Ned Wright's TBBNH Page (C)

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.


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) 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).

[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.

Hint: we know today that neutrinos *have* mass, hence that they *don't*
travel at the speed of light. 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!



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.


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.


[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. 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.

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. Furthermore, for the 5th time, at least, these
measurements could only place limits on the electron neutrino mass, not
on the other two masses.


Again, Wright's calculations above are much better;

Than what?

Than Lerner's unsupported assertions.


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, 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?


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. 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?


And the theories keep changing
(no problem with that).

The TGR hasn't changed since it was discovered.


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.

[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.



{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.


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.


I'm not 'attacking' anything. And I'm not providing
anything 'personal' against Ned. Only against his arguments.

I didn't mention "personal" anywhere.


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?


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), so no one had the possibility to make
any educated guesses on the masses of the mu and tau neutrinos.




[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.

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.

[snip]


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!!!


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.

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.


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 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.


This is the whole point of the thread!

The "whole point" I'm debating are Lerner's arguments about the
supernova measurements.


Lerner's supernova argument is nevertheless still bogus.

It still is.


[snip rest]

LOL! Another 'convenient' snip.

Well, I explained why I don't it to be relevant.


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.


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

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?


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. That such a
small mass could not be detected by the supernova measurments was
already known in 1991, too.


Might as
well chastise Newton for not discussing General Relativity.

What a nonsense.


Bye,
Bjoern