The Speed of Light (and Light from Nowhere)
This is interesting. Remember in September when the CERN OPERA project recorded Neutrinos travelling faster than the speed of light? Yea, you remember that. Well now CERN have just posted an update.
The Scientists at CERN have completed more tests and ruled out one possible source of systematic error.
One key test was to repeat the measurement with very short beam pulses from CERN. This allowed the extraction time of the protons, that ultimately lead to the neutrino beam, to be measured more precisely.
The beam sent from CERN consisted of pulses three nanoseconds long separated by up to 524 nanoseconds. Some 20 clean neutrino events were measured at the Gran Sasso Laboratory, and precisely associated with the pulse leaving CERN. This test confirms the accuracy of OPERA’s timing measurement, ruling out one potential source of systematic error. The new measurements do not change the initial conclusion. Nevertheless, the observed anomaly in the neutrinos’ time of flight from CERN to Gran Sasso still needs further scrutiny and independent measurement before it can be refuted or confirmed.
They have also submitted the paper for peer review to the Journal of High Energy Physics (JHEP), and you can see the paper at arXiv.org.
This doesn’t seem to have changed anything much from the original story, it certainly isn’t a confirmation of the results. There are still many more tests to be done before relativity gets revised or time-travelling particles are employed as an explanation.
In the meanwhile, you can make things travel faster then the speed of light in your own backyard! No need for fancy particle accelerators.
(From minutephysics, make sure to check out their other stuff too!)
Oh! Plus this is another cool semi-related story, physicists have created light out of nothing. This is pretty weird. In the words of one of the researchers “It’s a bit like shaking a sealed black box really hard, opening it and suddenly a flash of light comes out”.
According to ABC:
Researchers including Professor Tim Duty from the University of New South Wales in Sydney, used a strange phenomenon called the dynamical Casimir effect to force a mirror to make its own light rather than simply reflecting the light around it.
The study reported in the journal Nature uses the weird science of quantum fluctuations in which virtual sub-atomic elementary particle pairs continuously pop in and out of existence in a vacuum.
“Understanding vacuum fluctuations will help scientists researching physics raging from gravity waves to the evaporation of black holes,” says Duty.
Duty and colleagues were able to scatter half of the virtual particle pairs before the particles could reconnect and pop out of existence, forcing them to become real.
Interesting, huh? Hopefully your mind has been sufficiently blown, I know mine has!
Image Credit: Google Images