Re: Time for a photon.

Dear Phil,

Read it through, scream, then come back and reply...

"Phil" <toob-headman@xxxxxxxxxxxxx> wrote in message
news:44365A64.3040800@xxxxxxxxxxxxxxxx
David,

Well, I do appreciate your responses, even if it
sometimes LOOKS to me like you are not reading
what I say. For example, how many times do I have to say that I
do NOT believe -- and I have
said this in these posts from the beginning -- that
time stops for massless particles?

OK. I disagree with where you will go next, but OK.

....
So, hopefully, that point of false disagreement will
end.

Let's get to the interesting stuff! First, does the
ability of neutrinos to transform mean that they
have mass? Google nova neutrino rest mass

http://science.slashdot.org/article.pl?sid=06/04/01/227223&from=rss

States that:
....
Soudan, US. The set up established that fewer
particles were being detected at the Soudan site
than had been sent from Fermilab, which confirmed that some
neutrinos changed their
flavor on the way - an effect called neutrino flavor
oscillation, which requires them to have mass."

Excellent research. Thank you.

And from the following, much the same thing

http://www.fnal.gov/pub/presspass/press_releases/minos_3-30-06.html

Now, although they state categorically that
neutrinos MUST have mass because "neutrino
oscillation" (the correct term, not my "neutrino transform")
would otherwise not be possible,
but I have not yet found their reasoning as to
why.

It is in the links that I have provided, and it is periodically
discussed here as well (from time-to-time).

....
any student of the history of science, then you know
better. For one thing -- and this is a very suspicious
indication, not a proof -- why else would they think
that the ability to oscillate means that neutrinos MUST have
rest mass?

http://groups.google.com/group/sci.physics.relativity/msg/8aee1c69daedd0db
.... it is a requirement of the underlying theory. The "flavor
change" is just a "symptom".

....
At the second website they said:

....
disappearance and hence neutrino mass. The deficit as
a function of energy is consistent with the hypothesis
of neutrino oscilations and yields a value of delta m2,
the square of the mass difference between two different
types of neutrinos, equal to 0.0031 eV2 +/- 0.0006 eV2
(statistical uncertainty) +/- 0.0001 eV2 (systematic
uncertainty)."

A really sloppy presentation, they start of saying "energy", then
switch to "mass", then express the quantity in energy units...
what's a mother to do?

Here I'm a bit confused, perhaps you can help. The term
"eV2" is unfamiliar to me. It appears to mean "the square
of the mass difference between two different types of
neutrinos," their words, obviously, which I THINK means
that the difference in mass is sqrt(0.0031 eV2) = 0.056 eV?
Plus or minus the error, of course.

That is what it appears to say, yes. And they wave a little
magic wand and say (essentially) that they don't know where the
energy comes from or goes to.

The squared term like comes from the correct energy equation:
E^2 = (pc)^2 + (mc^2)^2
.... where the cleverly "massage" the c into some sort of
conversion constant yielding electron volts (eV).

Okay, some trimming:

[snip]

Let me ask you... does it matter? Current theory
requires the neutrino to have mass. Current
observation is that it has mass.

Actually, I believe that

Theory requires that it have mass. I have provided links. I
can't make you read them.

no one has "measured" the rest mass of a neutrino. They have
deduced from various
observations that it must have rest mass,

.... on theoretical grounds ...

and that the rest mass must be (1) below a
certain number,

.... on theoretical grounds ...

as the result of certain experiments, and
(2) that there is a difference in rest mass
between two types, per the article above.

And the entire family is required, by theory, to have a total
mass greater than zero and less than some small-but-finite
number.

In other words, it is current deduction, not direct
observation,
that indicates rest mass.

Science is deduction. We can't put them on scales, and if we
could, we'd have to deduce they didn;t have some hitherto unknown
effect on the mechanism of the scale.

A subtle, but significant, distinction, since the
latter rests on assumptions that may be either
false or not sufficiently inclusive.

Model, predict, experimentally verify/falsify, repeat. That is
all we have.

I don't understand what this has to do with neutrinos
changing, or the implications, if any, for the question
of whether they have rest mass.

I was attempting to locate massless particles with
any observed/predicted halflives. You seem to feel
that massless particles do not experience time.

See paragraph one on my repeatedly stated opinion
that we CANNOT assume that "massless particles
do not experience time."

I want you to see the subtle shift you have made...
... I do NOT believe ... that
time stops for massless particles?

You have changed from massless particles DO experience time.

[snip]

No quantum object ever ages. Only a population
of such objects do. So what quantum objects
must do is "change" in some way, and the
population accumulates this into "aging". I
welcome any/all more correct interpretations.

Yes, yes, that's why I put "aging" in quotes, so
that it would hopefully be clear that I was referring
to internal changes in the object, rather than some
deterioration.

Is "momentum" internal to the object? Is
"polarization" internal to the object?

I would say no, meaning that the fact that these
can be changed tells us nothing about the time-rate
of the object in question, but I suspect this all
relates to what appears to be your mistaken belief --
perhaps my fault for writing badly -- that I think
"massless particles do not experience time."

Phil, buddy...
Quantum mechanics "says" no quantum objects experience time. All
processes are fully reversible.
Photons are quantum objects.

Relativity "says" the question of time for a photon is
meaningless.

So what theory do you want to put forward that says they are both
wrong? I'm not trying to be argumentative...

....
I'm not sure I see your point. The LT definitely refers
to objects with rest mass, but not, as far as I know,
to objects without rest mass (to conclude that
since the time-rate of rest mass objects drops to
zero, THEREFORE anything moving at c must have
a time-rate of zero, is another example of what I
mean by "shift-error").

Forgive me, but I thought you said:

[Phil, three replies before]
I know of no theory that ACTUALLY predicts this,
but it seems to be a commonly held ASSumption
that, of course, this is one of relativity's predictions.

... it appears that whoever said that is expecting
all who have made this "ASSumption" to have
made your acknowledged "shift-error"...

Um, maybe? It would UNQUESTIONABLY be a shift
error to ASSUME that what applies to particles with rest
mass, AUTOMATICALLY applies to massless particles,

Agreed. Is moot anyway.

....
If it was a widely held
belief among physicists that "neutrino
transformation" did NOT at least indicate rest
mass, the odds of NOVA claiming otherwise
would be extremely low.

Why do you say this? First of all, you have to
be 100% sure that what you remember *now*
is what they said... in full context.

.... and fully supported by your link ...

As it turns out, NOVA DID SAY that oscillation
= rest mass, and the only remaining question for us
is whether they believe that massless particles
cannot oscillate because their time-rate is zero, just as it
would be for particles with rest mass
moving at c. Perhaps it is some other property of
massless particles that would prevent them from oscillating.

The list of massless particles is really small. They are their
own anti-particles. If they oscillated, how would we know it?

Can you come up with even one wild guess, other
than what I said that NOVA said (massless = c =
zero time-rate), that could explain why massless
particles cannot oscillate?

1) We can't know, because we cannot resolve the "oscillated
state".
2) Oscillation applies only to a population, and not individual
members. So we can infer nothing except about a time-embedded
series of measurements of a large population, assuming we know
all there is to know about how the neutrinos are formed.

[snip]


Yes, but unless I am misreading these, they are
discussing conditions and limits that must exist
IF neutrinos have rest mass. None of these are
discussing WHY physicists believe they must,
or should, have rest mass (the other reason I
have heard is that it would supply the "missing
mass" of the universe).

I think you are not reading deep enough. There
are theoretical requirements for the class of all
neutrinos that they sum to some finite non-zero
mass. The internet is full of the stuff. If NOVA
got you interested in the topic, then they did a
really good job.

Now here we agree, there are theoretical
requirements, reasons, for believing that neutrinos
have rest mass.

Now I understand that you will think I am
changing the subject, but I am trying to form a
simile: Teachers still teach Newton in physics.
Is it a "huge blunder", that you find hard to
believe, that they are still doing this to this day?

I'm trying, but I think you have me :-(

Newton has been experimentally falsified time and again. Yet we
continue to teach him to our children. If NOVA led you to
believe that the only reason that neutrinos are believed to have
mass is because they change flavors "in flight", is it any worse
than teaching "simple physics"?

If this still doesn't register, just snip it.

....
Yes, but that would merely easily explain their
"beating the photons to Earth" if they travel at c,
just like photons. If they have rest mass, then they
CANNOT travel at c, since that rest mass would
increase to infinity.

Wrong. Rest mass doesn't change with particle
speed. Note the word "rest". Note also that the
physics community at large accepts that mass is
invariant. So that leaves your statement saying
"since that [neutrino's energy] would increase to
infinity."

Yes, my typo. But read it with "since that mass
would increase to infinity." Do you see my point?

Yes. And it is just as wrong. "Relativistic mass"
increases to infinity, but it is a complex mistake,
combining scalar and vector components, and
doing neither well. And this term exists only because "common
understanding" is such
that E = m_o c^2 applies to something other than
a mass at rest in your frame.

Wait a minute, are you claiming that the total
energy of a neutrino does NOT vary as a function
of the neutrino's velocity,

No. I am claiming that its *mass*, your choice of word, doesn't
change with velocity. It's total energy most definitely does.

that neutrinos form a category of particles that
move at c, have a non-zero rest mass, but have a finite energy?
It sounds from what you
say below ...

No.

Whatever rest mass they have must be
increased to a ridiculous degree just to allow
them to "beat" the photons to Earth.

NO change in mass. Change in energy. That
is why I adjusted your statement the way I did.

... that the answer is no, meaning that neutrinos
CANNOT move at c, because their energy would
be infinite.

Correct.

I THINK you believe that the total energy of a
neutrino is its rest mass times gamma, 1/sqrt(1 - v^2/c^2),
true?

No.
E^2 = (pc)^2 + (mc^2)^2

"p" is momentum, but not by Newton's definition.

....
And if I am correct, the difference in arrival times for
the neutrinos and the photons matched predictions
which assume that neutrinos travel at c, not just
less than c, which means that difference in speed must make a
difference of just minutes or even
seconds over a travel time of 150,000 years!

Clearly ignoring the mechanics of how the neutrinos
are formed. You are aware that in "local" cases,
the neutrinos arrive *before* the light? Neutrinos are
formed *before* the outer sheath is blown away, and
maximum intensity occurs when the mass travelling
at 0.1c gets large and not-yet too cool.

Maximum intensity of photons or neutrinos?

We see a single "pulse" of neutrinos. We see a long series of
days for the supernova's light to wax to maximum (where hopefully
we see it), then wane along some characteristic "cooling curve".

I believe that max neutrino intensity occurs either when the
electrons combine with
the protons, or shortly after (the density is so great that
even neutrinos get delayed).

Right. At the "bang", and not the "flash" some days later. And
as far as "even the neutrinos get delayed", I'm not sure how
reasonable this is, given that fact that most neutrinos could go
though a light year of lead without being stopped. What is going
to slow them? They have no charge...

But hey, let's check:

http://zebu.uoregon.edu/~soper/StarDeath/sn1987a.html

The prediction was that the detectors should see
neutrinos from SN 1987A for about 10 seconds.
One recorded 5.5 seconds, the other 12.5 seconds. This occured
at (universal times) 7:36 Feb 23. An
observer saw nothing at 9:30 Feb. 23, but an
optical plate showed SN 1987A at 10:30 Feb. 23, between 2 and 3
hours after the neutrinos (core
collapse), in agreement with theory.

So the neutrinos are formed on core collapse, not even at the
instant the outer shell is blown away. Duration of 10 seconds
for a local SN.

Now, let's say that, in fact, the neutrinos had a 6-hour head
start --
contradicting theory

! What !

Core collapse, then explosion, then the star (that is commonly
too dim to see) "expands" large enough, at 0.1c for us to see it?
Maximum intensity *doesn't* occur at the instant the outer shell
starts to blow off.

....
So, just to make sure I'm not wasting breath
(or fingertips), would you agree that this also
puts a limit on the maximum rest mass of a
neutrino?

No real tight limit, no. Accelerating a ba-zillion
Mercedes Benz to 0.999999c might be more
energy that a supernova can produce. But
protons or something smaller, no I don't see
that it would be a problem.

As the article just listed shows, it did indeed
put a "real tight limit" on the rest mass of a
neutrino.

You cited tighter limits before. Theory provides one tighter
still on the entire family.

....
Come on, the models predict a certain time from
collapse to noticeable (here on Earth) photon
emmision. I don't remember the number, but I
believe it's less than a day, and even a week
would put severe limits on the neutrino rest mass.


I don't think you've got it yet. The neutrinos are
formed where in the process?
precrunch, crunch, cook, blast, expansion &
cooling to max intensity, expansion & cooling
beyond max intensity. We become aware of
supernovas by light, and that occurs (hopefully)
during the early expansion phases. Keep in
mind, light generated in the core of our own Sun
takes a month or more to reach the surface where we can see
it.

I assume you now know that 2 to 3 hours is the predicted time
difference.

Not at all.

the difference in velocity must be so small that
the photons cannot come close to catching up
with the neutrinos even after 150,000 years,
which means the "rest mass" of a neutrino

No need for quotes...

True, I was thinking massless particles, you
caught me.


I wasn't trying to "catch" you. I was trying to point out:
mass = gravitational mass = inertial mass = rest mass =/=
relativistic mass


must be so small as to be ridiculous (my bet is
no, that neutrinos have NO rest mass).

Here I was wrong, the rest mass is at most 20 eV.

I believe the rest mass total of the entire *family* is less than
2 eV. It might be 20, but I don't exactly recall now.

....
Has anyone PROVED that they have rest mass?

The data supports them having a mass less than
a threshold, and the data supports the entire
family having non-zero mass. Science isn't about
proof, but *disproof*. We can show something isn't right, or
we can show that it survives until the
next test. Period. So far theories that predict
non-zero neutrino mass are 100%, and ones that
don't are being revised.

The fact that so many theories are being revised
means nothing by itself, since both the truth, and
an error, could cause such revisions.

I think you haven't been reading the links. Theory *predicts*
rest mass. It further predicts mensurable quantities, that are a
result of the theory that expects them to have mass. The results
of experiment provide those quantites, that result in a value for
rest mass. The same theory-set that does all this *does not
recognize time*. It is quantum theory. All processes are
reversible.

What I am trying to say is that my GUESS -- and
yes it MIGHT be wrong, but you don't know that, so
why pretend you do --

Thanks. You have made your agenda clear.

WHAT??? I have an opinion that the belief in rest
mass MAY be based on a shift-error, I at least
thought I heard them say on NOVA just that error,
....
That's reality, agenda free. Unless, of course,
you call getting at the truth an "agenda." This
always pisses me off. Why is it that so many
people have to claim that any disagreement with
the current beliefs is based on some non-
scientific "agenda." Trust me, you are not alone ...

Phil, you look for "proof" where none can be had *ever*. You ask
for reasons why a phenomemon is assigned a value, then don't read
the information given. Then you accuse me of "pretending". I am
trying to give it to you as straight as I know how.

Why don't you simply ask the question you want to ask (or make
your declarative statement), instead of beating around the bush?

is that the theoretical requirements will turn out to
be based on faulty assumptions. For example, the
idea that since neutrinos transform, they must have
rest mass, because time "stands still" for massless
particles.

*You* have made assumptions, done so despite
the experimental data, showing no theoretical
premise for doing so, and performed a "shift-error"
in insisting that formulae derived for massive particles apply
to massless ones. Is that about
the size of it?

No. I just hope you have at least a vague
understanding of why "no" is in fact the correct
answer. The only assumption I can see that I made that was
wrong is that the neutrinos from SN 1987A
set limits on the rest mass of a neutrino that are
lower than they realistically can be, and even that
was a "I bet that the data will show," clearly stated
as an opinion, not an absolute fact. I see nothing
but increasing evidence that physicists have indeed
made a shift-error, although they may indeed have,
as you CLAIM (and claim your links prove, although
I haven't seen it yet), some other reason for
believing that "oscillations = rest mass."

OK. Now the finger pointing starts.

Phil, mass doesn't change with velocity, energy does. Quantum
theory predicts mass for a neutrino, and quantum theory "doesn't
do time". Neutrinos are created in a supernova long before they
expand big enough for us to see them. Relativity says "time for
a photon" is a non-sequitur. Science doesn't do "proofs", only
disproofs.

Before we kiss each other off, say what you need to say. You
already know you won't like the answer, and it appears you are
already jaundiced against anything I might say...

David A. Smith


.