Is the imperative of the two most powerful particle accelerators ever built—the Tevatron at Fermilab, now reaching the peak of its decades-long performance, and the Large Hadron Collider (LHC) at CERN, where beams will circulate for the first time around a 27-km track within the next few months. The Higgs has not yet been discovered, but at this week’s meeting of the American Physical Society (APS) in St. Louis dozens of talks referred to the status of the Higgs search. Why is the Higgs so important? Because it is thought to pervade the universal vacuum; not, as with the old aether, to provide a material substrate for the propagation of electromagnetic waves, but rather to interact with particles and confer mass upon them.
'Fizik' kategorisi için arşiv
Two separate experiments in Colorado compare the frequency of emissions from atoms or ions to an uncertainty of 10^-16 or better. Earlier atomic clocks operated by reading out the movements of internal transitions from one quantum state to another in cesium atoms; the light emitted was in the microwave range. With frequency comb techniques (http://www.aip.org/pnu/2008/split/853-1.html) measurement of optical-range frequencies can also be made with high accuracy.
