction begins (2004) |
| 2011 | IceCube reaches full size |
| 2013 | First evidence of cosmic high-energy neutrinos |
The lessons are not only about physics. The first results were disappointing: the bubbly upper ice blurred everything. The team kept going, learned to go deeper, and along the way produced a by-product nobody planned: one of the best maps of the properties of Antarctic ice at different depths. The Nobel committee credits Halzen with acting as a catalyst and building an international collaboration that turned an idea into precise measurements.
What Comes Next
- IceCube-Gen2, a planned expansion at the South Pole to about eight cubic kilometres of ice.
- Water-based telescopes in the northern hemisphere, in various stages of development: KM3NeT (Mediterranean Sea, off Toulon and Sicily), Baikal-GVD (Lake Baikal, Siberia), P-ONE (off Vancouver Island, Canada) and TRIDENT (South China Sea).
- Together they will watch the whole sky with the aim of naming the individual sources of cosmic neutrinos.
Neutrinos and the Nobel Prize
| Year | Laureates | Work |
|---|---|---|
| 1988 | Leon Lederman, Melvin Schwartz, Jack Steinberger | Neutrino beam method; discovery of the muon neutrino |
| 1995 | Frederick Reines (shared) | Experimental detection of the neutrino |
| 2002 | Raymond Davis Jr., Masatoshi Koshiba (shared) | Detection of cosmic neutrinos (from the Sun and a supernova) |
| 2015 | Takaaki Kajita, Arthur B. McDonald | Neutrino oscillations, which show that neutrinos have mass |
| 2026 | Francis Halzen | IceCube and high-energy astrophysical neutrinos |
Key Terms in Plain Words
| Term | Plain meaning |
|---|---|
| Neutrino | A tiny, uncharged, almost massless particle that passes through nearly everything |
| Flavour | One of the three kinds of neutrino: electron, muon, tau |
| Neutrino oscillation | A neutrino changing from one flavour to another as it travels; proof that neutrinos have mass |
| Cosmic rays | Fast charged particles from space, mostly protons; their paths are bent by magnetic fields |
| Electronvolt (eV) | The unit of energy for particles; TeV, PeV and EeV are a trillion, a thousand trillion and a million trillion eV |
| Muon | A heavier cousin of the electron, made when a muon neutrino strikes a nucleus |
| Cherenkov light | The bluish glow from a charged particle moving faster than light can in that material |
| Photomultiplier tube | A very sensitive light detector that turns a faint flash into an electrical signal |
| Atmospheric neutrinos | Neutrinos made when cosmic rays hit our air; the main background |
| Astrophysical neutrinos | Neutrinos from sources in space beyond the solar system; the target |
| Track / cascade | A long streak of light (good direction) versus a round burst (good energy) |
| Active galactic nucleus | The bright core of a galaxy powered by a feeding supermassive black hole |
| Blazar | An active galaxy whose jet points almost straight at Earth |
| Sigma | A measure of statistical certainty; 5 sigma is the threshold for “discovery” |
| Multi-messenger astronomy | Studying the universe with light, cosmic rays, neutrinos and gravitational waves together |
Common Misunderstandings
- “Neutrinos are dangerous radiation.” No. Billions pass through you every second without effect; they almost never interact with anything.
- “Cherenkov light means something beat the speed of light.” Only the speed of light in ice or water, which is slower than in a vacuum. Nothing outruns light in a vacuum.
- “IceCube looks up at the sky.” For its sharpest searches it looks down, through the Earth, using the planet to block the muons that rain from above.
- “IceCube has found where cosmic rays come from.” Not yet. It has proved that high-energy cosmic neutrinos exist and come mostly from beyond our galaxy, and it has strong candidates, but no single distant source has passed the 5-sigma bar.
- “Neutrinos have no mass.” They have a very small but non-zero mass; that is what oscillation shows.
- “IceCube is a telescope with lenses or mirrors.” The detector is the ice itself, a cubic kilometre of it, watched by thousands of sensors.
The India Angle
Kolar Gold Fields (KGF), 1965. Physicists from the Tata Institute of Fundamental Research and their Japanese and British collaborators recorded atmospheric neutrinos deep in the Kolar gold mines in Karnataka, among the first such detections anywhere. The mines closed in 2001 and the experiments ended.
India-based Neutrino Observatory (INO). INO was planned as an underground laboratory in the Bodi West Hills, Theni district, Tamil Nadu, with a large magnetised iron calorimeter (ICAL) to study atmospheric neutrinos. The project has been stalled for years over environmental and local objections and litigation.
The lesson. IceCube took about two decades from first trials to discovery, with steady funding and an international collaboration. Big-science projects need patient support, early engagement with local communities and clear environmental safeguards.
UPSC Relevance
GS Paper 3. Science and technology: developments and their applications; achievements of Indians in science (KGF); awareness in space science and particle physics. Prelims. Neutrino properties and flavours, cosmic rays, Cherenkov radiation, the electronvolt scale, blazars and active galaxies, Nobel bodies, multi-messenger astronomy.
Mains practice: “Neutrino astronomy has opened a new window on the universe. Explain the significance of neutrinos as cosmic messengers, and discuss why India’s own neutrino observatory has not taken off.” (250 words)
📌 Facts Corner, Knowledgepedia
Prelims, statement-ready facts:
- 2026 Nobel Prize in Physics: Francis Halzen (born 1944, Tienen, Belgium; University of Wisconsin-Madison), announced 6 October 2026.
- Citation: “for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin”.
- IceCube: 1 cubic kilometre of South Pole ice; 5,160 sensors on 86 cables at 1,450-2,450 m depth; full size in 2011; predecessor AMANDA (completed January 2000).
- Detection is through Cherenkov light, the blue glow from a charged particle moving faster than light in that medium.
- First evidence of cosmic high-energy neutrinos: 2013.
- Neutrino flavours: electron, muon, tau. Proposed by Pauli (1930); first detected by Cowan and Reines (1956).
- Cosmic rays were discovered by Victor Hess in 1912 (Nobel 1936); they are mostly protons and helium nuclei.
- The Milky Way is the first high-energy neutrino source past the 5-sigma discovery threshold (5.7 sigma, 12 years of data).
- Blazar: an active galaxy whose jet points at Earth; TXS 0506+056 was linked to an IceCube neutrino of September 2017.
- IceCube-Gen2: a planned expansion to about 8 cubic kilometres of ice.
- Physics and Chemistry prizes are awarded by the Royal Swedish Academy of Sciences.
- 2025 Physics prize: John Clarke, Michel H. Devoret, John M. Martinis, for macroscopic quantum tunnelling and energy quantisation in an electric circuit.
Prelims, the traps:
- Neutrinos have no charge and very small but non-zero mass (oscillations, 2015 Nobel); they are not massless.
- Cherenkov light does not mean a particle exceeds the speed of light in a vacuum, only the speed of light in that medium.
- Neutrinos are not deflected by magnetic fields; charged cosmic-ray protons are, which is why neutrinos can point to sources.
- IceCube’s cleanest searches look down through the Earth, at the northern sky, not up.
- IceCube is at the South Pole, not in the Arctic; INO was planned in Tamil Nadu, not at KGF.
Mains, arguments and keywords:
- Multi-messenger astronomy; basic research and serendipity; big-science collaboration; long-horizon funding; science and environmental clearance.
Interview, be ready for:
- “India detected atmospheric neutrinos in 1965. Why is it not part of this Nobel story?” Answer with continuity: KGF closed, INO stalled, and big science needs decades of uninterrupted support.
- “Explain a neutrino to a farmer.” Try: a messenger from distant stars that passes through the whole Earth as if it were not there, so we built a detector as big as a mountain of ice to catch a few.
Sources: The Nobel Prize, Press release: Nobel Prize in Physics 2026, 6 October 2026, The Nobel Prize, Popular information: Nobel Prize in Physics 2026, Nobel Committee for Physics, Scientific background: Nobel Prize in Physics 2026, The Hindu, 7 October 2026
Source: Nobel Prize in Physics 2026: Halzen, IceCube and Neutrinos — Ujiyari.com | Free UPSC & State PCS Current Affairs
