Neutrinos . . . Nature’s Speed Demons ?? Dr. Darrel Smith Department of Physics ERAU-Prescott Oct. 11, 2011
How do you measure something traveling faster than the speed of light? • Measure the distance between 2 points in space and use 2 synchronous clocks in the same inertial frame. • Velocity = distance / time • Event coordinates (x1,t1) for the protons hitting the target (CERN), and (x2,t2) for the neutrino interactions in OPERA
(tc -tn) = (60.7 ± 6.9 ± 7.4) ns . . . The neutrinos arrived too early compared to the speed of light. • Neutrinos appear to be traveling faster than the speed of light. • This would violate “causality,” something physicists cherish. • Need to modify Special Relativity (SR) . . . Or rewrite it. • Speed of light (or neutrinos) defines the one constant speed in all inertial frames (SR). • Open up an extra dimension to take a “short cut.” Speed of light not the same in the fifth dimension. What was observed?
They made a recent determination of the distance of the proton target (CERN, Geneva) to the OPERA experiment at LNGS (Grand Sasso, Italy). Claim is ≤20 cm. • They also improved the precision of their GPS measurements to the underground laboratory. • They included the location of the moon and the tidal bulges in the Earth’s crust. What did the OPERA physicists include in their calculations?
What went wrong? • We really need independent confirmation. • We really don’t want to give up the principle of “Causality.” What is the attitude of most physicists?
GPS synchronization. Is it really accurate to within 60 ns, or is there time drift in between the time stamps? Is an atomic clock used at both ends? • The proton buckets don’t really look as sharp as one would like in an actual proton beam line. What else might have gone wrong (my opinion)?
MINOS (2007) reported (with less precision) that “vn” was consistent with “c.” The far detector is located in the Soudan mine in Minnesota. The beam originates at Fermilab 455 miles away. • A supernova (1987a) in the the Large Magellanic Cloud (LMC) was observed by the IMB and Kamiokanda detectors where the neutrino burst was observed 3 hours before the light was seen. The light was delayed because of scattering throughout the SN remnants. If the neutrinos from 1987a exhibited the same odd behavior as the CNGS neutrinos observed in the OPERA experiment, then the neutrinos from 1987a should have arrived 4.14 years before the light did. However, this was not the case. The neutrinos and the light measurements were well documented for 1987a. Conflicts with previous neutrino data
We need independent measurements to confirm or deny the OPERA observation.MINOS is an ideal experiment for making similar measurements. • The OPERA physicists need to invite other scientists to look “over their shoulders” and question their calculations more diligently. This is most likely occurring as we speak. • Measuring the speed of neutrinos was only a “side ambition” of OPERA. It was not designed to investigate this phenomena. However, the triggers used in the experiment rely on the speed of the neutrinos being very close to the speed of light. • “Extraordinary claims require extraordinary evidence.” Carl Sagan • Pure logical thinking cannot yield us any knowledge of the empirical world; all knowledge of reality starts from experience and ends in it. A. Einstein (1933). • In other words, science is a self-correcting process. We will get this sorted out. Where do we go from here?