greywolf42 wrote:
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.
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.
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.
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.
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.
Care to come up with other possibilities, instead of simply asserting
that there are others?
[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.
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.
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"???
And we interpret this as 'evidence of mass.'
Do you have another explanation for neutrino oscillations which fits all
of the data?
However, this is still irrelevant to knowledge in 1991.
I never claimed that it were relevant.
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.
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!
Where on earth is your problem???
The supernova observations only showed that the mass of the electron
neutrino must be smaller than 23eV/c^2. This obviously doesn't rule out
a neutrino mass!
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 - try reading the original papers! (see my
references)
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?'
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.
[snip a bit]
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.
I provided references and calculations. You ignored both so far.
Hence it's you who is simply repeating a false claim, hoping that it
will become true.
[snip]
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.
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.
No, I gave you the formula which demonstrates this. I gave you
references for the data and the formula. You ignored both so far. It's
*YOU* who is asserting something over and over.
Please provide a pre-1991
reference for significant contribution to omega at this level.
Already done. I gave two references (in another post on last friday)
which, taken together, demonstrate the data from SN1987A give only an
upper limit for the contribution of the electron neutrinos to Omega of
0.39. Obviously such a number *is* cosmologically interesting.
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.
See above. Can't you do the math for yourself? The formula is really
easy (see the other post). Just plug the data in, and you'll see that
Lerner's claim is wrong.
I provided a standard one that refutes your claim.
I explained why your reference isn't relevant here. You ignored,
misunderstood, misrepresented, whatever, this explanation.
I'll try again: this reference
1) talked about measurements from beta decay, which supposedly showed an
electron neutrino mass of 17keV. Such a mass would have had strong
cosmological implecations. This data was shown to be wrong later, and
therefore the author in Nature concluded that the neutrinos apparently
have no big cosmological impact. I explained in detail why this
conclusion is questionable.
2) talked only about electron neutrinos and didn't rule out a
cosmologically interesting mass for the other neutrinos.
Furthermore, for the 5th time, at least, these
measurements could only place limits on the electron neutrino
mass, noton the other two masses.
And your continued repeat of irrelevant observations changes
nothing.
Why on earth do you think this is irrelevant???
You
never did provide any backup for this claim. Why repeat it 5
times?
The measurements the article in Nature talk about are about beta decays.
Surely you know that in beta decays, only electron neutrinos appear?
Again, Wright's calculations above are much better;
Than what?
Than Lerner's unsupported assertions.
Lerner's assertions are not unsupported.
He doesn't provide any concrete numbers. I would call this
"unsupported".
Wright's 'argument by definition'
is not a 'calculation.'
What "argument by definition" are you talking about?
I explained in detail (remember the formula for the contribution to
Omega?) why a mass of 5eV/C62, which Lerner assumed, is a sensible value
to use in the calculation.
[snip repetitions]
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.
Already done in another post to this thread on Friday and (big
surprise!) completely ignored by you. 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.
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.'
Absolutely wrong. 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).
Which was the point, of course.
The point is that you don't understand cosmology. Thanks for
demonstrating this.
All you can do is dig up some papers and misunderstand or misrepresent
them in a way so that they supposedly contradict Wright's statements and
support Lerner.
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.
The TGR doesn't need dark matter for anything. The Big Bang theory
"needs" this dark matter (better wording: by fitting the various
parameters in the BBT to observations, one sees that there is dark
matter in the universe). Thanks for demonstrating that you don't
understand the difference between these two!
And, BTW, do you ignore the *other* observations (from rotation curves
of galaxies and the behaviour of galactic clusters) which *also* show
that there is indeed dark matter?
[snip more repetitions]
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.
What is mis-stated about the supernova measurements, exactly?
The references I provided (hint: I'm talking about the ones you ignored)
show clearly that the supernova measurements could *not* rule out a
cosmologically interesting neutrino mass, no matter what someone in
Nature said. Don't rely on what's stated in journal articles. Do the
calculations for yourself! It's not hard to do.
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.'
You claim that Wright misrepresents Lerner. I would call this a
"personal attack".
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.
Hint: he wrote these pages. Hence an attack on the pages *is* an attack
on him.
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.
Any evidence for this assertion?
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.
Any evidence that Lerner even tried to respond?
[snip lots]
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).
What on earth are you talking about??? What theoretical predictions???
And what do you mean by "sure they can"??? Do you mean that one *can*
explain why the top quark is so heavy? If yes, would you please give me
this explanation?
That simply is a 'hit' against the standard model.
What is a hit against the SM? That the top quark is so heavy??? Why on
earth do you think so???
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.
This makes no sense at all. If the masses weren't known to be small,
obviously no one could have rule out them as the source of missing mass!
This would have been the most natural choice!
Theory said zero. Exactly zero.
What theory would that be?
Yes, I know that the Standard Model at that time treated the neutrinos
as massless. But that was not based on real experimental evidence that
they are indeed massless - only on experimental evidence that their
masses, if they exist, are negligible for essentially all interesting
cases.
And there was no evidence otherwise.
The only evidence available back then were upper bounds on the mass.
Hence obviously no one could have ruled out a cosmologically interesting
mass for them.
[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.
You don't ever get the point, do you?
The point is that Lerner claimed that the SN observations ruled out a
"cosmologically interesting" mass for the neutrinos, and that this claim
is wrong, because it doesn't provide any bounds on the masses of the mu
and tau neutrinos! It is absolutely *irrelevant* for the truth of this
claim if there was experimental evidence for masses of the mu and tau
neutrino at that time or not!
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.'
That's a wider assertion than the one you originally presented.
Originally you presented Lerner's assertion that the SN measurements
ruled out a cosmologically interesting mass. It's *that* assertion I'm
discussing, not the wider one. Moving goalposts indeed!
This is what Wright and yourself have been asserting.
No, what I (and Wright, too, at least in the quotes you provided - the
ones I'm discussing here!) assert is that the SN measurements were not
able to rule out a cosmologically interesting mass.
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!"
Yes. So what? It was explicitly discussed if the SN measurements were
able to detect such a mass.
Lerner *did* focus on SN1987a.
Yes, and Wright and I do, too.
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.
Lindley, as you yourself admit, doesn't mention SN1987A, hence what
Lindley wrote is *absolutely irrelevant* for evaluating Lerner's
assertion that the SN measurements rule out a cosmologically interesting
neutrino mass.
That in 1993 (and 1991) neutrinos weren't massive enough to be
'cosmologically interesting.'
That isn't the original assertion. The original assertion was that the
SN measurements ruled out such a mass. *That* assertion I'm discussing.
Can't you stay on focus?
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.
Wrong. See my references. Both from 1990, and containing data which was
known already earlier.
[snip]
this applies only to *electron* neutrinos!!!
Not according to David Lindley.
Well, he uses "neutrino" as a shorthand for "electron neutrino", because
these are the best known and most studied ones. If you don't believe me,
try looking up what experiments Lindley talked about. Hint: you will
find out that they only measured electron neutrinos.
Plus, you have already admitted that there
was no reason in 1991 to expect a (more) massive tau or mu
neutrino.
Which is beside the point.
[snip repetitions]
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.
Wrong. Judging from what you quoted, Wright's point was that the SN
observations couldn't have ruled out a cosmologically interesting mass.
[snip more of missing the point]
I suppose I could go hunting for another reference that in 1991
neutrinos
(all types) were not considered to have 'interesting' mass,
Again: that's beside the point. The point is Lerner's assertion that the
SN data was able to rule out such a mass.
[snip more of the same]
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.
Err, the mu and tau neutrinos are not "tangents"! They are crucial!
I'll try again, slowly:
1) Lerner claimed that the SN measurements ruled out a cosmologically
interesting neutrino mass.
2) Only electron neutrinos were measured from the SN.
3) Therefore only bounds on the mass of the electron neutrino could be
found.
4) Therefore a cosmologically interesting mass for the mu and tau
neutrino could not be ruled out based on the SN data.
5) Therefore Lerner's claim that the SN data ruled out a cosmologically
interesting mass for the neutrinos is obviously wrong.
Did you get it this time? If not, then I really have to give up on such
a granite head.
{replacing another 'invisible' snip}
Err, I mark my snips.
[snip lots of repetitions]
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.
Well, what I am discussing here is Lerner's claim that the SN
measurements ruled out such a mass, and Wright's calculations which
showed that this claim is wrong. If you are discussing something
different, then that's your problem, not mine.
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!
Then why the hell did you completely ignore my post in which I gave
these references 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?'
Because these points are relevant?!?!?!?!
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!
Already provided, oh cowardly ignorer of references!
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.
It was known in 1991. See my references. Do the calculation.
Bye,
Bjoern