Newsgroup sci.physics 204999

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>>Jupiter is an enormous gaseous planet with a nuclear furnace in it's core
>>(hence the radiation). What's this got to do with the Earth?
>>
>If Jupiter has a nuclear furnace at its core, then maybe Earth does too!
Jupiter is a hundred times too small to have any
self-sustaining fusion reactions going on. The infrared excess from
Jupiter is fully explained as the heat of helium condensing and raining
out into the core. In other words Jupiter is still losing the heat it 
inherited from the primordial nebula and shrinking as it cools.
>When we were proving what's happening at Jupiter's core, did we also prove
>what kind of gas forms long-lasting craters?)
Clouds, not craters. They disappered within a year.
>corresponding with the ice ages. The Saber-toothed Tiger didn't go as early
>as T. Rex did he? 
Of course not, since saber-toothed tigers did not evolve until 60 million
years after tyrannosaurus rex went extinct.

In article <327524A3.4B40@sdd.hp.com>, Steven Hines  writes:
>meron@cars3.uchicago.edu wrote:
>> 
>> In article <3274E91F.5247@sdd.hp.com>, Steven Hines  writes:
>> >Russell Turpin wrote:
>> >>[snip]
>> >> There is no faith to which one
>> >> must leap, no metaphysical tenets that one must accept.
>> >
>> >Don't you have to believe that every event has a cause? Doesn't
>> >acceptance of this proposition constitute a "passage of faith"?
>> >
>> Assume, yes, believe, no.  There is a difference.  Science is self
>> checking and self correcting.  It makes assumptions, draws conclusions
>> and checks the conclusions versus experimantal data.  But the
>> assumptions aren't sacred and if the data fails to support your
>> conclusions you may be forced to modify your assumptions.  It is the
>> continuous cross checking that distinguishes assumptions from beliefs.
>
>Okay. 
>
>I think I have a basic understanding of the model scientists
>use in settling on hypotheses, theories, and laws. I accept that 
>each of these must be consistent with observations in order to hold
>up and that theories that do not stand up to experimental rigor are
>discarded in time.
>
>I write the above paragraph in the hopes of establishing some common
>ground here and so you do not think that I am attempting to discard
>science and its accomplishments.
>
It was rather obvious from the beginning that this is not your 
intention.
>That being said, I have a hard time seeing how one can experimentally 
>determine that some events do not have causes and still be doing 
>science. That is, if a scientist observes an event, looks for a cause,
>and finds none, what is the consensus among other scientists in the field?
>Honestly... are they likely to say, "Ah, this event has no cause" 
>or instead will they say (perhaps to themselves) "This scientist has
>not looked hard enough, or in the right places."
>
OK, lets use some example, then we can return to the general issues.  
Assume we've a hydrogen atom in an excited state (meaning that the 
electron is not at the lowest energy state possible).  We know, both 
experimentally and theoretically (from quantum mechanics) that 
eventually there will be a transition, the electron will end up at the 
ground state and a photon carrying the excess energy will be emitted.  
We can calculate what is the probability per unit time for such an 
event to occur and how lon, on the average, we've to wait for it to 
occur.  But, we cannot predict at what moment exactly it'll occur and 
according to all we know such prediction is impossible.  
So, if you ask "what was the cause for the transition" I can tell you 
that it was caused by the system not being in its ground state and by 
its coupling withthe radiation field.  But then you can say "yes, but 
why did it happen at the specific moment it did" and I'll answer 
"according to all we know no cause can be specified for this".
So (now we're back to the general stuff) you can ask "how can you be 
sure that this apparent lack of cause is how things really work, not 
just a failure on your part to look deep enough.  How do you know that 
there is no better theory which explains this which you cannot 
explain."  And my answer is "I'm not sure and, what's more important, 
I know that I'll never be sure that I've the best theory possible.  
And, it doesn't matter."
You see, science is pragmatic, one may even say opportunistic.  Unlike 
religions and some philosophies it is not trying to come with the 
ultimate answers to everything (no cracks about 42, please).  And it 
is not claiming absolute certainties.  What it does is to try to come 
with as good answers and descriptions as it can given existing 
information, in the full knowledge that better answers and 
descriptions may be forthcoming in the future.  It is not claimming 
infallibility, thus when existing models are modified or replaced by 
newer ones it considers the change to be progress, not admission of 
failure.
>What I mean to say is that I can't see how science can proceed unless
>is assumes beforehand that observed phenomena can be explained
>(isn't that, after all, the job?). 
Yes, it is its job, and it assumes that observed phenomena can be 
explained, in some fashion.  How much of an explanation is full 
explanation, that changes over time.
>But what about this assumption?  Is it forced to stand up to the 
> same rigor as the hypotheses, theories and laws? 
What to you mean "stand to the same rigor".  If you mean "prove that 
the best explanation possible was achieved" that's unprovable.
>That is, how can one know for certain that _all_ avenues
>have been traveled in search of a cause, but to no avail, and that 
>therefore the phenomena has no cause? How many scientists would 
>accept this?
As I said, absolute certainties are for religion, not science.  
Science only offers the best current explanations.
>
>If the proposition "all events have causes" cannot be proven or
>disproven by experimentation, then isn't it true that the proposition
>is being accepted on faith?
No, it is accepted as working assumption, to be modifiesd as needed.  
It already has been heavily modified in the transition from classical 
to quantum mechanics, where the concept of cause is way weaker than it 
used to be.
Mati Meron			| "When you argue with a fool,
meron@cars.uchicago.edu		|  chances are he is doing just the same"

Steven Hines  writes:
> That being said, I have a hard time seeing how one can experimentally 
> determine that some events do not have causes and still be doing 
> science. That is, if a scientist observes an event, looks for a cause,
> and finds none, what is the consensus among other scientists in the field?
> Honestly... are they likely to say, "Ah, this event has no cause" 
> or instead will they say (perhaps to themselves) "This scientist has
> not looked hard enough, or in the right places."
In practice?  Yes, they'll probably start off by thinking that the
cause just hasn't been found yet, and they'll try to find it
themselves.
If, however, hundreds of smart people spend decades looking for a
cause, and all of them fail to find it, then eventually they'll stop
beating their heads against a brick wall and they'll decide that 
there probably is no cause to be found after all.
I'm not speaking hypothetically here: I'm describing a historical
event really happened.  I haven't done a poll, but I strongly suspect
that nowadays only a small minority of physicists believe that all
events have causes.

-*-------
In article <327524A3.4B40@sdd.hp.com>, Steven Hines   wrote:
> That being said, I have a hard time seeing how one can experimentally 
> determine that some events do not have causes and still be doing 
> science. That is, if a scientist observes an event, looks for a cause,
> and finds none, what is the consensus among other scientists in the 
> field?  Honestly... are they likely to say, "Ah, this event has no 
> cause" or instead will they say (perhaps to themselves) "This
> scientist has not looked hard enough, or in the right places."
It's a bit more complex than that.  Summarizing far too
simplistically, one can create physical systems that are
identical (actually mirror opposites in some measures), separate
them, and then observe their deviance from deterministic behavior
to identify which elements of behavior are intrinisically(*)
non-deterministic.  Some fairly rigorous bounds can be placed on
the "intrinsically" in the previous sentence: determinism can be
preserved only by faster-than-light communication, effects
preceding their cause, multiple universes, and other oddities.
Strictly speaking, one isn't *compelled* to believe that the
universe is inherently non-deterministic at bottom, but only to
consider this as one possibility from other -- equally weird and
disturbing -- choices.  The best popular introduction I have seen
to this is "Quantum Reality" by Nick Herbert, which should be
available through major bookstores.
Now, obviously, physics might be wrong about this in some crucial
regard.  Einstein thought so.  But it is evidence of how much 
more important evidence is to preferred metaphysical assumptions 
that physics as a field is guided by the former, not the latter.
> ... But what about this assumption?  Is it forced to stand up
> to the same rigor as the hypotheses, theories and laws? ...
Some of the key experimental evidence are the famous dual slit
experiment and Aspect's experiment.
> ... That is, how can one know for certain that _all_ avenues
> have been traveled in search of a cause, ...
No physical theory is known "for certain."  But the evidence is
pretty strong.
Russell
-- 
 The difference between life and a movie script is that the script has 
 to make sense.         -- Humphrey Bogart

 I said:
>>- When photons travel through a medium, they are being continually absorbed
>>  and re-emitted by the medium (its atoms or molecules or larger systems).
 Lloyd Johnson points out:
>Usually when a photon is absorbed, then re-emitted, it is emitted in
>some random direction.  Yet when a photon travels through glass, you
>say it is continually absorbed and re-emitted.  Why then is it
>preferentially emitted in the original direction?
An excellent question!!!  I've been away from Usenet for a few days, and this
thread has expanded beyond belief... browsing the replies, however, I think
there are several things that have not been pointed out, and some things
that have been misunderstood.
(emerging from bait shop, fishing lures hooked to hat... setting down a huge
metal can.  **** THHHHUUUUNNNNKKKKK!!!! ****   Inscription on side: "Very Big
Can-o-Worms."  **** CCCCCCRRRREEEEEAAAAAAKKK...**** .... opening the can,
very slightly:)
Judging from the newsgroups this thread is in, the readership is very large
and diversified.  I'd like to clarify a few things first off:
There are several different wavelengths of relevance here.  One is the
wavelength of the photons involved, which is given by the photons' energy
or frequency (energy/Planck's constant).  Divide the speed of light IN VACUUM,
c, by this frequency and you get the (vacuum) wavelength of the photon.
Another frequency of relevance is that of the natural oscillations of the
medium you're considering; 
these can be atomic, nuclear, molecular, crystal, or other transitions (quantum
mechanically speaking).  This frequency gives you another wavelength, by the
same method as above.  Finally, there is a length scale involved in the spatial
distance (averaged, if you like) between the molecules or other oscillators in
the medium.  This gives you yet another length scale.  When the photons'
wavelengths is near EITHER of the other length scales, special stuff happens
and we gotta be careful in describing the photons' behavior.
For the standard example (visible light in glass), the separation between
molecules is around 10^-8 or 10^-7 cm.  Visible light, on the other hand,
has a wavelength of several times 10^-5 cm... much larger than the typical
interatomic separation.
We are also safely away from the nearest relevant natural oscillation frequency
of glass, which is in the UV (shorter wavelength than visible).  It is these
properties which allow us to choose whether we use "classical electrodynamics"
(CED) to describe what's going on (easier in this case, but less general), or
"quantum electrodynamics" (QED...pain-in-the-A** in this case, but applicable
to other frequencies, and containing classical EM as a limit).  When someone
talks about "index of refraction" of a medium, or "wavefront" of a photon
or set of photons, they are implicitly in the classical limit; decrease the
wavelength of our photons to the hard X-ray or gamma-ray regime, and you won't
see anyone talking about the index of refraction at those wavelengths!
Why?  Because the description is inappropriate and not very useful.
Some terminology definition is necessary at this point as well.  In QED, we
describe the "scattering" of photons via what are known as "virtual"
transitions.
A free electron can "wiggle" as it likes... so that incoming photons of
any wavelength can be absorbed by it, and re-emitted.  If a photon is absorbed
and re-emitted RIGHT AWAY (with the same wavelength but possibly with a new
direction), it's called a "virtual" transition; one where the excited electron
sans photon is never directly observed.  It is also called "elastic scattering"
of the photon (the "elastic" refers to the photon's wavelength not changing).
So, whenever I say "scatter", I actually MEAN "virtually absorbed and
re-emitted";
they are the SAME thing.  In a molecule, metal, crystal, or whatever, the
electrons are confined to "wiggle" in certain ways only... these are the
transitions between the quantum-mechanical "states" of the system.
Now, it is natural to ask HOW this virtual absorption and re-emission leads
to the slowing of light in a medium, and why the direction isn't totally
randomized.  Read on...
(**** CRRRRREEEEAAAAKKKKK **** as we open the can of worms a bit more, but
still not all the way)
I'll now assume that the reader has some idea of quantum mechanics, and
I'll try to describe how normal optics comes out of this quirky QED....
Pretend, for simplicity, that we have a bunch of molecules with only one
transition possible, say a UV transition from glass.  Now, let's follow
a visible-light photon as it goes through the glass.  Wait... we're already
in trouble!!!  It turns out that we CAN'T say what happens to the photon,
unless we observe it to have happened!  This is an EXTREMELY important point.
Now, several things are possible as the photon goes through the glass:
1. It can go through unchanged, without interacting with ANY of the molecules.
2. It can "scatter" (be virtually absorbed and re-emitted) off exactly one
   of the molecules.
3. It can "scatter" off two of the molecules
4. and beyond... you get the picture!
Now, I'll be talking about the "amplitude" for a process to happen... if you
haven't had any QM (quantum mechanics) you can substitute the word
"probability" where you see "amplitude", but you'll run into trouble in
following how the
probablilities don't seem to add quite right.  The "amplitude" is a complex
number, or 2D vector if you like, whose length gives the probablility for a
process to have happened.
Now, the amplitude for number 1 above to happen is quite large!!  Photons would
be quite happy to pass through a medium without anything happening.
Let's look at number 2, the single scattering event.  For an isolated molecule,
the likelihood of scattering is much less than that of passing through
unharmed, so it seems that our photon will not even see the glass we've put
in front of it.  The scattering amplitude goes as the amplitude for the
absorption and re-emission (not very likely if the photon isn't at just the
right frequency), and has the fine-structure constant (about 1/137) in the
numerator, making it quite small indeed (it always has length smaller than 1,
even if you take the 1/137 out).
But wait... there are MANY ways number 2 can happen; the photon can scatter
off any of the 10^(23 +- 5) or so molecules that are present.
The amplitude for number 2 to happen is the sum of all the ways it can happen,
so all of a sudden number 2 is MUCH more likely than number 1!  Furthermore,
the photon's wavelength is much larger than the typical intermolecular
separation (as noted above), so MANY of the scattering sites are seen by
the photon at approximately the same "phase."  This leads to some
magical sort of stuff happening:
All of a sudden, the most likely direction for scattering becomes the original
direction of the photon, with the next most likely direction being directly
backward... contrast this with the more random direction associated with
scattering by a single molecule.  This has EVERYTHING to do with the number
of scattering sites that are approximately at the same phase, and with
the fact that we haven't observed which molecule actually absorbed and
re-emitted the photon.  If we do this latter observation, the photon all
of a sudden gets scattered all over the place again... and the single
molecule scattering results get reproduced!!!  Spooky, but wonderful.  It
is the fact that amplitudes are vectors (complex numbers...as opposed to
probablilites which are always real numbers)
that makes this happen... when the amplitudes point the same direction they
are "in phase" and add "coherently."  You then get a BIG probablility for those
events which can happen many different ways with the same phase... the forward
and backward directions survive while the other directions' probablilities are
swamped out.  Basically, if the photon makes a 10 degree turn, the molecules
on the "inside bend" of the turn have their contributions cancelled by those
on the "outside bend".  You can change this: take away selected molecules so
that those that are left are those which contribute in phase for scattering
into a 10 degree bend, and you'll find that you've likely produced a "prism"
which favors the 10 degree bend in the classical "index-of refraction"
treatment (although other, much more complicated, arrangements, are possible)
... this is left as an exercise ;-) !
(ooops... opened the can-o-worms too far... closing it a bit again now)
Anyway, this is where the term "coherent forward scattering" comes from, which
was brought up by another poster.  It could just as easily and correctly have
been called "coherent virtual absorption and re-emission."
Back to the different ways the photon can pass through... if it is scattered
TWICE, the amplitude for scattering is much higher than for scattering once,
due again to the large number of molecules present.  One might think that it
just keeps getting more and more likely to scatter lots and lots of times,
but the amplitude peaks for a certain number of scattering events, and finally
goes back down for larger numbers.  The reason is that the amplitude for N
scattering events to occur goes roughly as
(matrix element for scattering/137)^N,
which is always smaller than (1/137)^N, which gets pretty darn small
for large N!
The amplitude for the N scattering events goes up like the above times:
 number of molecules (M), for one scattering event
 M(M-1) for two
 ... smaller than M^N for N events.
So, no matter what our M (number of molecules) is, it finally becomes LESS
likely for more scattering events to occur.  The most likely number of
events goes (as you might guess) up linearly with the thickness of the
glass.  The time spent "during" each scattering event is VERY small, of the
order of
(Planck's constant/energy difference between photon and transition energy)
where Planck's constant is about 10^-34 Joules-seconds, in familiar units.
For a UV transition and visible photon, we get about 10^-32 seconds that
the molecule can "keep" the photon before conservation of energy forces it
to give it up.  Thus, "virtual" transitions still make themselves felt,
especially when a LOT of them could have occurred.
Why did I just say "could have?"  As mentioned above, we don't KNOW what the
photon did from when it was emitted until when it was detected!  The process of
passing through the glass is entirely probablilistic; repeating the experiment
with an identical photon and you'll get different answers for, among other
things:
- how long it took
- the EXACT direction it comes out
- the phase when it is detected
- etc.
This all falls nicely (although it's difficult) from the QED treatment.  You
never have to introduce ideas like: susceptibility of the material, index of
refraction, etc.  However, these concepts are VASTLY easier to use when one
is in the classical regime, and it's easier to think of the "wavelike"
properties of the light than the "particle" properties.  But, the originators
of this thread were interested in PHOTONS... particles of light.
To sum up:
- the photons are slowed down from "c" by virtual absorption and emission,
or "scattering" if you prefer;
- They travel at "c", whenever you are able to "see" them between
successive scattering events... the absorptions slow them down macroscopically.
If the wavelength is large compared to the distance between scatterers, you
can use classical ideas to simplify the interpretation of what goes on.
I hope that this has answered more questions than it brings up!!!
- Paul Arendt

In <327549CD.5D36@mindspring.com> Leonard Timmons
 writes: 
>
>Les Cargill wrote:
>> > > Secondly there is a mental trap if we refer to the entity that
you
>> > > describe as the Biblical God. Most people think of a 'Person' or
>> > > a personal god of a particular sort when we speak of the
Biblical
>> > > 'God'. The entity that you describe does not seem to be a
person.
>> >
>> > The word "person" has no operational definition (that is, I have
>> > no procedure for testing an individual to see if he is a person or
>> > not).  I asserted the God I defined acts in a manner very
>> 
>> Funny, I do. If an entity has the same number of chromosomes as I
do,
>> then it is a person. Of course, you have to allow for Mongolism, but
>> this should work.
>
>Try not to take all this too seriously.
>
>Let's say that this entity that you refer to is a single cell.  Let's 
>say that it is a cell from the lining of your stomach.  It is cultured
>in a dish in the lab.  Suddenly it is a person.
>
>I like to avoid definitions that contain within them large nebulous
>concepts such as "person", "conscious", etc.  These things just lead
>to more and more confusion.
>
>-leonard
    WOW! What can be more "nebulous" then "GOD"?

kunk@perseus.phys.unm.edu wrote:
: >
: Which reminds me of Pauli who classified science as being divided into
: physics, stinks (chemistry), and stamp collecting (all others).  He was
: mortified when he received the Nobel prize in chemistry for his statement
: of the exclusion principle.
 I believe you mean Rutherford and the experiment was him shooting alpha
particles at a thin metal foil. (Geiger 'n Marsden confirmed) The
conclusion of the experiment was that the atom 'looked' like a planetary
system with the nucleus as the sun and the electrons as the planets.
Took the plum pudding theory of the atom to hell. Rutherford won the
Nobel in chemistry because, Ias I understand it, the experiment was on
the atom an thus is chemistry. The pauli principle is physics, though
as physics professors joke, the chemists do use it incorrectly from time
to time. 
was I even close?
: Jim
"TM"

Timothy Ryan Froese wrote:
[snip]
> I think what magnus.lidgren was asking was do photons in the same
> medium travel at the same speed. I would think that no matter in what
> medium, ie. glass, water, air, or vaccuum, any two photons would travel
> at the same speed provided that they are in the same medium. This is no
> problem for the prism effect since two photons with different energies
> can still have the same speed.
> 
> Suspiciously Scientific,
> 
>         Tim
I just stumbled into this thread and might therefore ask something which
has already been answered.
My question: In what aspect or parameter do two photons differ, if the
first one corresponds to a infrared wavelength and the second one to one
of the ultraviolet part of electromagnetic radiation. As far as I know,
the mass of both is zero, the speed is the same, the size is suposed to
be a point, what characteristic is left ?
Achim

In article <552jba$mjk@news.acns.nwu.edu>,
Bob Michaelson  wrote:
>In article <550b6u$lco@lynx.unm.edu>, kunk@perseus.phys.unm.edu says...
>>
>>Which reminds me of Pauli who classified science as being divided into
>>physics, stinks (chemistry), and stamp collecting (all others).  He was
>>mortified when he received the Nobel prize in chemistry for his statement
>>of the exclusion principle.
>>
>>Jim
>
>Um, while Pauli would have been annoyed at a Chemistry Nobel, his prize
>was in Physics (1945).  It was Ernest Rutherford who divided science into
>physics and stamp collecting, and Rutherford who, to his annoyance, was
>given the Nobel in Chemistry (1908).  Since your message was posted on
>soc.history.sci, I thought I should correct the history.
>
>Bob Michaelson
>rmichael@nwu.edu
>
Thanks.  I am more often out to lunch on history than on physics.
Jim

In article <32754DBC.70BB@cam.org>, Achim Recktenwald  wrote:
> My question: In what aspect or parameter do two photons differ, if the
> first one corresponds to a infrared wavelength and the second one to one
> of the ultraviolet part of electromagnetic radiation. As far as I know,
> the mass of both is zero, the speed is the same, the size is suposed to
> be a point, what characteristic is left ?
Energy/momentum.  Even though the photon is massless, it has energy;
even though its speed is always 'c', its momentum depends on
wavelength (as does the energy).
-- 
Nathan Urban | nurban@vt.edu | Undergrad {CS,Physics,Math} | Virginia Tech

[Moderator's Note: It is a good idea to clearly indicate which material is
quoted and to attribute it properly when you respond to another's post. You
might want to consider trying it next time. -WGA]
: What is interesting about this stuff is that it seems to turn the 
one-line, layman's explanation of quantum mechanics (in particular, the 
uncertainty principle) on its head---it turns out that it *is* possible 
to observe an object without disturbing it.
BJ: Not sure how you are using "observe".
Much of what we term quantum weirdness comes from falsely interpreting
the rules for applying the mathematics of QM as statements about
how nature works. 
BJ: No. Nature simply is weird ... by our way of thinking. QM works as 
well as it does because it mirrors the weirdness to a good degree.
For example it is fundamental to the mathematics of
QM that identical particles can interfere with each other without
interacting and we can detect the effects of this interference.
BJ: How is interference not an interaction?
The uncertainty principle is perhaps the oldest example of this.
The experimental evidence is rather compelling that that there is
no such thing as an `object [to observe] without disturbing it'.
BJ: It is not a question of evidence, but of how we interpret the 
evidence.
Rather measurements seem to evolve from a process of observation.
They do not exist independently of that process. If observations
arise from some physical process of interaction then the constraints
of the uncertainty principle may be nothing more than a reflection
of the structure of that process.
BJ: For an outstanding introduction to these issues, you can do no 
better than to consult Jammer's *Philosophy of QM*.

trike@ix.netcom.com(Douglas Tricarico) wrote:

>You can teach
>anyone the metric system in 5 minutes since we already use the same
>base-10 method with the US monetary system.
I used to think that this was true until I started teaching Physical 
Science to 9th graders.  Despite 8 years in our educational system the 
vast majority seem to have escaped the metric system.
My own attempt to get them fluent in the system was about 50% successful 
(at least in the short term).  The only unit that they really understand 
100% is the second (probably due to years of dedicated clock-watching).
George Lyle

: >  Why anyone would make math a career when physics or biology or
: >chemistry or engineering offer less pain and exponentially more reward.
Precisely because of the difficulty, the rewards are greater.  You get 
back from sciences how much you put in with effort.

Jim F. Glass x60375 wrote:
> 
> The "movement" is called "Ludditism", and it is they who are mad;
> they want us to return to mud huts and digging for grubs in the
> dirt.
> 
> Tell you what.  YOU go live a subsistence lifestyle; enjoy the
> termites.
> 
> While you are at it, kindly forego the evil results of our "mad"ness,
> including computers, electricity, modern medicine, aircraft, etc.
> 
> THEN we might not call you a bunch of ignorant hypocrites.  The irony
> of seeing such blather as your posting on an internet newsgroup must
> escape you.
> 
> The rest of us will colonize space and keep working toward the stars.
> 
> Jim Glass
> 
> Opinions my own, and my own only--as if you could doubt it.
The likes of you have already colonised every last bit of habitable land 
on this planet. There is nowhere we can live as we want to. Some of us 
try but we are hounded of the land by armed thugs wherever we try to 
live. Your wonderful civilization is so insecure that it cannot even 
tolerate a few people living outside of it. We have no choice but to 
make the best of what is. We work to bring down your life-destroying 
dictatorship. We work for true freedom.
Your decadent system is already eating itself, all we want to do is 
speed up the process so there is a world left fit to live in after it 
collapses.
Your rantings re the colonisation of space are hilarious, more please...
andy
-- 
http://www.hrc.wmin.ac.uk/campaigns/earthfirst.html
South Downs EF!,  Prior House      
6, Tilbury Place, Brighton BN2 2GY,  UK
"Happy is he who dares to defend passionately
that which he loves" -Ovidius

Paul F. Dietz (dietz@interaccess.com) wrote:
: tooie@sover.net (Tooie) wrote:
: 
: >The human body contains about 1/2 lb of K-40 
: 
: Since K-40 is about .01% of natural potassium, you are saying
: the human body contains 2 1/2 tons of potassium.
: 
: I'd lay off the low-sodium salt substitute if I were you.
: 
: 	Paul
Paul is correct, the human body contains a 1/2 lb. of "normal" potassium 
of which .01% is K-40.  Rest of the math still holds together, I hope, :-)
tooie

nervous@netrover.com (nervous) wrote:
>In article <54r4h4$him@udevdiv.Unibase.COM>, john@petcom.com wrote:
>
>
>-> Why do I never see Simon's posts first-hand? And I never seem to receive a Cc
>-> either. Hmmph. Maybe my program needs debriefing.
>-> Yes, thank you Simon. I'm sorry for the finger-bite. :-) Keep it out there,
>-> please.
>-> My statement that there are no black holes is not to say that there aren't
>-> some extremely massive objects out there. The atomic model that I have
>-> developed, and from which my concept of gravity just seemed to drop out,
>-> postulates that energy assumes similar patterns at certain points as one
>-> moves up the scale. Just like one finds the same musical note as one 
>-> goes from one octave to the next. So, in comparing galaxies to atoms,
>-> I developed my Galaxy Model, which treats the arms of a galaxy as if
>-> they were the electrons of an atom. This means that the centers of
>-> galaxies compare to us as aggregations of protons compare to electrons-
>-> 1000 times denser and of opposite charge. Certainly these will be
>-> extremely massive bodies, but they are not such because gravity is
>-> crushing something which would otherwise be less dense- rather they
>-> are dense because that is their nature. Call them black holes if you
>-> want, but gravity will reach a limit before it breaks down atoms.
>
>Don't you high-school kids have anything better to talk about?  Galaxies as
>atoms! Hahahahah!!! Nice.
>
>-- 
If these are kids as you describe them, then they are very smart to think 
that much. And if they are not, I would still encourage them to go and 
explore further until they get matured understanding of what they are 
seeking. Laughing at man's inquisition about his own world should be 
resented by every grown up and responsible individual in a good society.
(Do we have one?)
Y.K

In article <32754DBC.70BB@cam.org>, Achim Recktenwald  writes:
-> I just stumbled into this thread and might therefore ask something which
-> has already been answered.
-> My question: In what aspect or parameter do two photons differ, if the
-> first one corresponds to a infrared wavelength and the second one to one
-> of the ultraviolet part of electromagnetic radiation. As far as I know,
-> the mass of both is zero, the speed is the same, the size is suposed to
-> be a point, what characteristic is left ?
The energy of the two photons is different.  The energy (E) of a photon
is related to its frequency (f) by E = hf where h is Planck's
Constant.  The greater the energy, the larger the frequency and
the bluer the light appears to be.
============================================================================
"One person can make a difference, but most of the time probably shouldn't."
============================================================================

On Sun, 27 Oct 1996, David Longley wrote:
> In article 
>            dyeo@tortoise "David Yeo" writes:
> 
> > In some senses it seems that Dennett uses "the intensional stance" much as
> > Quine uses "dispositions", i.e. as a communication device given our limited
> > knowledge of the physical details of the described process/event. 
> > 
> That's  interesting  - and something I will make some use  of  in 
> future if true. Can you substantiate your claim ('in some senses' 
> and 'seems' makes we wary ...:-)... 
> 
> -- 
> David Longley
For what it's worth, the reason for my caution is that an analogy can be
made to conflict or cohere in virtually an infinite number of ways.  While
I am certain of Quine's claim re: dispositions (to wit),
 "Where the general dispositional idiom has its use is as follows.  By 
  means of it we can refer to a hypothetical state or mechanism that we do
  not yet understand, or to any of various such states or mechanisms,
  while merely specifying one of its characteristic effects, such as
  dissolution upon immersion in water." 
     (Quine, 1974, "The Roots of Reference", p. 10)
 "I once expressed my view on dispositions by saying that a disposition 
  is a promissory note for an eventual description in mechanical terms." 
     (ibid, p. 14)
Dennett's "intentionality" theme continues to evolve (cf. "Content and
Consciousness" vs. "Consciousness Explained").  
Cheers,
- David Yeo (Applied Cognitive Science, University of Toronto)

In <3275691E.14F9@citicorp.com> Robert Fung 
writes: 
>
>Ken Fischer wrote:
> > 
> > Allen Meisner (odessey2@ix.netcom.com) wrote:
> > : In <3273879C.2735@citicorp.com> Robert Fung 
> 
> > : writes:
> > : >    If a constant current is supplied to a coil the electrons
> > : >    are accelerating about the center of the coil with a
> > : >    constant velocity. There is no EM radiation for the constant
> > : >    current i understand. Is there a force holding the electron
> > : >    in its orbit around the turns of the coil, or is the coil
> > : >    considered the curvature of the "space" that the electron
> > : >    must travel in ?
> > 
> > :     I would make the hypothesis that the protons in the coil
provide
> > : the spacetime curvature along which the electron must travel.
> > : Edward Meisner
> > 
> >            Let me explain how a Cathode Ray Tube, then
> > make up your own mind.
> > 
> >            A bias voltage is applied to the cathode, then
> > the cathode is heated with electrical resistance heating.
> >            A swarm of electrons are emitted from the cathode
> > and remain near it.
> >            A very high positive direct current is applied to
> > a conducting coating on the sides of the tube, and that
> > accelerates the electrons toward the front of the tube which
> > is coated with flourescent pigments.
> > 
> >            Four electromagnetic coils on the neck of the tube
> > are energized with the proper timing to cause the electron
> > beam to follow any path the design of the tube calls for.
> >            For television, this path is horizontal, with
> > each pass lower than the next.
> >            For some computer screens and oscilloscopes, etc.
> > the path may follow any designed vector.
> > 
> >            Electrons can be manipulated at will using
> > magnetic fields, most older TV CRTs even had a permanent
> > magnet to initiate a vector.
> > 
>
>      Yes, but in that case the electron is accelerated in 
>      both magnitude and direction. In the case of the coil 
>      with a constant current only the direction changes 
>      and the acceleration is more likened to that of an
>      object in free-fall orbit. As in GR, it seems to me there
>      is then some lee-way in defining the 'force' that
>      holds it in the circular orbit in the coil in terms of 
>      the shape of a space defined by the coil topology ?
    This a little too hard for me, but I think I would agree.
Edward Meisner

Emily Harrison Kelly (ekelly@world.std.com) wrote:
: Bo Bradham  wrote:
: >
: >The afu FAQ has 
: >F. Daylight sky appears dark enough to see stars from bottom of deep well.
: >
: >It's been a long time since it has come up on the newsgroup,
: >though.  And there's nothing about it in the afu archive as far
: >as I can tell.
The reason there's not much in the archives about it is that we discussed
it a long time ago.  It was an interesting discussion, and one I wouldn't
mind seeing again.
Someone else will have to give the science behind the explanation that the 
reason it doesn't work is the same reason that the sky still looks blue 
from the bottom of the well.  You've still got all those air molecules 
between you and the star, and they're still diffusing both sunlight and 
starlight, just as they were when you were at the top of the well.
Regards                                 
Ray "it's run-on sentence week" Depew  rrd@fc.hp.com 
Integrated Circuits Business Division 
Hewlett Packard Co, Fort Collins,  CO

Karthkikeyan Sinnadurai  wrote:
>I need help to solve this problem.
>
>Three forces are applied to an object:
>
>F = 10 N east, F = 20 N north 45 degree West, F = 15 N east 30degre South
> 1              2                              3
>Calculate the resultant force on the object. Find a fourth force that 
>will keep the object in epilibrium.
You must have mistaken this group for alt.do.my.homework.for.me!

But isn't the problem really that nothing in the Real Universe can travel
faster than the speed of light?  Isn't true that the only reason anyone
thinks that fsl travel is impossible the fact that at speeds past c, time
and distance become imaginary?  Does this mean that it can't happen?
No.
It simply means that you have to take into consideration the Imaginary
Universe.  The land where sqrt-1 and his friends hang out.  
Right?
Ash---------------------------------------"It only hurts if you let it"
JUST SAY NO TO DRUMS!!!---Join the Partnership for a Drum Free Amerika
------------------------------------------------
jsnodgrass  wrote in article <32732ED3.4036@mho.net>...
> Faster than light travel is not possible in a closed system. If you
> consider looking at a particle from 1000000000 miles away, it is
> conceivable to go faster than light, but if you look at it from 50ft
> away at all times, it is not possible. Look, this rule of light isn't
> only a rule for light, it is a property of space. If we want to
> understand this universe, we need to look at space with relativity in
> mind.
> 

About seeing stars in daylight from the bottom of a well, long tube,
etc.:
The last time this came up on alt.folklore.urban (and it was 
crossposted then, too), it was revealed as a joke.  A Boy Scout Joke,
no less.  A good old-fashioned Boy Scout Summer Camp Joke, right
up there with left-handed smoke shifters and snipe hunts.
In late afternoon, when everybody's feeling too tired to climb 
mountains or carve neckerchief slides but dinner's still an hour
or two away, some of the older Scouts start talking about working 
on their Astronomy merit badge.  One of them says he's going to go 
identify some constellations, and everybody waits for a tenderfoot 
to say "You can't see stars in the daytime!"
When the know-it-all tenderfoot finally says that, one of the older
Scouts sides with the tenderfoot and challenges the stargazer to
prove that it can be done.
Meanwhile, one of the other older Scouts says "I'm thirsty" and gets
himself a big glass of water.  He sips quietly, and watches the
proceedings with interest.
So the stargazer takes a long tube, like a mailing tube or a fly-rod
case, and a compass, and figures out an imaginary bearing on some
constellation or star that is not visible in the summer -- Orion, for
instance -- just to make it plausible.  He then orients the tube just
so, and invites the older skeptic to "take a look."  The guy looks,
is suitably impressed, and says so.  Other Scouts take turns looking
through the tube, and are also amazed that it works.
Finally the know-it-all Tenderfoot lets his curiosity overcome his
better judgement.  He swallows his pride and asks if he might take
a look.  The daylight astronomer obliges.  The tenderfoot squats, 
peers through the tube -- "you have to wait for your eyes to adjust," 
he is advised -- and the aforementioned thirsty Scout pours the glass 
of water down the tube.
Regards                                 |         "It does not do to
Ray Depew               rrd@fc.hp.com   | leave a live dragon out of
Integrated Circuits Business Division   |        your calculations."
Hewlett Packard Co, Fort Collins,  CO   |                 -- Tolkien       

Hello,
I'm looking for a source of information on time.  A couple of weeks ago, 
I was talking with a friend over a few beers, and he was talking about 
some interesting developments in the measurement of the speed of light 
over the period of time such measurements have been made.  He claimed 
that it appears that there seems to be some differences in c over time, 
which would indicate a slowing.  Now...is this BS?  (My friend has been 
known to see how much BS he can sling before being brought to post...)  
Anyone else heard anything like this?  Is there an WWW address I can 
look at if so?   In this same discussion he also claimed that studies of 
red-shifted light from surrounding galaxies, stars, etc. all fall into 
bands...or, in other words, are quantized.  So...more BS?
Thanks in advance,
Norm Young

In article <32743114.2A57@onramp.net>, Larry Richardson
 wrote:
[One more before leaving.  Couldn't resist]
>Louis Savain wrote:
>> 
>>   Sorry, that's not what I'm saying.  I'm saying that the traveling
>> twins first accelerates away (1) from the earth bound twin, then
>> applies negative acceleration (deceleration) (2) to come to a "stop",
>> then accelerates (3) toward the earth bound twin and again decelerates
>> (4) to come to a final stop.  That's two equal and opposite
>> accelerations going away and two equal and opposite accelerations
>> coming back.  Unless I'm missing something that is obvious to others,
>> it seems that the net total acceleration is zero.  The 4 of them
>> cancel each other out.  This could not be the reason for the time
>> dilation, IMO.
>> 
>
>Every time the traveller accelerates to create a net velocity with
>respect to the clock being used for comparison without a
>counterbalancing equal acceleration by that clock, the diparity between
>clocks becomes greater.
  Sorry, I can't agree with this.  Accelerations are vector
quantities.  Their effects are directed.  If the accelerations are
opposite and equal over the course of the twin's trajectory, their net
effect is null.  There is no need to counterbalance with the other
clock.  It is already counterbalanced.  I still think that time
dilation has nothing to do with the accelerations of the traveling
twin.  Also, the explanation that the traveling twin changes frames
and as a result, the change of frames somehow messes up the clock is
equally lacking in explanatory power.  The way I see it, the traveling
clock will slow down on the first leg of voyage and slow even more on
the second leg.  Direction does not matter.  Are these the only
explanations of the twin paradox going around?  If so, I'm afraid
they're not any good, IMO.  Sorry.  Still, I'm willing to change my
mind if someone can show me mathematically how the net zero
accelerations affect the traveling clock.
  A long time ago I remember reading an account of the twin paradox
that invoked the action of the entire mass of the universe as a
possible factor.  Sounds to me like this explanation is even worse
than the other ones.  Does anyone know about this?  If so, would you
care to comment on it?
  It's amazing how the physics community would rather stand on their
heads and do a collective neutron dance, than consider absolute motion
as the simple and easy solution to this problem.  Why is that?  What
is there to loose besides a few inflated egos?  Absolute motion does
not invalidate SRT, i.e., the relativity of observed motion.  Nor does
it invalidate the constancy of the speed of light.  SRT, IMO, is like
a federal mandate without the appropriate funding.  It postulates (at
least most physicists claim that it does) that the only form of motion
is relative motion, and yet does not offer a cause-and-effect
explanation for that relativity.  The funny thing is, physicists just
kick back as if this were no problem at all.  Since when did science
decide that cause and effect was no longer pertinent?  The logic of
cause and effect is the be-all of physics, as far as I can tell.  This
is why the lack of a cause-and-effect explanation for relative motion
is such a monstrous hole in the theory of relativity and the sooner we
come to realize this, the better.
  Is someone deliberately trying to keep the masses from figuring out
the cause of the constancy of the speed of light.  It might be my
paranoia kicking into overdrive but I don't think so.  I haven't seen
a single sensible reason why relativists absolutely refuse to have
anything to do with absolute motion when it would instantly explain so
many things in one fell swoop.  Why the reticence?  Did someone
decided that Occam's razor somehow lost its sharpness when it came to
relativity?  Or are some people afraid that its application might
inadvertently do away with a few huevos in the process?  :-) 
>  A crude analogy would be to have two cars at
>the same place with identical mileage on their odometers, then driving
>one of them a few miles away.  You couldn't get their odometers to match
>once again by driving the car that had moved back to meet the car that
>hadn't moved even though the movement exhibited some symmetry.
  It's a good thing you said this is a crude analogy.  Very crude, I'd
say.  :-)  Comparing lengths traveled with the rates of clocks can
only lead to confusion at best and wrong conclusions at worst.
Best regards,
Louis Savain

> Does someone know about the antigravity effects related to 
> superconductor rings, discovered by the russian scientist Eugene 
> Podkletnov?
They do not exist. Just more scam.
Daniel Morgan
[Moderator's note: "Scam" or experimental error?  They are very
different.  A quick search reveals some rather puzzling gossip:
http://www.ozemail.com.au/~joi/issue4/ar192.html 
- jb]

Allen Adler wrote:
> 
> What would be the best way to obtain numerical solutions of
> Maxwell's equations in an anisotropic medium?
> 
> Allan Adler
> adler@pulsar.cs.wku.edu
Try looking up work done with numerical computation of Chiral media. 
You
might start with:
     MARIOTTE F; GUERIN F; BANNELIER P; BOURGEADE A.
     NUMERICAL COMPUTATIONS OF THE ELECTROMAGNETIC FIELD SCATTERED BY
COMPLEX
   CHIRAL BODIES.
     JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS, 1995, V9
   N11-1:1459-1485.
and look at the references.
-- 
- Mike
  mdwhite@ucdavis.edu

Can you show that the relationship between the atomic radius
and the first ionization energy is expressed by _two_ curves
(Not one curve) by using semi-classical argument?
P.S.
I am sincerely sorry for my repeated posting because of my
inexperience of the mailer.
--------------
Syuzo TAMURA,     NIRIM,     E-mail: tamura@nirim.go.jp
meron@cars3.uchicago.edu wrote in article
<54tgep$snj@agate.berkeley.edu>...
> In article <54rh40$pc2@pulp.ucs.ualberta.ca>, Ross Larsen
>  writes:
> >It seemed very obvious to me.  It follows from simple semi-classical
> >arguments, too, doesn't it?
> 
> Yeah, you really don't need more then that.

Louis Savain wrote:
>   Is someone deliberately trying to keep the masses from figuring out
> the cause of the constancy of the speed of light.  It might be my
> paranoia kicking into overdrive but I don't think so.  I haven't seen
> a single sensible reason why relativists absolutely refuse to have
> anything to do with absolute motion when it would instantly explain so
> many things in one fell swoop.  Why the reticence?  Did someone
> decided that Occam's razor somehow lost its sharpness when it came to
> relativity?  Or are some people afraid that its application might
> inadvertently do away with a few huevos in the process?  :-)
Huevos?  Now you've proved that you are paranoid.  And you may 
personally have huevos, but you wouldn't make up a decent serving of 
brains and eggs.  You want machismo?  Let's go, mano a mano.  Read this:
http://www.mindspring.com/~mentock/twins.htm
and tell me *anything* that's wrong with it.  Anything.
-- 
D.
mentock@mindspring.com
http://www.mindspring.com/~mentock/index.htm

Lloyd Johnson wrote:
> 
> >That there is a difference can more easily be shown with a Michelson
> >white light interferometer. And yes, it has been done ... its an undergraduate
> >optics lab experiment.
> 
> This is exactly what I was asking.  Who was the first to insert glass,
> water, or whatever in the path and compare color fringes?
> 
Well, to continue, I would say that it was Michelson! After all,
he invented the Michelson interferometer, and was the master of
its manifold uses.  I would guess this was done by at least the early
1880's.
> Does sound of different frequencies also travel at different
> velocities?  Is this wave behavior unique to light?
> 
No, this is a general property of waves in a dispersive media.
The vacuum is the only non-dispersive media for light (though
air has very little dispersion).  I think that all waves that
travel through matter are dispersed ... and the dispersion
is always frequency-dependent.
That is, it is a property of the interaction-energy, which
varies with the frequency.
Best Regards, Peter

Louis Savain (savainl@pacificnet.net) wrote:
:   Ken even though I agree with you that time dilation is a direct
: consequence of making the speed of light constant mathematically, I
: don't think that Einstein just decided to do that our of the blue.  I
: would bet money that somehow Einstein got wind of the MM null result
: before submitting his paper for review.  Does anyone here know whether
: or not the SRT paper was submitted before of after the MM experiment?
I believe the MM exeriment was done while Einstein was still a child.
--
Aaron Adams
radams@paladin.wright.edu
***
Whether they ever find life there or not, I think Jupiter should be 
considered an enemy planet. I don't think I'm alone when I say I'd like 
to see more and more planets fall under the ruthless domination of our 
solar system.

Lloyd R. Parker (lparker@larry.cc.emory.edu) wrote:
: Mark Brindle (brindle@lf.hp.com) wrote:
MB: So, Lloyd, it's *MATHEMATICALLY IMPOSSIBLE* to formulate Planck's
MB: equation in terms of Joules/m^2 -- because *any* such form would
MB: constitute a *general proof* that Watts and Joules are identical.  
LP: But you CAN express Planck's equation in J/m^3.
So, what's your point?  I've *always* maintained that Planck's equation
describes the power-per-unit-area of a black body radiator -- and J/m^3
is a *direct* measure of power/area.
Are you *still* claiming that black bodies can be described in terms of
of "energy" or "energy-per-unit-area"?   Well, you're still DEAD WRONG!
MB: Words are cheap, Lloyd;  in *hard sciences* like chemistry/physics
MB: they're *useless* as ammunition against *MATHEMATICAL EQUATIONS*.
LP: Uh, no, Mark, perhaps if you had a real, liberal arts college education, 
LP: you'd realize words are as useful in science as any other discipline.  
LP: For example, explanations -- theories -- are formulated in words.
And *idiots* interpret the words incorrectly.  If you have something
quantitative to say, there's *absolutely no substitute* for equations;
if you have nothing quantitative to say, you really don't understand
what you're talking about -- at least in the sense of "hard science".
MB: Planck's *EQUATION* says:  There is *NO SUCH THING* as "the energy"
MB: of a black body radiator 
LP: Hmmm... Wall says you there is the energy density.  Guess what -- Silk's 
LP: book also does the same thing.  Energy density.  And total energy density 
LP: = aT^4, where a = 7.56 X 10^(-15) erg/cm^3 K^4.
Thanks, you have *AGAIN* proved my point.  There is *NO SUCH THING*
as "the energy" of a black body radiator.  By the numbers, Lloyd:
 1)  Energy is an *EXTENSIVE* property!
 2)  Temperature is an *INTENSIVE* property! 
 3)  Extensive and intensive properties are *DIFFERENT*!
 4)  Your quote from Silk's book *PROVES* that you are DEAD WRONG.
 5)  Silk says that "energy_density" depends *ONLY* upon temperature.
 6)  Silk's equation *PROVES* that erg/cm^3 is an *INTENSIVE* property!
 7)  With help from Silk and Wall, *you* have *PROVEN* yourself an IDIOT!
MB: Words are cheap, Lloyd.  In the *hard sciences* you need *EQUATIONS*;
MB: if you can't *SHOW US AN EQUATION* from Newtonian physics that uses
MB: Joules Of Gravity, you're just shoveling bullshit.  Shovel on, Lloyd!
LP: Words may be cheap to an engineer.  I'll remind you, Silk refers to 
LP: "short wavelength gravitons," "energy of a graviton," and "characteristic 
LP: energy distribution of gravitons."
So, I take it that you *CAN'T* come up with a Newtonian *equation*
that uses Joules Of Gravity?  Thanks for *AGAIN* proving my point,
Lloyd;  for *you*, words are EXTREMELY cheap and easy to come by...
...especially compared to equations,
Mark
 "There's no point in being precise when you don't know what you're
  talking about."
                     - unknown, apparently someone who's met Lloyd

Matt Austern wrote:
> 
> Steven Hines  writes:
> 
> > As I consider these two actions, though, I have a hard time seperating
> > them. What is different between having the notion that "every event
> > has a cause" and having the notion that "the universe is lawful"?
> > If an event happens _and_ the universe is lawful, how can the event
> > not have a cause? Isn't an event without a cause arbitrary (not following
> > any law)? What kind of law is: "uncaused things happen occasionally"?
> 
> If you sit and look at a particular tritium atom long enough, you
> might find that it will suddenly decay into an isotope of helium.  As
> far as today's physics is concerned, though, there isn't any way to
> predict just when it will decay.  We can predict the probability that
> it will decay, but its decay at any particular instant is, as far as
> we know, uncaused.
> 
> Some physicists believe that there really is some cause for the atom
> decaying at one instant instead of another instant, and that we just
> haven't found out yet what the cause is.  At this point, though, there
> is no evidence that those physicists are right.
All right. But consider this:
Richard Harter, to whom my paragraph above was first addressed, wrote:
> Urk.  Not only do you not have to believe that every event has a
> cause, you'll do well to lay any such notion firmly aside if you're
> going to come to terms with modern physics.  What you do have to "do"
> is accept *as a working hypothesis* that the universe is lawful.
Now, it may be that physicists disagree as to whether or not the decay
has been caused. As Richard says, I should discard my notion that
every event has a cause.
But Richard also says that I should accept a working hypothesis that
the universe is lawful. So: what about the physicists who do _not_
believe that the decay you talk about is caused? That is, some group
that believes that it is futile to search for the mechanism causing
the decay, because there isn't one. Do these physicists continue
to work under Richard's hypothesis that the universe is lawful?
For my part, I can't see how it is possible. If the decay is
spontaneous and uncaused, then no law can describe it. I suppose you
could try: "Decay is spontaneous and uncaused", but how are you going
to prove or disprove it through experimentation? And if no law can
describe it, the hypothesis that the universe is lawful must be
discarded.
Once again I find myself holding the position that holding the notion that
"all events have causes" is the same as working with the hypothesis that
"the universe is lawful." If you discard the first, how can you keep
the second?
In the end, of course, there are those other physicists who believe 
that the decay does have a cause, despite the lack of evidence. They are
continuing their search because their job demands that they search for
the law that describes the phenomenon. They assume that there is one to 
find, and may spend their careers looking. Thus, they have accepted 
Richard's working hypothesis that the universe is lawful. Haven't they
also accepted that all events have causes?
-----------------
Steve Hines
shines@sdd.hp.com

In article <3274fb10.64121084@news.ftn.net>,
   mrjones@yoss.canweb.net (Jones) wrote:
>Lets not get anal here, Einstein was a jew and it was because of his
>belief in god that he could not reconcile things like quantum theory.
Einstein was Jewish by ethnicity, not by belief. Take a look at his writings 
at my site: http://www.stcloud.msus.edu/~lesikar/ESR.html.
Your claim that it was Einstein's "belief in god" that inspired his disbelief 
in quantum indeterminacy would seem to rest mainly on that famous quote about 
God not playing dice with the universe. I think that that is a rather shallow 
reading of the man. First Einstein had inherited no faith in God. His ideas 
about God were inferred from his study of the universe. The universe seems 
lawful and orderly. Einstein was struck by the fact that universe seemed to be 
put together with a great subtlety, and yet it is possible to comprehend it. 
Indeed another famous tag line from Einstein was his expression of wonder at 
the fact that universe can be understood: "the most incomprehensible thing 
about the universe is that it is so comprehensible."
It was the comprehensibility of the universe and the beauty of its laws that 
led Einstein to the notion that some cosmic intelligence must be responsible 
for it. In short, Einstein arrived at his conception of "God" from looking at 
the universe. He did not have preconceived notions of "God" that led him to 
look at the universe in a particular way. It was the universe that Einstein 
knew. "God" was merely a personal hypothesis to explain the existence of the 
universe.
The regularity of the universe lay in the law of causation. It was that law 
that Einstein could not give up. This has nothing to do with God. It has 
everything to do with Einstein's conception of how the universe works. Quantum 
indeterminacy did not fit into Einstein's picture of the universe. Einstein 
was a determinist and remained a determinist until the day he died. Einstein 
had had great success in comprehending some of the fundamental laws of the 
universe. How could he accept of foundation of fundamental randomness 
underlying the apparent order that he had discovered? 
I am quite sure for Einstein a universe without a rigid deterministic law of 
causation, would have been a universe that was no longer comprehensible. And 
*that* IMO is what his statement about God playing dice really means. 
arn
lesikar@tigger.stcloud.msus.edu

"Paul G. White"  wrote:
>Alan \"Uncle Al\" Schwartz  wrote:
>
>
>>
>>
>>Euler's Equation unites algebra and analytic geometry. I'd be >real< 
>>curcumspect about minimizing that.
>>
>>-- 
>>Alan "Uncle Al" Schwartz
>>UncleAl0@ix.netcom.com ("zero" before @)
>>http://www.ultra.net.au/~wisby/uncleal.htm  (lots of + new)
>> (Toxic URLs! Unsafe for children, Democrats, and most mammals)
>>"Quis custodiet ipsos custodes?"  The Net!
>>
>>
>
>That's "circumspect".
It's a typo.  
Consider sodium diaminodihydroxyarsenobenzenemethanesulfonate.  What's 
a vowel here or there?
-- 
Alan "Uncle Al" Schwartz
UncleAl0@ix.netcom.com ("zero" before @)
http://www.ultra.net.au/~wisby/uncleal.htm  (lots of + new)
 (Toxic URLs! Unsafe for children, Democrats, and most mammals)
"Quis custodiet ipsos custodes?"  The Net!

Christopher Michael Jones wrote:
>By the way, in _French_ meter is spelled metre _not_ in English.
Sorry to introduce me with my bad English in your riot, but you are 
wrong.
I know all of you have ISO/ITC 8859-1 support, so I can write that 
the SI unit is spelled m�tre in French.
This will cost you 1 point (out of 20).
Thanks for your attention ;-)
Antoine

Stephen Holland wrote:
> 
> In article <32754DBC.70BB@cam.org>, Achim Recktenwald  writes:
> 
> -> I just stumbled into this thread and might therefore ask something which
> -> has already been answered.
> 
> -> My question: In what aspect or parameter do two photons differ, if the
> -> first one corresponds to a infrared wavelength and the second one to one
> -> of the ultraviolet part of electromagnetic radiation. As far as I know,
> -> the mass of both is zero, the speed is the same, the size is suposed to
> -> be a point, what characteristic is left ?
> 
> The energy of the two photons is different.  The energy (E) of a photon
> is related to its frequency (f) by E = hf where h is Planck's
> Constant.  The greater the energy, the larger the frequency and
> the bluer the light appears to be.
> 
But frequency is a characterisitc of a wave. How do you distinguish
photons, not waves, of different energy ?
Achim

mlyle@scvnet.com wrote:
> 
> trike@ix.netcom.com(Douglas Tricarico) wrote:
> >You can teach
> >anyone the metric system in 5 minutes since we already use the same
> >base-10 method with the US monetary system.
> 
> I used to think that this was true until I started teaching Physical
> Science to 9th graders.  Despite 8 years in our educational system the
> vast majority seem to have escaped the metric system.
> 
> My own attempt to get them fluent in the system was about 50%
> successful (at least in the short term).
I talked to a friend who is a teaching assistant here in an
undergraduate physics class. He observed that all non-U.S. students
nicely converted everything to SI base units and then calculated without
careing any more about the units. Over half of the U.S. students however
solved the exercises in pound-inch units, even if applying all the
conversion factors made up a significant amount of the work necessary to
solve the problem and even if the problem was formulated in SI units!
There seems to be some sort of mental barrier that allowed them to think
in SI units only when absolutely necessary.
He then constructed an example exercise where the advantage of using a
coherent (i.e., conversion-factor-less) system of units over the
inch-pound system became especially obvious and demonstrated his
students both the solution in SI base units and the solution in
inch-pound units. He also mentioned how often students solved a problem
correctly except for an error in some conversion factor. He was able to
demonstrate them that the inch-pound solution will take considerably
more time and that the many conversions are an excellent source for
mistakes and that everyone who uses the inch-pound units risks therefore
worse results in the exams (although both alternatives are allowed).
From this day on, noone ever used again inch-pound units in the homework
in this class.
Students grown up in the inch-pound world underestimate considerably the
obvious advantages of SI units and overestimate the effort necessary to
accept the SI units as the natural units in which a physics problem
should be understood and solved. Therefore, either a demonstration of
convincing examples and homework statistics or (less preferable) some
pressure (inch-pound units are simply not allowed) is necessary in order
to force them to accept and get familiar with SI units.
The best idea would be to ban inch rulers from classrooms entirely
and to do all geometric constructions, diagrams, etc. on paper with
a 5 mm grid (as I did it all the time in Germany). Unfortunately, I have
not even found a source of paper with a 5 mm grid here and now I have to
do all my work on 1/5" grid paper. In addition, all rulers I have found
in the local stationary shop had inch markers and only some of them had
additional cm scales. This school equipment market situations does not
make it easier for a teacher to educate the next generations in SI
units.
Markus
-- 
Markus Kuhn, Computer Science grad student, Purdue
University, Indiana, US, email: kuhn@cs.purdue.edu

candy@mildred.ph.utexas.edu (Jeff Candy):
> Each of your posts follows the same recipe:  two parts empty prose, 
> one part insult, and a dash of bad metaphor.  What is your goal 
> in writing?  
moggin :
> |> In this, particular discussion, it's to defend myself against 
> |> pig-ignorant attacks from people like you.  And yours, pray tell?
Jeff:
|> > I tried to be as polite as possible in my last post.  
moggin:
|>    Then perhaps you should stop trying.  I'm serious.  Your earlier
|> posts were entirely polite.  I replied in kind, and you dropped the
|> subject.  Your last post, in contrast, was just an attack.  Again I
|> replied in kind; now you've re-acquired a degree of your politeness. 
|> Go figure.
Jeff:
>After reading a good number of your posts, I noticed that you were 
>devoting (what I thought was) an inordinate amount of time to heaping 
>insults.  If you're really interested in making a point, I don't see 
>how that can help. 
     I already replied to this point -- you deleted the answer and then
repeated yourself.  "As I've observed to others in this discussion, if 
you intend to play Emily Post, you'll have to do more than criticize _me_
(at least if you hope to make your partisanship a wee bit less glaring)."
Jeff:
|> > One main point -- namely, that most of your posts include an insult -- 
|> > was unavoidable.  To call my comments "pig-ignorant" is not reasonable.
moggin:
|> In our earlier exchange (the one about the Sokal affair, a few days
|> ago), your comments were perfectly civil, and I replied to you in the
|> same style.  But you ignored that dialogue in order to claim that each
|> of my posts was insulting.  Thus you're a person who chooses ignorance,
|> the better to make fraudulent claims.  (There's plenty more like you
|> around here.)
Jeff:
>You were indeed civil to me previously.  Now read my passage above again:  
>I said "most" of your posts, not "each".  
     Bullshit.  You said, "Each of your posts follows the same recipe: 
two parts empty prose, one part insult, and a dash of bad metaphor."
_Then_ you retreated to "most."  You're headed in the right direction;
the next step to is march from "most" back to "some," and then consider
_which_ posts contain insults, and why.  There's no rush, but you might 
want to stop making accusations until you've done some thinking.  (If
you need a hint, you'll find it in my comments immediately below.)
moggin:
>l Please note that I'm the very soul of courtesy.  When you were civil,
>I I offered you a civil response -- when you wanted to exchange insults,
>I accomodated you there, as well.  (Or perhaps you wanted just to dish 
>l them out?)  
Jeff:
>I've never wanted to "exchange insults".  
     See above.
Jeff:
|> > What I think was stated explicitly.  I can restate it very succinctly 
|> > if you wish:  gamma -> 1 is an approximation which captures the 
|> > relevant physics in most situations.  One can, and should, use this 
|> > approximation in most applications.  On this, I know I'm right. 
|> > There.  Done. 
moggin:
|>    If I understand correctly, you're trotting out the Indy-cars, bridge-
|> building, moon-shots argument again.  But that was never a matter of any
|> dispute -- it's obvious to everyone concerned that Newton is good enough
|> for good ol' boys and government work.  So if that's the only conclusion
|> you want to reach, congratulations -- we've been there from the start.
Jeff:
lCan I translate this as:  
l"Correct.  However, Newton is wrong in a different, more subtle sense"  
     I'm agreeing (as I have from the start) that Newton's errors are
small enough to ignore while performing many common tasks.  Isn't that
obvious?
moggin:
|> I see.  So when you attack me with falsehoods and insults, that's
|> just fine -- but when I reply, you suddenly adopt a high moral tone. 
Jeff:
>-> Which falsehoods?
>-> Which insults (other than to imply that you insult others alot, and 
>   spend too much time coloring your language needlessly)?
     "Each of your posts follows the same recipe: two parts empty prose, 
one part insult, and a dash of bad metaphor."  (Insult and falsehood.)
"I submit that your difficulties in this matter were a result of your
willingness to argue without having thought carefully about what it was 
you  wanted to say."  (Insult.)  "After reading many of your posts (and 
you do produce a prodigious amount), I offered two tentative conclusions:
(i)  your posts contain more insults than original ideas (ii) you argue
at length about a subject you had not thought about.  (More insults.)
moggin:
|> Of course I'm not claiming to say anything original about Newton:
|> I've been clear about that.  I made what I once thought was a widely
|> accepted statement, only to find myself being attacked, months later,
|> by people yelling things like, "You idiot!  Don't you know that's 
|> widely accepted?"  Welcome to the party.
Jeff:
>I am sympathetic to the fact that there is no shortage of loudmouths on 
>this group (sci.physics) yelling "you idiot" without due provocation.
>I also apologize if anything I say is off the mark because I've not 
>read every article which preceded this out-of-control thread.  But 
>now its evolved into a very unfocused argument about Derrida and 
>all kinds of other foggy stuff, and I'm not convinced anything was 
>every *properly* resolved at a more fundamental level.  You could 
>simply summarize for me your most basic assumptions (if you indeed 
>argue from such) in this matter, *or* you could tell me to just go 
>away because you can't be bothered regurgitating what you consider 
>to have been stated sufficiently well already.  
     What matter are you concerned with?  And what do you want my
basic assumptions about?  Six months ago, during one of the periodic
round-robins between alt.postmodern, talk.origins, and sci.skeptic, I 
gave Newton as a counter-example to the proposition that "scientific
theories are never wrong."  Recently a post turned up quoting part of
that conversation.  Several members of talk.origins and sci.skeptic
saw the post, read my earlier comments, and felt compelled to dispute
me.  Michael Siemon called me a complete idiot, Bob Casanova accused
me of playing semantic games, and Matt Silberstein asked, in what may
have been plaintive tones, "But what about Indy cars?"  The ensuing
flame-war was cross-posted to rec.arts.books and sci.physics (in all
likelihood by Noel Smith).  The rest is history.
>Recap:  Its never been clear to me exactly what your position on 
>approximation in physics is.  What is it?
     Please explain how one takes a position on approximation.  What
are my choices?
-- moggin