[ExI] More on Neutrinos

[Dan]

On Friday, September 30, 2011 2:28 PM Alfio Puglisi alfio.puglisi at gmail.com wrote:
> On Fri, Sep 30, 2011 at 7:43 PM, Dan <dan_ust at yahoo.com> wrote:
>> A little context here for the ignorant: how well measured have these
>> quantities been for supernovae in general? How many data points are
>> there? Just want to see how likely this one might be an outlier or
>> observational error -- or even just something mundane missing from
>> the model of surpernovae events.
> 
> Just one event, the 1987A supernova in the Large Magellanic Cloud, about
> 170,000 light years away. A total of ~20 neutrinos were detected a few
> hours before the event was seen in visible light, in neutrino detectors
> that were built to observe the Sun. The detection was unexpected and,
> since it was a rather large flux, the physicists involved took a while
> to convince themselves that the data was correct, and learnt about the
> supernova only some days later.

So, sample size two. That makes me a bit skeptical of this being a strong challenge to the theory.
 
> Copious (enormous, in fact) neutrino production was expected by supernova
> simulations, and the delay between the neutrino burst and the observation
> of the supernova was attributed to the travel time of the bow shock inside
> the star's body, which indeed should take a few hours according to models
> of the star interior. At the time, no one theorized that the neutrinos
> were superluminal, and three hours over 170,000 years is a rather small
> error bar.

This was something else I was thinking of. The neutrinos, from my readings, tend to escape first before a lot of stuff gets up -- during the compression phase. So, differences in modeling this might lead to different predictions and these might lead someone to believe there's a strong theoretical challege to STR when it's actually just the model for star collapse that's wrong. (My understanding here is only qualitative. I haven't done any of the math for this -- much less done things like even attempt to build a mathematical model and then plug data into it. Aside from maybe lacking talents in this area, that'd be real work.:)
 
Regards,
 
Dan