[time-nuts] Opera coordinator has resigned

[Sanjeev Gupta]

.
On Mar 30, 2012 10:45 PM, "paul swed" <paulswedb at gmail.com> wrote:
>
> I have to say that in general I have been staying clear of this thread.
> But its really a surprise that they are that sloppy and basing the results
> on a Vectron OCXO. Not that I have ever had a complaint about those.
> It just seems like the stunt I would do in the basement on my surplus
> accelerator.

Their accelerator _was_ in their basement ;)

> Regards
> Paul.
>
> On Fri, Mar 30, 2012 at 12:57 PM, Tom Van Baak <tvb at leapsecond.com> wrote:
>
> > Hi Javier,
> >
> > Thanks very much for posting the link to the presentations.
> >
> > For those of you who just want a summary of the resolution of
> > the "neutrino faster than light" problem, here's what happened:
> >
> > 1) For several years an optical cable connector was loose. I have
> > attached photos from pages 7 and 8 of the G._Sirri.pptx where
> > you can see the actual connector and waveforms, before/after.
> >
> > 2) They used a Vectron OCXO to generate timestamps within each
> > 0.6 second measurement cycle. This oscillator was found to be high
> > in frequency by 0.124 ppm. Thus, depending on where within this
> > 0.6 s interval the timestamp was made a timing bias of 0 to 74 ns
> > would occur.
> >
> > Javier -- if you have contacts there, it looks to me like they forgot
> > to include OCXO frequency drift effects into their analysis. What
> > they did was compensate for linear time drift (which assumes a
> > fixed frequency offset). They call the 124.1 ns/s time drift "stable"
> > since 2008. What evidence do they have for this? We know that
> > OCXO will drift in *frequency* over time; the time drift is quadratic.
> > The time drift rate may be 124e-9 today, but it probably wasn't last
> > month or last year, etc.
> >
> > /tvb
> >
> >  There was a meeting in Gran Sasso on Wednesday. You can see some of
> >> the slides at http://agenda.infn.it/**materialDisplay.py?materialId=**
> >> slides&confId=4896<
http://agenda.infn.it/materialDisplay.py?materialId=slides&confId=4896>
> >>
> >> I found particularly interesting the ones by Maximiliano Sioli, where
> >> he explained the two mistakes found in the OPERA data acquisition
> >> chain and how, after correcting for their best estimate of their
> >> effects, the time of flight is compatible with a speed of c.
> >>
> >> I saw the webcast of the event. Some people did give the OPERA
> >> spokesman a hard time, and he admitted to not having fully checked
> >> everything they could have. Ah well, everyone makes mistakes. There
> >> will be another run with neutrinos spaced by 100 ns in May. If all
> >> four experiments in LNGS give the same result this time, I suppose the
> >> case will be closed. It will also be very interesting to see the MINOS
> >> results.
> >>
> >> In any event, from a time-nut point of view this is quite exciting. It
> >> is the first time neutrino speed is measured with this precision. I
> >> think this will pave the way for future experiments using precision
> >> geodesy and time transfer.
> >>
> >> Cheers,
> >>
> >> Javier
> >>
> >
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> >
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
 On Mar 30, 2012 10:45 PM, "paul swed" <paulswedb at gmail.com> wrote:

> I have to say that in general I have been staying clear of this thread.
> But its really a surprise that they are that sloppy and basing the results
> on a Vectron OCXO. Not that I have ever had a complaint about those.
> It just seems like the stunt I would do in the basement on my surplus
> accelerator.
> Regards
> Paul.
>
> On Fri, Mar 30, 2012 at 12:57 PM, Tom Van Baak <tvb at leapsecond.com> wrote:
>
> > Hi Javier,
> >
> > Thanks very much for posting the link to the presentations.
> >
> > For those of you who just want a summary of the resolution of
> > the "neutrino faster than light" problem, here's what happened:
> >
> > 1) For several years an optical cable connector was loose. I have
> > attached photos from pages 7 and 8 of the G._Sirri.pptx where
> > you can see the actual connector and waveforms, before/after.
> >
> > 2) They used a Vectron OCXO to generate timestamps within each
> > 0.6 second measurement cycle. This oscillator was found to be high
> > in frequency by 0.124 ppm. Thus, depending on where within this
> > 0.6 s interval the timestamp was made a timing bias of 0 to 74 ns
> > would occur.
> >
> > Javier -- if you have contacts there, it looks to me like they forgot
> > to include OCXO frequency drift effects into their analysis. What
> > they did was compensate for linear time drift (which assumes a
> > fixed frequency offset). They call the 124.1 ns/s time drift "stable"
> > since 2008. What evidence do they have for this? We know that
> > OCXO will drift in *frequency* over time; the time drift is quadratic.
> > The time drift rate may be 124e-9 today, but it probably wasn't last
> > month or last year, etc.
> >
> > /tvb
> >
> >  There was a meeting in Gran Sasso on Wednesday. You can see some of
> >> the slides at http://agenda.infn.it/**materialDisplay.py?materialId=**
> >> slides&confId=4896<
> http://agenda.infn.it/materialDisplay.py?materialId=slides&confId=4896>
> >>
> >> I found particularly interesting the ones by Maximiliano Sioli, where
> >> he explained the two mistakes found in the OPERA data acquisition
> >> chain and how, after correcting for their best estimate of their
> >> effects, the time of flight is compatible with a speed of c.
> >>
> >> I saw the webcast of the event. Some people did give the OPERA
> >> spokesman a hard time, and he admitted to not having fully checked
> >> everything they could have. Ah well, everyone makes mistakes. There
> >> will be another run with neutrinos spaced by 100 ns in May. If all
> >> four experiments in LNGS give the same result this time, I suppose the
> >> case will be closed. It will also be very interesting to see the MINOS
> >> results.
> >>
> >> In any event, from a time-nut point of view this is quite exciting. It
> >> is the first time neutrino speed is measured with this precision. I
> >> think this will pave the way for future experiments using precision
> >> geodesy and time transfer.
> >>
> >> Cheers,
> >>
> >> Javier
> >>
> >
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> >
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>