56 | New Scientist | 23 November 2019
The back pages Q&A
Jeffrey Hangst spends his days puzzling over
antimatter at CERN, the world’s biggest particle
physics lab. He wants to learn why there’s more
matter than antimatter in the universeAs a child, what did you want to
do when you grew up?
I always wanted to be a scientist. I grew up during
the space race, and I clearly remember thinking
that being an astronaut would be cool, but
that being a scientist would be cooler.Explain your work in one easy paragraph.
I work with antimatter, which is this weird, mirror
opposite to “normal” matter. It is a huge puzzle,
because we think matter and antimatter existed
in equal quantities just after the big bang, but
we can’t explain why only matter survived. My
ALPHA experiment is looking at the properties
of the simplest anti-atom, antihydrogen, to
see if there may be some small, overlooked
difference between matter and antimatter.Why did you choose this field?
I have always worked with antimatter. I guess
I like a challenge. Where’s the fun in getting your
atoms out of a gas bottle that anyone can buy?Did you have to overcome any particular
challenges to get where you are today?
Well, everything about antimatter is challenging.
You have to produce antiprotons in high-energy
collisions and then slow them down and stop
them to make antihydrogen. Even then, you only
get a handful of atoms that you have to keep in an
ultra-high vacuum away from normal matter.
I have been told by colleagues at every step of the
way that all this is impossible, but here we are.What’s the most exciting thing you’ve
worked on in your career?
Antimatter has been my entire career, and it has
always been exciting, if a bit daunting. It is cool
to work on something that fascinates people and
shows up regularly in science fiction. I like to be
the first to see something new, and that’s the
case with everything we measure.What achievement are you most proud of?
There are two. In the ATHENA collaboration,
we succeeded in producing the first low-energy
atoms of antihydrogen in 2002. The second was
the first confinement of antihydrogen by ALPHA
in 2010. I started ALPHA in 2005 to get to this, and
everything we do today is based on that result.Which discovery or achievement do you
wish you’d made yourself?
Paul Dirac’s insight, predicting the existence
of antimatter, is right up there – one of the truly
great intellectual leaps in the history of science.If you could have a conversation with any
scientist, living or dead, who would it be?
Could I exchange this to bring back John Bonham,
so I could go to a Led Zeppelin concert?If you could send a message back to
yourself as a kid, what would you say?
Get your atoms from a gas bottle.Do you have an unexpected hobby, and
if so, please will you tell us about it?
I play guitar in a rock band. We are three CERN
physicists and a singer from Transylvania. The
name of the band is Diracula. I also build my own
guitars. This is easier than making antihydrogen.What’s the best thing you’ve read
or seen in the past 12 months?
I really enjoyed Roger Waters’s movie Us +
Them, which was only shown for one day
in Geneva. I am a huge Pink Floyd fan.How useful will your skills be after
the apocalypse?
I am much more likely to be blamed for the
apocalypse... Seriously, though, experimental
physicists can build or repair pretty much
anything, and we are great scavengers of
equipment. And I was kidding, we could never
make enough antimatter to be dangerous to
anything other than our own sanity.OK, one last thing: tell us something that
will blow our minds...
I’ll tell you four things. Roger Waters visited
ALPHA this year. We had a beer. He autographed
my guitar. If I send him an email, he answers. ❚Jeffrey Hangst is spokesperson for the ALPHA
experiment at CERN in Geneva and professor
of physics at Aarhus University in Denmark“ I like to be
the first to
see something
new, and that’s
the case with
everything
we measure”
SIDE: RICHARD ISAAC/SHUTTERSTOCK