Neutrinos questioned

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z@z

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Oct 6, 1999, 3:00:00 AM10/6/99
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Jim Carr wrote on neutrinos (Re: Question about Gamma rays?):

> One can create all sorts of strawmen, but the fact is that there
> is such a "new particle", a fact that has been known for over 40
> years except to a small group of people living in a fantasy world.
> And, yes, there was both missing momentum and missing energy in
> the reactions that were studied -- all of which was found once the
> experiments reached the necessary sensitivity.

'Constructing Quarks', 'A Sociological History of Particle Physics',
Andrew Pickering, 1984, page 68:

"Beta decay, the emission of electrons and positrons from unstable
nuclei, was one of the principal themes of radioactivity research in
the early decades of the twentieth century. It was an especially
puzzling phenomenon that electrons were emitted over a range of
energies; their energy spectrum was contiuous, rather than discrete
as expected for transitions ocurring in a quantised system. Amongst
the fathers of quantum mechanics, Bohr, Heisenberg and Pauli
each proposed radical explanations for this observation - Bohr,
that energy was not exactly conserved; Heisenberg, that space-time
was not continuos - but it was Pauli's proposal that won the day."

Can somebody explain me why it was assumed that electrons emitted
during beta decay should not have a continuous energy spectrum?

Can somebody explain me why the continuous energy spectrum of
electrons emitted during beta decay cannot be explained in a simple
way but needs a "radical explanation".

Two other extracts from the same book (p.6, p.395):

"First, scientists' understanding of any experiment is dependent
upon theories of how the apparatus performs, and if these theories
change then so will the data produced."

"They had been monitoring 140 tons of iron for 131 days and had
observed around 200 events. Almost all of these could be ascribed
to the passage through their apparatus of muons, generated by
neutrino interactions in the overlying rock, but the experimenters
concluded that three events could not be so explained."

The experiment of the 'existence' of neutrinos should be repeatable.
Before one carries out the experiment, it should be possible to
calculate the result (but there are so many types of neutrinos with
the possibility of changing into other types, that I am not sure).
The confirmation of this result by the experiment is considered a
scientific conclusion of the existence of neutrinos.

But at least in such and similar cases, the conclusions depend much
more on a theoretical framework and even on ad-hoc-hypotheses
than on the experimental data.

Experiments on the one hand and interpretation of the experimental
data based on the neutrino hypothesis on the other had evolved
parallelly until finally (i.e. decades later) a repeatable
experiment could be interpreted as a proof of neutrinos.

So the later discovery of this particle seems to me rather a
consequence that Pauli once had "won the day" than a consequence
of its existence.


Wolfgang Gottfried G.
http://members.lol.li/twostone/E/physics1.html

Dr. Michael Albert

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Oct 6, 1999, 3:00:00 AM10/6/99
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> 'Constructing Quarks', 'A Sociological History of Particle Physics',
> Andrew Pickering, 1984, page 68:
>
> "Beta decay, the emission of electrons and positrons from unstable
> nuclei, was one of the principal themes of radioactivity research in
[snip]

> was not continuos - but it was Pauli's proposal that won the day."

I have not actually read this book, but from everything which
I've heard about it, it takes a very peculiar view of things.
While it is good to remember that science takes place in
the context of human societies, this book seems to lean
to the belief that there is no difference between scientific
and, say, shamanistic points of view. When it comes to
such fundamental issues as this, in the end each person
makes their own decission as to their personal beliefs, but
I will still argue that our modern science and technology
is "objectively real," as is evidenced by all of our
modern toys (computers, telephones, etc). Which of these
toys are truly beneficial to humans is a different question.
While philosophers can wax at length about exactly what
the phrase "objectively real" might mean, science is
at least "as real as it gets."

> Can somebody explain me why it was assumed that electrons emitted
> during beta decay should not have a continuous energy spectrum?

When a decay occurs in which the emitted electron has less
than the maximum possible energy, where did the rest of the
energy (which the electron could have had) go? Both experiment
and theory excluded any significant energy in the recoil
of the nucleus. Indeed, careful experiments were done in
which the temperature of an isolated sample was measured,
and the rise in temperature was consistent with the average
energy of the electrons emitted. Thus either the amount
of energy released in each decay varied from decay to decay,
or something very strange was "sneaking" out of the calorimeter
(a calorimeter is a device in which you try to keep something
thermally isolated while measuring it's temperature).

> Two other extracts from the same book (p.6, p.395):
>
> "First, scientists' understanding of any experiment is dependent
> upon theories of how the apparatus performs, and if these theories
> change then so will the data produced."

True, although again, this book makes it sound like science is
nothing but what we decided was true today. For example,
the fact that Mercury's orbit did not quite follow Newton's
laws was "known" before Einstein's general relativity, but
of course before general relativity this observation went
uninterpretted--or rather, folks kept looking for some
cause, such as the sun being not quite spherical.

[snip]

> The experiment of the 'existence' of neutrinos should be repeatable.
> Before one carries out the experiment, it should be possible to
> calculate the result

Yes, this has been done. In the end, all one can say is that
to within one's experimental uncertainties, a certain theory
agrees with observations. Currently, the number of neutrino
experiments which are in agreement with theory is large enough
that I think one can say it exists to the best of our ability
to say that anything exists. Of course, in principle, one could
imagine someone coming up with a completely new theory which
doesn't have something like a neutrino but somehow still explains
all of the observations. Coming up which such a theory
is actually far more difficult than it sounds.


>(but there are so many types of neutrinos with
> the possibility of changing into other types, that I am not sure).

This is a small effect, which is why "the possibility of
changing into other types" is still an area of active research.

[snip]

> But at least in such and similar cases, the conclusions depend much
> more on a theoretical framework and even on ad-hoc-hypotheses
> than on the experimental data.

There is something to be said for this, though I think the
example you choose doesn't well support your point. There is
an unfortunate tendancy in the experimental literature
to report "we have measured parameter X of Y's nuclear model"
when it would be better to say something like "we have
measured the angular distribution of such-and-such particles
being scattered off of a nucleus, and in Y's model this
allows us to measure parameter X."

[snip]

> So the later discovery of this particle seems to me rather a
> consequence that Pauli once had "won the day" than a consequence
> of its existence.

There's something to be said for this, but it isn't quite true.
For example, if Pauli had said "I predict you will find a new
particle", then of course, *any* particle fits that description.
If one says "I predict you will find a massless, or nearly
massless, electrically neutral spin 1/2 particle which
couples into nuclear decay in such-and-such a way" then
it seems more reasonable to say that, when one finds such
a particle, it is indeed the particle which was predicted.
It should be pointed out that very early on, when neutrinos
were only the funny things which carry away the missing energy
and are never seen again, the neutrino theory in terms
of a spin-1/2 massless fermion allowed one to theoretically
account for the distribution of the energies of the electrons
produced in beta-decay, thus even the early theory of the
neutrino "had teeth" (or, shall we say, was falsifiable).
My nuclear physics is a bit rustly, but for example, if one
decided to try to account for the missing energy in beta-decay
by a spin-1/2 fermion *and* a new spin-0 boson, you will find
that you get the wrong distribution of electron energies.

Best wishes,
Mike


Bryan W. Reed

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Oct 6, 1999, 3:00:00 AM10/6/99
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In article <7tga23$gft$1...@pollux.ip-plus.net>, z@z <z...@z.lol.li> wrote:
>
>'Constructing Quarks', 'A Sociological History of Particle Physics',

Warning sirens went up on that one. Sounds like one of those BS post-
modern all-truth-is-just-a-social-construct sorts of things. I haven't
read the book, though . . . but the title is awfully suggestive.

>Andrew Pickering, 1984, page 68:
>
> "Beta decay, the emission of electrons and positrons from unstable
> nuclei, was one of the principal themes of radioactivity research in

> the early decades of the twentieth century. It was an especially
> puzzling phenomenon that electrons were emitted over a range of
> energies; their energy spectrum was contiuous, rather than discrete
> as expected for transitions ocurring in a quantised system.

What does having a quantised system have to do with it?

> Amongst
> the fathers of quantum mechanics, Bohr, Heisenberg and Pauli
> each proposed radical explanations for this observation - Bohr,
> that energy was not exactly conserved; Heisenberg, that space-time

> was not continuos - but it was Pauli's proposal that won the day."
>

>Can somebody explain me why it was assumed that electrons emitted
>during beta decay should not have a continuous energy spectrum?
>

It's a simple result of conserving energy and momentum. If you've got
one particle (say, a neutron) decaying into two, how many different ways
can the energy released by the reaction be split between the two particles?
The total energy released will always be the same. If you analyze the problem
in the center-of-momentum frame, the final momentum of the two particles
will be equal and opposite. That constrains the particle energies to
single values. Add in a neutrino, and you get more degrees of freedom,
and it's possible to have a range of electron energies.


>Can somebody explain me why the continuous energy spectrum of
>electrons emitted during beta decay cannot be explained in a simple
>way but needs a "radical explanation".
>

Therefore, either there's a third particle that nobody could see, or
energy-momentum conservation was violated, or somethings else quite
odd. When people figured out how to look for the third proposed
particle, they found it, which pretty much answered the question.

>Two other extracts from the same book (p.6, p.395):
>
> "First, scientists' understanding of any experiment is dependent
> upon theories of how the apparatus performs, and if these theories
> change then so will the data produced."
>

Yes and no. Clearly the understanding of what's going on in an experiment
is a function of what models you're using. But the theory doesn't change
the outcome of a given experimental measurement!

The author is confusing "data" and "interpretation." Either that or the
word "experiment" is being used ambiguously.

. . .


>But at least in such and similar cases, the conclusions depend much
>more on a theoretical framework and even on ad-hoc-hypotheses
>than on the experimental data.
>

Theory suggests experimental setups, experimental data suggest theoretical
models. They work together. If the loop isn't closed, you get religion
or philosophy or something along those lines, not science.


>Experiments on the one hand and interpretation of the experimental
>data based on the neutrino hypothesis on the other had evolved
>parallelly until finally (i.e. decades later) a repeatable
>experiment could be interpreted as a proof of neutrinos.
>

>So the later discovery of this particle seems to me rather a
>consequence that Pauli once had "won the day" than a consequence
>of its existence.
>

The experiments that led to the discovery were, indeed, motivated by
theoretical considerations.

The existence of the neutrino itself, of course, has nothing to do with
whether humans are aware of the possibility of its existence.

I think I missed what your point was?

If you're trying to claim that neutrinos are a social construct, it would
be appreciated if you'd make direct, relevant arguments rather than mess
about with peripheral issues that really have nothing to do with the basic
ontological question.

Have fun,

Bryan

David McKee

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Oct 6, 1999, 3:00:00 AM10/6/99
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z@z (z...@z.lol.li) wrote:
: 'Constructing Quarks', 'A Sociological History of Particle Physics',
: Andrew Pickering, 1984, page 68:

:
: "Beta decay, the emission of electrons and positrons from unstable
: nuclei, was one of the principal themes of radioactivity research in
: the early decades of the twentieth century. It was an especially
: puzzling phenomenon that electrons were emitted over a range of
: energies; their energy spectrum was contiuous, rather than discrete
: as expected for transitions ocurring in a quantised system. Amongst

: the fathers of quantum mechanics, Bohr, Heisenberg and Pauli
: each proposed radical explanations for this observation - Bohr,
: that energy was not exactly conserved; Heisenberg, that space-time
: was not continuos - but it was Pauli's proposal that won the day."
:
: Can somebody explain me why it was assumed that electrons emitted
: during beta decay should not have a continuous energy spectrum?

Taking a fairly naive point of view, we can argue that they (e^- and e^+)
are coming from systems which mostly just sit there i.e. they are bound.

And bound (quantum) systems have discrete energy spectra.

At this point it is clear that a two-body final state should exhibit a
discrete spectum. (From energy and momentum conservation.)

For three- (or in general {n | n > 2})- body reactions, however, there is a
locus of possible solutions: the so-called phase-space. The size and shape
of the phase-space is controled by the number of bodies, their relative
masses, and any additional consevation prinicples that may apply.

An undergraduate exercise: Find the energy levels availible to a particle
of mass m which obeys the Schrodinger equ. moving in the 1-dim. potential:

/ 0 |x| > r+t
V = < E_0 + h r < |x| <= r+t
\ E_0 0 < |x| <= r

if the particle is initally "in" the square well. i.e. energy E, such
that E_0 < E < E_0 + h.

--
-- David McKee
-- dmc...@jlab.org
-- (757) 269-7492 (Office)

john baez

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Oct 6, 1999, 3:00:00 AM10/6/99
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In article <7tgj40$8d3$1...@news01.cit.cornell.edu>,
Bryan W. Reed <bw...@cornell.edu> wrote:

>In article <7tga23$gft$1...@pollux.ip-plus.net>, z@z <z...@z.lol.li> wrote:

>>'Constructing Quarks', 'A Sociological History of Particle Physics',

>Warning sirens went up on that one. Sounds like one of those BS post-


>modern all-truth-is-just-a-social-construct sorts of things. I haven't
>read the book, though . . . but the title is awfully suggestive.

It's actually a very informative history of a certain hunk of particle
physics. To me, the question of whether truth is "just a social construct"
(whatever *that* means) is a lot less interesting than the story of how
physicists came to believe in quarks. One can have a lot of fun reading
this book as long as you don't get caught up in the former question (which
we've all heard way too much about already).


Maynard Handley

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Oct 6, 1999, 3:00:00 AM10/6/99
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In article <7tgj40$8d3$1...@news01.cit.cornell.edu>, bw...@cornell.edu wrote:

>In article <7tga23$gft$1...@pollux.ip-plus.net>, z@z <z...@z.lol.li> wrote:
>>
>>'Constructing Quarks', 'A Sociological History of Particle Physics',
>
>Warning sirens went up on that one. Sounds like one of those BS post-
>modern all-truth-is-just-a-social-construct sorts of things. I haven't
>read the book, though . . . but the title is awfully suggestive.

While I am sympathetic to your opinion (and I suspect I'd also have no
patience with this book), not every book by sociologists looking at
physics is a waste of time. I enjoyed _Beamtimes and Lifetimes_ and I
think that when these books cover some issues (like what gets funded vs
what doesn't) they have something useful to say.

Maynard

Jim Carr

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Oct 7, 1999, 3:00:00 AM10/7/99
to
In article <7tgj40$8d3$1...@news01.cit.cornell.edu>,

Bryan W. Reed <bw...@cornell.edu> wrote:
}
} In article <7tga23$gft$1...@pollux.ip-plus.net>, z@z <z...@z.lol.li> wrote:
} >'Constructing Quarks', 'A Sociological History of Particle Physics',
}
} Warning sirens went up on that one. Sounds like one of those BS post-
} modern all-truth-is-just-a-social-construct sorts of things. I haven't
} read the book, though . . . but the title is awfully suggestive.

In article <7tgpks$6...@charity.ucr.edu>

ba...@charity.ucr.edu (john baez) writes:
>
>It's actually a very informative history of a certain hunk of particle
>physics. To me, the question of whether truth is "just a social construct"
>(whatever *that* means) is a lot less interesting than the story of how
>physicists came to believe in quarks. One can have a lot of fun reading
>this book as long as you don't get caught up in the former question (which
>we've all heard way too much about already).

Does it place as much emphasis on experiment as "Second Creation" does?

I think one of the strengths of "Second Creation" is that it shows
clearly that physics is an experimental science.

--
James A. Carr <j...@scri.fsu.edu> | Commercial e-mail is _NOT_
http://www.scri.fsu.edu/~jac/ | desired to this or any address
Supercomputer Computations Res. Inst. | that resolves to my account
Florida State, Tallahassee FL 32306 | for any reason at any time.

Jim Carr

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Oct 7, 1999, 3:00:00 AM10/7/99
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... note followups to particle physics newsgroup ...


In article <7tga23$gft$1...@pollux.ip-plus.net>,
z@z <z...@z.lol.li> wrote:
}
} 'Constructing Quarks', 'A Sociological History of Particle Physics',

} Andrew Pickering, 1984, page 68:
}
} "Beta decay, the emission of electrons and positrons from unstable
} nuclei, was one of the principal themes of radioactivity research in
} the early decades of the twentieth century. It was an especially
} puzzling phenomenon that electrons were emitted over a range of
} energies; their energy spectrum was contiuous, rather than discrete
} as expected for transitions ocurring in a quantised system.

In article <7tgj40$8d3$1...@news01.cit.cornell.edu>

bw...@cornell.edu writes:
>
>What does having a quantised system have to do with it?

Relatively little, until you get into details (like nuclei
that beta decay to several different excited states as well
as to the ground state). Otherwise, that phrasing seems to
be a "construction" for saying that atoms, electrons, etc
have a specific mass so that a specific amount of energy
should be released in beta decay just as was known for alpha
decay and would soon be known for fission.

<... snip good explanation of decay kinematics ...>

BTW, despite Baez's remarks about this book, if the poster
had to ask those questions the book does a really poor job
of presenting the physics.

>Therefore, either there's a third particle that nobody could see, or
>energy-momentum conservation was violated, or somethings else quite
>odd. When people figured out how to look for the third proposed
>particle, they found it, which pretty much answered the question.

Actually, there was excellent evidence that the neutrino
hypothesis was correct before the direct detection in 1957.

Electron capture is a 2-body process, and in that case you
can measure the recoil momentum of the daughter nucleus and
see that it is consistent with emission of a massless particle
subsequent to the electron capture.

Jim Carr

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Oct 7, 1999, 3:00:00 AM10/7/99
to

... followups to sci.physics ...


In article <7tga23$gft$1...@pollux.ip-plus.net>,
z@z <z...@z.lol.li> wrote:
}

...


} Two other extracts from the same book (p.6, p.395):
}
} "First, scientists' understanding of any experiment is dependent
} upon theories of how the apparatus performs, and if these theories
} change then so will the data produced."

In article <7tgj40$8d3$1...@news01.cit.cornell.edu>

bw...@cornell.edu writes:
>
>Yes and no. Clearly the understanding of what's going on in an experiment
>is a function of what models you're using. But the theory doesn't change
>the outcome of a given experimental measurement!

If the book failed to point out that the experimental measurements
being made were in no way dependent on the neutrino hypothesis
being right or wrong, then it failed to do its job -- or had an
unusual idea of what experimental physics is all about.

The first experiment was just calorimetry, working on the same
principle as other calorimeter measurements made at that time
and since. You measure the temperature rise. That result was,
and is, consistent with the neutrino even though no one had
thought of the idea at the time. The later experiments, like the
electron capture one, also used only physics methods from the
previous century.

Indeed, since the experiments were designed to _disprove_ the
hypothesis as well as to confirm it, the functioning of the
equipment did not depend on what was being tested.

>. . .


} Experiments on the one hand and interpretation of the experimental
} data based on the neutrino hypothesis on the other had evolved
} parallelly until finally (i.e. decades later) a repeatable
} experiment could be interpreted as a proof of neutrinos.
}
} So the later discovery of this particle seems to me rather a
} consequence that Pauli once had "won the day" than a consequence
} of its existence.

Only if the author misled you into thinking that he had "won
the day" prior to some later experiments supporting his idea
(never published, by the way).

>The experiments that led to the discovery were, indeed, motivated by
>theoretical considerations.

True for the direct detection of the neutrino, although earlier
experiments that confirmed Pauli's idea were motivated by trying
to disprove it. The important physics/philosophy point is that
just because some theory motivates an experiment is no guarantee
that you will find what you are looking for. Carezani did an
experiment to try to show his theory of Autodynamics was correct
and ended up proving that it was wrong. There are many examples
of this in the history of physics, which the author should have
discussed to give a full view of it.

Jon Bell

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Oct 7, 1999, 3:00:00 AM10/7/99
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z@z <z...@z.lol.li> wrote:
>
>Can somebody explain me why it was assumed that electrons emitted
>during beta decay should not have a continuous energy spectrum?

The initial nucleus has a well-defined mass. The final nucleus has a
well-defined mass. The electron has a well-defined mass. Therefore, *if*
the electron is the only particle emitted in the decay, it should have a
well-defined fixed energy, by conservation of mass-energy.

>Can somebody explain me why the continuous energy spectrum of
>electrons emitted during beta decay cannot be explained in a simple
>way but needs a "radical explanation".

It was observed that the electrons usually have less than the energy that
would be expected of them if they were the only particle emitted in beta
decay. Therefore, *either* another particle (or some kind of radiation)
is being emitted *or* the law of conservation of mass-energy is seriously
wrong.

Calorimeter experiments, which would be expected to pick up the total
energy released in the decay, also did not pick up the total energy.
Therefore, if other particles or radiation are involved, they must be very
penetrating.

You have to remember that at the time of these crucial beta-decay
experiments, the only fundamental particles known were the proton, the
electron, and the photon; and the photon was arguably a special case.
Proposing *any* kind of new particle was a radical idea at the time, let
alone one that hardly interacted with matter.

--
Jon Bell <jtb...@presby.edu> Presbyterian College
Dept. of Physics and Computer Science Clinton, South Carolina USA
[ Information about newsgroups for beginners: ]
[ http://www.geocities.com/ResearchTriangle/Lab/6882/ ]

Gregory L. Hansen

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Oct 7, 1999, 3:00:00 AM10/7/99
to
In article <7tga23$gft$1...@pollux.ip-plus.net>, z@z <z...@z.lol.li> wrote:

>Can somebody explain me why it was assumed that electrons emitted
>during beta decay should not have a continuous energy spectrum?

A neutron has a certain mass that was known. A proton and an
electron also have certain masses that were known. But the proton and
electron together have less mass than the neutron. This mass deficit
becomes the kinetic energies of the proton and the electron when the
neutron decays through Einstein's relation E^2=m^2c^4+p^2c^2. The
electron goes one way and the proton recoils the other way, with relative
speeds depending on their relative masses. The mass deficit is always the
same, the relative masses are always the same, and momentum is conserved,
so the energies will always be the same after a decay.

Except they weren't. When you add a third particle, that third particle
also carries away energy. Momentum is also conserved with that third
particle. Two particles can anly recoil along a straight line, but with a
third particle, they can recoil in any direction along a plane -- you're
essentially adding another dimension that momentum must be conserved in.
And because the possible directions that the particles can take, relative
to each other, becomes continuous instead of single-valued, the energy
spectra become continuous instead of single-valued.

It actually has nothing at all to do with quantization.

>Two other extracts from the same book (p.6, p.395):
>
> "First, scientists' understanding of any experiment is dependent
> upon theories of how the apparatus performs, and if these theories
> change then so will the data produced."

...


>Experiments on the one hand and interpretation of the experimental
>data based on the neutrino hypothesis on the other had evolved
>parallelly until finally (i.e. decades later) a repeatable
>experiment could be interpreted as a proof of neutrinos.
>
>So the later discovery of this particle seems to me rather a
>consequence that Pauli once had "won the day" than a consequence
>of its existence.

Since science is an inductive practice, we can never say for sure that we
really know The Truth. But that doesn't mean a physical theory is
completely arbitrary. It must be internally consistent (no logical flaws
or contradictions) and externally consistent (agrees with experiment).

There's always an interplay between theory and experiment. But the theory
doesn't need to only fit a particular peice of equipment during a
particular experiment. It also needs to fit in with the entire remaining
body of theory and experiment. If you find an alternative neutrino
hypothesis that explains the results of some experiment, that hypothesis
is useless if it contradicts a large body of other theory, like
relativity, that has been so successfully tested and used in other
contexts. Beta decay could as easily have been explained by a breakdown
of conservation of energy and momentum, except that was never observed
anywhere else, and doesn't explain the power cycles at nuclear plants that
neutrino detectors can see. And I could go on with the problems of that
interpretation, but I don't think I have to.

It's not so hard to make up a special-purpose theory that explains a
single phenomenon. Fitting it into the context of all other relevant
knowledge and experience is harder, and can really limit your options.

--
No electrons were harmed in the posting of this message.

Steven B. Harris

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Oct 8, 1999, 3:00:00 AM10/8/99
to
In <Pine.GSO.3.95.991006...@esther.rad.tju.edu> "Dr.

Michael Albert" <alb...@esther.rad.tju.edu> writes:
>
>> 'Constructing Quarks', 'A Sociological History of Particle Physics',
>> Andrew Pickering, 1984, page 68:
>>
>> "Beta decay, the emission of electrons and positrons from unstable
>> nuclei, was one of the principal themes of radioactivity research
in
>[snip]
>> was not continuos - but it was Pauli's proposal that won the day."
>
>I have not actually read this book, but from everything which
>I've heard about it, it takes a very peculiar view of things.
>While it is good to remember that science takes place in
>the context of human societies, this book seems to lean
>to the belief that there is no difference between scientific
>and, say, shamanistic points of view. When it comes to
>such fundamental issues as this, in the end each person
>makes their own decission as to their personal beliefs, but
>I will still argue that our modern science and technology
>is "objectively real," as is evidenced by all of our
>modern toys (computers, telephones, etc). Which of these
>toys are truly beneficial to humans is a different question.
>While philosophers can wax at length about exactly what
>the phrase "objectively real" might mean, science is
>at least "as real as it gets."

Yes. The social constructivist critics of science are another group
who I want to take into the desert and heave a tremendous rock at their
heads. Suggesting first that the theory of what is about to happen if
they don't duck is just a matter of opinion, in which theirs is as
valid as mine. And that they might want to disagree with me as regards
"objective empiric reality" (silly thing) just to prove their point.

Also, I want a social constructivist critique of whether or not it
is dangerous not to obey traffic laws. I have a social theory that it
is-- not that you'll just get citations, but that running stoplights
will eventually get you killed or wounded. But this is just my theory,
no doubt determined by my society and social standing. It's a white
male dominated culture theory, which doesn't take into acount the many
disempowering views we have of other, alternate views of reality. So I
want to see some shamans with driver licences. We need to talk.

john baez

unread,
Oct 10, 1999, 3:00:00 AM10/10/99
to
In article <7th0u8$f0e$1...@news.fsu.edu>,

Jim Carr <j...@ibms48.scri.fsu.edu> wrote:
>In article <7tgj40$8d3$1...@news01.cit.cornell.edu>,
>Bryan W. Reed <bw...@cornell.edu> wrote:

>} In article <7tga23$gft$1...@pollux.ip-plus.net>, z@z <z...@z.lol.li> wrote:

>} >'Constructing Quarks', 'A Sociological History of Particle Physics',

>In article <7tgpks$6...@charity.ucr.edu>
>ba...@charity.ucr.edu (john baez) writes:

>>It's actually a very informative history of a certain hunk of particle
>>physics. To me, the question of whether truth is "just a social construct"
>>(whatever *that* means) is a lot less interesting than the story of how
>>physicists came to believe in quarks. One can have a lot of fun reading
>>this book as long as you don't get caught up in the former question (which
>>we've all heard way too much about already).

> Does it place as much emphasis on experiment as "Second Creation" does?
>
> I think one of the strengths of "Second Creation" is that it shows
> clearly that physics is an experimental science.

I haven't read or even heard of "Second Creation", so I can't answer
your question. (What is it about?) However, "Constructing Quarks"
places a lot of emphasis on both theory and experiment. For example, the
work on renormalizability for gauge theories by Veltman and 't Hooft
helped convince people that something like QCD could make sense, while the
measurement of the jump in R helped convince people that quarks really
exist. The interplay between theory and experiment is really fascinating
here.

john baez

unread,
Oct 10, 1999, 3:00:00 AM10/10/99
to
In article <7th1mg$fcb$1...@news.fsu.edu>,
Jim Carr <j...@ibms48.scri.fsu.edu> wrote:

> <... snip good explanation of decay kinematics ...>

> BTW, despite Baez's remarks about this book, if the poster
> had to ask those questions the book does a really poor job
> of presenting the physics.

The book is not a physics popularization - don't read it to
learn particle physics. It's a detailed historical study of
how people came to believe in the existence of quarks. To
really understand it, it's best if you already know a fair
amount of physics.

francis Rey

unread,
Oct 14, 1999, 3:00:00 AM10/14/99
to

Objet: Re: Neutrinos questioned
Date: Thu, 7 Oct 1999 05:13:43 GMT
De: jtb...@presby.edu (Jon Bell)
Société: Presbyterian College, Clinton, South Carolina USA
Forums: sci.physics.relativity,sci.physics.particle,sci.physics

z@z <z...@z.lol.li> wrote:
>
>Can somebody explain me why it was assumed that electrons emitted
>during beta decay should not have a continuous energy spectrum?

The initial nucleus has a well-defined mass. The final nucleus has a


well-defined mass. The electron has a well-defined mass. Therefore, *if*
the electron is the only particle emitted in the decay, it should have a
well-defined fixed energy, by conservation of mass-energy.

>Can somebody explain me why the continuous energy spectrum of
>electrons emitted during beta decay cannot be explained in a simple
>way but needs a "radical explanation".

It was observed that the electrons usually have less than the energy that
would be expected of them if they were the only particle emitted in beta
decay. Therefore, *either* another particle (or some kind of radiation)
is being emitted *or* the law of conservation of mass-energy is seriously
wrong.

------------
Francis Rey
Richard Feynman himself has written about antineutrinos ( The character of
physical
laws ) :
The antineutrino which appears absorbs the energy.
One could say that its only reason to be is to validate the energy
conservation
law.

Well seen. The neutrinos are only the consequency of a failing on energies
measurements.
Instead to suspect the measures and the balance of energies they prefered to
invent an
hypothetical particle never seen.
It exists in physics a stroller coefficient 2 never explained, as well in
classical
mechanics as in atomic physics.
Some physicists renounced publishing their works because that 2 factor between

calculated results and measures.

However true, valid measures, not from measures done with a calorimeter (!!!),
the most
approximative measures in the world.
----------------

Calorimeter experiments, which would be expected to pick up the total
energy released in the decay, also did not pick up the total energy.
Therefore, if other particles or radiation are involved, they must be very
penetrating.

You have to remember that at the time of these crucial beta-decay
experiments, the only fundamental particles known were the proton, the
electron, and the photon; and the photon was arguably a special case.
Proposing *any* kind of new particle was a radical idea at the time, let
alone one that hardly interacted with matter.

--
Jon Bell <jtb...@presby.edu> Presbyterian College
Dept. of Physics and Computer Science Clinton, South Carolina USA
[ Information about newsgroups for beginners: ]
[ http://www.geocities.com/ResearchTriangle/Lab/6882/ ]

--------------------
--
francis Rey

The fact much to learn don't teach intelligence
Heraclite of Ephesus.

franc...@wanadoo.fr
http://perso.wanadoo.fr/francis.rey/

Jon Bell

unread,
Oct 14, 1999, 3:00:00 AM10/14/99
to
[followups set to go to sci.physics.particle only]

francis Rey <franc...@wanadoo.fr> wrote:


>
>Jon Bell wrote:
>> z@z <z...@z.lol.li> wrote:
>>
>>>Can somebody explain me why the continuous energy spectrum of
>>>electrons emitted during beta decay cannot be explained in a simple
>>>way but needs a "radical explanation".
>>
>>It was observed that the electrons usually have less than the energy
>>that would be expected of them if they were the only particle emitted in
>>beta decay. Therefore, *either* another particle (or some kind of
>>radiation) is being emitted *or* the law of conservation of mass-energy
>>is seriously wrong.
>

>Richard Feynman himself has written about antineutrinos ( The character of
>physical laws ) :
>The antineutrino which appears absorbs the energy.
>One could say that its only reason to be is to validate the energy
>conservation law.

That was not the case even when Pauli originally proposed the neutrino.
There were also serious problems with conservation of angular momentum,
involving the "spins" of the nuclei and the emitted electron, in certain
beta decays. A neutrino neutrino with spin one-half solves these
problems.

Now we also know that the neutrino is necessary for conservation of
momentum in various reactions. The first experimental evidence for this
was in the 1940s, I think, in studying the tracks of the recoiling nuclei
from beta decay in nuclear emulsions.

And since the 1960s there have been many experiments at particle
accelerators involving beams of particles with energy and momentum that
are consistent with (almost!) zero mass, with properties that are *very*
different from photons, and which match excellently with the properties of
neutrinos that are given by the "Standard Model" of elementary particles.

˘¤ĄAlkatrazĄ¤˘

unread,
Oct 18, 1999, 3:00:00 AM10/18/99
to
Does anyone have any good suggestions of places to find information about
neutrinos for the beginner. I haven't long been reading up on
quantum/particle physics and my knowledge, although extensive-ish, is still
very limited compared to some of you. If anyone has any good ideas of, for
example, books to buy/rent.. please let me know
------------------------------------------------------------
˘¤ĄAlkatrazĄ¤˘
alka...@eqla.demon.co.uk
http://fly.to/alkatraz
http://alkatraz.da.ru

To auto-reply,
remove NO-AUTO-SPAMMING from address.
------------------------------------------------------------

z@z wrote in message <7tga23$gft$1...@pollux.ip-plus.net>...


>Jim Carr wrote on neutrinos (Re: Question about Gamma rays?):
>
>> One can create all sorts of strawmen, but the fact is that there
>> is such a "new particle", a fact that has been known for over 40
>> years except to a small group of people living in a fantasy world.
>> And, yes, there was both missing momentum and missing energy in
>> the reactions that were studied -- all of which was found once the
>> experiments reached the necessary sensitivity.
>

>'Constructing Quarks', 'A Sociological History of Particle Physics',

>Andrew Pickering, 1984, page 68:
>
> "Beta decay, the emission of electrons and positrons from unstable
> nuclei, was one of the principal themes of radioactivity research in

> the early decades of the twentieth century. It was an especially
> puzzling phenomenon that electrons were emitted over a range of
> energies; their energy spectrum was contiuous, rather than discrete

> as expected for transitions ocurring in a quantised system. Amongst
> the fathers of quantum mechanics, Bohr, Heisenberg and Pauli
> each proposed radical explanations for this observation - Bohr,
> that energy was not exactly conserved; Heisenberg, that space-time

> was not continuos - but it was Pauli's proposal that won the day."
>

>Can somebody explain me why it was assumed that electrons emitted
>during beta decay should not have a continuous energy spectrum?
>

>Can somebody explain me why the continuous energy spectrum of
>electrons emitted during beta decay cannot be explained in a simple
>way but needs a "radical explanation".
>

>Two other extracts from the same book (p.6, p.395):
>
> "First, scientists' understanding of any experiment is dependent
> upon theories of how the apparatus performs, and if these theories
> change then so will the data produced."
>

> "They had been monitoring 140 tons of iron for 131 days and had
> observed around 200 events. Almost all of these could be ascribed
> to the passage through their apparatus of muons, generated by
> neutrino interactions in the overlying rock, but the experimenters
> concluded that three events could not be so explained."
>

>The experiment of the 'existence' of neutrinos should be repeatable.
>Before one carries out the experiment, it should be possible to

>calculate the result (but there are so many types of neutrinos with


>the possibility of changing into other types, that I am not sure).

>The confirmation of this result by the experiment is considered a
>scientific conclusion of the existence of neutrinos.
>

>But at least in such and similar cases, the conclusions depend much
>more on a theoretical framework and even on ad-hoc-hypotheses
>than on the experimental data.
>

>Experiments on the one hand and interpretation of the experimental
>data based on the neutrino hypothesis on the other had evolved
>parallelly until finally (i.e. decades later) a repeatable
>experiment could be interpreted as a proof of neutrinos.
>
>So the later discovery of this particle seems to me rather a
>consequence that Pauli once had "won the day" than a consequence
>of its existence.
>
>

Jim Carr

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Oct 18, 1999, 3:00:00 AM10/18/99
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... reduced followups ...


In article <940207363.13212.0...@news.demon.co.uk>

"˘¤ĄAlkatrazĄ¤˘" <alka...@NO-AUTO-SPAMMING-eqla.demon.co.uk> writes:
>
>Does anyone have any good suggestions of places to find information about
>neutrinos for the beginner. I haven't long been reading up on
>quantum/particle physics and my knowledge, although extensive-ish, is still
>very limited compared to some of you. If anyone has any good ideas of, for
>example, books to buy/rent.. please let me know

I am a fan of the book "The Second Creation" by Crease and Mann for its
emphasis on experiment as well as theory in the development of particle
physics. It is written for a general audience with references to the
primary journal articles for deeper reading. The Reines experiment is
described in there, for example.

One free source of information is the collection of review articles
produced by the Particle Data Group (pdg.lbl.gov) which are available
for free in either PDF or PostScript form. They do assume you know

a fair amount of physics.

--

Jim Carr

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Oct 18, 1999, 3:00:00 AM10/18/99
to

... reduced followups ...


In article <7tga23$gft$1...@pollux.ip-plus.net>,
z@z <z...@z.lol.li> wrote:
}

} Can somebody explain me why it was assumed that electrons emitted
} during beta decay should not have a continuous energy spectrum?

In article <7ti55m$skp$1...@jetsam.uits.indiana.edu>

glha...@steel.ucs.indiana.edu (Gregory L. Hansen) writes:
>
>A neutron has a certain mass that was known. A proton and an
>electron also have certain masses that were known. But the proton and
>electron together have less mass than the neutron. This mass deficit
>becomes the kinetic energies of the proton and the electron when the
>neutron decays through Einstein's relation E^2=m^2c^4+p^2c^2. The
>electron goes one way and the proton recoils the other way, with relative
>speeds depending on their relative masses. The mass deficit is always the
>same, the relative masses are always the same, and momentum is conserved,
>so the energies will always be the same after a decay.
>

>Except they weren't. ...

Between the time this was first noted (for the sum of the energy
deposited in a calorimeter, not the spectra mentioned below) and
the direct detection of the neutrino, there were studies of another
form of beta decay where the recoil energy was consistent with a
two-body final state. In electron capture, a bound atomic electron
disappears and the daughter nucleus recoils against the neutrino,
which carries off most of the energy and half of the momentum.
Since the energy of the electron is known, this is a simple two-body
decay where the recoil energy of the daughter can be measured and
was found to be what the neutrino theory predicted.

>When you add a third particle, that third particle
>also carries away energy. Momentum is also conserved with that third
>particle. Two particles can anly recoil along a straight line, but with a
>third particle, they can recoil in any direction along a plane -- you're
>essentially adding another dimension that momentum must be conserved in.
>And because the possible directions that the particles can take, relative
>to each other, becomes continuous instead of single-valued, the energy
>spectra become continuous instead of single-valued.

In addition, the energy spectrum of a three-body decay can
be predicted, and measurement of beta spectra are what you
would expect for a three-body decay.

z@z

unread,
Oct 19, 1999, 3:00:00 AM10/19/99
to
Bryan W. Reed wrote:
| Wolfgang G. (z@z) wrote:

| > 'Constructing Quarks', 'A Sociological History of Particle Physics',

| > Andrew Pickering, 1984, page 68:
| >
| > "Beta decay, the emission of electrons and positrons from unstable
| > nuclei, was one of the principal themes of radioactivity research in
| > the early decades of the twentieth century. It was an especially
| > puzzling phenomenon that electrons were emitted over a range of
| > energies; their energy spectrum was contiuous, rather than discrete
| > as expected for transitions ocurring in a quantised system.
|

| What does having a quantised system have to do with it?

"The neutrino was originally proposed as a solution to a serious
problem observed in the radioactive decays of certain atoms. In
a process known as nuclear beta decay, one of the neutrons in
the decaying nucleus is transformed into a proton, accompanied by
the emission of an electron. The law of conservation of energy --
one of the most basic principles of physics -- indicates that all
the electrons produced in this way should carry the same energy,
determined solely by the mass difference between the neutron and
the proton (that mass would be converted into its energy
equivalent)."
http://www.sciam.com/askexpert/astronomy/astronomy16.html

This reasoning makes sense only if one conceives atomic nuclei
as quantised systems. If physicists had known what they know
today, then probably nobody would have taken seriously the
neutrino hypothesis for the continuous energy spectrum of the
emitted electrons. According to sound reasoning it is expected
that an electron emerging somewhere in the nucleus cannot
leave the nuclues without any interactions at all. It seems
logical that a neutron decay at the edge of the nucleus can
result in the maximal electron energy if the electron is
emitted away from the nucleus. Pauli's 'original assumption'
that neither the position nor the emission direction of the
emerging electron do matter, is not very reasonable.

| > Amongst the fathers of quantum mechanics, Bohr, Heisenberg and Pauli
| > each proposed radical explanations for this observation - Bohr,
| > that energy was not exactly conserved; Heisenberg, that space-time
| > was not continuos - but it was Pauli's proposal that won the day."
| >

| > Can somebody explain me why it was assumed that electrons emitted
| > during beta decay should not have a continuous energy spectrum?
|

| It's a simple result of conserving energy and momentum.

It's not that simple because also gamma radiation is involved
and only in theory one can easily measure energy and momentum
of all decay products of a single beta decay.

| > Two other extracts from the same book (p.6, p.395):
| >
| > "First, scientists' understanding of any experiment is dependent
| > upon theories of how the apparatus performs, and if these theories
| > change then so will the data produced."
|

| Yes and no. Clearly the understanding of what's going on in an experiment
| is a function of what models you're using. But the theory doesn't change
| the outcome of a given experimental measurement!
|

| The author is confusing "data" and "interpretation." Either that or the
| word "experiment" is being used ambiguously.

There are almost no data in theoretical physics without some form
of interpretation. Most elementary particles are inferred from
very complicated statistical interpretations of photomultiplier
data. Photomultipiers do not work perfectly but register only
a fraction of the incoming photons. So not even the number of
the 'actually' incoming photons is independent of the theory of
photomultipliers. And the way from concrete numbers of photons
to the conclusion of existence or inexistence of a particle such
as a neutrino is normally long and often obscure.

If neutrinos do not emerge in beta decay, then also the occurence
of the inverse beta-decay reaction is no evidence of neutrinos,
because conditions other than the assumed participation of
neutrinos must be relevant.

The fact that the Nobel Prize for the 'experimental confirmation'
of Neutrinos of 1956 was awarded only in 1995 could be further
evidence that the experiment itself has not unambiguously
suggested the existence of neutrinos.

I don't exclude the possibility that neutrinos exist, but until
now I haven't seen anything really convincing. On the contrary
the many problems (e.g. deficit of solar neutrinos) could suggest
that the whole neutrino concept is fundamentally flawed.


Wolfgang Gottfried G.


My previous post of this thread:
http://www.deja.com/=dnc/getdoc.xp?AN=533624184

Matthew Nobes

unread,
Oct 19, 1999, 3:00:00 AM10/19/99
to

Huh? Nothing in that quote refers to quantization at all. The need for a
third particle to explain the continous spectrum of emmited electron
energy follws from conservation of energy and momentum alone. It applies
equally well in a classical or quantum context.

> If physicists had known what they know
> today, then probably nobody would have taken seriously the
> neutrino hypothesis for the continuous energy spectrum of the
> emitted electrons. According to sound reasoning it is expected
> that an electron emerging somewhere in the nucleus cannot
> leave the nuclues without any interactions at all. It seems
> logical that a neutron decay at the edge of the nucleus can
> result in the maximal electron energy if the electron is
> emitted away from the nucleus. Pauli's 'original assumption'
> that neither the position nor the emission direction of the
> emerging electron do matter, is not very reasonable.

Sure it is. Consider a free neutron, you're still going to need a thrid
particle. Your orginal quote from Pickering is simpley incorrect. The
problem had nothing to do with quantization of energy, since the emmited
electrons were free, and therefore had continous spectra.

>
> | > Amongst the fathers of quantum mechanics, Bohr, Heisenberg and Pauli
> | > each proposed radical explanations for this observation - Bohr,
> | > that energy was not exactly conserved; Heisenberg, that space-time
> | > was not continuos - but it was Pauli's proposal that won the day."
> | >
> | > Can somebody explain me why it was assumed that electrons emitted
> | > during beta decay should not have a continuous energy spectrum?
> |
> | It's a simple result of conserving energy and momentum.
>
> It's not that simple because also gamma radiation is involved
> and only in theory one can easily measure energy and momentum
> of all decay products of a single beta decay.

Huh? n -> p+e+nu is the reaction. THere is no gamma radiation whatsoever.
What was observed was n-> p+e. If this were the correct reaction, simple
relativisitic kinematics requires that the electron and proton have fixed
energy. They didn't, therefore something was wrong.

>
> | > Two other extracts from the same book (p.6, p.395):
> | >
> | > "First, scientists' understanding of any experiment is dependent
> | > upon theories of how the apparatus performs, and if these theories
> | > change then so will the data produced."
> |
> | Yes and no. Clearly the understanding of what's going on in an experiment
> | is a function of what models you're using. But the theory doesn't change
> | the outcome of a given experimental measurement!
> |
> | The author is confusing "data" and "interpretation." Either that or the
> | word "experiment" is being used ambiguously.
>
> There are almost no data in theoretical physics without some form
> of interpretation. Most elementary particles are inferred from
> very complicated statistical interpretations of photomultiplier
> data. Photomultipiers do not work perfectly but register only
> a fraction of the incoming photons. So not even the number of
> the 'actually' incoming photons is independent of the theory of
> photomultipliers. And the way from concrete numbers of photons
> to the conclusion of existence or inexistence of a particle such
> as a neutrino is normally long and often obscure.

Not really. Many of the early experiments used very simple setups (like
cloud chambers). Furthermore, the predictions of the theory is for very
specific energies of photons. THat is what you are looking for. If there
was no particle you would presumably see a random distribution.

>
> If neutrinos do not emerge in beta decay, then also the occurence
> of the inverse beta-decay reaction is no evidence of neutrinos,
> because conditions other than the assumed participation of
> neutrinos must be relevant.

Fine. But what about the piles of evidence confirming the standard
electroweak theory? THe whole thing doesn't work if you do not have
neutrinos. ARe all those experiments wrong as well?

>
> The fact that the Nobel Prize for the 'experimental confirmation'
> of Neutrinos of 1956 was awarded only in 1995 could be further
> evidence that the experiment itself has not unambiguously
> suggested the existence of neutrinos.
>

So the fact that the Nobel prize for the 'theoretical confrimation' that
Yang-Mill's theories were renormalizable in 1970 was awarded in 1999 could
be further evidence that the theory itself has not unambigouusly suggested
the renormalzablitiy of the Yang-Mills models? This point could be made
with almost any Nobel prize. It takes decades for the Nobel committee to
recognize importent work.

> I don't exclude the possibility that neutrinos exist, but until
> now I haven't seen anything really convincing. On the contrary
> the many problems (e.g. deficit of solar neutrinos) could suggest
> that the whole neutrino concept is fundamentally flawed.

Oh please. Super-K, SNO, Homestake, LNSD, etc. are all just totally
wrong? If you haven't seen anything really convincing yet you'll never be
convinced (unless of course you have really looked).

-------------------------------------------------------------------------------
|Matthew Nobes
|c/o Physics Dept.
|Simon Fraser University
|8888 University Drive
|Burnaby, B.C.
|Canada
www.geocities.com/CollegePark/campus/1098 |


Frank Wappler

unread,
Oct 20, 1999, 3:00:00 AM10/20/99
to
Wolfgang G. (z@z) wrote:
> Bryan W. Reed wrote:
> > Wolfgang G. (z@z) wrote:

> > > 'Constructing Quarks', 'A Sociological History of Particle Physics',

> > > Andrew Pickering, 1984, (p.6 [or] p.395):

> > > "First, scientists' understanding of any experiment is dependent
> > > upon theories of how the apparatus performs, and if these theories
> > > change then so will the data produced."

> > The author is confusing "data" and "interpretation."

> > Either that or the word "experiment" is being used ambiguously.

This omits that usually first of all one derives "measurements",
by applying preselected measurement procedures (ideally:
reproducible measurement procedures) to the "data/observations/counts".

Having obtained a set of measurements, very many different (corroborated)
"interpretations/algorithms/theories" will summarize this set,
for instance as a function of trial number; while very many different other
(falsified) "interpretations/algorithms/theories" fail to summarize this set.

> There are almost no data in theoretical physics without some form
> of interpretation. Most elementary particles are inferred from
> very complicated statistical interpretations of photomultiplier data.

(... as well as of observations/data/counts of other detectors;
and not only by analyzing them statistically by themselves,
but also in correlation with coordinate relations of the
various detector elements with each other.)

Yes, those are preselected measurement procedures; usually they're being
proposed long before any data/observations/counts are collected, if ever.
Eventually, those procedures may be applied to data/observations/counts,
quite independent of any subsequent interpretation of the results.


> Photomultipliers do not work perfectly but register only a fraction
> of the incoming photons.

What do you mean by "incoming photon", if this photomultiplier
didn't observe/count its exchange at all?

> So not even the number of the 'actually' incoming photons is
> independent of the theory of photomultipliers.

By which procedure would _you_ derive the number or rate of
"actually incoming photons" from the data/observations/counts
of various photomultipliers, sources, etc.?


> I don't exclude the possibility that neutrinos exist,
> but until now I haven't seen anything really convincing.

Here's what I'd find convincing:

Count Eb, the number of charged leptons (such as electrons)
within a given boundary before a particular experiment;
Ea, the number of charged leptons within this boundary
after the experiment;
and E_in, the number of charged leptons which entered
into the boundary, during the experiment.

The number Ea - Eb - E_in _is called_

"count of antineutrinos (if the number is positive) or of neutrinos
(if the number is negative) which were produced during this experiment".


> On the contrary the many problems (e.g. deficit of solar neutrinos)
> could suggest that the whole neutrino concept is fundamentally flawed.

Would it not be instead a remarkable success of the neutrino concept
if it thereby allowed to _unambiguously characterize_
the region containing the sun and various detectors in the first place?


Regards, Frank W ~@) R


Tom Roberts

unread,
Oct 20, 1999, 3:00:00 AM10/20/99
to
"z@z" wrote:
> This reasoning makes sense only if one conceives atomic nuclei
> as quantised systems.

Two points:
1) They are OBSERVED to be quantized systems -- the mass of a given
element is always measured to be the same (for a specific isotope)
within tiny error bars.
2) The original incentive for the neutrino was KINEMATICAL -- The
presumed decay n -> p + e was observed to not satisfy energy and
momentum conservation. Adding an anitneutrino on the right makes
it obey the conservation laws.


> If physicists had known what they know
> today, then probably nobody would have taken seriously the
> neutrino hypothesis for the continuous energy spectrum of the
> emitted electrons.

Nonsense.

> According to sound reasoning it is expected
> that an electron emerging somewhere in the nucleus cannot
> leave the nuclues without any interactions at all.

So what? The interactions the electron has with the nucleus must
leave the nucleus in the state it is observed in after the emission.
That is still a definite isotope with a definite mass.


> It's not that simple because also gamma radiation is involved
> and only in theory one can easily measure energy and momentum
> of all decay products of a single beta decay.

There is no gamma ray emitted from the _DECAY_, but the final-state
nucleus can be created in an excited state and subsequently emit a
gamma. In the appropriate detector (e.g. a bubble chamber in a magnetic
field) one can indeed measure the momentum of all decay products
_except_ any neutrinos. Those neutrinos are absolutely required to
maintain energy and momentum conservation, and because the mass
required to balance the reaction is consistent with 0 this implies that
only a single unobserved particle was emitted. And conservation of
antulag momentum implies that the unobserved emitted particle must
have spin 1/2 -- _THAT_ is an unabmiguous signature of a Fermion.


> If neutrinos do not emerge in beta decay,

Except, of course, that they _are_ emitted. There is absolutely no
question about their being generated by pion and muon decays --
thousands of physicists have performed experiments using such
neutrinos as the _incident_ particles. There are half a dozen
neutrino _BEAMS_ in the world.

(Full disclosure: I have worked in the neutrino beam at
Fermilab, and have performed several neutrino experiments.)


> The fact that the Nobel Prize for the 'experimental confirmation'
> of Neutrinos of 1956 was awarded only in 1995 could be further
> evidence that the experiment itself has not unambiguously
> suggested the existence of neutrinos.

More nonsense. The Nobel committee is not active in current research,
and has a clear history of awarding prizes for work done decades
previously. This is reasonable, as they can only know if a given
result is a major contribution after such a time lag.


> I don't exclude the possibility that neutrinos exist, but until
> now I haven't seen anything really convincing.

You clearly have not looked. If neutrinos do not exist, then something
else does which has _precisely_ the properties of the neutrino. "A
rose by any other name...."


Tom Roberts tjro...@lucent.com

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