Subject: Re: Frequency-Space paradox?
From: "Robert. Fung"
Date: Tue, 07 Jan 1997 10:01:57 -0500
meron@cars3.uchicago.edu wrote:
>
> In article <32D16582.9B4@citicorp.com>, "Robert. Fung" writes:
> >Jim Carr wrote:
> > >
> ... snip ...
>
> > > The coordinates q are chosen, the Lagrangian written in terms of
> > > q and q_dot, and then the conjugate momenta p are determined.
> > > >
> > Then it is apparent from this the dependency of p's on the q's.
>
> Not too fast. Functionally the p's and q's are independent.
Then the p's can be considered as "separate" coordinates ?
and we have some implied "dual" of space ( of the original
selection of coordinates q's) to work in which we can jump back
and forth between as you say below, with some canonical transform
like an FFT and IFFT or similar.
But they are dependent in say the Fourier/Heisenberg
uncertainty. A real "yin-yang", zero-sum game, trading with
conservation, relationship.
Also frequency and time being dependant, so in some sense
equivalant, but not without some entropy being paid for to
show the equivalence.
And, the conjugate measurements sometimes seem asymmetric:
The radio engineer measures a frequency-domain spectrum of
a time-domain signal or is it ever the other way around ?
A time base is generally implied (sweep scan, reference signal
in lissajous patterns...)
For a quantum physicist, the measure of the energy quanta
has little value at radio frequencies; the field strength
is not uniquely tied to specific frequencies.
> The
> specific form of p's in any case follows from your choice of q's but
> that's mostly a matter of convenience. In fact, one can perform a
> canonical transformation to a new coordinate set such that the p's
> become the new q's and vice versa. In other words, they have equal
> standing.
Subject: Re: Mars Rock Crock!
From: "Robert Imrie, DVM"
Date: Tue, 07 Jan 1997 05:49:48 -0800
~Word Warrior~ wrote:
> "Robert Imrie, DVM" wrote:
>Word Warrior wrote:
> >> People properly nourished in clean surroundings won't
> >> get cancer at all.
> > I sincerely hope this is a joke, because there's not the tiniest bit of
> > evidence to suggest it is true.
> That's not quite the case.
Actually, it is the case -- but don't take my word for it.
> > And there's a mountain of evidence indicating it's false.
> Specify. Go ahead and cite an example.
Sorry. You're going to have to do your homework for yourself. I will,
however, point you in the right direction. If you've got a solid
background in biology, biochemistry, and genetics, as well as well as a
good medical dictionary and access to a medical library, you might try
looking in any basic oncology text. Even some under-grad genetics texts
discuss the fundamentals of neoplastic transformation and oncogenesis.
Many basic virology and toxicology texts deal with these issues as well.
If you don't have a very strong background in the areas I mentioned,
your best bet would probably be to ask an M.D, a veterinarian, or some
other science-based medical practitioner to discuss the issue with you.
Of course, if you know any geneticists, biologists, or biochemists, they
would do quite nicely as well. You might learn a lot by asking various
"alternative" practitioners the same questions, but I advise against it
-- because most of what you learn is liable to be incorrect. ;-)
> So can =you= prove the stupid rock came from Mars?
Nope. Can't prove it at all. However, having read a summary of the
analysis to which it was subjected, I think its Martian origins have
been established with reasonable certainty.
Good luck,
Robert Imrie
Subject: Re: FTL Comm
From: heuvelc@primenet.com (Curt van den Heuvel)
Date: 7 Jan 1997 08:34:01 -0700
Ryan Hughes wrote:
>Okay, we'll pretend that I understood that experiment correctly. Here's
>where I get really crazy. Isn't there some stuff that behaves
>differently depending on whether or not you've measured it? Maybe an
>electron with a .5 probability responds to a magnetic field differently
>than one with 1P. Something like that. If _all_ of that's true (fat
>chance), could you build some sort of device where you could take one
>of a pair of linked particles and figure out whether the other one is
>being measured?
The problem is that you always bump up against the inherent
uncertainty of QM (Heisenberg rises up to bite us in the butt once
again). Basically, you can only measure the particle's property -
there is no way to actually influence it, as would be required if we
wanted to modulate a signal.
In the case of spin, for example, there is no way to tell beforehand
what the spin of the particle is. You speculated that an electron with
a 0.5 spin would behave differently than that with a spin of -0.5, for
example. This is true. The spin would, for example, control the
orientation of the particle in an electric field. However, once again,
there is no way to 'manufacture' a particle with a specific spin. All
we can say is that there is a 50% chance that the spin is goin to be
one or the other. Thus, the signal is always going to be random, no
matter how you construct the experiment, which makes it useless for
the purposes of communication.
There is no way to tell a 'measured' particle from an 'unmeasured'
particle. If you think about it for a while, you should be able to
figure out why.
As an aside, some researchers did manage to send an FTL signal a few
years back using a property of QM known as 'tunneling'. Unfortunately,
it only works over very short distances.
-Curt
Subject: Re: How to obtain other-than-red pocket laser ?
From: Brian Rich
Date: Sun, 05 Jan 1997 08:53:22 -0800
C++ Freak wrote:
>
> Many electronics stores sell pocket lasers for about $50 which are
> small but powerful for their size. They are usually operated by
> 2.5 Volts (2 AAA batteries) and draw only 60 mA, but the beam
> has a low divergence (1 mrad) and reaches easily over 300 meters
> (1000 ft) far away. I am talking about the 5 mW ones.
> They are sold as pointers in a pen-shaped package.
> They have one thing in common: they are red (635 nm) and monochromatic
> (my spectroscope shows a single sharp red line).
> But I know that bluish-green (krypton ?) lasers are common as well,
> e.g. in discos or on rock concerts. I never saw them
> offered in pocket size form.
> My question is: are pocket-lasers also available in other colors ?
>
> BTW: Another question: why does the spot lit by a laser (the red
> 635 nm diode one) show a dotted pattern ? The same occurs with
> 'professional' lasers, also in other colors (e.g. the bluish-green Kr
> one) ?
>
> Thanks,
>
> Klaas
Some frequency-doubled diode pumped YAG lasers are available as
hand-held units. The wavelength is 530 nm (green). I say them in an
article on lasers and entertainment in "Laser Focus World" magazine.
Sorry, I have since tossed the issue.
The spots you are referring to, if I understand your question correctly,
are called laser speckle. It is an effect that is caused by the
interference of parts of the beam that reflect off of different regions
of whatever is being illuminated. The interference actually happens in
your eye!
Note that for speckle to occur, not much coherence is required of the
laser. Even direct sunlight has enough coherence to cause mild speckle
effects, as you can see uf you look at a plain matte surface in direct
sunlight. You'll see multicolored speckle in this case, as the source is
not monochromatic. Try a dark-ainted surface, or a black vinyl notebook
cover.
Best regards,
--
Brian Wesley Rich
-------------------------------------------------
Visit my amateur science page.
Chemicals, sample experiments, and good ideas!
http://www.west.net/~science/
Subject: Re: PH.D.s are useless
From: John
Date: Mon, 06 Jan 1997 17:25:12 -0500
William R. Penrose wrote:
>
> In article <5apcci$otf@sjx-ixn4.ix.netcom.com> Alan \"Uncle Al\" Schwartz writes:
>
> >Tim Harwood wrote:
> >>It was revelaed in the Sunday Times over Christamas, those with a PH.D.
> >>in economics are 40 % worse at economic forecasting that those without.
> >>( This is absolutely true, don't flame me for this, read David Smiths
> >>round-up of the economic forcasts for 1996 ).
> >>
> >>Confirmed what I've always thought, academics with lots of with initials
> >>after their names can't see the wood for the trees. Lost in irrelevant
> >>detail, they lose all track of reality.
>
> >The "science" of economics is based upon unfounded assumptions and is
> >embodied within an unvalidated mathematical framework. Consider Soviet
> >central planning or the US Ford administration's "Whip Inflation Now."
> >You couldn't cook up bigger disasters if you put a government in charge.
> >So, what else is new?
>
> Economists, weather forecasters and astrologers exist because people want
> certainty in their lives, and are willing to ignore past experience to get it.
> Weathermen continue to give 6-day forecasts, even though no forecast is valid
> beyond 24 hours. Economists have been predicting the imminent fall of the
> stockmarket for 2 years now. Eventually it will fall, and they will have been
> proved right.
>
> The present status of economics is due to its promising show around the turn
> of the century, when it came up with pat and convincing explanations for the
> behavior of economies. The fact that even the simplest, like supply and
> demand, fail entirely as predictive tools, doesn't matter. People want the
> certainty of a forecast.
>
> Of the the recent nobelists in economics got his medal for expounding the law
> that "people will generally act in their own self-interest". As my five-yr
> old granddaughter would put it: "Duh-h-h". I would never have figured that
> one out myself, not being a genius.
>
> Don't paint other sciences with the same brush.
>
> Bill
>
> ********************************************************
> Bill Penrose, President, Custom Sensor Solutions, Inc.
> 526 West Franklin Avenue, Naperville, IL 60540
> 630-369-9618 (temporary)
> email wpenrose@interaccess.com
> ********************************************************
Bill, I take exception to your lumping weathermen in with the other two
groups. Why, next thing you'll be lumping lawyers in with politicians.
Seriously, a linguistic study would show, (I bet), that the language of
astrology, economics, meteorology and the evening stock market report
are homomorphic.!;?)
Subject: Re: A few dark matter questions
From: kunk@perseus.phys.unm.edu ()
Date: 7 Jan 1997 15:45:12 GMT
In article <32cc63aa.4876279@news.nn.iconz.co.nz>,
Eric Flesch wrote:
>On 2 Jan 1997 23:48:18 GMT, kunk@perseus.phys.unm.edu () wrote:
>>Ok, Erik, my silliness comes from an exercise (out of Weinberg, Cosmology
>>and Gravitation) which seamlessly traces an expanding universe through the
>>use of stat mech and GR from BB to current expansion, including creation
>>of primeval H and He. It starts with energy and satisfies simple minds
>>like mine. You can even use integrals and come up with numbers for your
>>own amusement.
>
>The Big-Bang is perhaps today's leading example of Bayesian science in
>action, as theoretical calculations and observations directed by those
>calculations gravitate towards eachother, with constant punctuations
>of new observations which disagree wildly with theory and so require
>the theoreticians to lurch a new appendage of theory toward it. A
>sort of Bayesian Scientific Amoeba in action, aglomerating all in its
>path -- todays melting pot of theories and minds. Cry, cry, the
>rationalist, clinging to his outmoded ideas of refutability. :-)
>
I'm not sure what the content, emotion aside, of this thicket of words
is. Perhaps it is an alternative statement of the scientific method,
where scientists make independent observations and then try to recon-
cile theories with the physical universe.
Bayes, of course, wrote a perfectly sensible theorem addressing the
inclusion of prior results in calculation of probabilities. It allows
us to make sensible statements about the probability of a concluded
event, which we all do instinctively anyway. The only use of Bayes
theorem of which I am aware in my field is in an analysis of the
neutrinos detected from SN87A.
Jim
Subject: Re: The "force" of gravity? Please explain.
From: mj17624@janus.swipnet.se
Date: Wed, 08 Jan 1997 00:27:35 GMT
kfischer@iglou.com (Ken Fischer) wrote:
>: If we call the doubling time T for a body with diameter 1m and mass
>: 1kg, and look at three such bodies:
>:
>: o -10m- o -20m- o
>:
>: at t=0
>:
>: then at t=T
>: the bodies now have diameter 2m
>:
>: O -9m- O -19m- O
>:
>: we can continue this and conclude: the attraction of two bodies of the
>: same size and mass is independent of the distance between them.
> I don't believe you have interpreted DM correctly here,
>it looks to me like you are using time units of the same length,
>if matter expands, all clocks must slow with time, giving the
>equivalent of 1,2,4,8..... as the lengthening series of T units,
>so you need to look at more T units to make thought experiment
>function properly.
I really don't see how this would affect the discussion. If time slows
down, there would still be equivalence in the relations of the bodies.
T aT d1 r1 d2 r2 d3
0 0 1 10 1 20 1
1 1 2 9 2 19 2
2 2 4 7 4 17 4
3 4 8 3 8 13 8
4 8 16 (-5) 16 5 16
T= slowed time
aT= "absotute" time
d1,d2,d3= diameters of the bodies
r1,r2= distances between bodies
Of course the (T=4) line doesn't agree with DM, but it is unimportant.
> Also, you have objects not having a motion of translation,
>which is more of a difficult thing to accomplish than first appears.
> You must consider how the objects got to where they are,
With these small bodies, we could simply try it in a space station in
orbit. We would just fix them to a iron bar (so there is no
mass-centre velocity in our frame, the "absolute" velocity can be
calculated using the doubling time for the bar) and drop them in
space.
>and the motion of translation of the centers of mass. I am not
>objecting to having zero motion of translation of the COMs, but
>it is something that must be considered, because as the meter
>stick lengthens (matter, all objects, are meter sticks), the
>"space" between objects _decreases_ UNLESS objects are moving
>apart.
> This is difficult to imagine unless a "fixed" meter
>stick is used, the length being -the-length-that-it-was-at-
>t = 0 (this _is_ a thought experiment), so this is possible.
What's the problem? The meter stick also expands at the same rate as
the bodies. We therefore know the size of a meter at any point in time
(if we know T)
> If done properly, I think you will see results
>essentially equal to Newtonian gravitation (I sure hope). :-)
Still you are unable to explain the dependance of distance (or mass,
for that matter).
> I don't understand why you have a preference for
>what form a theory takes, "quantum" merely means numbers
>or how many, expressed in integer units.
> If you mean that you prefer a model of gravitation
>that somehow reaches out, grabs distant things, and pulls
>on them, I think that is what Newtonian gravitation is.
> For this, you need magic, or a totally new means
>of interaction at a distance that we are not aware of,
>which I would not object to, if everybody would consider
>Divergent Matter until the means of magic is discovered.
Well, how come that EM is explained by the exchange of
photons (in QED)? Magic? OK, since it is based on QM I might agree,
but it can explain all known observations. GR can't, for example in
the very small scale and very strong gravity (black holes). This would
require a theory for quantum gravitation (in order not to violate QM
laws), but the two theories are incompatible. A theory is an attempt
to explain reality, and when it fails, alternative theories must be
considered. I think a theory of gravitation along the lines of QED
would be able to explain these phenomena (QM has never failed to
do so), and make it possible to combine all theories to one.
Sure we will consider your theory (and try to find faults in it), as
well as every other theory.
>: but space doesn't expand in your theory...
>
> The distance of separation (if that is what you mean
>by "space") does expand if you do the thought experiment
>properly, or else things would appear to real world observers
>to have a velocity towards each other.
Oh, they do, it's called gravity. :-)
> The thought experiment
>must establish whether or not there is an actual motion toward
>each other or not, or if there is a motion away from each other
>or not.
Can be easiely done as explained above.
> In complex geometry models, which General Relativity and
>Divergent Matter are, the prior history of the motion of an
>object is the important thing, rather than the position relative
>to a background "space".
> So, in Divergent Matter, "space" does expand, even though
>space has no intrinsic properties or attributes, that is why and
>how ""coordinate free" theories have to work.
I think you mean that space expands if two objects move away from each
other. But the galaxies are accelerating away from each other because
the space between them expand, the galaxies aren't accelerating.
> I agree that there may be things about General Relativity
>that may have been misinterpreted, or things added on that don't
>belong there.
> But I repeat, why have a preference for the form a theory
>takes, it must describe nature, and if there is nothing in nature
>that can reach out from every object and grab every other object
>in the universe at the same time and pull on all of them at the
>same time, then we might have to settle for Divergent Matter,
>whether it is attractive to us or not.
Sure, I will settle for any theory that explains reality. However
there are often interpretations within the theory itself, like in QM.
I think everybody accepts that QM describes reality, but very few
accept the current interpretations.
> It doesn't mean they _are_ the same, but it also doesn't
>mean they -can't-be- the same. Please point out the big
>problems, and I will be glad to consider whether or not to
>try to explain them.
Big problems:
1. GR and QM are incompatible
2. GR fails to explain reality at microscopic levels, and at high
energies.
Other reasons:
1. Since the forces are so similar, it would be nice to have a common
structure, so a TOE could be obtained.
2. The principle of equivalence doesn't automaticly lead to GR, it
could as well be interpretated in a different way.
3. If GR was proved wrong, SR would still be valid.
> In "down to Earth" situations, yes, but in astrophysics,
>merely being aware that a model of gravitation based on matter
>expanding, is enough to allow evaluation of processes taking
>place, and to compare the different models.
Perhaps, but it still is necessary to be able to explain all known
phenomena.
> This becomes even more interesting because hydrogen
>can appear to be invisible in visible light according to
>what the temperature is, and whether it is illuminated by
>it's own temperature or other radiant sources.
What do you think is the reason for this?
Mathias Ljungberg
Subject: Re: Solar radiation falling on a HORIZONTAL? surface. (site..)
From: Kevin
Date: Tue, 07 Jan 1997 07:31:30 -0700
Will Stewart wrote:
>
>
> That will give you an idea of the number of panels needed. You will
> find that the 'average' home requires a large amount of photovoltaic
> panels, whereas an energy-efficient home will get by with considerably
> less. Significant air conditioning requirements usually make off-grid
> solar photovoltaic systems cost prohibitive. See my home page for some
> empirical data.
>
Right, I understand that. I did the calcs about 3 months ago, using the
sun tables, etc. (6 hours of light/whatever its called) in the worst
average day of the year. I don't remember exact numbers, but I came up
with a price of about $8,000 (Real Goods Catalog) for just the
equipment, no labor involved.
My thought is that in an extreme area like Las Vegas (120+ F is not
uncommon in summer), you would be better served by co-generating, and
selling the excess back to Nevada Power in the winter. If you could
reduce your summer bills to maybe the $10-$20 rate, and your winter
bills to credits, it might be cost effective.
A rough guess was that the system would pay for itself in about 8 years.
Kevin
BTW, most of the power from the dam goes to LA, not Las Vegas. There is
a natural gas power plant in the southeast part of the valley that is
used when our demand exceeds the small amount we get.
Subject: Re: PH.D.s are useless
From: Anthony Potts
Date: Tue, 7 Jan 1997 15:10:03 GMT
On 6 Jan 1997, Paul J. Gans wrote:
> Anthony Potts (potts@cms3.cern.ch) wrote:
> : On Sun, 5 Jan 1997, Tim Harwood wrote:
> :
> : > after their names can't see the wood for the trees. Lost in irrelevant
> : > detail, they lose all track of reality.
> : >
> : You're only saying that because you have failed yourself, and ended up at
> : York university.
>
> Be nice. Just because you folks are experiencing a slightly cool
> winter doesn't mean you have to blame everything on York.
>
> Besides, a PhD in economics doesn't count.
>
How true that is.
I have a friend with an economics degree. I went through school with him,
where he failed all his A-levels.
Undeterred, he went off and took a foundation course in economics, which
he failed.
Fortunately for him, this was in no way detrimental to his degree, and he
passed with honours.
So, economics degrees would appear to be at least accesible to those who
otherwise could never be academics.
Anthony Potts
CERN, Geneva
