New Scientist Magazine - No. 3011

THEY call it “the desert” – a vast,empty landscape separating usfrom a promised land that shimmerslike a mirage on the horizon. A land fullof answers, where we finally achieve acomplete understanding of material reality.Stop dreaming: we can’t get to this nirvana.The way across the desert is too long and hot,and we have no vehicle to take us there. But ifphysicists’ hopes are realised, a machine justwaking from a two-year slumber could bringus a decisive step closer – and might evenreveal answers closer to home.The machine in question is the LargeHadron Collider, or LHC. This most muscularof particle smashers, situated at CERN nearGeneva, Switzerland, garnered fame fordiscovering the Higgs boson in 2012. Thatwas the last uncharted feature of a landscapethat’s now pretty well explored: the landscapeof the standard model, our current best theoryof matter and its workings.Since February 2013, the LHC has beenundergoing a comprehensive overhaul.It's backAfter a two-year makeover,could the rejuvenated LHCspy even wilder particles,asks Matthew ChalmersNow it is gearing up again, more powerfulthan ever before, for a journey towards thedesert – and the complete unknown. Theexcitement is palpable. “We are living in aonce-in-a-lifetime experience, opening thecurtains on a totally new energy scale,” saysJim Olsen of the LHC’s CMS experiment.Particle physicists measure out territoryusing energy as their yardstick. ThroughEinstein’s famous equation E = mc 2 , smashingparticles together at high speed converts theirmass into pinpricks of enormous energythat can in turn form other, more massiveparticles. Our universe started out in a hot,dense big bang, so the higher the energies wereach by ramping up the speed of the collidingparticles, the further back we reach into theorigins of the cosmos and matter itself.In this way the LHC and its predecessorshave allowed us to map out the standardENRICO SACCHETTI30 | NewScientist | 7 March 2015