Re: Time for a photon.

Dear Phil:

"Phil" <toob-headman@xxxxxxxxxxxxx> wrote in message
news:4432215F.30301@xxxxxxxxxxxxxxxx
N:dlzc D:aol T:com (dlzc) wrote:
Dear Phil:

"Phil" <toob-headman@xxxxxxxxxxxxx> wrote in message
news:442F932B.2030207@xxxxxxxxxxxxxxxx

googlegroupie@xxxxxxxxxxxxx wrote:
...
An excellent question. At least some physicists
think that because the "time dilation factor," or
"time-rate" (an object moving at high speed
*undergoes* time dilation, which *results* in a
slower time-rate) of an object WITH mass
would slow to zero if we could accelerate it to
the speed of light, that the time-rate of an
object WITHOUT mass must also be zero.


Why would they think this? Photons respond
to objects through/by which they pass. They
are "aware" of change.

David,

I wondered that myself! It was on a "layman's"
sho, NOVA,

I will make one comment, and you noted already that this is for
the layman. This obviates them (NOVA) from telling the "whole
truth". It also empowers them to work on glitz, to the point
that other facts may be missed (not included, or simply not
enhanced enough to be noticed by the viewer).

about neutrinos, but they were quite thorough, with
the two guys that (1) first predicted how many
neutrinos the sun makes and (2) first measured the number of
neutrinos the sun makes. For
decades, #2 measured 1/3 the number predicted
by #1, and the debate went back and forth, until finally
experiments that could measure all three
neutrino types showed that the sun does make
the number predicted by #1, but that they shift among the three
types, reducing to 1/3 the
number of neutrinos seen by #2's experiments,
which were designed only for the type made by
the sun (the reference you cite below refers to
the mystery of why the sun produces 1/3 of the
expected neutrinos). They categorically stated,
on the show, that physicists concluded that
neutrinos MUST have mass, because they
change, meaning "time passes" for them, and
that can only be done by objects moving at
less than the speed of light.

Pions and kaons have mass, and have a very short halflife
(labelled as unstable).
Majoron (a massless boson) seems to have a very long halflife
6*10^20 years, if I'm reading this correctly (probably not):
http://prola.aps.org/abstract/PRD/v33/i9/p2737_1

Please consider a "half-silvered" mirror. How are the photons
supposed to know which way to go?

I don't know that your comments are technically correct,
meaning that on object could perhaps be deflected,
absorbed, whatever, but without itself ever "aging."

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.

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.


Relativity says nothing about time rate for a photon,
only time rate for "frames" inhabited by massive
particles.

That's what I thought, too, hence the puzzlement on
the show's comments, which I still suspect most
physicists actually believe (that would be a pretty
serious blunder for NOVA to make; possible, but
doubtful).

*Always* doubt. In the limit, Lorentz transforms indicate that
time should not pass for any particle travelling at c. But in
the same limit, no finite result can be obtained for particle
energy, whether that particle be in the "c-frame" or in the rest
of the Universe. Yet photons always yield a finite result...
like any object travelling less than c.

This caused great confusion in the study of
neutrinos, because it turns out that by the
time the sun's neutrinos reach the Earth,
they have "had time" to transform, x number
of times, into any of the three types of
neutrinos, which caused the measurements
of the sun's neutrinos to be 1/3 of the
expected value (the experiments looked only
for the type known to be produced by the sun).
This fact, plus the assumption above, caused
many physicists to conclude that neutrinos
have mass since "only an object with mass,
which allows it to travel at less than c, can
have a non-zero time-rate."

The neutrino's mass derives from other
requirements.

Well, it looks like most physicists

Reminds me of a line from the movie "Two Weeks Notice"... "well
that's silly, have you met most physicists?"

view the ability of a neutrino to change state as a proof that
it has mass.
Perhaps NOVA was misleading on this point,
but again, it seems like such a huge blunder,
that I cannot, at this time, confidently believe
that.

Believe that any measured quantity has *many* theoretical
underpinnings.
http://cupp.oulu.fi/neutrino/nd-mass.html

http://www.physics.upenn.edu/neutrino/jhu/node2.html#SECTION00020000000000000000

The fact that they have mass *and* have a halflife could be
simply "coincidence".

However, if it turns out that massless particles like
neutrinos and photons do NOT have a time-rate of
zero, then the ability of the sun's neutrinos to shift
among the 3 types of neutrinos does NOT imply
that neutrinos have mass (and given that neutrinos
from the 1983 (?) supernova beat the photons here
to Earth by over a day, it is hard to believe that
neutrinos could travel at even slightly less than c).


http://www.highbeam.com/library/docfree.asp?DOCID=1G1:4757216&ctrlInfo=Round19%3AMode19a%3ADocG%3AResult&ao=

The same instant of the supernova process that is
recorded as peak intensity occurs at a different
time than the production of neutrinos.

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."

My point was, just how much less than c can the
speed of a neutrino be if it is to reach Earth ahead
of the photons? In your reference, they state that
it took the neutrinos 150,000 years to get here.
Even if the actual collapse of the core (which I believe
is when the neutrinos are produced) occurs a full day
before the light output rises to supernova level (not
necessarily the peak, but enough to show up as a
SN),

There is no reason, and no belief that SN reach peak in one day.
The ejected matter leaves at "0.1c", and starts to cool sometime
later.

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...

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

You'd lose. There are theoretical requirements for them to have
mass.

Note the speed of this very energetic proton:
http://www.fourmilab.ch/documents/ohmygodpart.html
.... crosses (into?) the Milky Way in one week proper time ...

For me, the fact that photons can be "short-circuited"
in a waveguide at some points in time, but not others
(basically when the EM field is passing through a
zero, we want the photons to reflect off the top or
bottom of the waveguide, to minimize the losses),
tells me that their state varies, like a neutrino,
meaning that both photons and neutrinos have
non-zero time-rates.

An individual photon is moving at c, or c_medium.
That leaves plenty of room for us turtles to see the
hare "changing state".

I don't know what you mean here,

We can't travel with the photon, and we can "only" detect
multiples, so all we *can* see is change. Maxwell says that a
photon doesn't change intensity on its E or M field strength.

but I think you and I agree, and disagree with NOVA, about the
ability of massless
particles to "change state."

I frankly don't know, Phil. I don't see that that "massless"
equates to "changeless".

David A. Smith


.

Relevant Pages

  • Re: Time for a photon.
    ... At least some physicists think that because the "time dilation factor," or "time-rate" of an object WITH mass would slow to zero if we could accelerate it to the speed of light, that the time-rate of an object WITHOUT mass must also be zero. ... This caused great confusion in the study of neutrinos, because it turns out that by the time the sun's neutrinos reach the Earth, they have "had time" to transform, x number of times, into any of the three types of neutrinos, which caused the measurements of the sun's neutrinos to be 1/3 of the expected value. ... However, if it turns out that massless particles like neutrinos and photons do NOT have a time-rate of zero, then the ability of the sun's neutrinos to shift among the 3 types of neutrinos does NOT imply that neutrinos have mass supernova beat the photons here to Earth by over a day, it is hard to believe that neutrinos could travel at even slightly less than c). ...
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  • Re: Time for a photon.
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  • Re: Time for a photon.
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