Neutrino

I was here last week where we talked about who might win the Nobel Prize.

And now we know because the 2026 Nobel Prize in Physics has gone to Francis Halzen for his decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin.

And Halzen, in- interestingly, is a theoretical physicist, even though I suppose this is an, an experimental, uh, prize.

He was born in Belgium, and he worked at CERN before moving to the University of Wisconsin, Madison, in the US, where he is currently professor of physics.

Yeah.

I think this is the first time I had met someone who won a Nobel Prize before they won the Nobel Prize.

Um, but Francis Halzen lectured for us at the International Neutrino Summer School when I organized it about eight years ago, um, he was a lovely man, um, very, very well-deserved.

He also wrote my favorite textbook on particle physics, uh, called "Quarks and Leptons" by Halzen and Martin, um, so two reasons to love him.

[Instrumental music] Hey, it's Flora, and you're listening to Science Friday.

This week is Nobel Prize week, and this year's prize in physics went to researcher Francis Halzen, quote, "For decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin." But way before all that excitement, back in 2013, Ira traveled to Madison, Wisconsin, and talked with Dr.

Halzen about his work, and I think you'll enjoy the conversation.

Here's Ira.

Wow, wonder if you have to fix that.

The frozen observatory is appropriately named IceCube, and it's, uh, not looking for your typical star stuff, but the elusive neutrino.

What are neutrinos? Why build a telescope a mile deep in the Antarctic ice? Well, here is a man with all the answers.

Francis Halzen is the Hilldale and Gregory Bright Professor in the Physics Department, University of, uh, Wisconsin in Madison.

For several years, he's been using the ice at the South Pole to capture the subatomic particles, and I've been speaking to Frank Close.

He's a particle physicist who's also the author of the book Neutrino, and, uh, my rather obvious first question was, what is a neutrino?

They're ghostly particles that are produced b- by the stars.

The sun produces neutrinos, and, uh, supernova explosions produce neutrinos.

But And you've got

Zoe going, Neutrino, Jamie!

Yeah, I could see all of them doing this.

And it's like you say, it would be one set, and this kind of reads...

Nobody has ever seen a neutrino with their eyes.

Even our best detectors don't see them the way we see a dust mote in a sunbeam.

Neutrinos were invented to solve a bookkeeping problem.

In radioactive beta decay, energy and momentum seemed to vanish.

The numbers didn't add up.

Yeah, so I loved hamsters.

Um, one was Neutrini, which was named after the neutrino.

Um-

Didn't you have a Gravitini at one point? Or am I-

The neutrinos.

There we are.

Neutrinos.

We solved it within 10 seconds.

That's great.

Toys were good.

There's the other Neutrino.

All three Neutrinos.