One Down, Several to Go

Neutrino experiment affirms faster-than-light claim

One set of concerns centered on the relatively long timescale – 10.5 microseconds, or 10.5 millionths of a second – of the proton pulses produced at CERN that result in the neutrino pulses OPERA detects. OPERA did not know whether individual neutrinos received at Gran Sasso corresponded to protons early or late in the proton pulse, creating uncertainty around their detection of them. In October OPERA therefore asked CERN to generate shorter proton pulses lasting just 3 nanoseconds. They have now recorded 20 events in the new data run and say that they have reached a similar level of statistical significance to the first time around, with the neutrinos again reaching Gran Sasso 60 nanoseconds faster than a light beam would do.

However,

But concerns about the experiment’s use of the Global Positioning System to synchronize clocks at each end of the neutrino beam are unlikely to be as easily allayed, The use of GPS is novel in the field of high energy and particle physics and the same system was used for both the original experiment and the new run.

I must point out that GPS common-view is not a novel technique outside of high energy and particle physics.

See Me, Feel Me

Seeing sound

The technique builds on a piece of technology developed for the study of mechanical vibration; the laser vibrometer, and relies on a phenomenon called the acousto-optic effect. This describes the slight change in the speed of light in air when it passes through an acoustic field, causing a phase shift in the light that can be detected using the vibrometer.

The construction of the walls of that studio is baffling.