876Re: Missing Solar Neutrinos
- Dec 21, 2001
> The construction of the SNO Laboratory began in 1990 and wasBeats me how anyone was persuaded that neutrinos were important
> completed in 1998 at a cost of $73M CDN... <snip>
enough to spend that kind of money, plus the ongoing expense of the
100 staff! -lar
"And all this science I don't understand ...It's just my job five
days a week" -Lyrics by Bernie Taupin, Music by Elton John
--- In CreationTalk@y..., "Chris Ashcraft" <ashcrac@y...> wrote:
> NEWS RELEASE:
> June 18, 2001 12:15 pm Eastern Daylight Time
> First Results from the Sudbury Neutrino Observatory Explain the
> Missing Solar Neutrinos and Reveal New Neutrino Properties
> Physicists from Canada, the UK and the US are today announcing that
> their first results provide a solution to a 30-year old mystery- the
> puzzle of the missing solar neutrinos. The Sudbury Neutrino
> Observatory (SNO) finds that the solution lies not with the Sun, but
> with the neutrinos, which change as they travel from the core of the
> Sun to the Earth.
> Neutrinos are elementary particles of matter with no electric charge
> and very little mass. There are three types: the electron-neutrino,
> the muon-neutrino and the tau-neutrino. Electron-neutrinos, which
> associated with the familiar electron, are emitted in vast numbers
> the nuclear reactions that fuel the Sun. Since the early 1970s,
> several experiments have detected neutrinos arriving on Earth, but
> they have found only a fraction of the number expected from detailed
> theories of energy production in the Sun. This meant there was
> something wrong with either the theories of the Sun, or the
> understanding of neutrinos.
> "We now have high confidence that the discrepancy is not caused by
> problems with the models of the Sun but by changes in the neutrinos
> themselves as they travel from the core of the Sun to the earth,"
> Dr. Art McDonald, SNO Project Director and Professor of Physics at
> Queen's University in Kingston, Ontario. "Earlier measurements had
> been unable to provide definitive results showing that this
> transformation from solar electron neutrinos to other types occurs.
> The new results from SNO, combined with previous work, now reveal
> transformation clearly, and show that the total number of electron
> neutrinos produced in the Sun are just as predicted by detailed
> The SNO scientists present their first results today in a paper
> submitted to Physical Review Letters and in presentations at the
> Canadian Association of Physicists Annual Conference at Victoria,
> and at SNO Institutions in the U.S. and the U.K. "It is incredibly
> exciting, after all the years spent by so many people building SNO,
> see such intriguing results coming out of our first data analysis -
> with so much more to come." says UK Co-spokesman Prof. David Wark of
> the Rutherford/Appleton Laboratory and the University of Sussex.
> The determination that the electron neutrinos from the Sun transform
> into neutrinos of another type is very important for a full
> understanding of the Universe at the most microscopic level. This
> transformation of neutrino types is not allowed in the Standard
> of elementary particles. Theoreticians will be seeking the best way
> incorporate this new information about neutrinos into more
> comprehensive theories.
with support from the Natural Sciences
> and Engineering Research Council of Canada, the National Research
> Council of Canada, the Northern Ontario Heritage Foundation,
> Science and Technology Canada, INCO Limited, the United States
> Department of Energy, and the Particle Physics and Astronomy
> Council of the UK. The heavy water is on loan from Canada's federal
> agency AECL with the cooperation of Ontario Power Generation, and
> unique underground location is provided through the cooperation and
> support of INCO Limited.
> Measurements at the SNO Laboratory began in 1999, and the detector
> been in almost continuous operation since November 1999 when, after
> period of calibration and testing, its operating parameters were set
> in their final configuration.
> Further information about the SNO detector can be found on the SNO
> Detector page.
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