Up, up and away

By Matin Durrani

The Physics World editorial team has been to a fair few places in the last couple of years as we try to make some interesting, entertaining and (hopefully) informative films about the world of physics.

We’ve been inside CERN to investigate the latest in the search for the Higgs boson. We’ve travelled to major international conferences from San Francisco to Boston. And then there was the time we went one mile underground to a dark-matter experiment in the north of England.

Yesterday, however, we shot a set of new films at this year’s Bristol International Balloon Fiesta, where thousands of people gather to watch as a series of hot-air balloons take off over a four-day period.

So what, you might wonder, is the link with physics? Well, as Alan Watson describes in this new article, this week marks the centenary of the discovery – during a balloon flight – by the Austrian physicist Victor Hess of what we now know as cosmic rays.

Physicists from the University of Bristol, led by David Cussans, decided to use the fiesta as an opportunity to showcase not only the centenary but also a new project that has allowed school pupils to build their own cosmic-ray detector.

The university launched two balloons, one of which you can see being filled with hot air (right). No, don’t ask me the cost in wasted greenhouse gases.

Sadly we didn’t hitch a ride in either of the balloons, but three of the pupils who were involved in the detector-building project were on board, as were three others who won a competition to take part in the flight.

As you can see, the view from the balloon over the festival site was fabulous.

Although Physics World editors didn’t manage to thumb a lift, a copy of the August issue of Physics World, which contains Watson’s article, did make the trip.

The pupils even took their detector in the balloon, but unfortunately – as is the way with experimental physics – someone had accidentally left the battery running and it had discharged completely so no data could be collected during the flight. Oops.

Apart from that, as we discovered when we returned to the fiesta this morning, the flight was a success and took the pupils and crew to a height of some 3000 m.

We’ll now set about turning our footage into a set of films, so stay tuned.

Meanwhile, for more about the cosmic-ray centenary, don’t forget the Physics World feature.

All pictures courtesy: Beth Cotterell