Coming up this month in Physics World…A testing time for strings

With its talk of D-branes, 10- or 11- dimensional universes and a myriad of possible solutions – 10500 at the last count – string theory looks to many outsiders more like an arcane branch of mathematics that says nothing new about the real world. Not surprisingly, string theory has come in for a lot of criticism in the last year, particularly with the publication of the books Not Even Wrong by US physicist Peter Woit and The Trouble with Physics by Lee Smolin.

But look into string theory in even a little detail, and it is clear why so many young physicists are lured into the field, as this month's special issue of Physics World reveals. First, although the details need to be worked out, string theory naturally unifies quantum mechanics and general relativity – two of the pillars of physics. Second, string theory is very much guided by problems in the real world – such as questions over the quark-gluon plasma and the entropy of black holes – no matter how remote these might seem.

With CERN's Large Hadron Collider (LHC) due to be switched on next year, now is the wrong time to slam string theory for its lack of predictive power. While not being able to prove string theory is right, the discovery of “supersymmetric” particles at the LHC would give it a major boost, as would the discovery of “Kaluza-Klein” particles and possibly even mini-black holes. A flood of cosmological data due in the next few years will also offer new ways to put string theory to the test.

String theorists can be rightly criticized for having in the past oversold their subject by making grandiose claims about “a theory of everything”. But the richness of string theory and its increasing contact with the real world give those involved something to shout about. As the views of even many non-string theorists in this issue of Physics World make clear, the theory still holds all the potential it ever did to revolutionize our understanding of the universe.

Also in this issue:
o GCSE science comes under attack
o Faults close new Australian research reactor
o UK science minister sets out his stall
o LISA Pathfinder: the technical challenges
o The potential of microfluidics
o Making condensates from “polaritons”
o The new language of “physglish”