Bjoern Feuerbacher wrote in message
...
greywolf42 wrote:
Bjoern Feuerbacher wrote in message
...
greywolf42 wrote:
[snip]
Since Lerner did not identify what value he used for
'interesting mass,'
the claim that his math was wrong is spurious.
Well, it's rather clear (if one knows a bit about cosmology)
what an
"interesting mass" would be (several eV will do it). Hence the
fact that
Lerner doesn't give a specific value is rather irrelevant.
It wasn't "clear" at all, in 1991. See report below.
I read the report below and explained that it doesn't support your point
- it only talks about *electron* neutrinos.
Electron neutrinos are the masses we are discussing. Kamiokande only
detects electron neutrinos.
There is still no basis for claiming that Lerner's "math is
wrong." As Lerner gave no math.
As I explained, if one takes reasonable values (and I explained (*why*
the numbers are reasonable)
No, you did not. You merely repeated the claim.
and puts them in, one sees that Lerner was
wrong. Hence there are only two choices, IMO:
1) Lerner didn't do any math and made the whole thing up.
2) Lerner did some math and screwed it up.
Ned Wright and me are only generous and assume that it was (2), not (1).
Ah, the refuge of the true believer. The fallacy of the excluded middle,
combined with a straw man.
[snip]
They appear to travel at the speed of
light, so must have no mass.
This argument doesn't make much sense. They *appear* to travel
at the
speed of light, so *must* have no mass? What a great logic!
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.
Hint: we know today that neutrinos *have* mass,
No, we see a discrepancy in theory. And we interpret this as 'evidence
of mass.' However, this is still irrelevant to knowledge in 1991.
hence that they *don't* travel at the speed of light.
Too bad that's what experiments show.
Therefore, obviously, the experiments
which showed that they travel *approximately* at the speed of light
weren't sensitive enough - and every experimental physicist should have
known that even back then!
ROTFLMAO! Rewrite the histories and the experiments, boys! We've found a
discrepancy in our theory, so experiment must be in error.
Additionally, there are theories which predict not only the
"light"
neutrinos we know, but additional neutrinos which are much more
heavy. Try reading up on "see-saw" mechanism.
No. Please stick to the issue.
Err, the issue is if the experiments back then were able to rule out
heavy neutrinos or not. The "see-saw" mechanisms is another point that
the experiments could *not* have rule this out. Hence this *is* the
issue.
Which leads us right back to that original issue, 'how heavy is heavy?'
However, particle 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.
I have to agree with Ned Wright: the supernova did *not* blow
away this
idea. His argumentation, which you quote above, makes perfect
sense.
Today. Not in 1991.
Absolutely wrong. It was clear even in 1991 that a mass of several eV
would
1) give a substantial contribution to Omega and
2) could not be detected by the supernova measurements.
Additionally, it was clear even in 1991 that the supernova measurements
could give limits only on the electron neutrino mass, not on the masses
of the other neutrinos.
Ned Wright is right, and you are wrong. Live with it.
LOL! Not according David Lindley (editor of Nature), as late as 1993.
Merely repeating a claim never makes it true.
[snip]
How does Lerner get from "they all arrived in a single bunch"
to "they
all travel at the speed of light"? This argument makes no sense
at all!
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'?
So, again, where does Lerner get
"they all travel at the speed of light" from? The only thing you can
deduce from the supernova measurements is (taking Wright's numbers) that
"they all travel at 0.999999999999875*c". And this doesn't help Lerner's
case, because this still would give a significant contribution of the
neutrino mass to Omega.
You just keep asserting this, over and over. Please provide a pre-1991
reference for significant contribution to omega at this level.
Lerner shows here quite nicely that he either doesn't bother to do the
math, or that he did it, but screwed it up somewhere. The supernova
measurements simply weren't good enough to rule out at significant
neutrino mass.
Please provide a pre-1991 reference that states this. I provided a standard
one that refutes your claim.
Furthermore, for the 5th time, at least, these
measurements could only place limits on the electron neutrino mass, not
on the other two masses.
And your continued repeat of irrelevant observations changes nothing. You
never did provide any backup for this claim. Why repeat it 5 times?
Again, Wright's calculations above are much better;
Than what?
Than Lerner's unsupported assertions.
Lerner's assertions are not unsupported. Wright's 'argument by definition'
is not a 'calculation.'
note that Wright, in
contrast to Lerner, presents specific numbers! Lerner says only
"a
single bunch" - but doesn't tell his readers that this "bunch"
had a
lenght of about 10 seconds, and that this is *way* too much
time to rule out a neutrino mass...
The key word being 'cosmologically interesting.'
I explained what "cosmologically interesting" means - that it is clear
(and was clear even in 1991) that a mass of several eV *would* have been
interesting,
Please provide even a single reference available in 1991 that this was the
case. As late as 1993, several eV was *not* considered 'cosmologically
interesting' -- as indicated in the reference of Lindley as late as 1993.
and that the supernova measurements weren't able to rule
this out, according to Wright's calculation. How often do I need to
repeat this argument until you understand it?
Repeating irrelevant statements will never matter. Try finding a reference.
Post it.
That Ned Wright disagrees with Lerner about what
constitutes
'interesting mass' is not an "error" on the part of Lerner.
Yes, it is. One can calculate what an "interesting" mass would
be: IIRC,
the contribution of neutrinos to Omega is equal to the neutrino
mass,
divided by 92 eV/c^2.
Where did you get the value, above? Try providing a reference from 1991.
Hence a cosmologically "interesting"
neutrino mass
is obviously a few eV/c^2 - just the number Wright used above
in his calculation!
Marvellous! But that is theory-dependent.
Well, it depends on the Theory of General Relativity, right. So what?
Not 'just' GR. But 'GR plus dark matter.' Which was the point, of course.
And the theories keep changing
(no problem with that).
The TGR hasn't changed since it was discovered.
Sure it has. Now it needs 'dark matter' to match observations.
But you contradict the 'wisdom' of 1991 -- when
Lerner's book was written.
I would say that you don't know what the "wisdom" of 1991 really were.
So quit just 'saying' it, and provide a reference.
[snip]
Then again, so is Ned's bald assertion
that 5 eV neutrinos are 'cosmologically interesting'.
See above.
Thanks. Now please provide one using only 1991 theory.
That the contribution of neutrinos to Omega is given by their mass,
divided by 92 eV/c^2 was known long before 1991. It's a quite easy
calculation which uses only long established theories.
Then it should be simple to provide a reference. Why do you keep dodging?
{snip the rest}
Since Eric Lerner did not identify a value of what he considered
'interesting mass' and because Ned Wright did not provide any
reference for
why he thought 5eV was cosmologically 'interesting,' it was
difficult to directly address the issue.
How about asking Ned Wright first about this, instead of at
once attacking him?
I'm not 'attacking him.'
Yes, you are.
No. See my next sentence. Ned Wright is not his web page. Ned Wright's
web page is not Ned Wright.
I'm pointing out the 'elemenatry errors' in Ned
Wright's webpage.
If you had ask him first about what seemed to be errors to you, you
would have learned that they aren't really errors - only your lack of
knowledge.
They are fundamental errors. The web page contains numerous mis-stated
excerpts from TBBNH. Those are elementary errors.
I'm not 'attacking' anything. And I'm not providing
anything 'personal' against Ned. Only against his arguments.
I didn't mention "personal" anywhere.
LOL! You claimed -- and reiterated -- that *I* was *attacking* Ned Wright.
That *IS* a claim of a personal attack -- even if you don't use the word
'personal.' For 'Ned Wright' is a person -- not a corporation or a web
page. I am not attacking the person of Ned Wright. I am pointing out
elementary errors that exist on Ned Wright's webpage.
But, if you think this is an 'attack,' why didn't Ned Wright ask
Lerner about his book, instead of 'attacking the book?'
How do you know that Ned Wright didn't discuss with Lerner?
Because he refuses to allow anyone to see any theoretical responses from
Lerner. If Ned's web page had been honest, and if Ned had actually entered
into discussion with Lerner, then Lerner would have been allowed at least
one round of response.
However, I have run across a contemporaneous
reference about the degree of support available for
'interesting mass' as things existed in 1991.
The reference is the book "The End of Physics," by David
Lindley ("Nature"
editor and referee). Publication date 1993. On page 199 to
200, Lindley
discusses the evidence for 'interesting' mass for the
neutrino:
===========================================
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 a
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 univsere could reach the critical
value. As a form
of dark matter, massive neutrinos had some appeal. Neutrinos
are known to
exist, and giving a previously unsuspected mass to an
existing particle is
more palatable than inventing a wholly new particle -- the
hypothetical
photino, for example -- to act the part of the dark matter.
On top of that,
the mass suggested by laboratory experiments was about the
right value to be
cosmologically significant. There were reasons for taking
'neutrino
cosmology' seriously.
IIRC, these experiments measured only the mass of the
*electron*
neutrino (the text doesn't say explicitly, but the only
experiments I
know of from that time which gave a hint on massive neutrinos
were the
ones where the beta decay was studied, AFAIK). Hence Wright's
point that
an "interesting" mass for the my and tau neutrino wasn't ruled
out at
that time remains still valid, and Lerner is still wrong.
There was no reason to suspect that mu and tau neutrinos had
significantly more mass than the electron neutrino, in 1991.
The point is that there were no measurements available to rule such
higher masses out. And "there is no reason to suspect" makes little
sense: little is known about the reasons for the various masses of the
particles (for example, no one can explain why the top quark is so heavy
compared to all the other quarks),
Sure they can -- because it was what was found by experiment (far above the
'theoretical' predictions). That simply is a 'hit' against the standard
model.
so no one had the possibility to make
any educated guesses on the masses of the mu and tau neutrinos.
That doesn't mean that it was 'known' that mu and tau neutrinos could be the
source of missing mass. Theory said zero. Exactly zero. And there was no
evidence otherwise.
[snip rest of article]
No, let's leave it in -- since it explicitly contradicts your
statements (and Ned's).
The article claims that a "cosmologically interesting" mass for the
neutrino was ruled out, right - but I already explained that this
applies only to the mass of the electron neutrino, not to the other two.
And you admitted, just above, that at the time there was no theoretical or
experimental reason to expect the mu or tau neutrino to be massive -- or
more massive than the electron neutrino.
Additionally, this article has nothing to do with the supernova
measurements, which, according to Lerner, ruled out a "cosmologically
interesting" mass for the neutrinos. I thought we were discussing this
assertion of Lerner? You are moving the goalposts, IMO.
The assertion of Lerner is that neutrinos weren't massive enough to make up
the 'cosmologically interesting.' This is what Wright and yourself have
been asserting. Statements of yours such as "One can calculate what an
'interesting' mass would be: IIRC, the contribution of neutrinos to Omega is
equal to the neutrino mass, divided by 92 eV/c^2. Hence a cosmologically
'interesting' neutrino mass is obviously a few eV/c^2 - just the number
Wright used above in his calculation!"
Lerner *did* focus on SN1987a. And David Lindley (1993) went into
theoretical failings of 'heavy neutrinos' as well as 'laboratory
experiments' -- and didn't mention SN1987a -- but came to the same
conclusion. That in 1993 (and 1991) neutrinos weren't massive enough to be
'cosmologically interesting.' It doesn't matter what you or Ned use --
today -- to determine what you think is 'cosmologically interesting' --
today. Lerner's statements were not in error in 1991 -- based on
information available in 1991.
[snip]
{putting back part of the reference that makes your claims look silly}
==================================
"... The uncollapsibility of massive neutrinos was too
much of a good thing. The large structures that would form in a neutrino
universe would be too large and too loose to correspond to the observed
galactic clusters. And it is impossible for neutrinos to be the dark matter
in individual galaxies, because they are too fast-moving to be retained by
the gravity of single galaxies. Massive neutrinos ended by failing on two
counts; they created too much large-scale structure in the universe, and
they could not account for galactic dark matter."
==================================
The original laboratory evidence that neutrinos might have a
small but
cosmologically interesting mass has now more or less been
discounted. ...
There, I guess you think that this contradicts my claims, and Ned's,
right? For the 10th time: this applies only to *electron* neutrinos!!!
Not according to David Lindley. Plus, you have already admitted that there
was no reason in 1991 to expect a (more) massive tau or mu neutrino.
So again, we see that Ned's accusations are completely
unsupported.
No, we see that they are well supported, sorry.
LOL! Only if you snip and ignore the evidence.
I only snipped irrelevant things: descriptions of experiments which
1) only refer to electron neutrinos and hence can't rule out
cosmologically interesting masses for the other neutrinos and
2) don't have anything to do with the supernova measurements, which,
according to Lerner, disproved such an interesting mass.
The fact that Lerner focused on SN1987a and Lindley didn't mention SN1987a
does not mean it's not a valid observation. After all, the point is that
neutrinos (electron and otherwise) were considered to have 'uninteresting'
mass in 1991 and 1993.
I'm only saying that Lerner is wrong when he claims that the supernova
measurements ruled out a cosmologically interesting mass, and from what
you quoted, I'd say that Wright argues the same thing. So, bringing up
*other* experiments which supposedly ruled out such a mass is beside the
point - in other words, it's moving the goalposts.
Not in the least. Wright's point was that neutrinos had 'cosmologically
interesting' mass in 1991. Now, Ned is welcome to examine any data provided
by Lerner in TBBNH and produce a different opinion. He is not welcome to
produce an opinion contrary to 'accepted wisdom in 1991' and then chastise
Lerner for providing 'accepted wisdom in 1991.' Even if we think
differently today.
I suppose I could go hunting for another reference that in 1991 neutrinos
(all types) were not considered to have 'interesting' mass, based on SN1987a
(I recall there were some such). But that would be beating a dead horse.
Perhaps you'd care to come up with a reference that claimed neutrino mass
WAS 'interesting' -- and written in the 1988 to 1991 timeframe. That would
give us something to discuss to effect.
It appears that Lerner correctly described the common opinion
that existed in 1991 (at least until 1993) -- that neutrinos
did not contain cosmologically 'interesting' mass.
Even if that was the opinion back then (and I'm not sure about
this),
The only reason you are 'not sure' is that you snipped the
evidence.
For the 20th time: I explained that this evidence refers only to
*ELECTRON* neutrinos! Did you get it this time?
And you also admitted that there was no reason to expect any more from mu or
tau neutrinos in 1991. So you can quit bringing up irrelvancies, now.
And if you're 'not sure', why are you butting in?
Because there is one thing I'm sure about: that Lerner's claims about
the supernova measurements are wrong. *You* started bringing up other
points, IIRC.
Nope. Lerner's claims are correct. Both specifically and the basic point.
In 1991, neutrinos were considered to have 'uninteresting' mass.
This is the whole point of the thread!
The "whole point" I'm debating are Lerner's arguments about the
supernova measurements.
Then kindly do so, and quit the tangents into mu and tau neutrinos.
{replacing another 'invisible' snip}
==============================
So again, we see that Ned's accusations are completely
unsupported.
No, we see that they are well supported, sorry.
LOL! Only if you snip and ignore the evidence.
It appears that Lerner correctly described the common opinion
that existed in 1991 (at least until 1993) -- that neutrinos did
not contain cosmologically 'interesting' mass.
Even if that was the opinion back then (and I'm not sure about this),
The only reason you are 'not sure' is that you snipped the evidence. And
if
you're 'not sure', why are you butting in? This is the whole point of
the
thread!
==============================
Lerner's supernova argument is nevertheless still bogus.
It still is.
You have to talk to yourself, just to make a point?
[snip rest]
LOL! Another 'convenient' snip.
Well, I explained why I don't it to be relevant.
No, you simply snipped it.
Replacing the rest of the paragraph:
============================
Now, if Ned (in the year 2000) feels that neutrino mass
is 'interesting' again, that's a valid point of discussion
between
theories -- if he can come up with a reference. However, it is
NOT in any
manner an 'error' on the part of Eric Lerner or TBBNH.
I don't see why you have a problem that I snipped this. It has
absolutely nothing to do with my point.
Truly pathological. Read the next sentence.
============================
Of course you snipped it. It showed your attempt to divert from
the issue under discussion.
Pardon? The issue under discussion was Lerner's argument about the
supernova, wasn't it?
No. It was Wright's claim that Lerner's statement about 'uninteresting'
mass was known to be incorrect in 1991.
You (and Ned) are trying to claim an 'error' within the
1991 book TBBNH because of theories not proposed until after
1993!
For the 20th time: that neutrinos with a mass of several eV would give a
significant contribution to Omega was already known in 1991.
Then why the hell don't you provide a contemporary reference for God's sake!
Why all this mealymouthed bushwa about 'the mass was not proved to be zero'
or 'what about mu and tau neutrinos?'
That such a
small mass could not be detected by the supernova measurments was
already known in 1991, too.
Please provide a reference, oh cowardly 'invisible' snipper!
Might as
well chastise Newton for not discussing General Relativity.
What a nonsense.
I agree that faulting someone in 1991 for not knowing something that wasn't
accepted until after 1993 is nonsense.
greywolf42
ubi dubium ibi libertas