IceCube is an example of how great science, and especially particle physics, now often works on timescales of generations. It took 30 years to get from IceCube’s idea of actually drilling its neutrino sensors into a cubic kilometer of Antarctic ice to locate a high-energy neutrino source. At the time, key executives retired, died, or moved on to projects that offered more immediate gratification. Whitehorn’s experience is the exception, not the rule—many scientists have devoted years, decades, or even entire careers to seeking results that never came.
The discovery of the Higgs boson lasted even longer than extragalactic neutrinos: 36 years from the first discussions about building the world’s largest and most energetic particle accelerator – the Large Hadron Collider (LHC) – to the now famous announcement of the discovery of the Higgs boson. the particle in 2012.
For Peter Higgs, then 83 years old, the discovery of his eponymous particle was a satisfying epilogue to his career. During the announcement, he shed a tear at the venue — 48 years after he and others first proposed the Higgs field and its associated elementary particle in 1964. For Clara Nellist, who worked as a PhD student on the LHC’s ATLAS experiment in 2012, it marked an exciting start to her life as a physicist.
Nellist and a friend showed up for the announcement at midnight with pillows, blankets, and popcorn and camped outside the auditorium hoping to get a seat. “I did that for festivals,” she says. “So why not do it for perhaps the biggest physics announcement of my career?” Her determination paid off. “To hear the words ‘I think we’ve got it!’ and the cheers in the room was just such an amazing experience.”
The Higgs boson was the final piece of the puzzle that is our best description of what the universe consists of at its smallest scale: the Standard Model of particle physics. But this description cannot be the last word. It doesn’t explain why neutrinos have mass or why there is more matter than antimatter in the universe. It does not include gravity. And there’s the small matter that it has nothing to say about 95 percent of the universe: dark matter and dark energy.
“We’re in a really interesting time because when we started, we knew the LHC would either detect the higgs or rule them out completely,” says Nellist. “Now we have a lot of unanswered questions, and yet we don’t have a direct roadmap that says if we follow these steps, we will find something.”
Ten years after Higgs’ discovery, how does she deal with the possibility that the LHC may no longer answer these fundamental questions? “I’m very pragmatic,” she says. “It’s a little frustrating, but as an experimental physicist I believe the data, and so when we do an analysis and get a null result, we go ahead and look in another place — we’re just measuring what nature provides.”
The LHC is not the only major scientific institution seeking answers to these existential questions. ADMX may be the garage band for LHC’s stadium rockers in terms of size, funding and staffing, but it also happens to be one of the world’s best shots at discovering the hypothetical axion particle – a main candidate for dark matter† And unlike the LHC, ADMX researchers have mapped out a clear path to find what they’re looking for.
