Ulukai on 20/10/2011 at 09:26
Caught this and it seemed pitched at just the right level. The professor managed to avoid being patronising but explained the concepts clearly.
In particular, the explanation of string theory and how the neutrinos could have jumped into the 'loaf' from the membrane to arrive earlier than expected was pretty mind blowing, although they then balanced this with another professor suggesting this isn't how he expected extra dimensions to manifest themselves should string theory prove to be true.
Can't help but think they did take a few cues from
Wonders, what with all the dramatic standing by the sea and staring at the waves though...
Shug on 20/10/2011 at 11:01
It's a common theme with BBC science programs, after all. They're generally pretty good on content, particularly the Horizons series, but can't quite stop themselves from "TV"ing it up on the visuals
zombe on 20/10/2011 at 18:44
Any youtube (or any other accessible source) copies of it around? Could not find anything.
heywood on 20/10/2011 at 23:59
I read (
http://arxiv.org/PS_cache/arxiv/pdf/1109/1109.6562v1.pdf) the BU paper. Here's what I got out of it:
The neutrino pair bremsstrahlung (braking radiation) process is analagous to Cherenkov radiation but the primary byproducts are pairs of electrons and positrons. The process operates through a weak force interaction rather than an electromagnetic force interaction so it doesn't require the FTL particle to be charged. And you don't have to observe the electrons and positrons to know whether the process is occurring, you can infer it from the neutrino energy loss. The byproducts would be hard to observe anyway since they are being produced in transit from the source to the detector.
Their main contribution is an analysis of the rate of neutrino energy loss over distance/time. They found that a superluminal neutrino would lose energy rapidly through electron/positron pair production and asymptotically approach a terminal energy level. The terminal energy is speed dependent. If you plug in the neutrino speed claimed by OPERA and the distance traveled, the probability of observing a neutrino with energy > 12.5 GeV at the detector is negligible. But the OPERA team measured the mean energy to be 17.5 GeV. Thus, their reported speed & energy measurements are inconsistent.
But I'm still confused about something. The pair bremsstrahlung process is only hypothetical. It's a prediction based on the standard model. So I'm thinking they might be overstating their claim. Instead of claiming that the measured energies of the OPERA neutrinos rule out superluminal speeds, it might be more accurate to say the OPERA results are inconsistent with the standard model.
SubJeff on 18/11/2011 at 12:30
Always in triplicate. Jokers.
Briareos H on 25/11/2011 at 08:58
Firstly, this is completely unrelated to "[re-analizing] the data and [coming] to a different conclusion". What this is is a different team of researchers trying to see whether the data fits an effect they studied, the description of which was, debatably, written in haste after the announcement of the OPERA results. Two problems already: your description is wrong, and their work is based on current models and theories.
Secondly, this Čerenkov-like effect was already presented a few weeks after the OPERA results, meaning that there is nothing new. The article should have been written a month ago, and is a fraud.
Thirdly, you can not debunk a new effect potentially contradicting current models with the observation that if this effect was real, we should have seen something else that we didn't see. That is not a proof, that is not how science works. What the ICARUS study does is add some weight to the burden of proof which lies onto the OPERA team shoulders. At this point, this doesn't make much of a difference.
Finally, this study doesn't take into account interesting new developments in the process of explaining how supraluminal neutrinos can exist, like theories which break CVA (constant velocity assumption) and may not exhibit the Čerenkov-like effect.
demagogue on 25/11/2011 at 09:49
So ... you're saying superluminal neutrinos are still in the cards?
