David Krofcheck: at the heart of the matter

Rocks were the catalyst for Dr David Krofcheck’s fascination with the Universe and its origins.

As a young boy growing up in the industrial US city of Pittsburgh, he would hunt for fossils in disused quarries near his home. Discovering shells, crinoids and other ancient forms of life sparked an early interest in science that quickly flourished.

His parents caught on, buying him a telescope, which he used to keenly observe the world around him – including watching his father, who worked at the steelworks three blocks from the family’s house, head home each day.

“When you’re in a hard neighbourhood, you look at buildings, windows, your neighbour’s houses. That was my first real experience doing something scientific,” explains the University of Auckland academic.

His fascination with science has since helped him see much, much further.
Since 2003, the only scientist in his field (high-energy nuclear physics) in New Zealand has also been working for CERN, the European Organisation for Nuclear Research. There he’s been involved with experiments involving the Large Hadron Collider (LHC) – the world’s biggest and most powerful particle accelerator.

In 2025, that work led David and the 13,507 other global scientists involved in LHC experiments to be awarded an ‘Oscar of the science world’ – the Breakthrough Prize in Fundamental Physics.

From Pittsburgh to Aotearoa

Aspiring to a university education was unusual for residents of a blue-collar city like Pittsburgh when David was growing up, he says, but his parents were determined it was a path he and his sister would follow. So, after high school, he enrolled in a Bachelor of Science at nearby Carnegie Mellon University.

It was there that he took a part-time job in a high-energy physics laboratory and found his niche.

“There were lots of people thinking the same way or who had similar experiences growing up,” he remembers. “I really felt like I found my crowd there.”

This sense of community continued at Ohio State University, where he completed a Master of Science and a PhD in physics. After graduating, he held postdoctoral positions at Michigan State University and the Lawrence Livermore National Laboratory in California. While at the former, he met his now wife – a New Zealander – on a blind date.

Looking to move down under, he saw that the University of Auckland was advertising for an oceanographer who could also teach electronics. To his surprise, he managed to convince the recruiters that a nuclear physicist would be a better fit and, in 1995, joined the Faculty of Science as a senior lecturer in physics.

Links to the Large Hadron Collider

This month marks David’s thirtieth year at the University, where he currently teaches three undergraduate courses and is the postgraduate adviser in physics. And for more than 20 years he has also been working alongside thousands of other scientists for CERN.

The intergovernmental organisation’s Geneva base is home to the largest particle physics laboratory in the world, and nearby, in a tunnel beneath the France-Switzerland border, lies the famed LHC. Widely regarded as the ‘world’s greatest science experiment’, the LHC has a circumference of 27km and a depth of 175m. Unsurprisingly, it took a decade to build and was the result of a collaboration between more than 100 countries.

On paper, the LHC’s purpose sounds straightforward: to facilitate scientists in testing the theories of particle physics. Putting this into practice, however, is an extremely precise process.

Using electromagnetic fields, the LHC accelerates beams of charged particles to travel close to the speed of light before colliding. These particles are so minute it is comparable to lining up two needles 10km apart and engineering them to meet in the middle. The collision produces new particles, which scientists then analyse through detectors to gather data about the building blocks of matter.

It was one such detector that was the initial focus of David’s involvement at CERN. He joined forces with Professor Phil Butler, a physicist at the University of Canterbury, and his son Professor Anthony Butler, a radiologist at the University of Otago, to spearhead a novel project: building part of the Compact Muon Solenoid (CMS) detector. This giant 3D camera would document particle collisions through millions of images every second.

In 2012, the team’s CMS detector collected information that contributed to the breakthrough discovery of the Higgs boson.

“In the periodic table of particles, there is one particle that is missing – an energy field known as the Higgs field with which all other particles interact to generate mass,” David explains. “Particles and fields are supposed to be interchangeable, so the theory in the 1960s was, if you propose the Higgs field, there should be a Higgs particle.”

To create one of these particles, an accelerator powerful enough to disturb the Higgs field was needed. Enter the LHC, which possessed just the right energy range to produce collisions that would create a Higgs particle. As the particle fell apart, the Kiwi-built contribution to the CMS detector identified its characteristic fingerprint and confirmed the existence of the Higgs field.

The significance of this discovery was momentous: it substantiated scientists’ understanding of how particles gain mass, thereby verifying the Standard Model of particle physics.

Peering further into the future

While honoured to be among the team of scientists who received the Breakthrough Prize in Fundamental Physics this year, David is excited about other discoveries high-precision measurements with the LHC can reveal.

“We want to understand the processes that happened in the early Universe,” he explains. “Nobody really knows what happened during the Big Bang, but in this magic laboratory that New Zealand found its way into we can study the microseconds after and know something real about how the Universe works.”

David will be sharing more about his research this month at his Raising the Bar talk, ‘Out of this world: the smallest and most surprising liquid in the Universe’ – including a major finding made by CERN scientists.

“It turns out that the secret of the early Universe is a fluid, with the lowest viscosity of any fluid ever discovered. It’s the littlest liquid in the Universe.”

When he’s not studying physics or thinking about physics – which is most of the time, he admits – David is an avid reader and keeps close to 4,000 books in his garage-turned-library. He also enjoys getting outside and cycling or, when he’s back in the US, cross-country skiing.

But everything always comes back to physics, he says. Why?

“It’s purely curiosity-driven research,” he explains. “Nuclear and particle physics goes back to the beginning, to the earliest fractions of a second of the Universe. To me that is a mind blowing concept.”

– Nikki Addison

Raising the Bar is an annual event hosted by the University since 2017, featuring 20 talks by academics across ten bars. See David’s talk on 26 August at The Conservatory. Tickets are free and available now.