Nobel Prize in Physics 2026: Francis Halzen | Hacker News Reader

Nobel Prize in Physics 2026: Francis Halzen

nobelprize.org

584 pointssolarist211 comments

A breakdown of why the awarded work, Ice Cube, is significant:

  - A neutrino is an elementary subatomic particle. Neutrinos are produced by nuclear reactions inside stars, supernovae, radioactive decay. They are one of the most abundant particles in the universe.
  - Neutrinos are known as "ghost particles". They have 0 charge and near-zero mass. They only react with the weak nuclear force and gravity. Incredibly hard to detect. Trillions can pass through a whole planet without hitting a single atom!
  - Neutrinos give us a pristine snapshot into the origin of the universe. They have travelled billions of years and trillions of miles without interacting with anything. Unless...we catch them!
  - Ice Cube does this. Located in Antarctica, the project turns a cubic kilometer of ice into a neutrino detector. How? Scientists drilled boreholes 2.5km deep into the ice and placed 5000 optical detectors to catch a neutrino interaction.
  - When a neutrino, rarely, collides with an atom, it produces charged particles. In ice - not vacuum! - certain particles can travel faster than light. This produces something similar to a sonic boom. A faint, blue glow known as Cherenkov radiation (see it in action https://youtube.com/watch?v=hSuSG19Pcoc).
  - IceCube was first to detect neutrinos coming from outside the solar system, establishing the source of high energy cosmic radiation. It also opened a whole new chapter of neutrino astronomy.

" - When a neutrino, rarely, collides with an atom, it produces charged particles. In ice - not vacuum! - certain particles can travel faster than light."

That confused me for a moment so it seems worth clarifying: in ice, certain particles can travel faster than light does in ice.

This is also the source of the classic blue glow in water cooled nuclear reactors. Electrons move through the water faster than light and leave behind a kind of 'sonic boom' of photons in its wake.

Thank you, I lost my mind, briefly, reading that part.

Light slows down in dielectric materials because as an em wave it interacts with the polarization of molecules. Neutrino has very little interaction with matter, OTOH.

https://news.ycombinator.com/item?id=49977885

>Neutrinos give us a pristine snapshot into the origin of the universe. They have travelled billions of years and trillions of miles without interacting with anything. Unless...we catch them!

I assume this is not a hard, totalizing law since it seems we're able to get samples of neutrino collisions in just a kilometer sized chunk of ice on Earth (meaning that the probability of collision is not absolutely zero and there's no way to know the full neutrino travelogue through the universe)

Correct, they do have a probability of interacting, but it's extremely low, depends of the energy of the neutrino (its momentum) but basically it can go through 1 light year of lead and still have only a 50/50 chance of interacting.

to put things to scale 1 ly is 9,460,730,472,580,800 meters, or 63,241.077 astronomical units, the distance from the Earth to the Sun.

Needless to say, it's pretty weakly interacting as far as interaction goes...

> a cubic kilometer of ice into a neutrino detector. How? Scientists drilled boreholes 2.5km deep into the ice

Seems odd that boring 2.5km into ice would protrude 1.5km out the other side of a cubic km.

A cubic kilometer is a volume, it does not dictate the shape.

The upper layers of detectors are buried over a kilometer below the surface in order to shield the array from most cosmic rays.

If they drilled down any further they'd reach the interior of the hollow earth, obviously not permitted

We wouldn't want to cause a leak!

> neutrinos coming from outside the solar system How do we know this and why do we care where they came from?

Since neutrinos don’t interact with much of anything, its path doesn’t deviate from its origin. Different origins emit neutrinos with different levels of energy. When a neutrino hits a nucleus, the blue light emitting particle in ice follows closely the same direction. Measuring the direction and the magnitude (lighting energy) of the vector we can classify its origin. Collecting a bunch of the same signature we know there's an object at that direction emitting at that energy level. From the vector and energy we kind of know whether it’s from the solar system or not.

Identifying the origin let us see objects behind dust clouds or other obstacles.

> When a neutrino hits a nucleus, the blue light emitting particle in ice follows the same direction.

How does this not violate conservation of momentum? Are you saying every single collision is head-on?

Most paths of the high energy observable collisions follow a very close alignment to the original neutrino's path. The forward momentum of a high energy neutrino completely dominates the collision. Imagine an one-ton ball hitting a billiard ball. Doesn't matter what direction the billiard ball was going; the resulting path is the one-ton ball's path.

In other cases, the particle being collided is scattered and won't show up in the detector. Low energy neutrino collisions also have very faint light and difficult to detect. Solar system produced neutrinos are in this category.

We know this because

- In the beginning, for the first couple of events, only because they have way higher energies than anything in the solar system could produce - By now, with enough data collected, their origin correlates very well with the milky way - we are close to identifying several far away galaxies as well

This is the significance. Contrary to some statements published today, IceCube was not primarily built to study Neutrinos, it was built to study the universe using Neutrinos.

That's why we care where they are coming from, we want to learn about the astrophysical objects that produce them.

" in February 2023, [KM3NeT] detected the most energetic neutrino ever observed. It's called KM3-230213A, and its estimated energy was 220 PeV (220 x 10^15 electron volts or 220 million billion electron volts) "

- https://phys.org/news/2026-04-energetic-neutrino-primordial....

That's an insane amount of energy. If your are knowledgeable about this do you know why some neutrinos have more energy than others? surely it is just a relationship with it's speed. I thought all neutrinos moved close to the speed of light.

If my quick math is correct that is equivalent to dropping 3.59g one meter in a vacuum in earths gravity. insane that a subatomic particle can have that much energy.

Neutrinos interact only to the weak interaction and (IF they have rest mass) to gravity. (They have no charge.)

This article has some ideas on such an energy:

https://phys.org/news/2025-05-physicists-route-neutrinos.htm...

It says "typically, energetic neutrinos from active galactic centers are thought to originate from interactions between protons and photons, producing gamma rays of comparable intensity." and suggests other theorized sources.

Another good source on this new branch of astronomy:

https://arxiv.org/html/1501.07798v1

Newer idea (May 2026): blazars

https://www.sciencedaily.com/releases/2026/05/260523103912.h...

Particle physics processes in the sources we suspect accelerate particles in a way that results in a power law distribution of energies. So you can get extremely high energy particles, but the higher the energy the rarer.

And sources have a maximum energy they can accelerate particles to.

https://en.wikipedia.org/wiki/Fermi_acceleration

Didn’t the big bang theory show have an episode about this?

If it did they should get the Novel prize.

what is so special about ice?

Neutrinos are very weakly interacting and hence you need a massive amount of some matter through which they can pass so as to have a decent probability of getting an interaction.

Ice at kilometer level depths is exceptionally clear and transparent since the pressure (from layers above) removes any air bubbles and hence any Cherenkov radiation due to neutrino interaction does not get scattered. This means observations can be done clearly and precisely.

Finally, the rigidity of Ice can hold the sensors precisely and the depth guarantees that no unnecessary external noise from the surface can affect the measurements.

All the above are ideally met by the Ice at the south pole and hence the IceCube Neutrino Observatory was established there.

H2O is the key, not ice. Ice is nice because it's rigid, so you don't need a boat [1]. They're also working on making detector under the sea [2].

[1] https://www.amusingplanet.com/2015/07/the-surreal-world-of-n...

[2] https://news.cnrs.fr/videos/detecting-neutrinos-at-the-botto...

Among other things this ice is super transparent.

interesting

He receives the prize for conceiving the IceCube neutrino detector, a cubic-kilometer-sized detecter in the Antarctics.

https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory

Mechanism is via conversion of neutrinos into charged particles which are then detected via Cherenkov radiation which is produced when a charged particle moves with speeds larger then the speed of light in the medium. (That is only possible because it is less than the speed of light in vacuum which cannot be exceeded.)

This was also discussed recently if you are interested: https://news.ycombinator.com/item?id=49655286

https://en.wikipedia.org/wiki/Cherenkov_radiation

If anyone was wondering how some of that heavy stuff gets to the south pole to build such a large engineering project, at the farthest possible end of any logistics chain:

https://www.google.com/search?client=firefox-b-d&q=south+pol...

https://en.wikipedia.org/wiki/South_Pole_Traverse

https://octanepress.com/content/south-pole-traverse_antartic...

Significant amounts of things still come in by air cargo at great cost, but a lot also comes the long slow way.

I am adopting “Furthest possible end of any logistics chain” as a more refined version of “middle of fucking nowhere”. Thank you.

It would probably be harder if they wanted to put it, for instance, on the ocean floor at Point Nemo, but for sure the literal south pole is pretty damn expensive on a $ per kg to get stuff sent to. And on an ongoing basis to sustain operations 24x7x365 (it's my understanding it runs almost entirely on diesel fuel and/or Jet-A for a big-ass set of generators).

It is expensive and it doesn't need to be there, but the reason its at the south pole is that the US has money for SOMETHING at the south pole. They want to maintain a presence at the south pole for international relations reasons. To be consistent with insternational treaties they need to do science there.

So, the US/NSF is like "we have a bunch of money to do science, but it has to be at the south pole". People like Halzen who had a crazy idea go to NSF and say how can I get a bunch of money to do this. NSF says, we don't have that kind of money in our physics budget, but if you were to do it at the southpole we could fund it.

That's such interesting context. Thank you!

Is the cynical take on this experiment the one where the detectors have a dual purpose?

I was interested to see the photos of the modules. LEDs and an Ethernet port!

I disagree: anywhere in the ocean is easier logistics than crawler trains over land: ship it there and chuck it overboard. They do that to install oil rigs all the time (but that's more like float it there and sink it). Eg: https://www.wired.com/2014/07/dockwise-vanguard-shipping

Yeah, but now imagine the cost of putting large active electronics 4,000 meters down on the sea floor and keeping it running, and getting the data back off it... The cost of running the drill rig seen in the photos of the icecube detector would be a fraction of that.

That’s also a thing, e.g. in the Mediterranean.

https://en.wikipedia.org/wiki/KM3NeT

why would "ship it there and chuck overboard" be easier than "crawler train it there and chuck overboard"?

Because shipping is easier than trucking at subzero temperatures on roads constantly being covered in snow.

Also, we've been shipping by water much longer than we've been trucking things on wheels, because the tech is easier: get on floaty wood and paddle.

For sure, there are more difficult places, but I don’t think there is any conceivable place where the supply chain runs through the South Pole on its way. I hope not.

This was fascinating, thank you for posting! Here is a video I found of the different types of sleds they use on the traverse - https://www.youtube.com/watch?v=mjrQrKjotpA

The Telescope in the Ice was a solid book about this.

https://www.amazon.com/dp/1137280085

The book about it can also be used to detect neutrinos too?

Only if you bury it a kilometer below the ice.

> produced when a charged particle moves with speeds larger then the speed of light in the medium.

Thanks, I had no idea this was possible!

https://xkcd.com/1053/

This is quite nuanced and not as most people assume.

It is the "phase velocity of light in that medium" that is exceeded.

phase velocity of light in a medium = speed of light / refractive index of the medium.

Thus the EM wave is slowed down in a medium and so a charged particle can exceed it producing Cherenkov radiation. This is similar to a sonic boom in atmosphere when speed of sound is exceeded. In both cases the object is traveling faster than the wavefront.

It is only in vacuum that "phase velocity of light" = "group velocity of light" = c (i.e. 300,000 km/sec)

What really is the speed of light in a medium/vacuum, group or phase velocity? - https://physics.stackexchange.com/questions/450377/what-real...

IIRC the group velocity in a medium can also exceed c when you send pulses through certain nonlinear media. Basically, the "lump" of the pulse can appear to "exit before it entered," but what really happens is that the tiny tip of the pulse has already gone through at <= c, and starts growing into the body at the exit before it has completely shrank at the entrance because of the nonlinearity. So it is actually the information/"signal" velocity (the tip of the signal) that cannot exceed c.

AFAIK there are three scenarios;

1) Non-Dispersive medium (eg. vacuum) : v(g) = v(p) = c

2) Normal Dispersion medium (eg. in water) : v(g) < v(p)

3) Anomalous Dispersion medium (eg. absorbing materials) : v(g) > v(p)

where (simplified);

v(g) : group velocity which can be thought of as a function of the overall wave packet (i.e. pulse) and hence contains the actual energy/information/signal.

v(p): phase velocity which can be thought of as a function of a single wave frequency and hence the crest of that wave.

To be more perfectly precise, it is only in a vacuum with an infinitely repeating regular signal that "phase velocity of light" = "group velocity of light".

The deviation caused by uncertainty in the package arrival time is typically extremely short, but not zero, for finite signals.

The actual "entity" that is restricted to be <=c is "information velocity". An infinitely repeating pattern would have travel at (phase velocity)=c ... but would ironically transmit no actual information (the bit value is restricted to 1, not 0 or 1).

Nice. Trying to read/understand "RF Systems and Modulation" is what got me interested in this subject in the first place.

So in my mind i map your comment as; the "carrier signal" single analog frequency is the infinitely repeating regular wave (no information) traveling at v(p) while the "information signal" (analog/digital) imposed on top of it (frequency/amplitude/phase modulation) creates the informational pulse/wave packet traveling at v(g).

Add in different media in the real world and you have a difference between v(g) and v(p) - https://news.ycombinator.com/item?id=49988070

Wow, yes, great perspective!

Are there interesting relativistic effects related to this other than this Cherenkov radiation?

Yes, there are. Checkout the "see also" section of Cherenkov radiation on wikipedia which lists some of them - https://en.wikipedia.org/wiki/Cherenkov_radiation

Here is the relevant chapter from the Feynman lectures, Relativistic Effects in Radiation - https://www.feynmanlectures.caltech.edu/I_34.html

If you ask AI, you will get a list with nice short explanatory notes; check it out.

Finally on a related and very interesting vein, Physicists have even brought light to a standstill in tiny gas clouds of sodium atoms cooled to near absolute zero! See the pdf of Scientific American article "Frozen Light" by Lene Vestergaard Hau from her publications webpage - https://groups.seas.harvard.edu/haulab/publications/HauPubli...

And remember, the "speed of light in the medium" depends on the wavelength of the light. This is why prisms separate light by color.

More clearly, in a dispersive medium like a prism, the wavelength of the light depends on its frequency.

Because the speed of light (in the sense of phase velocity) is the product of wavelength with frequency, both the speed and the wavelength vary with frequency, thus also the refractive index varies with frequency.

Optical sonic boom.

Actually called a "Luminal Boom" or "Photonic Boom".

Okay but how is this useful to humanity (since thats part of the prizes condition)? Its cool that we can detect them but...now what?

How can we make neutrinos useful to us? - https://www.youtube.com/watch?v=F0HQp2nBFhI

What are neutrinos good for? - https://www.youtube.com/watch?v=-6iyyM5XRx4

If it moves, we can communicate with it. Your mobile phone's neutrino signal will not lose a single bar, wherever you are on Earth, or in the solar system, or in the galaxy.

And now we come to the Macroscope.

I read all of that and other resources online and still couldn't understand why the hell we need to build that and especially in south pole antartica

Neutrinos need a large detector volume for efficiency because they interact so rarely. You can’t detect them directly so you need a transparent medium to detect their collision byproducts. Good detector mediums are water and ice, and are underground to minimise background light. There are relatively few places you can do this. Mine caverns and under the sea are the most common, but marine detectors are notoriously hard to build. Francis Halzen proposed using ice. At the Pole, the glacial plateau is 2 miles high and the breakthrough was confirming that the ice is in fact highly transparent if you go deep enough.

Why the pole specifically? You could probably build a second IceCube 100 miles away, but how are you going to get that materials there? Pole has a skiway for large aircraft and infrastructure to house a large number of people. The traverse (SPoT) only became operational near the end of construction - the initial holes were drilled in 2005 and almost everything had to be flown in.

Telescope In The Ice does a great job of explaining the history and science behind the experiment.

The biggest challenge is finding ice without dust layers from historical volcanic activity, and the South Pole is particularly clean because of it's remoteness as well as the prevailing wind directions. There is, however, one big dust layer that causes signal distortion.

dust layers wont effect them neutrinos can pass anything or I am missing a point

You have to see the light from when a neutrino interacts with something, so you want very clear water or ice for that.

The best science comes from areas that have no obvious use. The original insights into nuclear physics, quantum physics and relativity were all pure thought experiments. They led to the world we live in.

I'm personally very happy that we're still funding science that isn't obviously monetised.

The reason for Antarctica is that it's the only place you find cubic kilometres of stable ice that doesn't drift around.

No they weren't.

All of it was driven by a flood of experimental results that were not compatible with classical physics.

See "Ultra Violet Catastrophe" in black body radiation, photo effect.

Planck famously performed curve fitting on the black body spectrum and only afterwards found the theoretical foundation for the function that fit the data.

https://en.wikipedia.org/wiki/Ultraviolet_catastrophe

"No they weren't."

I'm actually not sure exactly what "they" is in this sentence.

I know about the Ultraviolet catastrophe, but that's cherry-picking.

Dirac predicted the Positron before it was discovered.

Quantum entanglement was predicted by Einstein, Podolsky and Rosen before it was shown ("Spooky action at a distance")

Black Holes and Gravitational waves were both predicted before they were detected.

Einstein predicted time dilation before it was detected.

Szilard predicted chain reactions in Nuclear fission before they were demonstrated.

And probably most pertinent to this discussion, Pauli predicted Neutrinos before they were detected.

Half of the list above are critical for GPS, energy, semiconductor research and many other fundamental technologies of the modern age. They were researched and predicted without any thought of a "monetisable" product.

> And probably most pertinent to this discussion, Pauli predicted Neutrinos before they were detected.

Because of the experimental result of missing energy in the beta radiation spectrum.

Bone of these were "pure thought experiments" as you describe. Many were side effects, new predictions of theories to address other experimental results, but none of them happened in isolation.

You simply don't make predictions about the real world in "pure thought experiments".

My best guess would be just the remoteness.

1: Ice-mass that isn't contaminated by atomic testing fallout (if the ice has been there since the 40s it's without radioactive waste (faschinating to read about how WW2 wrecks is a prime resource of steel since it's a huge amount of steel without trace amounts of radionucletiods from testing fallout).

2: No current interference (nuclear power, radiowaves,etc) creating possible test uncertainties.

3: I'm sure there are other reasons

The negative naturally is cost, but since the expriment succeeded it will probably be useful for any attempts to send robots or even humanity into space beyond the solar system.

Where else would you go look for a cubic km of ice?

Greenland, though that is probably not much better in any measurable way, when it comes to transport.

Greenland is much better logistically in some ways (I work on experiments both in Greenland and in Antarctica), but the ice in Greenland is unlikely to be as good for IceCube as in Antarctica, due to a presumed larger number of dust layers from dry periods in Europe.

The US has a research station at Summit Station Greenland but compared to South Pole, it's spartan (like, the first time I went there, I slept in a tent because of lack of hard-sided berthing, but then a Polar bear came a few years later and now hard-sided berthing is required). There are longer-term plans to improve the station in Greenland but we'll see.

Another option that's been popular is to get it as deep underground as possible, hard rock mines with empty areas:

https://en.wikipedia.org/wiki/Sudbury_Neutrino_Observatory

https://en.wikipedia.org/wiki/SNO+

https://en.wikipedia.org/wiki/Super-Kamiokande

There's a weird overlap in engineering and physics disciplines between the hard engineering/business practices of the mining industry, and particle physics.

Right, but for those they need to make/move/collect a large amount of transparent material, like heavy water etc for the particles to interact with. But they get that 'for free' with the ice.

and another option is putting it in the sea, see KM3NeT: https://en.wikipedia.org/wiki/KM3NeT

Logistics is much easier for Greenland, but the optical properties of the ice are not as good as at the south pole.

If we're serious about AI taking over jobs, we'll probably need to get more comfortable with any kind of undirected work-for-its-own-sake, not less.

> which are then detected via Cherenkov radiation which is produced when a charged particle moves with speeds larger then the speed of light in the medium. (That is only possible because it is less than the speed of light in vacuum which cannot be exceeded.)

I have been researching applications of FTL as well;

Where is there an actual vacuum on Earth or in microgravity? So, there are Proca waves within dielectric Proca metamaterials and plasmas and waveguides; and photons can have effective mass and/or longitudinal charge Ez in ionized plasma?

So, Maxwellian waves with no longitudinal (Ez,) component can exist in what fraction of the universe if they can only exist in a vacuum?

A Twistor model can model such;

Perhaps this was downvoted in ignorance?

This question could have avoided the offense:

What is the relation between Cherenkov relation and effective mass in longitudinal plasma waves?

I'm in love with the cute little figure that came with the press release: https://www.nobelprize.org/uploads/2026/10/fig_fy_26_3x2.jpg

I appreciate the boldness of this project, it has an element of sci-fi to it. Building a base at the south pole to bury sensors in ice to measure elusive particles. The stuff of dreams!

The same guy (Johan Jarnestad) has been doing all the nobel prize illustrations and infographics for years!

https://www.infographics.se/

https://www.behance.net/JohanJarnestad

Looking at the behance site it's a pretty good choice, glad some illustrators are still making a living in the AI age.

To be fair, the base was already there and logistically essential. The IceCube topside building is just a part of the Amundsen-Scott South Pole Station, about a km or so from the Elevated Station.

This image* from Wikipedia surprised me. The topside building is...you could say...the tip of the iceberg. The detectors span a huge area going over 2km deep. The predecessor AMANDA array was also down there.

*https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory#/...

Yes. It spans a cubic kilometer.

The building is just for housing the data gathering and comms equipment and whatever maintenance and engineering stuff the array needs. I don’t think anybody physically works there regularly.

Umbrella corporation.

A trillion of these silly small guys pass through us every second. Funny to imagine them like that.

There are many things that my brain just can't handle, the size of the universe, more than 3 dimensions and this fact especially.

I will argue on your behalf that your brain can handle just one more dimension than the 3 you are likely referring to. :)

Most people are pretty bad at accounting for the effects of time.

Is this a Gödel Completeness thing?

If you ever feel lonely, think about all those little friends who come visit you!

We rarely bump into each other, actually. When we do it happens in a flash.

Depending on how much space you occupy, closer to 500 trillion per second

You can follow along with the researchers here https://icecube.wisc.edu/news/life-at-the-pole/2026/10/week-...

What an amazing accomplishment! I played a very tiny part in this project and went to the South Pole in 2009 to help with construction. Didn't see any neutrinos the entire time I was there though :/

I worked with a guy who worked on IceCube. He flew down to the South Pole, went all the way to the station, just to install debian for their data processing systems. I was... a bit jealous.

I wintered for IceCube - most of the job is on-call Linux admin, cluster management and a bit of field work depending on the year.

A friend did that too, a lot of his job was going out in the snow and changing tapes, I guess better internet connectivity changed a lot

Must have been a while ago!

IceCube sends housekeeping and priority transient events (like a supernova) over satellite, selected high quality events get synced over satellite daily and everything else gets stored and shipped out in the summer. There is a redundancy everywhere - it’s a very thoughtfully designed system.

You travelled on-site?

They didn't just travel on-site, they over-wintered, which means travelling to the site and then staying through the worst weather, while it's completely dark, without any practical means of leaving for months.

I feel obliged to say that while it gets cold over winter, the weather isn’t particularly bad by Antarctic standards; the coast is much worse. In places like McMurdo it can get bad enough that travel between buildings is prohibited, South Pole not so much. I also wintered for SPT which involves one of us going out to the telescope, daily. There were only a couple of days when it was marginal. Even then, winds and low visibility usually means cloud cover and warmer weather (-40 vs -90). The worst days are windy with clear skies.

As for darkness; consider a single day is stretched out over the year. There’s only a two months of astronomical night and the moon is up every couple weeks. You’re correct though, that the station is isolated between mid Feb and late October.

Thanks! Early polar pioneers will find the content of this thread crazy.

On the other hand, Francis Halzen reportedly never went down to the South Pole to the facility at all, as probably the only person working on IceCube :D

Honestly, for a person like him, time spent flying and staying there is a waste.

A guy I knew back in college (in the same computer club) work on the IceCube project in Lawrence Berkeley Lab. Hello, Art Jones!

"You know I could just do it remotely. Hmm wait... never mind, forget I said anything... when does my flight leave?"

We think of receiving a Nobel Prize as something super rare and exceptional and it is. What still always astounds me though, is this:

There are nearly 300 living laureates. Enough to hold a yearly meetup for them in Lindau, where usually about 40 gather. This year, for the event's 75th anniversary, there were even about 70. Imagine that.

> yearly meetup for them in Lindau

IIRC Oppenheimer facilitated / sponsored a meeting there after the Manhattan Project, as a gathering where physicists could talk freely about physics for a change.

Every year a few of the Nobel Prize winners attend the IgNobel Prize ceremony and dance on stage.

Oppenheimer was not associated with the meetings:

https://www.lindau-nobel.org/meetings/

The first time in as long as I can think that a single physicist was chosen.

All of science is collaborative and this is especially true in these big experiments: the IceCube collaboration is over 400 people [1] from several dozen institutes. There are a lot of experiments where giving a Nobel prize would be impossible because there's no "principal investigator" for the experiment.

[1]: https://icecube.wisc.edu/collaboration/meet-the-collaboratio...

I wonder - was there really no other people they could have given it to? The detection of gravitational waves was split between a theorist, experimentalist and a person who had a big hand in shepherding the project along. Could not the same have been done here?

I would imagine the problem is that there are too many of them.

For better or worse the prize can only go to 3 people. Over the years there are generally many dozens of people who make absolutely critical contributions to these kinds of experiments. In this case, though, the same guy was listed as the PI of the UW Madison group, and Madison is very clearly "the" operator of the project.

Halzen is by any measure an awesome physicist, but he's also a good "fit" for the Nobel because of this unique situation.

I was in the IceCube experiment for a bit as well as the ATLAS Experiment at CERN. So you could say I contributed a bit to both this and the Higgs Nobel. Being part of these big collaborations, you know what the deal is. The Nobel is excellent PR for physics, and science in general, but it is just a prize. Francis is the singular leader of IceCube, and a visionary in the area, it is perfectly fair to award it to him, if not to the total collaboration. As for theory, I don’t think this award hinges on theoretical predictions but the enablement of observation itself.

other relevant people are probably dead

I can confirm. The most relevant other contributors are dead but even then Francis is the most deserving.

1992

Here's the APOD for IceCube back from 2011

https://science.nasa.gov/image-article/apod-2011-february-13...

Pretty cool. One of the big challenges in trying neutrino detection in ice is dealing with funding agencies. The optical properties of ice only get good when you are actually a few kilometers deep in very old ice. That is you can't just build a demonstrator in the nearest glacier with a few leftover photomultipliers, you need to go directly to Antarctica and bore a three kilometer hole into the ice. And projects where the MVP is quite expensive are always very hard to get funded.

I remember one of my professor, a pioneer of neutrino detectors in Europe, mentioning Ice Cube in a lecture more than 20 years ago. Long time scale (due to funding).

Great news for UW-Madison and all the work that went into such a forward thinking, creative scientific instrument!

Well holy shit. I didn't expect to wake up this morning and see the "outside" guy from my thesis committee (aka, the only one who wasn't a rubber stamp) winning the Nobel Prize.

Francis isn't the first Nobel Prize winner I've crossed paths with. But I think he's the only one I'd call a "decent human being". (When I use it, that phrase has a meaning roughly comparable to "nontrivial", so, saying it is nontrivial.) He was well enough liked by faculty and students during my time at UW-Madison.

It's important to note that he's not getting the prize for "conceiving of IceCube" like some people are saying. It's for "conceiving of IceCube and somehow actually making it happen". The latter is the achievement.

Congratulations.

Anyone else romanticize going to work at some remote location like the IceCube? Probably some escapism going on

I worked on IceCube. Was at the South Pole for a little over a month. Wild once in a lifetime experience. And if I am being honest I was terribly bored after the first 2 weeks. Its very flat and white and cold and not much to do. I was asked to go back the next year and I said no.

Field work even in beautiful places can get stifling. When you don't have access to friends, family, routine, various freedoms... It can be a bit much.

I romanticized that kind of work, but I think my limit is roughly what you said at around 2 weeks. The novelty wears off. Especially because I miss my kids a lot after a few days.

Actually, another big one: I love cooking. When you eat what you're given and don't have a choice, even if the food is pretty good it's kind of... I don't know... I really just want to go home and make something that is distinctly 'my food', something I would only have at home.

Even so, I absolutely love field work. The stuff I do is nowhere near as crazy as the Antarctic. I'm typically on the semi-remote islands of the British Columbia coast. My wife goes to the Arctic; her experience is probably more like yours. Lots of time isolated on icebreakers. Occasionally visiting remote navy or military bases, though. Some indigenous communities. Not as middle-of-nowhere as the Antarctic! The longest she has done is 7 weeks, with ~4 days off of the ship.

Username checks out, Sir. Any interesting anecdotes? I too wish to feel bored sitting at the South POLE!

was there any clear sky ever? how did it look like? I'm assuming you went during daylight?

Clear skies happen regularly enough. You can see refractive phenomena frequently (sun dogs, moon halos and the like). Same for night, plenty of clear skies and auroras during the winter when it’s dark enough to see them.

Not right now though! https://www.usap.gov/videoclipsandmaps/spwebcam.cfm

I spent a bit over a year at South Pole for IceCube. There's an old joke in the Antarctic: the first time is for the adventure, the second time is for the money, and the third time is because you don't fit in anywhere else anymore.

Anyway, I'd love to do it again

We hire two people to stay over the winter and operate the detector each year. No icecube affiliation or physics background required, although a technical background helps.

Sounds like the intro to a horror.

The Shining with a nerd cast

The scariest thing about the Neutrino Monster is that you can't see it and it can walk right through you.

I had a professor who talked about working there. In his words, “Thank God for whiskey!”

While there is some romantic imagery (penguins!) down there, and the disconnect from the rest of the world might be appealing, for large parts of the year you’re just stuck inside.

It depends on where you are, Away from the coast, there's no penguins or any large creatures.

Absolute loved this book by Halzen and Martin

https://archive.org/details/quarksleptonsint0000halz

Neutrino physics is the frontier. It’s one area where we know there are “physics beyond the standard model” though IceCube hasn’t quite been able to answer the neutrino mass question.

IceCube Neutrino Observatory - https://www.youtube.com/watch?v=gLbegYWCqkg

This is awesome! When I was a student at UW I worked with the CHTC (Center for High Throughput Computing) and we provided a ton of compute to the Ice Cube project. Happy to see something big come from that!

https://htcondor.org/featured-users/2026-10-06-francis-halze...

Congrats to Francis and the whole team!

Last years favorite finally wins it this time. https://www.rtbf.be/article/avec-icecube-le-physicien-belge-... (2025)

https://news.ycombinator.com/item?id=39489395. Related old submission by me. Did you guys know we have a neutrino image of the Sun? Remarkable stuff. The Japanese really led the groundwork on this one.

Madison WI mentioned!

Time for cheese curds at the Old Fashioned!

The last time a physicist won the award alone dates back to 1992, 34 years ago

Sometimes I think it would be nice if there were biographies that laid out when and how Nobel laureates made their discoveries. Then wouldn't it be possible to pattern how people discover certain phenomena?

Not Nobel laureates, but people have tried this. I once was looking for the early education of famous scientists and found the book Cradles of Eminence [1], which compares the childhoods of several hundred famous people.

One thing I noticed was that more than a few were seriously sick in childhood and had to be homeschooled. This includes Edward Morley, Peter Higgs, René Descartes (though I'm not sure how rare it was at his time), and the mathematician Julia Robinson, who was bedridden with scarlet fever at 9 years old, then had to get tutoring to catch back up, and had this to say about it [2]:

> I have since read that a solitary childhood or, what amounts to the same thing, a period of isolation resulting from an illness is frequently noted in the early lives of scientists. I am not sure what the significance of this finding is. Obviously I had to amuse myself for long periods of time, but I didn’t do so with mathematics. I am inclined to think that what I learned during that year in bed was patience.

> By the time I was well enough to go back to school, I had missed more than two years. My parents arranged to have me tutored by a retired elementary school teacher. In one year, working three mornings a week, she and I went through the state syllabuses for the fifth, sixth, seventh, and eighth grades. It makes me wonder how much time must be wasted in classrooms.

Sidenote: I found the book [1] through asking a free LLM what source this quote might be referring to. They are reasonably good at this kind of literature search, especially because it's easy to judge whether they gave you something useful.

[1] https://archive.org/details/cradlesofeminenc0000goer_l9f8/pa...

[2] https://web.archive.org/web/20181207045746/https://www.maa.o...

thanks!

Uh not sure Halzen personally made discoveries, in the original sense of the word!

Indeed, "in-spiraling" seems more like a one-man discovery (or has more of a chance to become one) than many (not all, obv) nobel prize winning work

The mechanism for which Higgs was awarded was also independently discovered by at least ten other people (I can't count)

>The Higgs mechanism is therefore also called the Brout–Englert–Higgs mechanism, or Englert–Brout–Higgs–Guralnik–Hagen–Kibble mechanism,[9] Anderson–Higgs mechanism,[10] Anderson–Higgs–Kibble mechanism,[11] Higgs–Kibble mechanism by Abdus Salam[12] and ABEGHHK'tH mechanism (for Anderson, Brout, Englert, Guralnik, Hagen, Higgs, Kibble, and 't Hooft)

https://en.wikipedia.org/wiki/Higgs_mechanism

Can't wait for OpenAI to get the nobel prize; Swedes are more sympathetic than mathematicians!! (so that human beings might completely separate discovery from reward/awards/recognition. Discovery is a human right!!!)

> wouldn't it be possible to pattern how people discover certain phenomena?

This question in the field of "general problem-solving" (inventions etc.) was investigated by studying patent literature by Genrich Altshuller in the former Soviet Union and systematized as TRIZ - https://en.wikipedia.org/wiki/TRIZ

Theory of inventive problem solving' is a methodology which combines an organized, systematic method of problem-solving with analysis and forecasting techniques derived from the study of patterns of invention in global patent literature.

TRIZ developed from a foundation of research into hundreds of thousands of inventions in many fields to produce an approach which defines patterns in inventive solutions and the characteristics of the problems which these inventions have overcome.

See also my older comment for more resources - https://news.ycombinator.com/item?id=45976697

thanks!

Given your profile, you might want to search for how Samsung used/uses TRIZ ;-)

Thank you always for your consideration and for showing me a broader world. I know I can be a nuisance, but I’d appreciate it if you could think of me as a younger, more foolish junior programmer.

Ha, Ha, You are being too self-effacing and self-deprecating ;-)

Don't worry about etiquette too much; And you are not being a nuisance. We just need to focus on gaining and sharing knowledge on this forum while being polite, that's all.

thank you

The common denominator is money and time. The only way to get more results is to put more funding out there (and accepting that not everything is about a direct ROI).

I love Ice Cube, as it is great engineering contributing significantly to science. It is also the perfect way to describe the concept of a great “hack” to people outside the field.

As we celebrate the IceCube neutrino detector for wining this year Nobel Prize in Physics, people in my country India should feel lost for missing the opportunity to setup INO (https://en.wikipedia.org/wiki/India-based_Neutrino_Observato...)

https://timesofindia.indiatimes.com/city/chennai/why-the-neu...

That's an uncharitable take. The proposed observatory was through pristine dense forest, and one of the most important elephant corridors in Asia. It was opposed by the democratically elected government, and litigated in courts in an open and transparent way. The physics gains do not outweigh the environmental cost, and the fact that scientists were able to get valuable data from an observatory in the lifeless Antarctic is further justification not to build this.

IceCube observatory is for studying the high energy cosmic neutrinos from a distant galaxy or black holes. But the one proposed INO is to study the low and medium energy atmospheric neutrinos. INO was designed to study the mass ordering of neutrinos. Both observatories are for studying different aspects and properties of neutrinos and are not the same.

But all the objections GP mentioned are still valid.

As a trained high-energy physicist who loves the subject, I wouldn't want the destruction of forests, tiger and elephant habitats (or any other habitats) for "science". There are always alternatives - alternate sites, alternate designs, alternate experiments.

One of my primary disagreements with my friends and colleagues was based on their insistence that opposing a new facility was anti-science and only done by the "uneducated". IMO, while this was true for a small subset of opposing factions, there were often real reasons for not building which took realities outside research into consideration.

isnt theni the place where hemp farm were destroyed in 1800?

Its rare to have noble prize given to just one person! This feels extra special for the work he has done.

Shouldn't the prize have been co-awarded to Ice Cube for inspiring the name?

Noble prize is only given to individuals

See https://en.wikipedia.org/wiki/Ice_Cube

My wife is Frances Haugen, I almost thought her 30 minutes of fame became 45

Has not been renamed yet to Francis of America?

Quite rare for a it to be awarded to just one person.

Can anyone explain the practical benefit of this discovery? How does this make life better in the next 10 years?

Sabine Hossenfelder roasted this prize, and I think she's right.

woah, mindblowing!

> Six days, six prizes

What? Since when does even the Nobel Institute themselves proclaim that economics of all things is as much part of the pantheon of science as fundamental physics, the same economics that was deliberately added to that list by the same powers that made free-trade economics the only allowed form within catholic economics, the same powers that funded research and shaped policy worldwide to first normalize neoliberalism and then to turn it into the only orthodoxy in economics, that prize that is actually the mundane "Bank of Sweden Economics Prize" is not only mentioned, it is treated as part of the holy set (of actually five) by the institute themselves?!

Just happy it's not another AI related prize.

Still no affordable antigravity? Dang.

He's working on it; still in deep black.

Makes me sad, that even there we put our human stuff and Metal boxes

Just woke up this morning to this news. Thank God. Today is a good day.

Oh, it's amazing that the AI didn't prize.

Why? They gave that out already.

There's no such thing as AI, it's just Jürgen Schmidhuber in a small room typing really really quickly. And no way they're giving him a Nobel Prize.

What is practical application of Francis work?

It could be the beginning of Neutrino astronomy [1]. So far, we only used the electromagnetic spectrum, from radio waves to gamma rays, to observe the universe. If we could equally leverage neutrinos or gravitational waves, we could observe much more of the universe. For example, the cosmic microwave background radiation enables us to deduce the conditions at 300ky after the Big Bang. The cosmic neutrino background [2] could give us insight in the conditions 1s after the Big Bang.

[1] https://en.wikipedia.org/wiki/Neutrino_astronomy

[2] https://en.wikipedia.org/wiki/Cosmic_neutrino_background

The million dollars. A Nobel prize is worth a million dollars.

Similar to the Millennium prize by the Clay institute, the amount of luck and effort you need to receive the prize don't make it worthwhile. Plus, it's generally expected to use that money for further research. It would be advisable to focus on other endeavors, if money is your motivator.

So, two years salary in the Bay Area where it's a lot warmer?

Neutrino detectors are essential in receiving communication from other galaxies.

That doesn't make any sense. Photons would work much better.

Photons work better for driving a car too but being able to hear is still quite useful.

In other words: we already have lots of things that measure photons. You see things on two totally different media it's a lot more compelling than just one.

That may be the case, but it doesn't explain why neutrinos would be essential for intergalactic communication. Maybe the person I was responding to didn't realize neutrinos travel very close to the speed of light, not infinitely fast?

Neutrinos might be a better medium for intergalactic communication, since they can travel through most objects.

Or we can all just think big thoughts at the same time... https://en.wikipedia.org/wiki/Calling_Occupants_of_Interplan...

There isn't anything in the way that would require this. I mean, we can see back to (shortly after) the Big Bang.

Kind of contrived, but if you're sending a signal from some other planet to our planet, depending on the geometry, there will be times of the year that our local star is in the way of photons.

Also, if you're sending out photons from a planet, chances are there's a local star nearby. Stars tend to be a broad-spectrum photon source, which is going to make it tough for receivers to decode the intentional signal.

Which is more difficult:

(1) Putting a telescope in space

(2) Focusing and detecting very high energy neutrinos

This is especially the case when photons will have, what, 15 orders of magnitude less energy than the neutrinos?

> Which is more difficult:

This is why I always search for my keys under the streetlamp, even though I dropped them in the unlit field nearby.

That said, putting a telescope in space is easy; we've done it several times...

But, can we filter photons intentionally sent from some far off solar system out of the stream of photons coming from their local star?

Yes. It's been proposed for SETI inside our galaxy too, and could be done with current technology (at least, receiving).

It would be VASTLY easier than using neutrinos.

Neutrinos are not an analog to sound in the point you are trying to make. They are many orders of magnitude more weakly interacting and much, much difficult to measure.

Knowing the properties of neutrinos is essential for building the neutrino bomb, the most ethical weapon possible.

Reply on news.ycombinator.com