Subject: Re: Sophistry 103 (was: I know that!)
From: moggin@nando.net (moggin)
Date: 6 Nov 1996 10:09:44 GMT
Derrida:
>>>>>>"I believe, however, that I was quite explcit about the fact that nothing
>>>>>>of what I said had a destructive meaning. Here or there I have used to
>>>>>>word _de'construction_, which has nothing to do with destruction. THat is
>>>>>>to say, it is simply a question of (and this is a necessity of criticism
>>>>>>in the classical sense of the word) being alert to the impliations, to
>>>>>>the historical sedimentation of the language which we use-- and that is
>>>>>>not destruction. I believe in the necessity of scientific work in the
>>>>>>classical sense, I believe in the necessity of everything which is being
>>>>>>done and even of what you are doing, but I don't see why I should
>>>>>>renounce or why anyone should renounce the radicality of a critical work
>>>>>>under the pretext that it risks the sterilization of science, humanity,
>>>>>>progress, the origin of meaning, etc. I believe that the risk of
>>>>>>sterility and of sterilization has always been the price of lucidity."
zeleny@oak.math.ucla.edu (Michael Zeleny):
>>>>>Derrida is lying. Since his term `déconstruction' is derived from
>>>>>Heidegger's term `destruktion', the destructive implications are there,
>>>>>brought out by the argument from etymology, favored by the Nazi and the
>>>>>Nazi apologist alike.
Silke:
>>>>Zeleny is lying, but he can't help it.
Zeleny:
>>>You are out of it. See Rodolphe Gasché, _The Tain of the Mirror:
>>>Derrida and the Philosophy of Reflection_, Chapter 7, pp 109-121.
moggin@nando.net (moggin):
>> I don't have the book handy, but the last time I heard Gasche,
>>he was arguing that the implications of Heidegger's _Destruktion_
>>differ significantly from the English "destruction." David Farrell
>>Krell takes the same tack, noting that _Zerstorung_ would have been
>>closer.
zeleny@oak.math.ucla.edu (Michael Zeleny):
>Arguing about implications is scarcely a Heideggerian move.
Neither do I dance like an Egyptian.
>Check his Greek etymologies against Liddell & Scott -- always good for
>a giggle.
I thought we were discussing the relation of _destruktion_ and
deconstruction: you claimed Derrida is lying when he distinguishes
them, and stated that "deconstruction" possesses the "destructive
implications" of Heidegger's "_destruktion_." All this on authority
of Gasche, in a passage you didn't quote; but as I said, I've heard
Gasche contend that "_destruktion_" doesn't imply "destruction" (an
argument also forwarded by Krell, on the basis I mentioned).
>What better way to judge a writer than by applying his master's lofty
>intellectual standards?
I can't see Heidegger as Derrida's "master" -- but more to the
point, Heidegger doesn't rely on Gasche to authorize his etymologies.
-- moggin
Subject: Re: How Much Math? (not enough)
From: mkagalen@lynx.dac.neu.edu (Michael Kagalenko)
Date: 6 Nov 1996 00:05:38 -0500
Russell Turpin (turpin@cs.utexas.edu) wrote:
]> Q: Can I make an upside-down pendulum stable; that is, can I
]> make the pendulum oscillate about the normally unstable
]> top equilibrium point by forcing the hinge to oscillate
]> vertically? If so, what frequency and amplitude of
]> up-down hinge motion would do it?
]
]Since we are on the topic of monotonic functions, let me offer an
]alternate solution: whenever the pendulum is 14 degrees from
]vertical (either direction), give the hinge enough jerk (time
]derivative of acceleration, remember?) downward to reverse the
]pendulum's horizontal motion. Between times, let the hinge slide
]freely downward. (OK, so the hinge doesn't oscillate, and it
]requires a very deep well to do this long ... BUT the pendulum
]oscillates over the hinge!)
Actually, this guy has in mind so-called "Kapitza pendulum". This
isn't really calculus, I would say. That thing is counterintutive
and, although easy, nontrivial to derive. In short, you can make
pendulum to be in stable rest upside-down if you vibrate its hinge with
sufficiently
high frequency. Amplitude of vibration doesn't have to be large - you
can demonstrate this pendulum with electic razor. This is easy
physics, but, surprisingly enough, it is the one used in
accelerators to keep the beam focused.
--
LAWFUL,adj. Compatible with the will of a judge having jurisdiction
-- Ambrose Bierce, "The Devil's Dictionary"
Subject: Re: Attract Lightning Strikes??
From: ohnuki@oxy.edu (Tohru Ohnuki)
Date: Wed, 06 Nov 1996 02:34:26 -0800
In article <5563m3$le8_002@phy.hw.ac.uk>, phynkt@pp.hw.ac.uk (Soapy) wrote:
[snip prev post]
> Erm.. simple EM theory here..
> Pointed objects have a higher electric field at their points than
> flat things do. For the same charge, the pointed object will have
> a higher electric field strength. Ok, now, thats why an antenna
> gets hit, not the chimmey next to it. The reason that having a
> conducting rod on your antenna attracts lightening more than one
> which doesnt, is that the one with the earth connection has a
> lower resistance. Hence it is easier for the lightening to go
> down the conducting route. So if the neighbour has a lightening
> conductor on his house, yours wont get hit, if it is shorter, or
> the same height, and less pointy!
>
> all opinions are home grown...
My understanding was that the earth is more negatively charged with respect
to the stormclouds, so a sharp grounded object in the air would encourage
electrons to ionize the air molecules and dissipate the charge, reducing
the likelihood of a strike above that area.
In the broadcast industry there is a product called a Staticat which looks
like a rod with a bunch of nails welded to it with the pointy ends out. You
put this on your already grounded tower, and it's claimed to reduce
lightning strikes.
--
Tohru sagt,"Spork!"
Subject: Re: Science, Values and good old-fashioned essentialism
From: pritchjm@muss.cis.McMaster.CA (J.M. Pritchard)
Date: 5 Nov 1996 13:10:38 -0500
In article ,
Adam Hibbert wrote:
>In article <558oon$ims@muss.CIS.McMaster.CA>,
>pritchjm@muss.cis.McMaster.CA (J.M. Pritchard) wrote:
>> In this sense, "danger" merely points to the more or less objective
>> fact that some things do indeed die, and others live. Some are happy,
>> others are not. Some are beautiful, and others ugly. Now there's nothing
>> especially analytic about any of this, that's just the way things are.
>Well, that's kind of what I was arguing for in the first place; that
>despite our inability to provide an absolute basis for our beliefs re: the
>world, we can develop our knowledge from 'less' to 'more' 'objective
>fact'.
Naturally, you were right. But all I'm doing is clairifying
terms. The problems arise when people state certain facts as "objective"
and others as "subjective" without qualifying the terms; in fact, the
former is only relatively stable and the latter, relatively precarious.
In particular it is misleading to invoke the word "essentialism" which
has a lengthy history, and a lot of baggage which is not necessarily
related to this discussion.
This is nit-picking, but I'm a philosopher so what did you expect?
>> And as regards evolution, I am proposing that
>> we explode this notion *into* those other fields you mentioned,
>> especially language.
>Well, OK, but go easy: everyone doing this seems to chuck-out precisely
>the relationship that we're attempting to investigate, here. Natural
>evolution describes the bumping together of objects, of physical
>determinants - what I'm interested in is the self-organisation and
>refinement of concepts conducted by rational *Subjects*.
But witness our own "rational encounter"; this discussion. In it,
certain points are raised, and certain others are dismissed, some
agreements are formed, other lines of disagreement are consolidated.
The points that are accepted, kept, revised and agreed upon - arguably
these are the ideas that have an "adaptive" value; that is, they jive
better with our experience and with our other beliefs than their
competitors - they allow us better "options" for the future. The ones we
dismiss or react against are taken to be fruitless, or even dangerous.
In any event, our beliefs are behaviors, not "states of mind", so
the "subjects" you are looking for might already have dissolved into their
environments.
>IMHO, if we allow
>an evolutionary analogy into this too carelessly, we end up in Dennet &
>Dawkins' impenetrable bio-psychological planet, where conscious,
>1st-person Subjects are entirely replaced by swarms of memes, which
>somehow 'trick themselves' into 'conceiving' of themselves as 'a Self'.
The problem there is biology, not evolution. I am proposing a
non-biological style of evolutionary description. "The selfish gene"
seems to make alot of sense in some particular contexts; but it is only
another way of talking about the world, not the *ultimate* way. Take a
subject that is attracted to redheads. Perhaps Freud would tell him that
he is thusly attracted because his mother had red hair. But does this
make his attraction "less" of an attraction, now that he has been shown a
psychological basis? "Really, you are only attracted to redhaired women
because your mother had red hair." Let's get rid of the "really." It is
merely *another* description of a certain event (i.e. "attraction"),
which will be more or less useful in different situations, as a saw is
more useful to cut boards than to hammer a nail.
>> joke is that we never "had" it. There is no ethos, there is only pathos,
>> only language constantly feeding back upon itself. At least that is what
>> the postmodern philosophers will tell you, the ones who have erased the
>> boundaries between poetry and philosophy, people like Rorty, Derrida,
>> Foucault, etc.
>Jus' seems like a lot of self-supporting idealism to the uninitiated; I
>really wish I could abandon my materialism for long enough to discover
>some logic in there. In particular, I don't understand how there could be
>any differentiation or meaning in the first place to get the system
>started (a sort of language-game Big Bang, perhaps?), unless through a
>relation to something outside the system (ie physical universe). I think I
>wandered off the original question ages ago . . . sorry.
The concern you have is something like the chicken and the egg,
but the point is that it was always language *and* world, not one before
the other. When we speak about the past or the future, we are literally
bringing them *into* the present. "Now". Kind of like how an amoeba
brings food in through the cell walls...
Jeff
Subject: Re: Science, Values and good old-fashioned essentialism
From: pritchjm@muss.cis.McMaster.CA (J.M. Pritchard)
Date: 5 Nov 1996 13:36:06 -0500
In article ,
wrote:
>We see alike on the trap, the joke, and the postmoderns, Jeff.
>As I see it, we have this problem with language (to restate the obvious,
>but it bears repeating)... we cannot "get outside" it to have a good look
>at it, so it is at the heart of our self-reference dilemma. I recently ran
>across a concept of Owen Barfield's (ref below) which seems helpful: that
>of "polar contraries." He (Talbott) summarizes it somewhat thusly with
>respect to precision and meaning: they are poles apart, but exist only *by
>virtue* of each other. Thus if we attempt to see them as opposites,
>explaining one or the other out of context, we are doomed to failure just
>as we would be in trying to explain the essence of a magnetic north pole
>without reference to its southern polar contrary. And Talbott describes
>Barfield's anti-intuitive (at least to me) result: absolute precision (if
>attainable) would result in *total* loss of meaning!
>A good mystery is a wondrous thing to behold! Thank God for 'em, sez I!
>The Future Does Not Compute - Transcending the Machines in Our
> Midst. Author: Stephen L. Talbott Publisher: O'Reilly & Associates
> ISBN: 1-56592-085-6..
Nice to hear from someone as obviously erudite and with as much
good taste as I. As it happens, I am writing a thesis which touches
on the topics you mention - and that explains my verbosity on the
newsgroup: I pass it off as "research". In fact I am developing a
pragmatic analysis of language which divides it into the "lateral" and
"layered", although they are obviously interdependent somewhere along
the line. It is an attempted response to the Rortain "knowledge does not
progress". So thanks for that reference; I will surely look it up in the
near future. And depending on your interest on the topic, you might want
to check out William Barrett's "The Illusion of Technique."
Jeff
Subject: Re: [Fwd: Re: The Conscious Mind -- David Chalmers]
From: jqb@netcom.com (Jim Balter)
Date: Wed, 6 Nov 1996 07:40:32 GMT
In article <55o198$io2@usenet.srv.cis.pitt.edu>,
Anders N Weinstein wrote:
>Not anything can be viewed from the design stance. Rocks for example,
>can't.
I won't debate it, but it is irrelevant, because I never said otherwise.
>I also think that while Dennett is pretty good, he is far from the
>last word. for example, I think there is an important difference between
>artifacts, that have their design norms imposed on them by an intelligent
>designer, and organisms, that have design norms naturally.
Since Dennett deals with this at length, this doesn't serve as your example.
Certainly I am more interested in what he *argues* than in what you *think*.
>>>Now: it is Dennett's and others' program to explain natural function in
>>>terms of design produced by natural selection. This may be all right,
>>>it does not show biology reducing to physics, in my view, since it
>>>still acknowledges that there can be norms in nature in a way the
>>>physical stance does not.
>>
>>physics != the physical stance! Stop making this silly category error!
>
>All right: physics is the science that attempts to understand a region
>of reality through adoption of the physical stance. The physical world
>(or physical reality) is the set of facts that are revealable through
>the adoption of this stance. In like fashion, biology is the science
>that understands a region of reality through adoption of what I might
>want to call the biological stance. The biological world is the
>set of facts revealable through this stance -- including facts about
>proper function and forms of life.
Since I have repeatedly pointed out how and why this is wrong but you seem
unable to get the point, further discussion strikes me as pointless.
--
Subject: Re: FOSSIL: human skull, old as coal, is C-14 biblical Flood
From: "Michael D. Painter"
Date: 6 Nov 1996 00:43:10 GMT
My life is complete. Ted, Mr. Ed and Eli-god all in the same place. Add to
that the joy of them being right next to AD in this newsgroup and it can't
get much better.
EJ Thinks the world ended acouple of months ago for those who have not seen
his unique ramblings for a while.
Eliyehowah wrote in article <327F2ADB.15A0@wi.net>...
> ** BIBLICAL COAL THEORY **
> The increase of radiation by 12 times after the water above our nitrogen
atmosphere
> dropped, has also increased C-14 by 12 times. Being toxic we age 12 times
faster
> and live 12 times less. This is revealed in C-14 data lists.
> Human chronology is basically aligned against Egypt being viewed as the
> most stable filled centuries of history in contrast to China, India,
Europe, etc.
>
> [1] First, the charts available...
> (fellow men of faith, ask me if you want a scan of it; but critics stay
away,
> since you charge others cash to hear or see all your profound theories)
> prove that Egypt C-14 dates correctly with Hebrew Genesis but because
> Egyptologists favor the Turin Papyrus canon written in 1290 BC, they
insist
> the chronology is 720 years further back. This would force the soil of
Egypt
> to be 720 years before the biblical global Flood. However, as stated the
> C-14 correctly supports the shorter history. Dendrochronology is used
> to satisfy Egyptologists who demand that the Bible and C-14 are 720 years
> in error.
>
> [2] With this in mind, the difference of C-14 levels 12 times lower must
be calculated.
> Of which this produces a shift of 20,000 years. Interesting the C-14
dates of
> all coal and tar and oil and petroleum and gasoline are not millions of
years
> but 20,000 years. (C-14 cannot date more than 70,000 years.) Thus
biblically
> anyone dying in the Flood would likewise falsely date as 20,000 years as
> does the coal and organic life crushed and formed by the Earth's global
flood.
>
> This means that the first five dynasties of Egypt
> (768 yrs Turin Papyrus canon = 338 yrs Hebrew Genesis)
> must be dated according to this immence curve from 20,000 false yrs to
> its actual position (2321 BC TPC = 2030 BC Hebrew Genesis).
>
> It would still make this finding of a skull as something highly valued
> by creationists as it is to evolutionists. The dating is merely to
another scale.
>
> ************
> A voice crying out and going unheard,
> (40 years Oct 7) Nehemiah's (9:1) 50th JUBILEE of Tishri 24
> God's 1000 years has begun Sep 14 of 1996.
> http://www.execpc.com/~elijah/Ezra1991CE.gif
>
> Discover the world's true chronology thru the Bible at
> http://www.execpc.com/~elijah
>
Subject: Re: Hermeneutics and the difficulty to count to three...
From: mkagalen@lynx.dac.neu.edu (Michael Kagalenko)
Date: 6 Nov 1996 00:12:27 -0500
Jeff Inman (jti@coronado.santafe.edu) wrote:
]matts2@ix.netcom.com (Matt Silberstein) writes:
]>jti@santafe.edu (Jeff Inman) wrote:
]
]matt:
]>Instead we have a standard for making our judgements. If the theory
]>does a better job at explaining and predicting we will (provisionally)
]>accept it. They do not say that metaphysics is just hot air, but that
]>metaphysics does not get us anywhere, so we ignore it.
]
]I don't see the difference. You claim that metaphysics is irrelevant
]to knowledge and has no bearing on whether a theory does a better job
]at explaining and predicting, yet it seems quite obvious that one has
]nothing to explain or predict without metaphysics.
Metaphysics deals with the question of possibility of knowledge.
Scientist does not need anything from metaphysics beyond the
fact of possibility of knowledge, much like humans managed to do
ad-hoc genetic engineering thousands of years before discovery of genes.
]
]The step between CM and GR may be "well defined, explicit, and clear"
]without implying that the metaphysical underpinings of CM are clearly
]continuous with those of GR. It only works in retrospect, as a sort
]of "fixing" of what was understood in the past. But, in fact, the
]nature of what an "object" was in CM and what it is in GR is vastly
]different. Before you can understand what Newton means when he speaks
]of an "object", you must enter a different world. The facility for
]translation between these worlds is so well developed that one doesn't
]see it happening.
All this is usual pomo nonsense. GR is currently used in engineering.
Cars in Europe use GPS already, and GPS would not work without
GR.
]In similar terms, one imagines that the physicists of 500 years hence
](assuming that humans are still around, then) will look back on y'all
]just as you look back on your forebears: as a bunch of well-meaning
]but myopic dunderheads, who can't see the noses on their own faces.
That would be strange developments indeed. Certainly, this is
nothing like view of modern physicists on Newton, or, say
Maxwell. All physicists I discussed Newton with had a great
repect for his insight.
]More generally, it suggests that one can't help being "passionate"
]despite all attempts to be "objective".
Relativistic electrodynamics was shown to agree with experiment
up to more the tenth digit of precision. Looks quite objective to me.
] The notion of "objectivity"
]ought to be appreciated as being somewhat comical. What would it even
]mean? When Jeff Candy pointed me towards "objectivist metaphysics", I
]should have asked him "*which* objectivist metaphysics?"
--
LAWFUL,adj. Compatible with the will of a judge having jurisdiction
-- Ambrose Bierce, "The Devil's Dictionary"
Subject: Re: holonomic constraints and generalized coordinates
From: checker@netcom.com (Chris Hecker)
Date: Wed, 6 Nov 1996 11:45:52 GMT
Sorry for taking so long to compose a reply to the people who posted to
this thread; your replies were all very helpful! I've consolidated my
responses here to save bandwidth. I'll also cc: the people I quoted, I
hope they don't mind. A response in the newsgroup would probably be
best, in case others are interested...
As a refresher, I couldn't figure out why I couldn't seem to eliminate
the constraint equation if I wanted Cartesian coordinates instead of
polar for the following constraint:
x^2 + y^2 - c^2 = 0
candy@mildred.ph.utexas.edu (Jeff Candy) writes:
>There is really no problem with this. Consider your example of motion
>on a circle. For simplicity, let mass=1 and c=1.
>...eye-opening Lagrangian stuff omitted...
> (1-x^2) x'' + x (x')^2 = 0
>Then, as expected,
> (theta)'' = 0
This was a great post, thank you. I probably should have tried to do
the Lagrangian myself before posting, and I would have seen this. So,
basically, what this is saying is that as long as the constraint is
satisfied at the start, then the Lagrange equation will keep x on the
circle. Now my question becomes, why is there a singularity at x=1?
In other words, if I solve for x'' I get:
- x(x')^2
x'' = -----------
1-x^2
This makes sense as an equation of motion (meaning x accelerates as
you'd expect as it goes around in circles), and I worked out the
version with external generalized forces and it seems right as well,
but where does the singularity come from?
Perhaps the next post, from vdananic@jagor.srce.hr (Vladimir Dananic),
offers a clue:
> Perhaps you're missing the fact that the constraint x^2+y^2-c^2=0
> CANNOT be solved neither for x nor for y in a one-valued way i.e.
> either is y=+sqrt(c^2-x^2) or is y=-sqrt(c^2-x^2). In order to resolve
> this two-valuedness you must transform (x,y) coordinate to some other
> coordinates (not necessary polar) in which the constraint CAN be solved
> in an appropriate way.
I guess I'm not sure why the double-valuedness makes a difference,
could you explain more?
Finally, Charles Torre writes some great stuff about
manifolds:
>Unless the submanifold is
>topologically trivial, you will need some "non-trivial" coordinates (e.g.,
>theta) or more than one coordinate patch (e.g., ranges for x or y).
>...
>my point is just that generalized coordinates are
>intrinsic coordinates on a submanifold and are usually of a local nature.
>...
>The general rule is that one can expect only to find coordinates that
>cover a portion of the constraint submanifold and one must then solve the
>dynamics in enough overlapping patches to completely specify the motion.
Are there any books that talk about this (specifically, that you'll
need more than one set of coordinatess to cover the manifold)? All the
books I have, including Goldstein and Arnold, seem to gloss over
actually finding the coordinates (although it seems like Arnold might
get into it later, but I didn't see anything when I skimmed).
>For
>example, go up one dimension to a sphere and consider how to describe the
>points at the north and south poles, where the azimuthal angle isn't even
>defined.
But the equations don't blow up there, like the above equation, do
they? I guess I should work it out myself...
Thanks to everyone for responding, and again, sorry for the delay.
Chris
Subject: Re: Curious Cosmologies of Primitive Man.
From: "David Byrden"
Date: 6 Nov 1996 12:33:42 GMT
Keith Stein wrote in article
...
> THE BIG BANG MYTH
> An Essay on Cosmology by K.Stein
> For example if the density
> of the universe is decreasing with time, then we should expect to
> see density increase as we look further out into space.
> Similarly, as the universe is fueled by Hydrogen, we might expect
> to see the proportion of Hydrogen in the cosmos appear to
> increase as we look out from the earth. Nowhere have I read that
> either of these trends is actually found.
Keith, when you say "we should expect", you ought really to
say "I, Keith Stein, happen to expect, based on what I happen to have
read, or rather the parts of it that I have managed to comprehend".
> "When the Universe was
> still a hot plasma at the 100,000 year mark, its temperature was
> roughly the same as the surface of the Sun today...Just before
> escaping from matter, this radiation was predominantly composed
> of visible and shorter wavelength ultraviolet light."
> It is not obvious why Big Bang cosmology should attribute the
> background radiation to an original temperature only a few
> thousand degrees,
Not obvious to YOU, perhaps, Keith. To me, it's very obvious.
What is not obvious to ME is why you are willing to post an
essay titled "THE BIG BANG MYTH" which tells us nothing except
that you do not understand much of the big bang theory.
David
Subject: Re: What is the Cause of Time Dilation?
From: bjon@ix.netcom.com (Brian D. Jones)
Date: Wed, 06 Nov 1996 12:57:35 GMT
Christopher R Volpe wrote [in part]:
>Brian Jones wrote:
>>
>> Christopher R Volpe wrote[in part]:
>>
>> What's really amazing is Volpe's supreme confidence despite his
>> total wrongness.
>I invite any professional physicists out there to inform me of any
>unjustified criticisms I have made of bjon's claims about SR.
Your wrongness: You made the claim that there was a recordable
(timewise) clock event. This is patently false. No event occurred at
the clock in question whose time was recorded by this clock. You have
not given a time reading of any event. That's why you are wrong.
>>
>> In 1905, in a small paper, Einstein wrote:
>> "We have to take into account that all our judgments in which time
>> plays a role are always judgments of _simultaneous events_. If, for
>> instance, I say, 'That train arrives here at 7 o'clock,' I mean
>> something like this: 'The pointing of the small hand of my watch to 7
>> and the arrival of the train are simultaneous events.'
>In the above paragraph Einstein does nothing more than indicate the
>importance of the concept of simultaneity and the implicit use of the
>concept in such statements as "The train arrives at 7'oclock". What bjon
>continually fails to understand is that Einstein goes on later to
>demonstrate that the notion of simultaneity is *frame* *dependent*, and
>most assuredly *not* absolute. In fact, there's an entire chapter in
>Einstein's popular book devoted to this assertion. The title of the
>chapter is "The Relativity of Simultaneity". I wonder what bjon thinks
>those words mean.
>--
>Chris Volpe Phone: (518) 387-7766
>GE Corporate R&D; Fax: (518) 387-6560
>PO Box 8 Email: volpecr@crd.ge.com
>Schenectady, NY 12301 Web: http://www.crd.ge.com/~volpecr
It is clear that Volpe is clueless. The above from Einstein says
plainly that there must be a "superimposition" of an an event with a
clock in order for there to be any recorded event time. This is
obvious, and, as I said above, Volpe has obviously failed to present
any clock time for any event AT the rear clock. And for good reason
-- there was no specified event. Of course, Volpe probably does know
this, but hopes that by confusing the issue, the whole problem will go
away. Note that Einstein said "ALL" time judgments; this is a general
thing. And the event must be near enough to the clock that is
recording the event's time so that there's no problem with "distant
simultaneity." And if an event happens directly AT a clock, then the
event AND the clock reading of the event's time ARE indeed truly
simultaneous, and this is obviously the only way to obtain a time
reading for any event. There must be a clock AT the event, and this
is all Einstein was saying above. If an event occurs where there is
no clock, it is impossible to record the time of that event. This
should be clear even to Volpe. And it's even worse in the example I
gave Volpe --- there was NO event happening at the clock (except the
perfectly trivial clock hands' positions, which is merely the clock's
reading -- not matching ANY external event at all).
§§ ßJ §§
bjon @ ix. netcom. com
Subject: Re: What is the Cause of Time Dilation?
From: bjon@ix.netcom.com (Brian D. Jones)
Date: Wed, 06 Nov 1996 13:05:53 GMT
throopw@sheol.org (Wayne Throop) wrote [in part]:
>: bjon@ix.netcom.com (Brian Jones)
>: given any two events, each observer will find a different time between
>: them. This tells us that their clocks all read differently at these
>: same two events. And yet the events themselves obviously can have
>: only a single time between them.
>That doesn't follow. Consider: given any two points on a plane,
>each observer will find a different delta-x between them. This tells
>us that their x-coordinate rules all read differently at these
>two points. And yet the points themselves obviously can have
>only a single delta-x between them.
>Bjon simply ignores that the two cases are exactly and precisely analogous.
>He says, yes, there's no absolute direction, but there must be absolute time.
>Yet he argues for the necessity of "absolute time" via a schema that
>is obviously vacuous and a non-sequitur.
Nope, Throop, there was no "argument for absolute time." Apparently,
there's no way (within a finite time) to get the message across to
you.
>The point is, it is SR's model that two events do NOT have
>"only a single time between them".
>: The invariant interval has no physical meaning, being a mere
>: mathematical construct.
>This claim is exactly as convincing as a claim that "distance" has
>no physical meaning, being a mere mathematical construct (x^2+y^2).
>I've lost count of the number of times I've pointed out to bjon the
>physical meaning of the interval: it's the number of times a clock will
>tick in uniform motion between two events.
You're referring not to the invariant interval but to "proper time."
>::: There must be some nonclock event AT the clock. This is standard SRT fare.
>:: A substantiating reference (that this is "standard SRT fare") would be
>:: appreciated.
>: See my Throop reply.
>Ah. Since I'm "Throop", this IS your "Throop reply".
>So I can only assume bjon has no such reference, but is shy to admit it.
>--
>Wayne Throop throopw@sheol.org http://sheol.org/throopw
> throopw@cisco.com
OK, so it must have been Mr. Volpe
§§ ßJ §§
bjon @ ix. netcom. com
Subject: Re: How Much Math? (Was: Re: How much to invest in such a writer?)
From: +@+.+ (G*rd*n)
Date: 6 Nov 1996 08:12:48 -0500
+@+.+ (G*rd*n) writes:
| >| >The mystery for me is this: I studied and got a reasonably good
| >| >grade in elementary Calculus. Prior to this study, I had what we
| >| >might call an intuitive grasp of Newtonian mechanics -- for instance,
| >| >I could "feel" and visualize the planetary system, and beyond that I
| >| >could do the arithmetic given reasonably simple cases. According to
| >| >a lot of people in these threads, however, at that time I did not
| >| >_understand_ Newtonian mechanics, because I didn't know Calculus.
C369801@mizzou1.missouri.edu (Walker on Earth):
| >| Can't resist - OK, I'll bite: how does your 'intuition' explain
| >| the fact that spherical bodies act like point masses? ...
+@+.+ (G*rd*n) writes:
| >Intuition doesn't explain things; explanation is a textual
| >or rhetorical act.
| >
| >In contemplating a system where extended bodies appeared to
| >act like point masses, one might make up a theory as if
| >extended bodies acted like point masses, and see if it
| >worked -- especially if one had a previous theory (Kepler)
| >which pointed that way.
meron@cars3.uchicago.edu:
| I don't see that much "understanding" involved in saying "things are
| the way they are". Agreed, sometimes that's the only option you've
| left. But if you apply it across the board, to everything ...
That's not what I was trying to describe. Suppose Newton
finds that if he treats planetary bodies as point masses,
his theories about their motion work. This would be a
considerable advance in the art of theory fabrication of
his times, even without being able to show why extended
bodies can be treated as point masses. If he can now go on
to explain this treatment mathematically, so much the
better; but it wasn't necessary to the validity of the
theory using point masses, which worked whether some of its
features could be explained or not.
g*rd*n:
| >I have cut off the remainder of your article because it
| >appeared to be a Calculus test. Reversion to academic
| >procedures of domination has been another feature of these
| >discussions, and a rather tiresome one.
meron@cars3.uchicago.edu:
| The complaints about "academic procedures of domination" are by now an
| old and rather tiresome whine. When you make statements relevant to
| some field of activity (whether academic or not) it is quite
| reasonable for people in this field to question your knowledge. I
| certainly wouldn't expect a different treatment when venturing to
| other fields.
I wasn't whining about it, I was declining to play the
game, and I thought I might as well say what game it was I
was declining to play, since there are several games going
on. My knowledge of Calculus is irrelevant to this
discussion, because (1) I am not posing as an authority,
and (2) the discussion is not about Calculus. An attempt
to introduce a math test was, then, a rhetorical ploy
derived from the power structure of an academic environment
whose purpose was to win advantage rather than advance an
argument. Do you really want to disagree with that? It
seems kind of obvious. I'm not against people playing
that game if they want to, but I don't want to.
g*rd*n:
| >No one cares
| >whether I know Calculus or not, nor does it matter in
| >the slightest.
meron@cars3.uchicago.edu:
| Indeed, no. But you claim to possess an "intuitive understanding" of
| Newtonian mechanics, specifically you claimed previously to possess
| intuitive understanding of cellestial mechanics. When you make such
| claim somebody may ask "OK, what is it that you understand?"
Very simple things; I can visualize a body moving in an
ellipse about another body, for example, and moving more
rapidly when near the other body then when far from it.
As, probably, can everyone else in this discussion. I
thought this sort of thing was taught in grade school.
I think we're coming back to the problem in the word
_understand_. Fortunately I have another article ready
to go on this subject, which will appear momentarily.
--
}"{ G*rd*n }"{ gcf @ panix.com }"{
Subject: Re: How Much Math? (Was: Re: How much to invest in such a writer?)
From: +@+.+ (G*rd*n)
Date: 6 Nov 1996 08:15:36 -0500
+@+.+ (G*rd*n) wrote:
| [snip]
| >
| >Well, I should review the problem out of which this
| >discussion of _understand_ arose. Some people may wish to
| >write about, discuss, speculate on, critique, place in a
| >cultural context, situate, view the aesthetics of, etc.,
| >Newtonian mechanics. I don't think anyone here denies that
| >scientific theories are devoid of connection to areas of
| >human life outside their domains, so in theory one could,
| >say, discuss the possible political implications of Newton's
| >work; Locke and Jefferson seem to have thought so.
| >
| >But it has been said that one cannot properly do this sort
| >of thing without _understanding_ the subject. In the case
| >of Newton's mechanics, it was said that I could not discuss
| >it because I didn't know Calculus.
matts2@ix.netcom.com (Matt Silberstein):
| I have a strong feeling this was me, and it was not what I said. I
| said you needed, at the least calculus to understand modern physics,
| which begins with Newton. I never said you did not have the right to
| talk about it. But the question was what did you need to understand
| it.
I'm going further back in time. One of the common
arguments brought by the science campers (not scientists,
science campers) against out-of-camp commentary about
science is that the commentators don't know the math. When
they do know the math, then they don't know enough math,
etc. etc. etc. When asked how the math relates, the answer
has been that if you don't know the math, you can't
understand what it means to know / not to know the math.
It's a closed system.
(My apologies to those readers for whom this review is yet
another tedious repetition.)
g*rd*n:
| >Unfortunately for this
| >argument, I have studied Calculus, as I recently revealed.
matts2@ix.netcom.com (Matt Silberstein):
| I don't think that is unfortunate, I don't think it is even
| meaningful. Knowing calculus does not mean you automatically get to
| know physics, merely, IMHO, it is a prerequisite.
You see, it's getting worse. My dog and I have demonstrated
our respective intuitive grasps of instantaneous
acceleration and velocity, I can trace the courses of the
planets and give the formulas for the forces acting between
them (in the Newtonian model).... If pressed, I could
probably come up with a derivative of something.
It's never enough.
g*rd*n:
| >(Although in a previous iteration of this thread someone
| >tried to give me a Calculus test.) So the argument had to
| >be moved; and while the moving was going on, I decided I
| >wanted to know what _understand_ meant, because it seemed a
| >little bit too rhetorically fluid for my interlocutors.
| >That brings us up to the present.
matts2@ix.netcom.com (Matt Silberstein):
| BTW, I posted what was probably an arrogant view of "understanding"
| elsewhere in this thread. I would appreciate some comments. It seems
| reasonable to me, but I don't really know. And I think the subject is
| worth exploring. What does it mean to understand something? Does it
| mean something different to understand Kant, Newton, and Shakespear?
| ...
_Understanding_ seems to be fairly ill-defined. So my
suggestion would be to stop trying to disqualify would-be
participants in discussions of these matters by claiming
they "lack understanding." After all, this is an ill-
defined proposition, as well as an ad-hominem argument,
_understood_ even in antiquity to be invalid.
--
}"{ G*rd*n }"{ gcf @ panix.com }"{
Subject: Re: Hectopascals: the CONSUMMATE pressure units?
From: 71754.3505@compuserve.com (Gene Nygaard)
Date: Wed, 06 Nov 1996 13:38:33 GMT
Pirmin Kaufmann wrote:
>Steve Emmerson wrote:
>>[omitted]
>> `Hectopascal' is, thus, a prefixed, derived SI unit.
>Precisely. Gene, if you don't believe him, download the
>"Guide for the Use of the International System of Units (SI)"
>from physics.nist.gov/Pubs/SP811/sp811sl.pdf
>It's an Acrobat(TM) Reader File.
Thank you, Pirmin. That's the type of information I was looking for.
NOTE: the above URL is directly to the half a megabyte, 86 page long
.pdf file; if anyone wants to see the table of contents first or get a
link to download an Acrobat Reader, go to
http://physics.nist.gov/Pubs/SP811/sp811.html
>See chapter "4.4 Decimal multiples and submultiples of SI
>units: SI prefixes", especially Table 5 on page 8 of said guide, where
>hecto is listed and defined as SI prefix, and chapter "7.9 Choosing
>SI prefixes" of the same, where it sais: 'It is often recommended
>that [...] only prefix symbols that represent the number 10 raised
>to a power that is a multiple of 3 should be used' but
>'however, the values of quantities do not always allow this
>recommendation to be followed, nor is it mandatory to try to do so.'
You have misinterpreted section 7.9. This is referring to the OTHER
SI preference violated by using hectopascals for atmospheric
pressure, a preference for numbers in the range from 0.1 to 1000.
The intervening discussion of "10 raised to a power that is a multiple
of 3" might create some ambiguity, but that was not what was
being referred to in the "it is not mandatory" language. I may
explain
that in more detail later, after I look through the rest of this
document.
>Because hPa is SI and mbar not, I do prefer hPa over mbar.
>I also prefer kPa (or whatever, as long as it is SI) over mbar.
>I don't care a bit if someone uses hPa or kPa.
At least you do see that there is a difference between millibars
and hectopascals, even if you come to a conclusion opposite from
mine as to which is better. The big problem with using both
hectopascals and kilopascals is that it is easy to confuse units this
together in size. Since the kilopascals are the units used in
every other field of science and industry, they are the obvious
best choice.
Gene
Subject: Re: What is the Cause of Time Dilation?
From: throopw@sheol.org (Wayne Throop)
Date: Wed, 06 Nov 1996 13:49:00 GMT
:: throopw@sheol.org (Wayne Throop)
:: [bjon] argues for the necessity of "absolute time" via a schema that is
:: obviously vacuous and a non-sequitur.
: bjon@ix.netcom.com (Brian D. Jones)
: Throop, there was no "argument for absolute time."
Really? Then what was that bit that my comment referenced:
::: There are quite definite and real physical results of such clocks
::: that directly reflect the absoluteness behind the definition. For
::: example, given any two events, each observer will find a different
::: time between them. This tells us that their clocks all read
::: differently at these same two events. And yet the events themselves
::: obviously can have only a single time between them.
Bjon now claims this isn't an argument for "absoluteness behind the
definition" of synchronization, ie time?
Do tell.
Well, OK. It's not an "argument for absolute time".
It's still obviously vacuous, and a non-sequitur, and bjon posted it.
::: The invariant interval has no physical meaning, being a mere
::: mathematical construct.
:: This claim is exactly as convincing as a claim that "distance" has no
:: physical meaning, being a mere mathematical construct (x^2+y^2).
:: I've lost count of the number of times I've pointed out to bjon the
:: physical meaning of the interval: it's the number of times a clock
:: will tick in uniform motion between two events.
: You're referring not to the invariant interval but to "proper time."
And of course, bjon has yet to notice that they are the same thing.
Despite having it pointed out to him multiple times. The physical
meaning of the invariant interval is that it is the proper time
of an object in uniform motion between events.
Bjon's seems to have some prejudice against treating proper time
as the absolute time, and coordinate time as observer-dependent.
He keeps insisting there must be some absolute coordinate time.
This is equivalent to having a prejudice against treating distance
as the absolute, and delta-x-coordinate as observe dependent,
and insisting there must be some absolute x direction.
::::: There must be some nonclock event AT the clock.
::::: This is standard SRT fare.
:::: A substantiating reference (that this is "standard SRT fare") would
:::: be appreciated.
::: See my Throop reply.
:: Since I'm "Throop", this IS your "Throop reply". So I can only
:: assume bjon has no such reference, but is shy to admit it.
: OK, so it must have been Mr. Volpe
So I can only assume bjon has no such reference, but is shy to admit it.
--
Wayne Throop throopw@sheol.org http://sheol.org/throopw
throopw@cisco.com
Subject: Re: Do gravitational waves carry momentum? was: Does gravitational waves carry momentum
From: kfischer@iglou.com (Ken Fischer)
Date: Wed, 6 Nov 1996 13:25:58 GMT
Peter Diehr (pdiehr@mail.ic.net) wrote:
: Ken Fischer wrote:
Somebody else wrote this, and the discussion was about my stating
that gravitation is not part of, and is not like the propagated
electromagnetic spectrum:
: > : Let's compare the field of a proton acting on other electrons to
: > : that of gravity. Now both are atractive force fields.
: >
: > I see nothing about gravity that resembles magnetic
: > attraction of opposite charges.
: > I am not aware of any direct experiment using a
: > single proton and electrons, although I assume it has
: > been done if it is possible.
: Thousands of experiments have been done, of a very detailed nature,
: with electrons and positrons.
And none of them show any resemblence to gravitation.
: > If gravity is not anything like opposite charge
: > attractions, then it must be different.
: Of course it is different! The field structure has a tensor, and
: not a vector nature.
How can you ignore the physics to the point of making
the math take a dominant role? And by doing so, the physics
of whether or not gravitation is a long range force field
is side-stepped.
The point that I am trying to make is that gravitation
is purely geometric in nature, and does not involve a "field".
I can accept "ripples in spacetime", but attributing
the mechanism of gravitation to gravitational radiation is
far fetched at best.
: > Gravity can not be "created", can not be shielded,
: > can not be deflected, can not be reflected, can not be
: > amplified, can not be weakened, never fails, and the
: > mechanism by which it operates is not known.
: I've previously mentioned the evidence for gravitational waves.
: Like any waves, these should be able to be reflected and refracted.
The binary star study is well known to me, but I
consider it to be an interpretation suggesting the cause
is gravitational radiation.
But what bothers me is that gravitational waves
may be too weak to detect, yet the binary study seems to
say gravitational radiation is powerful enough to affect
the orbits of the binary pair, and this doesn't seem
consistent.
: Why do you worry about the mechanism? If gravitation is fundamental,
: then it just _is_ ... there will be no mechanism, only laws.
The mechanism is _physics_, without physics we
will never know the mechanism.
The math is pretty well covered, it is the
understanding that is lacking.
Some of the literature on gravitation makes
about as much sense as the current threads on absolute
velocity and the existence of an aether.
: > The only thing that is known is the effect, and
: > it works on all known elements and compositions equally.
: This seems to be true.
: >
: > The mathematical representation of fields may seem
: > to be somewhat alike, but the gravitational "field" is not
: > really a "field" in the same sense as a magnetic field.
: They are both mathematical fields ... they have values every
: where. But the field structures are different. For example,
: the gravitational field for a spherical body has no dipole
: component.
They perhaps can be expressed mathematically,
but the "fields" are more than mathematics.
Gravitation is far more complex than the description
of the field structure. I think a great deal can be learned
by a rational discussion of other properties of gravitation
besides the field and it's mathematical description.
For instance, I feel my Steady State-Big Bang-
Grand Unified Theory reference model predicts a greater
gravitational red shift of the light from the Sun's edge
than from the center of the Sun's disk.
Is that a subject that anyone is interested in?
: > If it were a "field" then there should be some way
: > to alter the gravitational field, and there is no way known
: > to alter it.
: Of course there is! Just move the mass around ... split it up,
: rearrange it, add or remove some!
You know what I mean, in an electron-positron
interaction an electromagnetic field will affect them,
but there is nothing that can affect a gravitational "field".
: > I wouldn't read too much into statements about the
: > gravitational field generating more field, the reason that
: > gravitation does not fall off as precisely the inverse
: > square is apparently not well understood else there would
: > not be dozens of theories with only minor differences.
: That is exactly _why_ there are lots of attempts ... the effect
: is weak, and we don't have the right "laboratory" for it. But
: most of the alternative theories have been disqualified by
: the evidence. And the parameterized theories are ever more
: constrained. I can give you some refernces, if you like. Clifford
: Will's book is a good place to start.
I have the books and read them, but theories are
never "disqualified" except in the minds of people who
tire of them. A good consistent theory or model live
on, as a reference guide to guide the path toward a better
model or theory.
: > I think the gravitational field is purely geometrical
: > and can not be acted on, the effects are observed from a
: > biased reference frame, with the observers seeing accelerations
: > where no accelerations exist.
: Well, that is one possibility! And has a good deal of truth to it.
I would not bother saying that unless I can
proffer a model where gravitation is _purely_ a
geometrical "field" simply because there is no field,
there is simply something that matter is doing that makes it
appear that there is a "field"
: > Gravity is a riddle of major proportions.
: And very interesting, too!
Then why can't I get a rational discussion going on
possible advances to general relativity? :-) :-( :-)
: > I am pretty sure that photons do not attract anything,
: > in fact, I don't think free electrons produce gravitational
: > attraction, but I am still trying to research current thought
: > on this,
: I think that current thought is that all forms of energy cause
: gravitational attraction. Current thought being consistent with
: General Relativity. Thus if it contributes to the stress-energy
: tensor, it contributes to gravity.
My opinion is that only quark structures provide
the basic component of the tensor, but the thermal energy,
etc., complete the tensor.
But all things are affected by gravity, I just don't
think everything contributes to the gravitational "attraction",
like free electrons, but then the number of free electrons are
certainly too small to consider.
: > I am not impressed by the possibilities of mathematical
: > representations, they can be very precise and formal, but they
: > can also be misleading.
: >
: While it is true that they can be misleading, I'm still very impressed
: by it all. But then you already knew that ;-)
Yes, and I should have said I am very impressed by
both the capability of advanced math to solve problems to
high accuracy, and I am impressed with the people that can
do the math.
But I want to see the physics.
: > As I said, LIGO is an important experiment, whether
: > it is a null experiment remains to be seen, as there needs to
: > both, be a model of gravitation that does not require gravitational
: > radiation (I am not convinced that GR does), and, LIGO would
: > have to fail, for it to be a null experiment.
: Ken, General Relativity very definitely predicts gravitational waves.
: Yes, the prediction is mathematical. But so is the definition of
: a wave!
If there were no other way for gravity to work than
by long range "field", then I would certainly agree, but
since I think there is a more basic way that gravitation can
work, I will have to wait and see what LIGO turns up.
Ken Fischer