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Neutrino Oscillations Confirmed 122

mfg writes "The Sudbury Neutrino Observatory has found evidence that neutrinos can change type between the Sun and Earth. See the BBC news story for more details."
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Neutrino Oscillations Confirmed

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  • or did they just come out of the closet?

  • Boredom? (Score:4, Funny)

    by Anonymous Coward on Tuesday April 23, 2002 @07:02AM (#3393608)
    Well, it's a bloody long way, do you really think they'd sit still? More likely they'd jump around on the back seat, play I-spy and shout "Are we there yet?" every million miles or so...
  • The equipment they use is interesting. Yet again its a shame i dont understand it...guess i have to get my ex-girlfriend to explain it to me...

    There seems to be no cover of what effects proving this is...or is it like:

    "Hey lets build a lab on how to mesure the perfect time to dunk a biscuit"

    I an't tryin to be a troll, just want to know what effect this will have on future research

    • Re:Point? (Score:4, Interesting)

      by hij ( 552932 ) on Tuesday April 23, 2002 @07:15AM (#3393631) Homepage
      Its not possible to figure out what direction this sort of information will lead the science community. That is why it is called "basic research." The principle argument is that it helps us understand the universe around us. The implicit assumption is that people will be able to exploit whatever knowledge eventually comes out of this research.

      There is a good deal of tension between advocates of basic versus applied research, and there needs to be a better dialog. Currently it is a bunch of people throwing around assumptions about the merits of both types of research, but no one seems to really engage the other. (IMHO).

      As an aside, there was a link [] from the article about the Japanese detector. Seems that one of the tubes blew which set of a cascade that destroyed most of the remaining tubes. I can't imagine the boom that one made...

    • by wass ( 72082 ) on Tuesday April 23, 2002 @10:30AM (#3394458)
      That's like asking Faraday, Ampere, Maxwell, Tesla, and others why they were bothering to play around with these obscure facets of electricity 100-200 years ago. Sure, it's neat watching a giant lightning bolt jump across two electrodes, but what real purpose will it have for future research?

      Hopefully you won't find it difficult to answer that question, as you power up your Pentium IV processor to hack some PERL code, crunch some numbers to decode your encrypted email, and look at the latest NASA gallery images represented on your monitor as a rasterized RGB image driven by an electron beam.

      And as you insert a CD into the CD player which is read by a GaAs laser and decrypted by more microelectronics, so you can listen to the solid-state (or vacuum-tube if you prefer) amplifier drive a magnetic speaker coil for your listening pleasure.

      And then as you get in your car, with the engine ignited by carefully-timed spark plug firings, where you turn on the radio and pick up frequency-modulated electromagnetic radiation and decode it into stereo sound, again sent to an amplifier and speakers for your listening pleasure.

      So, you see, it's hard to determine, a priori, the benefits of certain scientific advances and the effects they'll have on civilization. Neutrino oscillations are important because they put another piece into the puzzle that high-energy physicists are trying to solve relating how all the elementary particles fit together.

      Some potential uses for this might deal with gaining further insights into nuclear power and better ways to do it. Specifically, fusion power. The sun is a fusion reactor, but scientists haven't been able to efficiently harness fusion power here on earth yet. This neutrino puzzle helps verify some of the hypotheses scientists had about nuclear processes in the sun that weren't fully understood or adequately measured with older neutrino counters.

      It might also help long-range communication. Neutrinos can pass through the earth without being affected, and scientists had once tried to use this method for talking to submarines on the other side of the planet. The obvious problem is how do you detect said neutrons. I think I heard something that they were able to make a receiver that could receive data at a rate of a few bits per day. Not very efficient. Well, learning more about neutrons and their oscillations might give insight into ways to improve neutrino communications.

      There are most likely many other things too, that we just don't know about or don't have use for. Maybe they'll prove efficient for long-range communications to other planets, and possibly for quantum encryption during these communications. We just don't know yet, but if we don't try we'll never know.

  • They beat em (Score:5, Informative)

    by qqtortqq ( 521284 ) <tort@kco[ ] ['nli' in gap]> on Tuesday April 23, 2002 @07:11AM (#3393625)
    Fermlab [] is in the process of building an X million dollar project to send neutrinos 735km to minnesota to see if they oscilatte during the trip... Kinda pointless now. The project is called NuMI, its kinda interesting, they were going to send neutrinos through the ground to an old mine- check out the NuMI web site [].

    For the people who have no idea what neutrinos oscillating is about - try here. [] It gives a good overview, made so someone like me could even understand it.
    • It doesn't hurt to verify something as basic as neutrino oscillation. It implies other particles (such as protons) are not stable.
    • Fermlab is in the process of building an X million dollar project to send neutrinos 735km to minnesota to see if they oscilatte during the trip...

      Well they get an in flight meal? First class or coach?
    • Not at all (Score:5, Informative)

      by DoctorNathaniel ( 459436 ) <> on Tuesday April 23, 2002 @08:16AM (#3393767) Homepage
      As an ex-member of SNO (my name (N. Tagg) is on the papers []) as well as a current member of MINOS (the experiment you're reffering to at Fermilab) I can say that this is simply not true; the experiments are complimentary, not exclusionary.

      In fact, there is a large quantity of work going on in this field. Current experiments include KamLAND, Borexino, Opera, NuMI-MINOS, Super-Kamiokande (when they finish their repairs in a year or so), K2K (KEK to Super-K), MiniBOONE the new JHF facility, plus a bunch more I'm forgettting.

      There are several reasons for all this activity. First, there are at least two different types of oscillaitions. (The naive and over-simplified theory is that there is nu-electron to nu-mu oscillation, and nu-mu to nu-tau oscillation, the first of which is seen by SNO, the second of which is seen by atmosphereic neutrinos and by the beam experiments). There may be a third mode, which implies a new variety of neutrino (nicknamed 'sterile' for various reasons).

      In addition, we're looking to prove that our theory about the oscillations is correct; that they really oscillate in the way we think they do (i.e. change back and forth between flavours on a given time scale that is dependent on energy and suchlike). We want to know the exact parameters in the theory, so the theorists have some hard numbers to much on to make better overarching theories. And, there's always the possibility that something entirely new will crop up in these studies.

      (A note on that last: modern neutrino detectors were born out of eariler attempts to build proton decay experiments... but the neutrinos kept getting in the way! On the 'don't beat 'em, join 'em' approach, people started looking at the neutrinos themselves with more interest.)

      --Nathaniel, prowling his favourite topic.
      • So I've been out of the field for a while... What are the implications to the standard model now that these oscillations have been confirmed?

        Is there an upper/lower limit to the nu mass? (I'm more of a cosmologist - and nu mass amounts are interesting, especially in working out the virial relations for Galactic clusters... and geometry of the Universe.)
        • Doing my best Tom Lehrer impersonation:

          It's time for "nu mass"
          nu-hu-hu mass...

          I'm so ashamed.
        • Well, I'm NOT much of a cosmologist. The new results confirm the Large Mixing Angle solution, which puts the first neutrino mass difference at 10^-2 eV. This means that the minimum mass of the second generation nu is 10^-2 eV, which is pretty darn small. As I understand it, this makes neutrinos a few percent of the total universal mass budget, somewhere on the same order as bright matter (i.e. stars): 5% or so. Nothing that will prove a big crunch either way. This has been known for a while.

          Of course, this is only the mass _difference_. There's very little direct mass evidence, so the maxixum mass could still be up high enough to be more interesting, but it's viewed as unlikely.

          • Well, let's see... if neutrinos were relativistic at decoupling, then:

            Omega_nu h^2 = (sum of neutrino masses) / 93.5eV
            (Peacock 1999 p.281)

            For h=0.7 and a total neutrino mass of 0.1eV, that gives Omega_nu=0.002, which is negligible for cosmology (and probably for structure formation too, though I'm not sure exactly how much HDM you need to add to start wiping out small scale structure).

            Of course, if the neutrino mass is large enough that they're cold when they decoupling, all bets are off...

    • Re:They beat em (Score:2, Informative)

      by kkumer ( 36175 )
      Ferm[i]lab is in the process of building an X million dollar project to send neutrinos 735km to minnesota to see if they oscilatte during the trip... Kinda pointless now.

      This is not a pointless experiment. In both experiments that the article mentions (SNO and SuperKamiokande) neutrinos are produced by a natural process (either nuclear reactions in the Sun or cosmic rays in atmosphere). There is always a possibility that we don't understand these natural processes good enough and that we misinterpret the data.

      In these planned terrestrial neutrino oscillation experiments (such as NOMAD [], K2K [], OPERA [], MINOS [], etc.) neutrinos will be produced in controlled reactions on Earth, making interpretation and measurements easier, more precise and more model-independent.

  • by ShakaGreyHat ( 195940 ) on Tuesday April 23, 2002 @07:22AM (#3393640)

    Here's [] a link to some background on neutrinos, and particle physics in general (from the American Institute of Physics).

    The basic idea is this: neutrinos seem to be fundamental particles. The more we understand about them (properties, interactions, etc) and the other elementary particles, the more we understand about how the universe works. This usually has "practical" applications in fields like astronomy and cosmology first. But don't worry, eventually there will be nice day-to-day applications (neutrino toasters, etc :-)
    • by Jodrell ( 191685 ) on Tuesday April 23, 2002 @07:59AM (#3393700) Homepage
      it's a funny idea, but a "neutrino toaster" would be quite difficult to create...

      At normal neutrino flux levels, it'd take several times the lifespan of the universe for neutrinos to deposit even the tiniest amount of energy into a slice of bread. Consider the fact that many billions have passed through your body in the time you've been reading this comment. It's unlikely a single one of them would actually collide with a particle in your body.

      A neutrino toaster would probably need the total neutrino output of the sun to toast a slice of bread in a reasonable time period - and if you've got that, why not just stick your bread on a real long fork and toast it over the sun's corona :-)
      • Well, that's just why we need this kind of research. Maybe we'll figure out how to make neutrinos interact with everyday matter on demand. :-)

        My "neutrino toaster" could just be a box where neutrinos passing thru WOULD interact with the slice of bread inside. Since there are more than 4x10^10 neutrinos / cm^2 incident on the earth every second, I think it could be a handy energy source. Why use a long fork when then energy will come to you? A lot more convenient than solar power, etc - the neutrinos pass right thru the atmosphere, even the whole planet! No worries about power when the sun goes down....
      • That can't be true, I saw Wesley use a tunneling neutrino beam to rid the Enterpise of bacteria. Star Trek wouldn't lie to me, would it?
      • by gnalre ( 323830 )
        (Apologies to V.Vinge) What about imaging applications. Could we use neutrino's to map the center of planets oe even the sun?

        Lets ignore the technical impossibilities for a second here.

        Actually we already have a good application already. we have proved that the sun is working as we expect. There was two possibilities for the missing neutrino's.

        1. The theories were wrong
        2. The sun was very ill.

        Personally I feel a lot richer for knowing 2 is not the case.

        Can we use this technology as a way to monitor the sun?
      • It's unlikely a single one of them would actually collide with a particle in your body.

        This is true. Most people will "experience" a neutrino collision in their body once or twice in their lifetime. Of course, you'll never know it when it happens.

        If there were a wall of solid lead, 1 light-year thick, out in space, only 50% of the neutrinos passing through it would actually collide with a lead atom. The other 50% would pass right through as if it weren't there.
        • This might be a good place to mention my calculation [] that looks at a quote from the late latmented Douglas Adams:

          "It all depends on what you mean by 'hit' of course, seeing as matter consists almost entirely of nothing at all. The chances of a neutrino actually hitting something as it travels through all this howling emptiness are roughly comparable to that of dropping a ball bearing at random from a cruising 747 and hitting, say, and egg sandwich."

          Also incidently, the neutrino toaster is not an invetion, it's a discovery: being close to a supernova would make you feel mighty warm, even if you did have shielding to protect you from the light and the matter shockwaves. Supernovae release 90% of their energy as neutrinos.

          ---Nathaniel, on the Neutrino Prowl, co-author on the recent SNO papers.
          • Supernovae release 90% of their energy as neutrinos

            They do? How was this discovered?
            • It wasn't exactly discovered; although I believe that the results from SN1987A are in rough agreement with the theory.

              The idea is a collapsing star is opaque, like a light bulb painted black: the light is being made, but can't get out. Because of the very high temperatures and the density of the neutron soup in the centre, making neutrinos by pair-production becomes a method for the supernova to shed all that energy without using photons.

              This is in addition to the neutronization burst that comes at the start, when the neutron star is formed.

          • Hmm... I think if you get enough ionizing radiation to "feel mighty warm" (a paper I read soon after the 1987A supernova said neutrino interactions averaged about 1MeV) you'd likely be dead before you could perceive the heat.

            Back then, there was an article saying that people on Earth averaged one or two neutrino interactions in their bodies just from 1987A. Based on that, the energy of the interaction, and the good old inverse square law, I figured you'd get a lethal dose of radiation (500 REMs) at about 12 AU from the supernova. At Earth's distance, it might even be enough to kill you before the blast vaporizes you.

            I've since similar numbers in other places, so I guess I didn't drop a decimal point anywhere.
        • This is true. Most people will "experience" a neutrino collision in their body once or twice in their lifetime. Of course, you'll never know it when it happens.

          If there were a wall of solid lead, 1 light-year thick, out in space, only 50% of the neutrinos passing through it would actually collide with a lead atom. The other 50% would pass right through as if it weren't there.

          There is something I would like to ask you very smart people. Would there be any way you can generate neutrinos in a manner so that you could piggy back information on them and detect that information at some distance? Kind of the way radio works. If so, it would be really nice because dense objects such as the earth and buildings would no longer be a problem for communications.

          Just a thought.

      • Why would anyone want to toast a nice little neutrino?
  • by Brightest Light ( 552357 ) on Tuesday April 23, 2002 @08:00AM (#3393704) Journal
    here's the text

    Experiment confirms Sun theories

    The SNO was constructed to solve a mystery

    By Dr David Whitehouse
    BBC News Online science editor

    Neutrinos - some of nature's most elusive sub-atomic particles - do change their properties as they travel through space.

    We are much more certain now that we have really shown that solar neutrinos change type

    Prof Dave Wark, University of Sussex New evidence confirms last year's indication that one type of neutrino emerging from the Sun's core does switch to another type en route to the Earth.

    This explains the so-called solar neutrino mystery, which has had scientists puzzled for 30 years - why so few of the particles expected to emerge from the nuclear furnace in our star can actually be detected.

    The new data mean the reactions put forward by physicists to describe how the Sun works are correct.

    The data were obtained from the underground Sudbury Neutrino Observatory (SNO) in Canada.

    Going underground

    Neutrinos are ghostly particles with no electric charge and very little mass. They are known to exist in three types related to three different charged particles - the electron and its lesser-known relatives, the muon and the tau.

    Electron-neutrinos are created in the thermonuclear reactions at the solar core. Because these reactions are understood, it has been possible to estimate the number of electron-neutrinos that should emerge from our star.

    But it has baffled scientists for decades as to why just a third of this expected number could actually be detected.

    Using the underground Sudbury neutrino detector, an international group of researchers has been able to determine that the observed number of electron-neutrinos is only a fraction of the total number emitted from the Sun - clear evidence that the particles change type en route to Earth.

    SNO Project Director, Dr Art McDonald, of Queen's University, Canada, said the number of electron-neutrinos detected combined with the numbers of other types picked up at Sudbury gave a total that was consistent with scientists' understanding of the nuclear reactions occurring at the Sun's core.

    All types

    The Sudbury Neutrino Observatory is a unique neutrino telescope, the size of a 10-storey building, two kilometres underground, down a mine in Ontario.

    The SNO detector consists of 1,000 tonnes of ultrapure heavy water, enclosed in a 12-metre-diameter acrylic-plastic vessel, which in turn is surrounded by ultrapure ordinary water in a giant 22-metre-diameter by 34-metre-high cavity.

    The observatory detects about one neutrino per hour

    Outside the acrylic vessel is a 17-metre-diameter geodesic sphere containing 9,600 light sensors or photomultiplier tubes, which detect tiny flashes of light emitted as neutrinos are stopped or scattered in the heavy water.

    At a detection rate of about one neutrino per hour, many days of operation are required to provide sufficient data for a complete analysis.

    Because SNO uses "heavy" water - the hydrogen atom in the water molecule has an extra neutron - it is able to detect not only electron-neutrinos through one type of reaction, but also all three known neutrino types through a different reaction.

    Very accurate

    Dr Andre Hamer, of the Los Alamos National Laboratory, US, said: "In order to make these measurements, we had to restrict the radioactivity in the detector to minute levels and determine the background effects very accurately to show clearly that we are observing neutrinos from the Sun."

    The research not only improves our understanding of the Sun but of the elusive neutrinos as well.

    The latest results, entirely from the SNO detector, (and which have been submitted to Physical Review Letters) are said to be 99.999% accurate.

    Dr MacDonald said: "The SNO team is really excited because these measurements enable neutrino properties such as mass to be specified with much greater certainty for fundamental theories of elementary particles."

    Mass differences

    This announcement is confirmation of indications released in June 2001 that suggested that it was highly likely that neutrinos changed type on their way from the Sun.

    However those conclusions were always tentative because they were based on comparisons of results from SNO with those from a different experiment, the Super-Kamiokande detector in Japan.

    Professor Dave Wark, of the University of Sussex and the Rutherford Appleton Laboratory, UK, commented: "Whenever a scientific conclusion relies on two experiments, and on the theory connecting them, it is twice as hard to be certain that you understand what is going on.

    "We are therefore much more certain now that we have really shown that solar neutrinos change type."

    Professor Hamish Robertson of the University of Washington, US, added: "There's absolutely no question the neutrino type changes and now we know quite precisely the mass differences between these particles."

  • Wasn't it done by Super Kamiokande [] experiment back in 1998? (presence of mass is equivalent to the presense of mixing in current theory)
    • Yes, but not conclusively. It's in the BBC article. Besides, there's nothing wrong with double checking!
    • Wasn't it done by Super Kamiokande experiment back in 1998?

      This was the anouncement of the atmospheric neutrino results which pinned down neutrino mixing between muon and tau nus better than ever before.

      SK also sees solar nus but only the electron neutrinos. In addition to the electron neutrino, SNO can also see the sum of all solar neutrino types (ie, the electron type as well as other types that the e-type may have oscillated to). Their first result relied on SK's measurement of the electron type nus because SNO has a smaller mass, thus lower count. The latest announcement appears to be stating that they have collected enough events that they can have a similar result as before but with out relying on some of SK's data.

  • by Anonymous Coward on Tuesday April 23, 2002 @08:36AM (#3393847)
    I've been confused about neutrinos ever since I found out they had mass. Who'd have imagined that they were Catholic?
    • Who'd have imagined that they were Catholic?

      All the neutrinos are born Catholic, but only a third of them are Catholic by the time we detect them. The rest oscillate to other faiths, which are also known to have mass, just in different amounts.
  • by ancarett ( 221103 ) on Tuesday April 23, 2002 @08:51AM (#3393905)
    *Yawn* We knew about it last week. Here's a snippet from the copy [] released by PR people at Laurentian University [] in Sudbury:

    New scientific results from the Sudbury Neutrino Observatory to be announced

    April 18, 2002

    (Sudbury, Ontario) - Scientists from Canada, the United States and the United Kingdom, working at the Sudbury Neutrino Observatory (SNO), a unique underground laboratory built to provide insights into the properties of neutrinos and their emission from the core of the Sun, will submit a scientific paper with important new results later this week. They will announce these research findings in a scientific presentation by Dr. Andre Hamer on Saturday, April 20, at the Joint Meeting of the American Physical Society and the American Astronomical Society in Albuquerque, New Mexico. A copy of the first scientific paper and news release summarizing SNO's findings and their importance will be posted on the SNO website ( at 1:20 p.m EDT (10:20 a.m. PDT) on Saturday, April 20. A summary talk on the implications of these neutrino measurements will be presented by Dr. John Wilkerson on Monday, April 22, at the same conference.

    "We look forward to this opportunity to share these new findings with the scientific community and the general public," says Dr. Art McDonald, SNO Project Director and member of the Department of Physics at Queen's University. "For the first time, we are reporting on an important neutrino reaction in the SNO detector - a reaction in which all known neutrinos participate, regardless of their type. The successful observation of these neutrino signals has been a chief goal of the years of intense work by a collaboration of close to 100 scientists at 11 universities and national laboratories in Canada, the United States and the United Kingdom, and we are very pleased with the quality of the data obtained."

    In June 2001, the SNO scientific collaboration announced definitive results based on two other reactions seen in the SNO detector, and on measurements at the SuperKamiokande neutrino detector in Japan, establishing that neutrinos from the Sun change from their original electron neutrino type, to a mixture of electron and other (mu or tau) neutrino types. The new data from the Sudbury Neutrino Observatory to be announced on April 20, enables this question to be addressed accurately from data obtained entirely from SNO, and is expected to enhance significantly our understanding of these important properties of neutrinos from the Sun and of the Sun itself.

    Additional information about the conference presentations, the SNO laboratory, the neutrino measurements being made and the participating institutions can be found at [].

  • This article [] does contain a good overview of recent results of different neutrino measurements.
  • So - do Neutrinos have mass now or not? Seems that every time I pick up New Scientist theres a new experiment to find the answer.

    I suspect they DO, which is a pain in the ass as I bet a million pounds in 1995 that they would be proven to be massless by 2005. Jesus! The stuff that seems important when you're at University!

    Better start saving!
    • Re:Neutrino MASS?? (Score:2, Interesting)

      by PhxBlue ( 562201 )

      But it is important. . . isn't it? If I recall my physics correctly, neutrinos with mass = closed universe.

      It's funny when you think about it, that probably the smallest particle in the universe will decide its fate. . . but it's true. Pretty amazing stuff, physics.

      • It's most interesting to me, because I remember seeing articles presented evidence that the universe was expanding at a rate that would imply it's open (no big crunch, right?).

        I remember hearing the same thing you mentioned - that the shear number of neutrinos in the universe meant that the universe would be closed if they had mass.

        Interesting. I wonder if anyone is doing prominent work on this question...
    • The fact that neutrinos oscillate indicate that at least one of the flavors of neutrinos has a nonzero mass. However, I believe that the upper limits on neutrino masses and current theories on the number of neutrinos present in the universe still leave some mass unaccounted for, for a closed universe.
  • Yes, the information is easy to understand as presented: usually only 1 neutrino per hour is detected, yet current theory dictates that it should be ~ 3 per hour. Via use of D20 (heavy water) SNO must be detecting the missing 66 1/3% (it's implied, but never clearly stated... odd).

    As a debugging freak and mechanical moron, I'm curious why they're so sure that the extra muons and gluons are coming from the sun, versus being sourced from the fusion of a million billion stars in the universe? Do we have proof that detection levels rise when the sun is positioned directly over the NDS's - I doubt even the mass of the earth shields the station from a tiny percentage of such tiny bits, leaving me wondering...

    I'm sure that there's some statistical 3D reasoning behind our certainty, like "the sky's dark at night because the universe is expanding, dork!" - same reasoning applies here? If so, we're using the same reasoning which applies to photon saturation to neutrinos, and we can be sure that's a valid assertion? (I.E. dark matter isn't going to present a barrier to nuetrinos, correct? But a sheet of paper will block all of the light from a starry night, so shouldn't the level of neutrino saturation be significantly higher than that of photons?)

    Hey, I'm just a backyard mechanic and C code tweaker, but these are questions I don't see being asked in the public domain... maybe a physics geek can explain it. If so, can you also describe the rate at which these suckers are chugging along through the universe, and maybe how we figured what their relative speed is?

    Lord of the satanicult: we love everything but science, coding, small fuzzy rodents and the PLO, cuz they bedevil the hell out of our intellect...
    • at "night" the sun is on the OTHER side of the earth, meaning that there is a larger bulk of mass shielding the detector. During the "day" the shielding is only as thick as the depth the detector is buried under the ground. They based their results using this difference in shielding.

      • Actually the day/night ratios detected at SNO
        is more complex than this, the neutrino capture
        cross section in matter is so small that the
        even the whole mass of the earth doesn't block
        a signicant fraction of the neutinos, the detected
        flux of 1 neutrino per hour at SNO as a testament
        to the vest number of neutrinos emitted by the
        Instead what is happening is that (according
        to theory), the neutrino oscillation rate becames
        signicantly increased while the neutrino is
        travelling through matter, so that at night
        detented particles contains less electron neutrinos and more of the other types.
        Oh, and finally, the neutrino captured in SNO emit a cone of UV light (checknov radition), and
        the cone points in the direction the neutrino
        came from, so scientist at SNO can have a good
        idea weather the neutrinos came from the sun or
        from deep space.

  • I'm having a hard time understanding the conclusions reached in the announcement, given the data described in the announcement.

    How does precisely measuring a number that is 1/3 of that predicted by the solar neutrino model prove that the neutrinos are changing and not that the model is incorrect?

    Isn't that a bit like publishing Hubble's constant to 800 decimal places, but knowing that your answer is only accurate to +/- 10 orders of magnitude?
    • Re-read the press release. What they measured was not simply that there were 1/3 of the expected number of electron neutrinos - that's been measured many many times over the past couple decades. What's important is that they measured the total number of neutrinos (electron, mu and tau flavours) to be right.

  • I keep trying to argue that sub-typing is a bad software modeling technique for real world applications, and here you guys go and start showing nature dividing into "subtypes". Jeeeez! What's an anti-OOP troll to do now?

    (Actually, subtyping may be fine for modeling nature, since God doesn't request changes in natural laws anywhere near as often as PHB's change business rules, strategies, and organization.)

All science is either physics or stamp collecting. -- Ernest Rutherford