Anniversary issue inspires debate

John Preskill at Caltech comparing his group’s choices with ours for the top discoveries of the last 25 years and the biggest unanswered questions. (Courtesy: IQI, Caltech)

By Louise Mayor

Unless you’ve been living under a stone or aren’t a regular reader, you’ll know that this month marked the 25th anniversary of Physics World – the member magazine of the Institute of Physics (IOP).

We pushed the boat out by turning our October issue into a celebration of all things physics – past, present and future – by picking our top five discoveries in fundamental physics over the last 25 years, the top five images during that period, the five biggest unanswered questions, the top five people changing how physics is done, as well as the top five spin-offs from physics that will improve people’s lives over the next quarter century.

Apart from the special 25th-anniversary issue being the top story on the BBC website for a glorious few hours early in October, we were particularly pleased to see that our pick of the top breakthroughs in fundamental physics inspired a fascinating discussion at John Preskill’s group meeting over at Caltech’s Institute for Quantum Information and Matter.

Preskill challenged his group members to guess what we chose for two of our categories: the top five discoveries over the last 25 years, and the five biggest unanswered questions. His group guessed several choices for each category, and we were delighted to see that their guesses included all of our choices!

The group’s guesses can be seen in the photo above showing Preskill himself, with the Physics World team’s choices marked with red crosses.

(In case you can’t make out his writing, our top five discoveries were neutrino mass, the accelerating expansion of the universe, the Higgs boson, Bose–Einstein condensation and quantum teleportation, while the top five unanswered questions related to the nature of time, life elsewhere in the universe, quantum gravity, quantum weirdness and the dark universe.)

Our choices were first brought to Preskill’s attention a few months ago when we invited him to write about one of our five unanswered questions – he tackled the issue of “Can we exploit the weirdness of quantum mechanics?” and you can read his thoughts on the matter here.

If you’re a teacher or lecturer in physics, why not try out Preskill’s exercise on your students? Let us know how you get on.

And don’t forget, if you haven’t tried them yet, why not have a go at our five fiendish physics puzzles created with GCHQ.

Finally – and I promise this will be the last time we mention it – the special 25th-anniversary issue of Physics World is available in print, online and via our apps (from the App Store and Google Play) to all members of the IOP, but to share it more widely, anyone – members and non-members alike – can download a free PDF of the entire issue. (Remember that to get Physics World each month, you can join the IOP quickly and easily online with IOPimembership costing just £15, €20 or $25 a year.)