Ned Wright's TBBNH Page (C)

"g" == greywolf42 writes:

g Bjoern Feuerbacher wrote in
g message ...

Kamiokande only detects electron neutrinos.

Right - and therefore, as Wright and me correctly point out,
Kamiokande couldn't have rule out "cosmologically interesting"
masses for the other two neutrinos.

g And -- as you have admitted before -- there was no reason in 1991
g (either theoretical or experimental) to expect that mu and tau
g neutrinos were fundamentally more massive (or more 'interesting')
g than electron neutrinos.

Other than the fact that the mu and tau particles are both more
massive than the electron?


That's a lie. I gave you the formula with which one determines if a
neutrino mass is cosmologically interesting or not (neutrino
mass/92 eV/c^2). Using the formula, it turns out that 5eV/c^2 (...)
*is* a reasonable value.

g It is not a lie. You did not state why this equation that you
g pulled out of thin air gave you an 'interesting' mass. Nor did you
g indicate that this equation was derived or accepted prior to 1991.

As I recall the statement simply was that the neutrino mass would be
something like Omega/92 eV. It should be fairly obvious that this is
relevant, given the presence of Omega. As for indications that this
was known in 1991, I just posted something as a followup to George
Dishman describing the neutrino background. My reference was MTW's
_Gravitation_, which was published in the early '70s. The idea that
neutrinos might have cosmological implications did not appear in the
early '90s.

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Bjoern Feuerbacher wrote in message ...

I've digged up some references.

Thanks. Sorry my newsreader missed these. It sure would have saved
us both a lot of trouble.

First:
G.G.Raffelt, What have We Learned from SN 1987A?, Modern Physics Letters
A, vol.5, no.31, 20 Dec. 1990 p.2581-92.
(notice that this is a review article; what is told in it wasn't known
only at the end of 1990, but already earlier - e.g., a reference is
given to a paper by Loredo and Lamb from 1989).

References don't always share conclusions. This paper wouldn't have
been accepted for publication, if there weren't at least something
new.

This article gives the limit of the mass of the *electron* neutrino
obtained from the observation of the supernova (eq. 9):
m_{\nu_e} 23 eV (at 95% confidence level).

What neutrino pulsewidth did this paper use? (The paper is not in
NASA ADS)

I did find a different paper with the same date and author: "Core mass
at the helium flash from observations and a new bound on neutrino
electromagnetic properties" ApJ, Part 1, vol. 365, Dec. 20, 1990, p.
559-568. But nothing on SN1987a or neutrino mass.


Second:
E.W.Kolb, M.S.Turner, The early universe, Frontiers in Physics,
Addison-Wesley (1990). This is a well-known book on cosmology by two
famous cosmologists; it summarizes what was known on cosmology back then
and hence includes lots of things which were already long known at that
time. Equation (5.33) is the interesting one in that book:
\Omega_{\nu} h^2 = m_{\nu}/91.5 eV
(hey, the 92 eV which I remembered where quite accurate!).

Excellent.

I don't know exactly what value of h was available back then, but let's
use the (quite high and therefore favourable for you!) value of h = 0.8.

According to Peebles' "Principles of Cosmology," 1993, equation 3.18,
the values of h were between 0.5 and 0.85.

Then we get:
\Omega_{\nu} = m_{\nu}/58.56 eV.


Putting these two things together

Is there a reference where these two *were* put together, prior to
12/1990?

(which both were known *BEFORE* 1991,
when Lerner published his book!),

My apologies for the confusion on publication date (the copyright is
given as
1991). The month of the year did not matter, prior to your proffering
of a
December 1990 paper and a book published in 1990.

According to the preface of TBBNH, the first edition was published in
"late
1990," a "year and a half" before the completion of the preface
(written for a
different publisher) in "May, 1992." So the first paper was
undoubtedly
published AFTER TBBNH was printed.

we get:
\Omega_{\nu} 0.39.
Obviously, a value of 0.39 *IS* quite significant cosmologically!

And using Ned's value of 5 (calculated in 2000), we get a value of .39
(5/23) = .08.

Hence, contrary to Lerner's claims, the supernova observations did *not*
rule out a mass for the neutrino which would have been cosmologically
relevant. Lerner is wrong there, live with it.

And now we return to what Lerner actually claimed in TBBNH. Lerner
did not make any claims about neutrino mass that was 'cosmologically
interesting' or 'cosmologially relevant.'

And my apologies for allowing myself to get sucked into Ned Wright's
diversionary strawman definition of 'interesting mass.'

What Lerner actually *wrote* begins on p 157 of TBBNH. He is
discussing the genesis of the 'inflationary' Big Bang model -- and the
cosmologists' desire for a value of omega of 1.0. Lerner uses the
term "missing mass":

"... Cosmologists knew that an opmega of 1 would solve at least the
flatness problem and probably the problem of anisotropy. Yet all the
known matter added up to a few percent of that density -- there just
wasn't enough. If the Big Bang was to be saved, there had to be far
more than we can see, so cosmologists decided that most of the
universe was dark, or "missing. ..."

The specific statements about SN1987a in TBBNH are on p.160:

"... (P)article theorists postulated that neutrinos do have
mass, and some cosmologists decided that these massive neutrinos could
be
the missing mass."

"A supernova blew away this idea. Supernovas produce large quantities
of
neutrinos when they explode. In 1987, when a supernova occurred in the
Large Magellanic Cloud, a satellite galaxy of our own Milky Way,
scientists
were able to detect the neutrinos released, using the same arrays that
had
been patiently waiting for a decaying proton. The neutrinos all
arrived in
a single bunch, showing that they all travel at the speed of light and
have
either no mass or so little that they couldn't fill up the universe.


So, we see that Lerner was describing the "filling up" of the universe
to the desired 1.0 value of omega, from the observed value of between
..02 to .03. Thus, a value of even .39 is a factor of 3 too small to
"fill up the universe."
Thank you for providing calculational support for Lerner's statements
in TBBNH. The main problem was another of Ned's mischaracterization
of Lerner's statements.

(and please stop whining about the other report you quoted - the *only*
thing I wanted to discuss is if Lerner's claim, that the supernova
observations ruled out a cosmologically interesting electron mass, was
right!)

LOL! But that wasn't what Lerner claimed! You fell for Ned's strawman
rewording, just like I did.

But it's even funnier, because you fully believe that neutrino masses
are a factor of 10,000 times lower. Which is not cosmologically
significant, let alone capable of 'filling up' the universe to an
omega of 1.0. The essence of TBBNH (at least that section) is that
'heavy neutrinos' cannot solve the Big Bang's problems.


And again, please notice that this (and the other report you quoted)
only applies to the electron neutrino - *much* less was known about the
other neutrinos masses back then. IIRC, the mass bound for the mu
neutrino was something like 25 keV, and the mass bound for the tau
neutrino was somewhere in the MeV range!

Contrary to your claim, the other book (Lindley) was not limited to
electron neutrinos. See my post of Sept. 10, the content of which you
have snipped.

greywolf42
ubi dubium ibi libertas

Joseph Lazio wrote in message
...
"g" == greywolf42 writes:

g Bjoern Feuerbacher wrote in
g message ...

Kamiokande only detects electron neutrinos.

Right - and therefore, as Wright and me correctly point out,
Kamiokande couldn't have rule out "cosmologically interesting"
masses for the other two neutrinos.

g And -- as you have admitted before -- there was no reason in 1991
g (either theoretical or experimental) to expect that mu and tau
g neutrinos were fundamentally more massive (or more 'interesting')
g than electron neutrinos.

Other than the fact that the mu and tau particles are both more
massive than the electron?

Do electrons ever decay into mu or tau particles?

That's a lie. I gave you the formula with which one determines if a
neutrino mass is cosmologically interesting or not (neutrino
mass/92 eV/c^2). Using the formula, it turns out that 5eV/c^2 (...)
*is* a reasonable value.

g It is not a lie. You did not state why this equation that you
g pulled out of thin air gave you an 'interesting' mass. Nor did you
g indicate that this equation was derived or accepted prior to 1991.

As I recall the statement simply was that the neutrino mass would be
something like Omega/92 eV. It should be fairly obvious that this is
relevant, given the presence of Omega.

Yes, an equation of this sort is relevant. But it's not a reference --
which was the request.

As for indications that this
was known in 1991, I just posted something as a followup to George
Dishman describing the neutrino background. My reference was MTW's
_Gravitation_, which was published in the early '70s.

That post has nothing whatsoever about the date 1991.
http://groups.google.com/groups?selm...ms.patriot.net
(Please learn how to give a proper reference. Which includes page or
equation number.) Your total quote is:

"I'm looking at the discussion in MTW's _Gravitation_. They estimate that
neutrinos decoupled from matter at a time about 100 seconds or when the
scale factor was about 1E-9 of its current value. That would suggest a
redshift z ~ 1E9. "

Specifically, what page in MTW?

The idea that
neutrinos might have cosmological implications did not appear in the
early '90s.

True, but no one said that it did appear in the '90s. The idea that
neutrinos might make up all of the 'missing mass' ended in prior to 1990.
That was the point made by Eric Lerner in TBBNH, also made by David Lindley
in 1993, and verified by Bjoern in the parallel thread.

According to Lindley:
===================================
"There was a moment in the early 1980s when it seemed possible that this
dark matter had been identified. A few experiments around the world came up
with some evidence that the neutrino, in standard physics strictly a
massless particle, might actually have a small mass. The mass per neutrino
was tiny, but because there are as many neutrinos in the universe at large
as there are photons in the three-degree microwave background, even a tiny
mass could add up to a lot for cosmology. It was entirely conceivable that
there could be about ten times as much neutrino mass as normal mass, in
which case the overall density of the universe could reach the critical
value. ..." (omega = 1.0)

(see the intervening quote from my post on Sept. 10th)

"The original laboratory evidence that neutrinos might have a small but
cosmologically interesting mass has now more or less been discounted. But
the brief and glorious effort that went into the construction of neutrino
cosmologies was the opening of a Pandora's box. Particle physicists had
offered one candidate for the role of dark matter; it had been rejected, but
they had plenty more up their sleeves. Supersymmetry could provide all
manner of particles. The photino, for example, is likely to be more massive
than the neutrino, but much less numerous in the universe, so that its
overall contribution to the cosmic density could conceivably be about the
same. Because they are more massive, and therefore more slow-moving,
photinos are capable of being entrained in the gravity of individual
galaxies, thus constituting the required dardk matter, and like neutrinos
they can also maintain structures on large scales, because, like neutrinos,
they do not easily give up their energy to normal matter. If the
fast-moving neutrinos were a forem of 'hot' dark matter, then the
slower-mivoin photinos were merely 'warm.' They did a better job, but in
the end they, too, failed."

"What cosmologists decided they needed was something more sluggish yet --
something that could be called 'cold' dark matter. Cold dark matter would
be able to collapse into galaxy-sized units, but also, because it interacted
little with normal matter, could sustain structures on the scale of galactic
clusters without falling apart."

"Cold dark matter it was, then. But here was a historic moment in the
subject. Until this point, cosmologists had asked the particle physicists to
supply the dark matter, in the form of one hypothetical particle or another,
and had then done their best to make a workable cosmology from it. When the
effort failed, they had gone back to the particle phyuscists for a new kind
of dark matter, something a little more recherche. But after a few
go-rounds, the cosmologists had become frustrated. They decided that they
could tell, from what they knew about the disposition of galaxies in the
sky, what sort of dark matter had to be up there, and they went back to the
particle physicists, told them what was desired, and waited to see if the
particle physicists could find a way of providing it."

"They could, of course. There was a particle known as the axion, which had
been invented to account for some small details of quantum chromodynamics,
the theory governing the interactions of quarks and gluons. The axion could
have almost any mass you cared to give it, so it was convenient to give it
the kind of mass the cosmologists wanted. And it would be cold. With this
backing from the particle physicists, cold dark matter, based on axions,
became, in the late 1980s, the most popular cosmological medium. It seemed
capable of getting structure right on the small and large scales equally,
and had the right properties to constitue the dark matter in individual
galaxies. But the dold dark matter used by the cosmologists was something
of their own devising -- and the fact that it might be made of this particle
called the axion was secondary. If the axion fell into disfavor among
physicists, or if it could not continue to meet cosmological requirements as
the galaxy-formation models were increasingly refined, it could be set
aside, and the cosmologists would wait for the physicists to come up with
some other inventions. Cold dark matter is first and foremost a
cosmological idea, and something for particle physicists to explain if they
can."

Again, we see that 'massive neutrinos' as a solution to the 'missing mass'
had been abandoned by the mainstream, prior to 1990.
===================================


This narrative history is essentially the same as that provided in TBBNH (p.
157 et seq) -- except that Lerner focuses on observational contradiction
(SN1987a), while Lindley focused on theoretical failings:
===================================
"... The third version of the Big Bang was internally implausible and, in at
least one respect, its predictions about microwave smoothness clearly
contadicted observation. ..."

"At this point cosmologists appealed to their colleagues in particle
physics, who were probing the fine structure of matter. The cosmologists
knew that an omega of 1 would solve at least the flatness problem and
probably the problem of anisotropy. Yet all the known matter added up to a
few percent of that density -- there just wasn't enough. If the Big Bang
was to be saved, there had to be far more than we can see, so cosmologists
decided that most of the universe was dark, or missing.' Like a worried pet
owner searching for a lost dog, cosmologiests asked particle phyusicists if
they could help find a missing universe."

"One such theorist, Alan Guth, succeeded after a fashion. Guth knew that
all GUTs assume a hypothetical, omnipresent force field called the Higgs
field. In 1980 he realized that it could provide energy not just for a Big
Bang, but for a far faster expansion, an exponential explosion he dubbed the
'inflation.' ... "

"Inflation solved the flatness problem, because the universe blew up to such
a huge size, far bigger than the part we can observe, that it MUST appear
flat (omega equal to 1), just as the Earth appears flat because we see only
a minute part of it...."

"Guth's theory wasn't PERFECT, though. It did not say what the missing 99
percent of the univers is, but only gave theretical justification to the
cosmologists' desire for it. And the theory had, it turned out, internal
inconsistencies. But both these problems were of minor importance in light
of its major result -- the link between particle theory and cosmology had
been made."

"A period of enormous theoretical ferment now began. Every year, or even
twice a year, theorists from around the world would replace existing
inflationary theories with newer versions -- inflation was follwed in 1983
by New Inflation, and then by Newer Inflation. ...."

"... Some underlying difficulties were ignored -- for example, there wsn't a
shred of evidence that omega equals 1, in fact evidence suggested it is
around .02, as we've seen. so, despite the fact that the GUTs themselves
lacked any experimental confirmation, omega BECAME 1 because this was
predicted by all of the GUTs through Guth's inflationary models. One
hypothesis without any observational foundation was used to supprt otgher
such baseless speculations."

"But the GUTs did make ONE testable prediction, a dramatic one: they all
predicted tha protons decayed. ..."

"But nothing happened -- for days, weeks, months, years. Protons do not
decay. By 1987 it was clear that the GUTs were wrong. However, that didn't
stop the particle physicists or the cosmologists. They went back their
blackoards and proved that the lifetime of the proton stretched to 10^33
years, beyond the limits set by experiments, and everyone got back to his
work...."

"Cosmologists weren't perturbed, though, because particle theorists had
provided an entire zoo of particles to make up the missing mass. First came
heavy neutrinos. ... " "... In 1987, a supernova occurred ..., showing
that (neutrinos) ... have either no mass or so little that they couldn't
fill up the universe." (See beginning of this thread for full quote)

"So cosmologiests, except some diehards, turned to other particles, which,
being wholly hypothetical, could not be eliminated as missing-mass
candidates by inconvenient supernovas. Particle physicists supplied these
in large numbers, equipped with whimsical names -- axions, WIMPs, photinos,
and so on. None had ever been observed, but all came with good credentials,
having been predicted by someone's GUT."
===================================

Do you need more references?

greywolf42
ubi dubium ibi libertas

greywolf42 wrote:

Bjoern Feuerbacher wrote in message
...
greywolf42 wrote:

Bjoern Feuerbacher wrote in message

[snip]


We are discussing if 1991 it was known if neutrinos have an
"cosmologically interesting" mass. Not only electron neutrinos.
*All* neutrinos.

Kamiokande only detects electron neutrinos.

Right - and therefore, as Wright and me correctly point out,
Kamiokande
couldn't have rule out "cosmologically interesting" masses for
the other two neutrinos.

And -- as you have admitted before -- there was no reason in 1991
(either
theoretical or experimental) to expect that mu and tau neutrinos
were fundamentally more massive (or more 'interesting') than
electron neutrinos.

1) That's beside the point. The point is if the SN measurements were
able to rule out such masses or not - and they weren't.
2) There *was* reason to suspect that the mu and tau neutrinos are
heavier than the electro neutrino - because the belong to families in
which all of the particles have higher masses.


[snip]


That's a lie. I gave you the formula with which one determines
if a
neutrino mass is cosmologically interesting or not (neutrino
mass/92
eV/c^2). Using the formula, it turns out that 5eV/c^2 (the
number Wright used) *is* a reasonable value.

It is not a lie. You did not state why this equation that you
pulled out of thin air

I mentioned that this is the formula to calculate the contribution of
neutrinos to Omega. Looking into any textbook on cosmology would have
given you that equation, too. Right, I didn't provide a reference at
first - but "pulling it out of thin air" is nonsense.


gave you an 'interesting' mass.

Err, I explained to you that it gives a contribution to Omega of about
0.05 (using Wright's number). Don't you consider this to be an
interesting contribution???


Nor did you indicate that this
equation was derived or accepted prior to 1991.

I stated this several times.


[snip]


Well, yeah... if the 'appearance' is the result of an
experimental measurement. Can you say 'arbitrarily close
to?'

No experiment can ever measure "arbitrarily close to", so
this makes no sense at all.

Bingo! Claiming evidence of mass when all we have is upper
bounds is indeed senseless.

What on earth are you talking about??? No one claimed that in
1991, we
had evidence of mass; the only thing which was said is that
with the
numbers available in 1991 (for which I gave references!), a
cosmoligically interesting mass could not be ruled out -
contrary to Lerner's assertion.

You contradict the reference I gave (1993, Lindley).

Which
1) only refers to electron neutrinos (although he doesn't mention this
explicitly, but it's clear if one knows what experiments he is talking
about)
2) is from 1993 - weren't we talking about the knowledge of 1991?


And you continue to
refuse to provide references of your own.

Well in the meantime, apparently you discovered my references.


Hint: we know today that neutrinos *have* mass,

No, we see a discrepancy in theory.

Pardon??? What on earth are you talking about???

Neutrino oscillations are clear evidence for neutrino masses.
So where is "a discrepancy in theory"???

Neutrino 'oscillations'. They are postulated to explain a
discrepancy between theory and observation.

When you say "theory", do you mean the standard solar model? If yes,
then you are wrong - neutrino oscillations weren't postulated only
because of the observations of solar neutrinos which contradicted this
model.

And today, this discrepancy has disappeared: when measuring *all*
neutrinos (the SNO measurements), it turns out that the result agrees
well with the predictions of the solar model.


And we interpret this as 'evidence of mass.'

Do you have another explanation for neutrino oscillations which
fits all of the data?

Neutrino oscillations ARE a theoretical explanation. Not data.

O.k., then let's word it in another way:
Do you have another explanation, besides neutrino oscillations, for the
experimental facts that
1) Superkamiokande measured more atmospheric neutrinos from above than
from below, with a systematic dependence on zenith angle
and
2) the total neutrino flux from the sun matches nicely the predicted
electron neutrino flux from the standard solar model?
There are some more experiments which show similar things, but these are
the best known.



However, this is still irrelevant to knowledge in 1991.

I never claimed that it were relevant.

Then don't waste everyone's time with irrelevant things.

I only mentioned that according to current knowledge, neutrinos *have*
mass in order to refute Lerner's assertion that neutrinos can have no
mass, because they "appear to travel at the speed of light".


hence that they *don't* travel at the speed of light.

Too bad that's what experiments show.

The experiments show that they travel *approximately* at the
speed of
light. No experiment can ever show that they travel *exactly*
at the
speed of light. Hence the experiments which measure the
velocities of
neutrinos couldn't rule out a neutrino mass ever.

They are the speed of light to at least 13 decimal places.

And according to modern determinations of neutrino masses, they should
be at the speed of light to about 20 decimal places.


As good as many
of the best precisions in physics (and higher than that if you
consider the
inherent size of the supernova neutrino production burst).

Well, you are right, this measurement has a high precision -
nevertheless, it makes no sense to summarize its result as "neutrinos
travel *AT* the speed of light and therefore can't have a mass". And
that's exactly what Lerner did, and what I critize here (so I got drawn
away a bit from the original arguments about SN 1987A...)

[snip another request for references]


We've found a
discrepancy in our theory, so experiment must be in error.

What discrepancy are you talking about???

And where did I say that an experiment is in error? I only
pointed out that it wasn't *sensitive* enough!

Neutrino oscillations point to neutrino masses around 10^(-3)
eV/c^2;
that the supernova measurements weren't sensitive enough to
detect such a mass is a simple fact -

So the accepted neutrino masses are a factor of 10,000 too small
to be 'cosmologically interesting.'

Right. So what? Did I ever claim anythere that they are "cosmologically
interesting"? The point here was *ONLY* if the SN measurements were able
to judge this or not!!!


Why are you spending all that time arguing
about 'smaller than 23 eV' if you know the answer is 10,000 times
smaller?

BECAUSE WE ARE TALKING ABOUT THE KNOWLEDGE OF 1991!!! AS YOU YOURSELF
KEEP INSISTING!!!


[snip another request for references]


This wasn't the original issue. The original issue was "Were
the
supernova measurements sensitive enough to rule out a
cosmologically
interesting neutrino mass?", and the answer to this is no - see
my references.

No, the question was -- were neutrino masses too small to be 'cosmologically interesting.'

Ned and I (in your quoted sentences) do discuss the question above, not
the more general question below.


If you and Ned agree about this, then the whole thing is a
tempest in a teapot.

Well, Ned and I are arguing that Lerner's argument that the SN
measurements ruled out such a mass is bogus. If you consider a
discussion about this to be "a tempest in a teapot", then why did you
start it?


[snip another request for references]



They arrived in a 'bunch', (a period of 6 sec) after
travelling 160,000 light years.
And arrived minutes before the SN light pulse. So, they
were
travelling at around 0.999999999999875*c (according to
Ned).

Right. 0.999999999999875*c. Not c.

That is c to 13 decimal places. How many decimal places do
you want before you admit that it's 'c'?

If neutrinos have a mass of around 10^(-3) eV/c^2, as the
neutrino
oscillation measurements imply, and an energy of 10 MeV, the
travel at a
speed of v/c = sqrt(1 - 10(-10)^2), which is approx.
1 - 0.5 * 10^(-20). So, in order to "see" the neutrino mass in
experiments which measure their speed, you have to measure
their speed
with a sensitivity of 20 decimal places. Good luck.

In other words, it's not 'c' until we exceed even the claimed
precision of
the most precise measurements made in physics.

No. Still wrong. It is *never* c, because no experiment will ever be
able to *ever* measure the speed *exactly*. It can be "very, very, very
close to c", and you can derive from this "mass is smaller than x
eV/c^2" - but no experiment can ever tell you "neutrinos travel exactly
at the speed of light and therefore their mass is exactly zero".


But, since you admit that neutrino masses are not 'cosmologically
interesting', and since it was commonly accepted that neutrion
mass was not 'cosmologically interesting' in 1991,

Were is a reference for this claim? The only one you gave so far is from
1993, not 1991.


there is no point to your continued argument.....

Well, I think there is no point to *your* argument, so apparently we at
least agree on this one thing. ;-)

[snip more requests for references]



The measurements the article in Nature talk about are about
beta decays.
Surely you know that in beta decays, only electron neutrinos
appear?

This is the closest to a reference that you can come? An
'article in Nature'?

No, sorry. I didn't ment an article in nature, I meant your text from
Lindley's book (you mentioned that he is an editor and referee for
"Nature", and I confused this, sorry).

[snip]


Already done in another post to this thread on Friday and (big
surprise!) completely ignored by you.

That post doesn't show on my newsreader.
However, I did find it on Google.
http://groups.google.com/groups?selm...-heidelberg.de

I commented on your answer to this post in the meantime - I hope that
this post will show up on your newsreader!


The reference is to the well-known
book by Kolb and Turner "The early universe", which was
published in
1990 and includes lots of material which was known already long
before.

Why the need to try to 'extend' your arguments by implying it was
known "long before?"

I wanted to emphasize that this was established knowledge already in
1991, not some far out reaching hypotheses.


If it was known "long before," please provide a reference
from 'long before.'

In the book, references are given for that formula; it was derived first
in 1966 and further discussed in several later papers, in 1972.


Both references were published at the end of 1990. The first
paper (G.G.Raffelt) on 12/20/90.

And the result for the neutrino mass they give comes from a paper from
1989, which I unfortunately can't access here.


The second, "a well-known book on cosmology by
two famous cosmologists" may not have been 'well known' in 1990.

Thanks for showing that you have no clue of cosmology. Kolb and Turner
are "big names" in cosmology, and this book is considered to be the
"Bible" of cosmology in many places.


According to the preface, the first edition of TBBNH was
published in "late
1990," a year and a half before the completion of the preface
(written for a
different publisher) in "May, 1992." So the first paper was
undoubtedly published AFTER TBBNH was printed.

See above.


Apologies for the confusion on publication date (the copyright is
given as
1991). The month of the year did not matter, prior to your
proffering of a
December 1990 paper and a book published in 1990.

Well, my argument still stands.


{snip}

The formula for the contribution of massive neutrinos
to Omega does in no way at all depend on the assumption of the
existence
of dark matter. Only GR is used, plus some thermodynamics and a
little
Special Relativity (which must be used because the velocity of
the
neutrinos is so high). Try opening the book and looking at the
calculation if you don't believe me. It's in chapter 5, the
relevant formula I'm talking about is (5.33).

Well, I'll give the book a try -- right after my next trip to the
library.

Good luck, and have fun with it! It is a bit outdated partly, but
nevertheless it's still one of the best books on cosmology available! (I
hope you have the necessary mathematical skills? So far, you quoted only
from popular science sources...)


Until then, could you clarify the month of publication, in 1990?
Thanks.

Well, I think in light of the fact that the first reference uses results
from 1989, and the second reference a formula which was first published
in 1966, I think quibbling about months of 1990 is rather futile.


Bye,
Bjoern

greywolf42 wrote:

Joseph Lazio wrote in message
...
"g" == greywolf42 writes:

g Bjoern Feuerbacher wrote in
g message ...

Kamiokande only detects electron neutrinos.

Right - and therefore, as Wright and me correctly point out,
Kamiokande couldn't have rule out "cosmologically interesting"
masses for the other two neutrinos.

g And -- as you have admitted before -- there was no reason in 1991
g (either theoretical or experimental) to expect that mu and tau
g neutrinos were fundamentally more massive (or more 'interesting')
g than electron neutrinos.

Other than the fact that the mu and tau particles are both more
massive than the electron?

Do electrons ever decay into mu or tau particles?

1) Huh??? How should this be possible??? They are *heavier*!
2) Tau and mu particles, OTOH, *do* decay into electrons.
3) How is this relevant here?

[snip]


According to Lindley:
===================================
"There was a moment in the early 1980s when it seemed possible
that this
dark matter had been identified. A few experiments around the
world came up
with some evidence that the neutrino, in standard physics
strictly a
massless particle, might actually have a small mass.

And I already pointed out that the experiments which gave these results
only searched for masses of *electron* neutrinos.

[snip lots]


Again, we see that 'massive neutrinos' as a solution to the
'missing mass'
had been abandoned by the mainstream, prior to 1990.

Mr. Lindley in the beginning only talks about electron neutrinos, so it
makes no sense that in the end he concludes that *all* neutrinos can't
masses which "solve" the "missing mass" problem.


===================================

This narrative history is essentially the same as that provided
in TBBNH (p.
157 et seq) -- except that Lerner focuses on observational
contradiction (SN1987a),

And the point is still that the observation of the SN could *not* rule
out relevant neutrino masses.

[snipping again lots]



Bye,
Bjoern

greywolf42 wrote:

Bjoern Feuerbacher wrote in message ...

I've digged up some references.

Thanks. Sorry my newsreader missed these. It sure would have
saved us both a lot of trouble.

First:
G.G.Raffelt, What have We Learned from SN 1987A?, Modern
Physics Letters
A, vol.5, no.31, 20 Dec. 1990 p.2581-92.
(notice that this is a review article; what is told in it
wasn't known
only at the end of 1990, but already earlier - e.g., a
reference is
given to a paper by Loredo and Lamb from 1989).

References don't always share conclusions.

Err, this reference was given explicitly for the value of the neutrino
mass reported in this paper.


This paper wouldn't have
been accepted for publication, if there weren't at least
something new.

Right, probably there was something new; however, the bound for the
neutrino mass reported therein was known already before (the paper by
Loreda and Lamb, and several others).


This article gives the limit of the mass of the *electron*
neutrino
obtained from the observation of the supernova (eq. 9):
m_{\nu_e} 23 eV (at 95% confidence level).

What neutrino pulsewidth did this paper use? (The paper is not
in NASA ADS)

Try going to the nearest university library. The journal "Modern Physics
Letters" should be available there".

Unfortunately, as far as I can see, the neutrino pulse width
isn't given in this paper. There are very little actual calculations in
it; as I already mentioned, it's a review article - and therefore mainly
gives results. The reference given for the value of 23 eV/c^2 for the
bound on the electron neutrino mass is:
T.J.Loredo and D.Q.Lamb, Ann. N. Y. Acad. Sci. 571 (1989) 601.

Even more unfortunately, that journal isn't available at the university
library here...



I did find a different paper with the same date and author: "Core
mass
at the helium flash from observations and a new bound on neutrino
electromagnetic properties" ApJ, Part 1, vol. 365, Dec. 20, 1990,
p. 559-568. But nothing on SN1987a or neutrino mass.

So what? Do you want to pretend now that the paper I cited above doesn't
exist, or what?



Second:
E.W.Kolb, M.S.Turner, The early universe, Frontiers in Physics,
Addison-Wesley (1990). This is a well-known book on cosmology
by two
famous cosmologists; it summarizes what was known on cosmology
back then
and hence includes lots of things which were already long known
at that
time. Equation (5.33) is the interesting one in that book:
\Omega_{\nu} h^2 = m_{\nu}/91.5 eV
(hey, the 92 eV which I remembered where quite accurate!).

Excellent.

I don't know exactly what value of h was available back then,
but let's
use the (quite high and therefore favourable for you!) value of
h = 0.8.

According to Peebles' "Principles of Cosmology," 1993, equation
3.18, the values of h were between 0.5 and 0.85.

Well, then the value 0.8 *is* indeed rather high.

But just for fun, I'll do it again with 0.85:
\Omega_{\nu} = m_{\nu}/66.11 eV,
which, when inserting the bound mentioned above, gives
\Omega_{\nu} 0.35
- which is still a very significant number.


Then we get:
\Omega_{\nu} = m_{\nu}/58.56 eV.


Putting these two things together

Is there a reference where these two *were* put together, prior
to 12/1990?

I don't know, but this would be absolutely obvious to do! This *is* the
way to determine if the neutrino mass is cosmologically significant or
not - hence if Lerner claims that the SN observations showed that the
neutrinos don't have such a mass, then he *must* have used this formula.


(which both were known *BEFORE* 1991,
when Lerner published his book!),

My apologies for the confusion on publication date (the copyright
is given as 1991). The month of the year did not matter, prior to
your proffering of a
December 1990 paper and a book published in 1990.

According to the preface of TBBNH, the first edition was
published in "late
1990," a "year and a half" before the completion of the preface
(written for a
different publisher) in "May, 1992." So the first paper was
undoubtedly published AFTER TBBNH was printed.

Well, the paper of Loredo and Lamb mentioned above, from which the this
review article took the value of 23 eV, was published in 1989.



we get:
\Omega_{\nu} 0.39.
Obviously, a value of 0.39 *IS* quite significant
cosmologically!

And using Ned's value of 5 (calculated in 2000), we get a value
of .39 (5/23) = .08.

Which still would be significant.


Hence, contrary to Lerner's claims, the supernova observations
did *not*
rule out a mass for the neutrino which would have been
cosmologically
relevant. Lerner is wrong there, live with it.

And now we return to what Lerner actually claimed in TBBNH.
Lerner did not make any claims about neutrino mass that was
'cosmologically interesting' or 'cosmologially relevant.'

I repeat the quotes you gave from Lerner's book here (with slight
spelling corrections, and some added comments):

"Cosmologists weren't perturbed, though, because particle theorists had
provided an entire zoo of particles to make up the missing mass."

Lerner insinuates here that these particles were all made up only
because of the problem of missing mass, which is quite wrong. Lots of
these particles were theoretical predictions which weren't in the least
based on the fact that there was apparently missing mass in the
universe.

"First came heavy neutrinos."

I very much doubt that these came first. IIRC, they were one of several
parallel proposals.


"Neutrinos are real particles, observed in laboratory experiments, but
they are quite hard to detect because they interact so little with
matter. They appear to travel at the speed of light, so must have no
mass."

Jumping to conclusions. From "appear to travel at the speed of light"
does not follow "must have no mass" - only "must have at most a mass of
x eV/c^2", where x is a number which can be calculated from the
sensitivity of the velocity measurements.


"However, particle theorists postulated that neutrinos do have
mass,"

Well, that postulate wasn't a big deal. Yes, the Standard Model at that
time treated the neutrinos as massless - but there was no theoretical
reason at all why they really should be massless; the SM mainly treated
them as massless because it was already known that their masses must be
very low and hence are negligible for most effects.


"and some cosmologists decided that these massive neutrinos could be the
missing mass."

Right, some, not all. Others made other proposals. Sounds a bit
contradictory to "Cosmologists weren't perturbed, though, because
particle theorists had provided an entire zoo of particles to make up
the missing mass. First came heavy neutrinos.", IMO.


"A supernova blew away this idea."

Lerner is partly right: the supernova blew away the idea that the
*electron* neutrinos could provide *all* of the missing mass.
Nevertheless, he conveniently never mentions that the SN measurements
were not able to place constraints on the *other* neutrino masses - and
that the SN therefore did *not* blew away the idea that *all* of the
neutrinos could perhaps provide *all* of the missing mass.


"Supernovas produce large quantities of neutrinos when they explode. In
1987, when a supernova occurred in the
Large Magellanic Cloud, a satellite galaxy of our own Milky Way,
scientists were able to detect the neutrinos released, using the same
arrays that had been patiently waiting for a decaying proton. The
neutrinos all arrived in a single bunch, showing that they all travel at
the speed of light"

Again, jumping to conclusions.


"and have
either no mass or so little that they couldn't fill up the universe."

Well, the measurements showed that the *electron* neutrinos couldn't
"fill up" more than about 0.39 of the universe (very strange wording
here!). They didn't show anything about the other neutrinos. Lerner
conveniently doesn't mention this.


And my apologies for allowing myself to get sucked into Ned
Wright's
diversionary strawman definition of 'interesting mass.'

I think the greater problem here is that Lerner pretends that looking at
measurements of the mass of the electron neutrinos is enough to rule
*all* of the neutrinos out as being able to "fill up the universe".


What Lerner actually *wrote* begins on p 157 of TBBNH. He is
discussing the genesis of the 'inflationary' Big Bang model --
and the cosmologists' desire for a value of omega of 1.0.

Well, this value was measured, hence speaking of a "desire" makes little
sense.


Lerner uses the
term "missing mass":

"... Cosmologists knew that an opmega of 1 would solve at least
the flatness problem and probably the problem of anisotropy."

IIRC, this wasn't the reason to introduce the concept of "missing mass".
The reason was more that Omega was *measured* to be close to 1.0.

And what "problem of anisotropy" does he talk about here?


"Yet all the
known matter added up to a few percent of that density -- there
just wasn't enough. If the Big Bang was to be saved, there had
to be far
more than we can see, so cosmologists decided that most of the
universe was dark, or "missing. ..."

That's a strong misrepresentation of what actually happened. Already at
that time, it was known from 1) theoretical predictions and 2)
measurements of the rotation curves of galaxies that there indeed exists
"dark matter". It wasn't made up simply to "rescue" the BBT.


The specific statements about SN1987a in TBBNH are on p.160:

[snip - see above]



So, we see that Lerner was describing the "filling up" of the
universe to the desired 1.0 value of omega, from the observed
value of between
.02 to .03. Thus, a value of even .39 is a factor of 3 too small
to "fill up the universe."

Hint: there are three neutrino flavours. 3 * 0.39 = 1.17.


Thank you for providing calculational support for Lerner's
statements in TBBNH. The main problem was another of Ned's
mischaracterization of Lerner's statements.

You are right, Wright apparently misrepresented Lerner a bit here.
But what you won't ever admit, apparently, is that Lerner misrepresented
lots of things, too.


(and please stop whining about the other report you quoted -
the *only*
thing I wanted to discuss is if Lerner's claim, that the
supernova
observations ruled out a cosmologically interesting electron
mass, was right!)

LOL! But that wasn't what Lerner claimed!

Wouldn't you call a neutrino mass which would enable them to "fill up
the universe" "cosmologically interesting"?


You fell for Ned's strawman rewording, just like I did.

Well, the argument still stands - 3 * 0.39 = 1.17, so the SN
measurements did *not* show that the neutrinos weren't able to "fill up
the universe".


But it's even funnier, because you fully believe that neutrino
masses are a factor of 10,000 times lower.

A few years ago, when little data was available (only the LSND
measurements, which were very questionable), I believed that neutrinos
have no mass. Then came the Superkamiokande measurements, the SNO
measurements, and some others. This changed my opinion - now I don't
believe any more that neutrinos have no mass. I *know* that they have a
mass of about 10^(-3) eV/c^2. This has nothing to do with "belief" -
this is based on *experimental evidence*.


Which is not cosmologically significant, let alone capable of
'filling up' the universe to an omega of 1.0.

Right. So what? Weren't you the one who insisted to concentrate on the
knowledge of 1991? Moving the goalposts again?


The essence of TBBNH (at least that section) is that
'heavy neutrinos' cannot solve the Big Bang's problems.

I never claimed that they are able to solve any (perceived) problems in
the BBT. So what's the problem?



And again, please notice that this (and the other report you
quoted)
only applies to the electron neutrino - *much* less was known
about the
other neutrinos masses back then. IIRC, the mass bound for the
mu neutrino was something like 25 keV, and the mass bound for
the tau neutrino was somewhere in the MeV range!

Contrary to your claim, the other book (Lindley) was not limited
to electron neutrinos.

Wrong. It was. It doesn't say "electron neutrino" explicitly, right -
but it says the following things:

"There was a moment in the early 1980s when it seemed possible that this
dark matter had been identified. A few experiments around the world
came up with some evidence that the neutrino, in standard physics
strictly a massless particle, might actually have a small mass."

These "few experiments" he mentions here measured only the mass of the
electron neutrino - hence obviously everything that follows can refer
only to the electron neutrino, too.



See my post of Sept. 10, the content of
which you have snipped.

I explained why I snipped it - I didn't consider it to be of much
relevance to the question in discussion (if the SN measurements rule out
an "interesting" mass or not - or, if you prefer, if they rule out the
possibility of neutrinos "filling up the universe" or not). The SN
wasn't mentioned in the text, hence I didn't consider it to be relevant
to this question. What's so hard to understand here?


Bye,
Bjoern

Bjoern Feuerbacher wrote in message
...
greywolf42 wrote:

Joseph Lazio wrote in message
...
"g" == greywolf42 writes:

g Bjoern Feuerbacher wrote in
g message ...


I'm trying to tie up the various dangling threads with Bjoern. Most of the
details apply to the "references" post provided by Bjoern. Since that's the
most concrete of the three parallel posts in this thread. Almost everything
contained in these other two are repeats of arguments made therein. So,
please refer to my parallel post, there.......

greywolf42
ubi dubium ibi libertas

Bjoern Feuerbacher wrote in message
...
greywolf42 wrote:

Bjoern Feuerbacher wrote in message
...
greywolf42 wrote:

Bjoern Feuerbacher wrote in
message


I'm trying to tie up the various dangling threads with Bjoern. Most of the
details apply to the "references" post provided by Bjoern. Since that's the
most concrete of the three parallel posts in this thread. Almost everything
contained in these other two are repeats of arguments made therein. So,
please refer to my parallel post, there.......

The only non-duplicated subject in this thread deals with more modern
discussion of 'neutrino oscillations.' So I'll move those to a different
thread.

greywolf42
ubi dubium ibi libertas

Bjoern Feuerbacher wrote in message
...
greywolf42 wrote:

Bjoern Feuerbacher wrote in message
...


I thought I had hit 'save' instead of 'send', but an earlier draft of mine
went into my files as sent. But it hasn't shown up on the newsgroups. My
error, apparently. My apologies if this becomes a semi-duplicate.

I'm trying to tie up the various dangling threads with Bjoern. Most of the
details apply to the "references" post provided by Bjoern. Since that's the
most concrete of the three parallel posts in this thread. Almost everything
contained in the other two are repeats of arguments made herein.

{snip higher levels}

First:
G.G.Raffelt, What have We Learned from SN 1987A?, Modern
Physics Letters
A, vol.5, no.31, 20 Dec. 1990 p.2581-92.
(notice that this is a review article; what is told in it
wasn't known
only at the end of 1990, but already earlier - e.g., a
reference is
given to a paper by Loredo and Lamb from 1989).

References don't always share conclusions.

Err, this reference was given explicitly for the value of the neutrino
mass reported in this paper.

Then why didn't you say so? "A reference is given to a paper..." does not
tell me what the reference is used for.

This paper wouldn't have
been accepted for publication, if there weren't at least
something new.

Right, probably there was something new; however, the bound for the
neutrino mass reported therein was known already before (the paper by
Loreda and Lamb, and several others).

Again, your statement did not indicate this, your reference wasn't listed in
ADS, and I haven't gotten to the library to check it out. How was I to
know? (Try not to skip interim steps when you write.)

This article gives the limit of the mass of the *electron*
neutrino
obtained from the observation of the supernova (eq. 9):
m_{\nu_e} 23 eV (at 95% confidence level).

What neutrino pulsewidth did this paper use? (The paper is not
in NASA ADS)

Try going to the nearest university library. The journal "Modern Physics
Letters" should be available there".

I said I would, what's your problem?

Unfortunately, as far as I can see, the neutrino pulse width
isn't given in this paper.

There are very little actual calculations in
it; as I already mentioned, it's a review article - and therefore mainly
gives results. The reference given for the value of 23 eV/c^2 for the
bound on the electron neutrino mass is:
T.J.Loredo and D.Q.Lamb, Ann. N. Y. Acad. Sci. 571 (1989) 601.

Even more unfortunately, that journal isn't available at the university
library here...

Let me provide another contemporary reference. The standard text, "The
Stars: their structure and evolution," R.J. Tayler, 2nd ed, 1994, p 303.

"Although only about twenty neutrinos were detected, a considerable amount
of useful information was obtained. ... (T)his observation places an upper
limit to the mass of the electron neutrino. If a neutrino has a very small
mass its velocity is not quite equal to c and the velocity depends on the
energy of the neutrino. The spread of neutrino arrival times at Earth can
arise from three sources: spread of times of emission, differing travel
time from different points in the pre-supernova and variation in neutrino
energy. If the whole spread of travel times is attributed to neutrino mass,
which cannot be correct, an upper limit to the neutrino mass of order 15
eV/c^2 is obtained. ..."

First, here is yet another 'value' of the upper limit -- 15 eV. Obviously,
there was only one event, and there was only one set of data to be
analysed -- in 1987. If you pick and choose your analyses to find the
largest number, you can come up with an upper limit that barely makes up
'enough' neutrino mass to make up the 'missing mass.' So far in this
thread, we've seen contemporary references of 23 and 15 -- and Ned Wright's
estimate of 5 eV. All from the same data. And all marginal, at best.

Second you only get your "upper bound" by ignoring the rest of the
physics -- by assuming an instantaneous collapse to a mathematical point,
with neutrinos emitted only at a mathematical point. Which Tayler
explicitly notes "cannot be correct." This is why I asked about the
neutrino pulse width in your reference. You missed the significance of the
question. Which indicates that you never really thought about what was
contained in that 'upper bound' you were pushing.

I did find a different paper with the same date and author: "Core
mass
at the helium flash from observations and a new bound on neutrino
electromagnetic properties" ApJ, Part 1, vol. 365, Dec. 20, 1990,
p. 559-568. But nothing on SN1987a or neutrino mass.

So what? Do you want to pretend now that the paper I cited above doesn't
exist, or what?

No aspersions were being cast upon yourself. However, I have had bogus
references provided to me in this newsgroup before. I thought it possible
that you might have made an error when citing the reference (we all make
mistakes). Since the paper you cited doesn't show up in ADS, but there is
another paper with the same author and same date. The concurrent publishing
of two different papers by the same author on the same calendar date is
improbable -- especially when one is in ADS and the other isn't. Which is
not to say it didn't happen.

Second:
E.W.Kolb, M.S.Turner, The early universe, Frontiers in Physics,
Addison-Wesley (1990). This is a well-known book on cosmology
by two
famous cosmologists; it summarizes what was known on cosmology
back then
and hence includes lots of things which were already long known
at that
time. Equation (5.33) is the interesting one in that book:
\Omega_{\nu} h^2 = m_{\nu}/91.5 eV
(hey, the 92 eV which I remembered where quite accurate!).

Excellent.

I don't know exactly what value of h was available back then,
but let's
use the (quite high and therefore favourable for you!) value of
h = 0.8.

According to Peebles' "Principles of Cosmology," 1993, equation
3.18, the values of h were between 0.5 and 0.85.

Well, then the value 0.8 *is* indeed rather high.

It's not 'high' at all. It's within the 'expected' range.

But just for fun, I'll do it again with 0.85:
\Omega_{\nu} = m_{\nu}/66.11 eV,
which, when inserting the bound mentioned above, gives
\Omega_{\nu} 0.35
- which is still a very significant number.

A moot point, however, because Lerner never mentioned 'significant.'

Then we get:
\Omega_{\nu} = m_{\nu}/58.56 eV.


Putting these two things together

Is there a reference where these two *were* put together, prior
to 12/1990?

I don't know, but this would be absolutely obvious to do! This *is* the
way to determine if the neutrino mass is cosmologically significant or
not - hence if Lerner claims that the SN observations showed that the
neutrinos don't have such a mass, then he *must* have used this formula.

Lerner never discussed 'cosmological significance.' And we don't know what
formula he used. He may have had a different constant than you provided.
We don't know what value for neutrino mass that he used (or referenced). We
don't know what equation he used (or referenced). So there's no *must*
about it.

(which both were known *BEFORE* 1991,
when Lerner published his book!),

My apologies for the confusion on publication date (the copyright
is given as 1991). The month of the year did not matter, prior to
your proffering of a
December 1990 paper and a book published in 1990.

According to the preface of TBBNH, the first edition was
published in "late
1990," a "year and a half" before the completion of the preface
(written for a
different publisher) in "May, 1992." So the first paper was
undoubtedly published AFTER TBBNH was printed.

Well, the paper of Loredo and Lamb mentioned above, from which the this
review article took the value of 23 eV, was published in 1989.

Now a moot point. But I still would like to know the month in 1990 when the
Kolb book was published? Did it also come up in December (i.e. post-TBBNH)?

we get:
\Omega_{\nu} 0.39.
Obviously, a value of 0.39 *IS* quite significant
cosmologically!

And using Ned's value of 5 (calculated in 2000), we get a value
of .39 (5/23) = .08.

Which still would be significant.

Now a moot point.

Hence, contrary to Lerner's claims, the supernova observations
did *not*
rule out a mass for the neutrino which would have been
cosmologically
relevant. Lerner is wrong there, live with it.

And now we return to what Lerner actually claimed in TBBNH.
Lerner did not make any claims about neutrino mass that was
'cosmologically interesting' or 'cosmologially relevant.'

{You made an 'invisible' snip. Can I guess why?}

I repeat the quotes you gave from Lerner's book here (with slight
spelling corrections, and some added comments):

And I will bypass commenting on your individual comments until you are
through.

"Cosmologists weren't perturbed, though, because particle theorists had
provided an entire zoo of particles to make up the missing mass."

Lerner insinuates here that these particles were all made up only
because of the problem of missing mass, which is quite wrong. Lots of
these particles were theoretical predictions which weren't in the least
based on the fact that there was apparently missing mass in the
universe.

"First came heavy neutrinos."

I very much doubt that these came first. IIRC, they were one of several
parallel proposals.

"Neutrinos are real particles, observed in laboratory experiments, but
they are quite hard to detect because they interact so little with
matter. They appear to travel at the speed of light, so must have no
mass."

Jumping to conclusions. From "appear to travel at the speed of light"
does not follow "must have no mass" - only "must have at most a mass of
x eV/c^2", where x is a number which can be calculated from the
sensitivity of the velocity measurements.

"However, particle theorists postulated that neutrinos do have
mass,"

Well, that postulate wasn't a big deal. Yes, the Standard Model at that
time treated the neutrinos as massless - but there was no theoretical
reason at all why they really should be massless; the SM mainly treated
them as massless because it was already known that their masses must be
very low and hence are negligible for most effects.

"and some cosmologists decided that these massive neutrinos could be the
missing mass."

Right, some, not all. Others made other proposals. Sounds a bit
contradictory to "Cosmologists weren't perturbed, though, because
particle theorists had provided an entire zoo of particles to make up
the missing mass. First came heavy neutrinos.", IMO.

"A supernova blew away this idea."

Lerner is partly right: the supernova blew away the idea that the
*electron* neutrinos could provide *all* of the missing mass.
Nevertheless, he conveniently never mentions that the SN measurements
were not able to place constraints on the *other* neutrino masses - and
that the SN therefore did *not* blew away the idea that *all* of the
neutrinos could perhaps provide *all* of the missing mass.

"Supernovas produce large quantities of neutrinos when they explode. In
1987, when a supernova occurred in the
Large Magellanic Cloud, a satellite galaxy of our own Milky Way,
scientists were able to detect the neutrinos released, using the same
arrays that had been patiently waiting for a decaying proton. The
neutrinos all arrived in a single bunch, showing that they all travel at
the speed of light"

Again, jumping to conclusions.

"and have
either no mass or so little that they couldn't fill up the universe."

Well, the measurements showed that the *electron* neutrinos couldn't
"fill up" more than about 0.39 of the universe (very strange wording
here!). They didn't show anything about the other neutrinos. Lerner
conveniently doesn't mention this.


And my apologies for allowing myself to get sucked into Ned
Wright's diversionary strawman definition of 'interesting mass.'

I think the greater problem here is that Lerner pretends that looking at
measurements of the mass of the electron neutrinos is enough to rule
*all* of the neutrinos out as being able to "fill up the universe".

So, you prefer dishonesty to imprecision?

If Ned thought there was a problem with focusing on "electron neutrinos", he
could have said so. There then would have been no need to distort Lerner's
statement. So I conclude that your own, personal view about the possible
role of mu and tau neutrinos was not shared by Ned Wright. And that he knew
5 eV was insufficient to 'fill up' the universe to omega = 1.0. So he
distorted Lerner's claim, to make it attackable.

What Lerner actually *wrote* begins on p 157 of TBBNH. He is
discussing the genesis of the 'inflationary' Big Bang model --
and the cosmologists' desire for a value of omega of 1.0.

Well, this value was measured, hence speaking of a "desire" makes little
sense.

ROTFLMAO!! Omega = 1.0 has NEVER been measured!!!! That's what the whole
issue of "dark matter" is about!!!!

Look at the reference (Peebles) given by Ned Wright! Table 20.1.

Lerner uses the term "missing mass":

"... Cosmologists knew that an opmega of 1 would solve at least
the flatness problem and probably the problem of anisotropy."

IIRC, this wasn't the reason to introduce the concept of "missing mass".
The reason was more that Omega was *measured* to be close to 1.0.

LOL!!! Too rich. Read the reference. You just shot any faith I had in your
historical memory. You seem to remember numbers, but not where they came
from.

And what "problem of anisotropy" does he talk about here?

Read the book and find out.

"Yet all the
known matter added up to a few percent of that density -- there
just wasn't enough. If the Big Bang was to be saved, there had
to be far
more than we can see, so cosmologists decided that most of the
universe was dark, or "missing. ..."

That's a strong misrepresentation of what actually happened. Already at
that time, it was known from 1) theoretical predictions

Uh, bubby, that's what Lerner SAID. Theoretical predictions were the
problem. Because the "predicted matter" wasn't observed.

and 2)
measurements of the rotation curves of galaxies that there indeed exists
"dark matter". It wasn't made up simply to "rescue" the BBT.

But the theoretical ad-hoc *assumption* of 'galactic' dark matter only got
one to omega = 0.1. Which was insufficient for the BB. That is, it was
assumed -- it was not *known.*

The specific statements about SN1987a in TBBNH are on p.160:

[snip - see above]

So, we see that Lerner was describing the "filling up" of the
universe to the desired 1.0 value of omega, from the observed
value of between
.02 to .03. Thus, a value of even .39 is a factor of 3 too small
to "fill up the universe."

Hint: there are three neutrino flavours. 3 * 0.39 = 1.17.

According to Ned, it was only 3 * .08 = .24. According to Tayler, it was at
most 3 * .15 = .45 -- and that value was 'known to be too high" on it's
face. The paper *you* used (published after TBBNH) assumed an instantaneous
(i.e. unphysical) supernova.

Thank you for providing calculational support for Lerner's
statements in TBBNH. The main problem was another of Ned's
mischaracterization of Lerner's statements.

You are right, Wright apparently misrepresented Lerner a bit here.

A BIT????

Here????

Wright misrepresented damn near EVERY statement of Lerner's to which he
referred.

But what you won't ever admit, apparently, is that Lerner misrepresented
lots of things, too.

Name one. What you claim above, is that Lerner was insufficiently detailed.
That is not the same as misrepresenting an argument!

(and please stop whining about the other report you quoted -
the *only*
thing I wanted to discuss is if Lerner's claim, that the
supernova
observations ruled out a cosmologically interesting electron
mass, was right!)

LOL! But that wasn't what Lerner claimed!

Wouldn't you call a neutrino mass which would enable them to "fill up
the universe" "cosmologically interesting"?

Why would I bother making up a phrase that was not used? One only performs
such strawman maneuvers in order to avoid unpleasant truths. Or to be lazy.

You fell for Ned's strawman rewording, just like I did.

Well, the argument still stands - 3 * 0.39 = 1.17, so the SN
measurements did *not* show that the neutrinos weren't able to "fill up
the universe".

*Ned's* argument was simply .08 = .08. Using your (2003) logic, it would be
3 * .08 = .24. So *Ned's* argument still falls. What you do with
references published after TBBNH is your own problem.

But it's even funnier, because you fully believe that neutrino
masses are a factor of 10,000 times lower.

A few years ago, when little data was available (only the LSND
measurements, which were very questionable), I believed that neutrinos
have no mass. Then came the Superkamiokande measurements, the SNO
measurements, and some others. This changed my opinion - now I don't
believe any more that neutrinos have no mass. I *know* that they have a
mass of about 10^(-3) eV/c^2. This has nothing to do with "belief" -
this is based on *experimental evidence*.

OK, I'll reword to remove the word 'belief':

But it's even funnier, because you fully accept that neutrino masses are a
factor of 10,000 times lower.

Which is not cosmologically significant, let alone capable of
'filling up' the universe to an omega of 1.0.

Right. So what? Weren't you the one who insisted to concentrate on the
knowledge of 1991? Moving the goalposts again?

My point was to concentrate on the statements actually made in TBBNH (late
1990), and Ned Wright's unprofessional webpage attack on same (2000). You've
admitted that Ned misrepresented the statements in TBBNH -- by bringing in a
strawman 'argument by definition.' *You* -- in 2003, using a reference
published after TBBNH -- have been able to 'just barely fit' an upper bound
to declare "it can't be ruled out" -- even though you know the estimate was
fundamentally incorrect -- and even though you know that the 'real' value is
at least 10,000 times lower.

But the "truth" remains that the 'massive neutrino' solution for the Big
Bang *was* generally abandoned during the late 1980s. And Ned's
misrepresentation of Lerner's argument was NOT the argument you bring to his
defense.

The essence of TBBNH (at least that section) is that
'heavy neutrinos' cannot solve the Big Bang's problems.

I never claimed that they are able to solve any (perceived) problems in
the BBT. So what's the problem?

The whole point of the argument in TBBNH is that massive neutrinos were
postulated to comprise the 'missing mass' -- and failed 'round about 1987.
And Ned Wright and you are busting Lerner's chops for so stating. You want
to say -- well yes, Lerner was right about the abandonment of the theory --
but not JUST because of the reason he mentioned.

And again, please notice that this (and the other report you
quoted)
only applies to the electron neutrino - *much* less was known
about the
other neutrinos masses back then. IIRC, the mass bound for the
mu neutrino was something like 25 keV, and the mass bound for
the tau neutrino was somewhere in the MeV range!

Contrary to your claim, the other book (Lindley) was not limited
to electron neutrinos.

Wrong. It was. It doesn't say "electron neutrino" explicitly, right -
but it says the following things:

"There was a moment in the early 1980s when it seemed possible that this
dark matter had been identified. A few experiments around the world
came up with some evidence that the neutrino, in standard physics
strictly a massless particle, might actually have a small mass."

These "few experiments" he mentions here measured only the mass of the
electron neutrino - hence obviously everything that follows can refer
only to the electron neutrino, too.

Nope. See the *rest* of the quote (which you removed). About the
'theoretical' failings -- which AREN'T limited to electron neutrino
experiments.

See my post of Sept. 10, the content of
which you have snipped.

I explained why I snipped it - I didn't consider it to be of much
relevance to the question in discussion (if the SN measurements rule out
an "interesting" mass or not - or, if you prefer, if they rule out the
possibility of neutrinos "filling up the universe" or not). The SN
wasn't mentioned in the text, hence I didn't consider it to be relevant
to this question. What's so hard to understand here?

If anyone expresses the slightest doubt of the BB, you see nothing wrong
with distortions made to smear the heretic (i.e. Ned Wright smearing
Lerner)? And if anyone (i.e. me) dares to point out the arguments are based
on distortions, *you* go to extreme lengths to support the smear -- when you
already understand that the point you are pushing is wrong by at least a
factor of 10,000?

I must admit, that I'm not surpised. Only disappointed that such is the
norm here in a "sci." newsgroup.


Let's take a look at what you'd like Lerner to have 'more properly' stated
in TBBNH:

In 1987, a "supernova completely blew away the idea that electron neutrinos
could provide all of the missing mass." If you ignored the physical time it
takes to make a supernova, and ignored the size of the supernova, and
assumed all of the difference was in travel times, you could -- just
barely -- make up enough mass to fill up the universe. It was not
*absolutely* ruled out that mu and tau neutrinos might be significantly
'heavier' (there being no significant experimental evidence on either) and
make up the 'missing mass.' However, there were also serious theoretical
problems with the 'heavy neutrino' theory, and the theory was abandoned.
Even though it was not yet 100% disproved by experiment.

The above paragraph meets the arguments of both you and Ned. Yet the
essence of the information communicated is unchanged. Since it is now
'accepted' by you that neutrino masses are 10,000 times smaller than the
'upper bound' estimates that we knew "could not be correct" at the time.
Why the heck are you trying to bust Lerner's chops?

Hello? Heavy neutrinos filling the universe to omega = 1.0 WERE abandoned
around 1987. I'm sure SN1987a played some part in that. Yet both you and
Ned Wright fight on! As if 'heavy neutrinos' were still a valid and ongoing
effort in 1990. And Lerner's description of the abandoning of the theory
(which is a historical fact) was not SOLELY due to SN1987a, and it was not
absolutely, positively impossible that 'heavy neutrinos' existed.

greywolf42
ubi dubium ibi libertas

"g" == greywolf42 writes:
[regarding what was known from astronomical measurements regarding the
mass of the (electron) neutrino about 1990]

g First, here is yet another 'value' of the upper limit -- 15 eV.
g Obviously, there was only one event, and there was only one set of
g data to be analysed -- in 1987. If you pick and choose your
g analyses to find the largest number, you can come up with an upper
g limit that barely makes up 'enough' neutrino mass to make up the
g 'missing mass.' So far in this thread, we've seen contemporary
g references of 23 and 15 -- and Ned Wright's estimate of 5 eV. All
g from the same data. And all marginal, at best.

For other readers of the newsgroup, it might be worth pointing out two
facts. First, the Standard Model of particle physics (at the time)
expected that the mass of the electron neutrino (and the other two
neutrino species) would be 0 eV, so any value is significant (though
perhaps not cosmologically).

Second, one must understand that many measurements in astronomy are
not made to the 50th decimal point, as in some branches of
experimental astronomy. As an initial measurement (or upper bound) on
the electron neutrino mass 5 eV ~ 15 eV ~ 23 eV. These various
estimates are all within a factor of 4 of each other, not so bad for
an initial measurement given the uncertainties and the fact that we
don't control the supernova explosion.

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