CERN a rychlost světla

Pátek Září 23 09:59:28 CEST 2011

tu je kompletna tlacova sprava aj s detailami. Synchronizacian na 
nanosekundovej urovni a vzajomna poloha znama s presnostou do 20cm :-)
Som velmi zvedavy na ten seminar, tak nejak tusim ze tam bude celkom 
narvano :-)

http://press.web.cern.ch/press/PressReleases/Releases2011/PR19.11E.html

OPERA experiment reports anomaly in flight time of neutrinos from CERN 
to Gran Sasso.

Geneva, 23 September 2011. The OPERA experiment, which observes a 
neutrino beam from CERN 730 km away at Italy’s INFN Gran Sasso 
Laboratory, will present new results in a seminar at CERN this afternoon 
at 16:00 CEST. The seminar will be webcast at http://webcast.cern.ch. 
Journalists wishing to ask questions may do so via twitter using the 
hash tag #nuquestions, or via the usual CERN press office channels.

The OPERA result is based on the observation of over 15000 neutrino 
events measured at Gran Sasso, and appears to indicate that the 
neutrinos travel at a velocity 20 parts per million above the speed of 
light, nature’s cosmic speed limit. Given the potential far-reaching 
consequences of such a result, independent measurements are needed 
before the effect can either be refuted or firmly established. This is 
why the OPERA collaboration has decided to open the result to broader 
scrutiny. The collaboration’s result is available on the preprint server 
arxiv.org http://arxiv.org/abs/1109.4897.

The OPERA measurement is at odds with well-established laws of nature, 
though science frequently progresses by overthrowing the established 
paradigms. For this reason, many searches have been made for deviations 
from Einstein’s theory of relativity, so far not finding any such 
evidence. The strong constraints arising from these observations make an 
interpretation of the OPERA measurement in terms of modification of 
Einstein’s theory unlikely, and give further strong reason to seek new 
independent measurements.

“This result comes as a complete surprise,” said OPERA spokesperson, 
Antonio Ereditato of the University of Bern. “After many months of 
studies and cross checks we have not found any instrumental effect that 
could explain the result of the measurement. While OPERA researchers 
will continue their studies, we are also looking forward to independent 
measurements to fully assess the nature of this observation.”

“When an experiment finds an apparently unbelievable result and can find 
no artefact of the measurement to account for it, it’s normal procedure 
to invite broader scrutiny, and this is exactly what the OPERA 
collaboration is doing, it’s good scientific practice,” said CERN 
Research Director Sergio Bertolucci. “If this measurement is confirmed, 
it might change our view of physics, but we need to be sure that there 
are no other, more mundane, explanations. That will require independent 
measurements.”

In order to perform this study, the OPERA Collaboration teamed up with 
experts in metrology from CERN and other institutions to perform a 
series of high precision measurements of the distance between the source 
and the detector, and of the neutrinos’ time of flight. The distance 
between the origin of the neutrino beam and OPERA was measured with an 
uncertainty of 20 cm over the 730 km travel path. The neutrinos’ time of 
flight was determined with an accuracy of less than 10 nanoseconds by 
using sophisticated instruments including advanced GPS systems and 
atomic clocks. The time response of all elements of the CNGS beam line 
and of the OPERA detector has also been measured with great precision.

"We have established synchronization between CERN and Gran Sasso that 
gives us nanosecond accuracy, and we’ve measured the distance between 
the two sites to 20 centimetres,” said Dario Autiero, the CNRS 
researcher who will give this afternoon’s seminar. “Although our 
measurements have low systematic uncertainty and high statistical 
accuracy, and we place great confidence in our results, we’re looking 
forward to comparing them with those from other experiments."

“The potential impact on science is too large to draw immediate 
conclusions or attempt physics interpretations. My first reaction is 
that the neutrino is still surprising us with its mysteries.” said 
Ereditato. “Today’s seminar is intended to invite scrutiny from the 
broader particle physics community.”

The OPERA experiment was inaugurated in 2006, with the main goal of 
studying the rare transformation (oscillation) of muon neutrinos into 
tau neutrinos. One first such event was observed in 2010, proving the 
unique ability of the experiment in the detection of the elusive signal 
of tau neutrinos.

On Sep/23/2011 2:20, Pavel Kutina wrote:
> A jeste se mi tak vkrada jedna otazka - jestlize tvrdi, ze je uz tri
> roky chytaji driv, nez by meli, podezrele to koresponduje s datem
> spusteni (2008). Otazka tedy zni, zda vubec nekdy prislo nejake neutrino
> z tohoto smeru ve spravnem case - to by ukazovalo na nejakou chybu
> kalibrace.
>
> Ale predpokladam, ze v CERNu nejsou zadni blbci a tohle maji podchycene
> (treba vcetne pohybu zemske kury a podobnych geofyzikalnich jevu, ktere
> se mohou podilet prave na dilataci te skutecne vzdalenosti), narozdil od
> fyziku-amateru. Jestli ne, tak by mi padla dalsi zivotni jistota :)
>
> Pavel Kutina
>
>
> ----- Original Message ----- From: "Pavel Kutina" <hw na prelude.cz>
> To: "HW-news" <hw-list na list.hw.cz>
> Sent: Friday, September 23, 2011 2:06 AM
> Subject: Re: CERN a rychlost světla
>
>
> Uvaha se mi zda celkem logicka, ale uplne nespravna :)
>
> Ono by to fungovalo, kdyby bylo namereno zpomaleni neutrina pod c, tam
> by se
> treba asi nejak dalo ocekavat, ze doslo ke zpomaleni vlivem materialu.
>
> Jestlize ale doslo k tomu, ze tam maji neutrino rychleji, nez by teoreticky
> mohlo ve vakuu byt, pak ma rychlost vetsi nez c, coz by podle toho
> rozcuchaneho pana asi za zadnych okolnosti mit nemelo, bez ohledu na
> material, kterym prochazi - takze zase az tak klidne spani (pokud se to
> opravu prokaze) mit nebude.
>
> Mne by spis zajimalo, jak se domerili te vzdalenosti, abychom se nakonec
> nedozvedeli, ze se nam vyfukuje globoid :)
>
> Pavel Kutina
>
>
> ----- Original Message ----- From: "gatilo" <gatilo na centrum.cz>
> To: "HW-news" <hw-list na list.hw.cz>
> Sent: Friday, September 23, 2011 1:15 AM
> Subject: Re: CERN a rychlost světla
>
>
> 23.9.2011, 0:51:02
>
> Sice nevim, jak merili vzdalenost, ale asi to nejak jde.
> Jenze samotna vzdalenost by stacila, jen tehdy, pokud by mereni
> probihalo ve vakuu. Jenze ini ty mrnave potvory posilaji pres zemskou
> kuru. A rychlost svetla zavisi na prostredi. Takze je krom vzdalenosti
> potreba znat i presne slozeni toho prostredi. Coz v pripade neceho tak
> ruznorodeho jako je zemska kura je IMHO nemozne.
> Neutrina byla zhavim kandidatem na Velkeho Boritele soudobe fyziky uz
> jednou, celkem nedavno, kdyz experimenty merily pouze 1/3 slunecnich
> neutrin, nez predpovidala teorie. Nicmene se brzy ukazalo, ze pricinou
> je tzv. oscilace neutrin o ktere se zpocatku nevedelo. Fyzika tedy
> byla zachranena, a prodavaci teblet proti boleni hlavy se museli
> prestehovat z univerzit jinam. :-)
> Odhadoval bych, ze pokud se nenajde nejaka chyba v mereni, pak bude
> pricinou opet nejaka dosud neznama vlastnost neutrin a ten chlapik s
> vyplazenym jazykem muze dal klidne spat.
>
> Druhou moznosti je, ze pricinou je ten strangelet, co ho na LHC vyrobi
> pristi rok. ;-)
>
> S pozdravem Pavel
> mailto:gatilo + zavinac + centrum.cz
>
> --
> Miroslav Šinko napsal:
>
>> Zaujimalo by ma (fakt, nemyslim to ironicky), ako urcili presnu priamu
>> vzdialenost medzi generatorom a detektorom.
>
>> miro
>
>> 2011/9/22 balu na home <daniel.valuch na orange.fr>:
>>> Asi ale tusim preco nesedi cas doletu, tunely v cngs su strasne krive.
>>> Oficialna verzia je ze chlap ktory ovladal raziaci stroj nebol zrovna
>>> expert
>>> na riadenie toho stroja a ten sa podarilo vyrazit trochu klukaty
>>> (preco ma
>>> zase napada slovne spojenie francuzsky robotnik).
>> _______________________________________________
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>
>
>
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