Hultqvist is professor emeritus at Stockholm University and one of the Swedish researchers who has worked with Nobel Prize winner Francis Halzen, whom he describes as a bundle of energy.
"He has a very high energy level, as high as neutrinos. He is very nice and enthusiastic, full of ideas," Hultqvist adds.
“Crazy idea”
Francis Halzen's idea of building a neutrino detector at the South Pole has been described as a "crazy idea".
The Nobel laureate himself pointed out during the Nobel Committee's press conference that Uppsala University and Stockholm University joined the collaboration early on. Klas Hultqvist thinks that was a good thing:
He was right about that. Otherwise we might have been upset, he says jokingly.
Stockholm and Uppsala were involved from the beginning in an experimental project called Amanda in the early 1990s. The goal was to detect neutrinos, which are very difficult to find and therefore require large volumes of something transparent.
That's why ice has been used at the South Pole, explains Klas Hultqvist.
Built in Stockholm
The IceCube observatory consists of 5,000 light detectors built at Stockholm University and tested in Uppsala, he says.
The main development of the concept was done in the US and, to some extent, in Stockholm. There are many contributors.
High energy level
Despite the project's growth, everyone involved feels it is clear that Francis Halzen should be honored with the Nobel Prize for IceCube, Klas Hultqvist says.
He's been driving it all from the beginning. It's called an "ice cube" because it uses a cubic kilometer of ice, and he published early on that that's what was needed. Since then, he's worked tirelessly.
He takes it for granted that Francis Halzen will tear himself away from work and visit Stockholm in December.
He's a bit older now, but he's been constantly traveling around the world. And he really appreciates the good things in life too.
