HDTenEightyP/NetNews huggingface dataset:
Newsgroups: sci.physics
Date: Tue,  6 Oct 1992 13:21:05 -0400 
From: Lawrence Curcio <lc2b+@andrew.cmu.edu>
Subject: Rocket Altitude Simulation

I'm a model rocket hobbyist, investigating the predictive
validity of rocket altitude simulation programs. These programs
use a subsonic drag model (Drag Force = -K*Vel^2) to numerically
predict altitudes of model rockets, which are fitted with (legal,
non-metallic) professionally manufactured engines of known
characteristics. No one in the hobby has done this investigation
before because K is, in general, unknown. The programs also
predict ascent time, however, and it turns out that if you know
any one of K, Altitude, or ascent time, you can find the other
two. Thus, for each rocket configuration, I graphed allowable
values of ascent time and altitude (each of which corresponded to
a unique K); I then measured altitude and ascent time directly.
The measured points fell nowhere near the curves. Actual ascent
times were, in general, much shorter than simulated ascent times
for any measured altitude. More sophisticated software, using
Runge-Kutte methods didn't do much better.

Altitude was measured with 3 elevation-only theodolites, and
since vertical trajectories were required, the only accepted
flights were those that yielded horizontal coordinates close to
the launch pad coordinates. Speeds, estimated directly from the
data, are very squarely sub-sonic (using twice average speed).
Altitudes are all below 700 feet. Rocket lengths varied between
15 cm and 1 meter. Sensitivity analysis on impulse (I have
statistical data on this from static tests), time measurement,
launch angle, and altitude demonstrate that the discrepancies are
real. Also, I have just found some data taken by another
investigator on another project that show the same, very-short
ascent times. 

Could anyone direct me to a helpful source? I'm not a physicist,
but I've had math through complex analysis and linear algebra.
Also, any helpful comments would be appreciated. Could this, for
example, be the result of viscous flow at low speeds?

Thanks in advance (Sorry it's so Newtonian),
-Larry C.
From: stone@cwis.unomaha.edu (Travis Stone)
Newsgroups: sci.physics
Subject: Aye, I Agree...
Keywords: Quite so, quite so..
Date: 5 Oct 92 15:20:01 GMT
Article-I.D.: cwis.stone.718298401
Organization: University of Nebraska at Omaha


To those of you who E_Mailed me about my Mattel post:

(1) You ain't telling me anything I don't already know
    from direct experience; I work in the University's
    Math Lab with the algebra and precalc-algebra students,
    and the majority of these folks tell me the same thing
    time after time: "I hated math in High School...I think
    math is tough...I was never any good at math, especially
    in High School...It just seems SO COMPLICATED..." Etc. etc.

(2) YOU know that it's *really* not that tough...I know it's
    really not that tough...but YOU must realize that our
    attitudes towards the subject are radically DIFFERENT
    than those of the poor buggers who are just now being
    exposed to symbolic math.  I don't mean to sound elitist
    or anything, but have you considered the nonzero
    possibility that attitudes like ours might, I say, just
    MIGHT be the exception, rather than the rule?  If it
    WEREN'T, then one would expect alot more people would
    be devoting themselves to mathematics, no?....

To the folks at sci.physics: I apologize for not "sticking to
the subject", i.e., Physics; I would also like to ask the
mathematically well-versed out there for some help/advice:

Can any of you suggest a good beginner's-level text in
Perturbation Theory?  I seek a book that has the following
requirements:

  (i) Introductory Level--not too much on the theoretical side
 (ii) Lots of worked examples
(iii) Lots of problems to work at the end of the chapter, and
      MOST IMPORTANTLY: ANSWERS IN THE BACK OF THE BOOK!

The reason that I pose this conundrum to you, the friendly
folk of sci.physics, is that as Physics-oriented people,
you are much more likely to know some good applied-math
texts; asking the sci.math folks would most likely net me
a list of theoretical texts explaining the "why it works"
aspect, and not the "how to do it"---which is what I'm after.

Thanks in advance!

T.R. Stone
University of Nebraska-Omaha
Sometimes a bit too tongue-in-cheek for His own Good..
D
D
D
D
D
D
aspects, and not the "how to do it"
Newsgroups: sci.physics
From: daryl@oracorp.com (Daryl McCullough)
Subject: Re: Simple observation about Quantum Kitty Cats
Organization: ORA Corporation
Date: Thu, 1 Oct 1992 12:53:05 GMT

In article <297@mtnmath.UUCP>, paul@mtnmath.UUCP (Paul Budnik)
writes:

>> 1. QM, with its quaint axioms about measurement processes is
>> an enormously successful theory; there are absolutely no hints
>> to the limitations to its applicability.
>
>That depends on what you consider a hint. Quantum mechanics predicts that
>by changing the setting on an instrument we can influence what happens
>arbitrarily large distances away. There has never been a shred of
>experimental evidence supporting such action at a distance. This is more
>than a hint at limitations. It is a powerful argument suggesting that
>quantum mechanics is false.

The EPR-like correlations are certainly strange, but as far as I know
there is no experimental evidence contradicting the predictions of QM.

>The fact that general relativity and quantum mechanics are not mutually
>consistent is another hint that all is not well.

I should have made it clear that I was talking about empirical
evidence. You're right, there are theoretical problems that suggest
troubles for QM.

>I have repeatedly challenged this group to come up with objective reasons
>for preferring existing formulations of quantum mechanics to the assumption
>that quantum collapse is local physical process. If you are convinced
>there are no hints to the limitations of quantum mechanics, you must
>have excellent arguments against quantum collapse as a physical local
>process. I would love to see them.

It seems clear to me that the wave function is not a physical field,
in the sense of the classical electromagnetic field. The problem shows
up when you consider the quantum mechanics of more than one particle;
the wave function becomes a function of position in configuration
space, rather than space-time. That is, in general the wave function
is of the form Psi(r1,r2,...,rn,t), where rj is the position vector
for the jth particle. As far as I know, there is no way to interpret
such a thing as a field---what is its value at the North Pole, for
instance? There is no such thing as the value of the wave function
at a particular space-time point, so it doesn't make much sense to
talk about that value collapsing.

Daryl McCullough
ORA Corp.
Ithaca, NY


Newsgroups: sci.physics
From: John.C..Baez@mailbox.bison.mb.ca (John C. Baez)
Newsgroups: sci.physics
Subject: Re: Michelson-Morley and the Spacetime Lattice
Date: 25 Sep 92 07:54:26 GMT

Organization: MIT Department of Mathematics, Cambridge, MA

In article <1992Sep25.033514.2485@prim> prim!dave@germany.eu.net (Dave Griffiths) writes:
>(Sounds like an Enid Blyton book :)
>
>I'm still trying to resist the claim of special relativity that the speed
>of light is constant relative to all observers. It plays havoc with trying
>to build a model where space is a lattice.

Good!  (heh-heh)

 * Origin: The Electronic Mailbox (1:348/7.0)
From: ssivakum@hopi.intel.com (Sam Sivakumar)
Newsgroups: sci.physics
Subject: Spending 1 year preparing for a Physics Ph.D program
Date: 30 Sep 92 22:37:52 GMT
Organization: Intel Corporation

Hi folks,
		I am contemplating a return to grad school, probably in
Fall 1993 or Spring 1994, to get a Ph.D in Electrical Engineering or
Physics.  
	I have a M.S. in Electrical Engineering from the U. of Illinois,
where I plan to return.  My M.S. work was in the field of compound
semiconductor devices, especially high speed transistors.  Therefore,
apart from the usual E.E. background in circuits and so on, I have a
reasonably deep exposure to solid state theory, laser physics, quantum
theory, etc.  However, most of this exposure has been with a decidedly
EE bias, namely high on the practical aspects and low on the rigorous
physics.
	What I wish to do is to beef up my fundamentals before my return
to grad school.  I therefore took a grad level classical thermodynamics
class at the local university, to help me progress to get me ready for
statistical thermodynamics and surface physics a little better.  At the
same time, I would like to do something similar in mechanics and optics.
Note that I have had most of this stuff before, but always with a
engineering flavor.  I have a hankerin' for the rigorous treatment that
a physics course would provide!
	So, if YOU had a year's time to prepare for a Physics-oriented 
Ph.D, how would you go about it?  I have thought about it and here is
what I have come up with:
i) Classical Mechanics
ii) Electromagnetics
iii) Optics and Quantum Theory
iv) Some Applied Mathematics - diff eqns, transforms, vector calculus,
theory of functions, etc.  

	This would enable me to register for Quantum Mechanics 1 and
possibly a course in Statistical Thermodynamics in Fall 1993.  
	I would like to hear your collective opinions on what you think
my preparatory schedule should be like.  I would also appreciate
recommendations of textbooks.  Goldstein seems to be a perennial
favorite for Classical Mechanics.  I especially would like
recommendations for mathematics books that cover some of the topics I
mentioned above, especially special functions.
	E-mail is fine, although I think this topic could generate a
lively thread.
	Thanks!

--
                                  | "I am not a satanist!  I find it hard
Sam Sivakumar                     | enough to conjure myself out of bed
ssivakum@hopi.intel.com           | every morning, leave alone conjure up
                		  | the devil!"  --  Ozzy Osbourne
From: crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass)
Newsgroups: sci.physics
Subject: Re: Mattel Protest
Keywords: So What?
Date: 5 Oct 92 16:53:27 GMT
Article-I.D.: murdoch.1992Oct5.165327.16115
Organization: University of Virginia

In article <BvnJnx.52y@helios.physics.utoronto.ca> dooley@helios.physics.utoronto.ca (Kevin Dooley) writes:
>In article <stone.718289960@cwis> stone@cwis.unomaha.edu (Travis Stone) writes:
>> ...
>>Mattel may be doing the nation's kiddies a service
>>by protecting their fragile self-esteem.
>>...
>>See? A little good can come out of every dark situation, nicht?...
>>
>
>NICHT!  This is a very bad thing!  Kids do badly in math not because
>it is hard, because it isn't, but rather because they perceive it as
>hard.  This is especially true with girls who are repeatedly told that
>they should not be good at math or science courses because their brains
>don't work that way.  Nothing could be farther from the truth.  Let's
>not permit marketing idiots to create yet another generation of math
>anxiety and women who believe that they are somehow inferior!

    Most kids who do badly in Math do so because it *is* hard, just
    as English is hard, Chemistry is hard, Social Studies is hard.
    Also, I hardly think that most girls are told that they should not
    be good at math.  If you want to change math anxiety,
    you're going to have to replace the teachers that instill it, but
    don't think that it it is a recent phenomena for either males *or*
    females because the subject *is* difficult in a number of ways.

    Further, do you actually believe that the words of Barbie hold
    such sway over the delicate collective psyche of American children?  
    Do you hunch in fear when someone says 'boo' at night?
    
    By the way, my wife was a math major who got her master's degree
    in Computer Science, not because math was too hard, but because it
    was not lucrative enough.  If you want women math majors, simply
    make the profession pay an average of $140,000 when one walks out
    of four years of graduate study and two of journeymanship.  After all,
    there seem to be plenty of women doctors.

    Don't hold your breath on society making this offer.

                                   dale bass

-- 
C. R. Bass                                           crb7q@virginia.edu
Department of Mechanical and Aerospace Engineering
University of Virginia
Charlottesville, Virginia                            (804) 924-7926
From: ronnie@cisco.com (Ronnie B. Kon)
Newsgroups: sci.physics
Subject: Re: Physics project
Date: 1 Oct 1992 03:36:30 GMT
Organization: cisco Systems, Incorporated
Distribution: world
NNTP-Posting-Host: lager.cisco.com

In article <1992Sep29.194540.11451@news.ysu.edu>, ag206@yfn.ysu.edu (David Barzilai) writes:
|> 
|> Hello.  I am currently taking a first-year honors physics course in
|> which quarterly physics projects are required.  A am a highly motivated
|> student who is willing to invest as much time as necessary to make a
|> good project.  Unfortunately, I have been having trouble coming up 
|> with ideas for a project that does not require difficult to access lab
|> equipment, and yet is creative(novel) and challenging.  Any ideas you
|> have for such a project would be greatly appreciated.  Thank You,
|> 
|> -D.B.

It seems to me that a "highly motivated" student would have noticed all
the postings about the H bomb secret being out, and would not have to ask
for project suggestions.

				Ronnie

-------------------------------------------------------------------------------
Ronnie B. Kon           | "Boy, they were big on crematoriums, weren't they?"
ronnie@cisco.com        |
(415) 688-4592          |           -- George Bush at Auschwitz, Sept 1989
-------------------------------------------------------------------------------
Newsgroups: sci.physics
From: jbaez@riesz.mit.edu (John C. Baez)
Subject: Re: Do physicists wax metaphysical?
Organization: MIT Department of Mathematics, Cambridge, MA
Date: Tue, 6 Oct 92 16:50:17 GMT

In article <1992Oct6.012221.28431@access.usask.ca> choy@skorpio.usask.ca (I am a terminator.) writes:
>Our world seems made to order for life and happiness.

I have become increasingly puzzled with Choy's posts.  First, on
sci.math, he touted the idea of a vast computer-generated database of
theorems that mathematicians could sift through to find useful results.
The on sci.physics he asked if there was a handbook somewhere that
contained all the formulas of quantum field theory and particle physics.
The above quote somehow explains everything.  

Anyway, let me comment on a few of his cosmic scenarios:

>  + We come to understand and control nature as metaphysics and
>    observations mesh to clue us into what makes everything tick and
>    why.

We are clearly doing this to a limited extent but there is no reason
apart from irrational optimism to think that we will do this in some
kind of complete and finished fashion.

>  + We fizzle out, party's over.

This sounds quite probable.  Of course one should read Dyson's ideas on
how an infinite amount of computation (e.g., thinking) can get done even
in a universe that is running down to a heat death.  Whether we would
ever get our acts together to accomplish such a feat is another
question.  We can't even handle the budget deficit.

>  + It's an endless joyride.

The best hope for this at present seems to be the notion, currently
fashionable among some quantum gravity folks, that black holes seed new
baby universes.  Check out Hawking, Mod. Phys. Lett. A5 (1990) 145, 453
and the refs therein.  (This is Preskill's best bet as to where the
information goes - and baryons? - when a black hole forms.  Of course
it's sheer speculation but that's what we're talking about here.)

>  + The universe is a large computing device bound and run by God knows
>    what (but God knows I'm going to find out). We're here as something
>    is being computed (or the machine is idle).

This is sheer verbiage devoid of operational content; if it makes one
feel better go ahead and believe it, but one is just wasting neurons.
Getting solace for ones angst by postulating massive unobservable
computers is such a late-20th-century thing to do.
From: aw3@ukc.ac.uk (A.Wilson)
Newsgroups: sci.physics
Subject: Re: Rosalind Franklin (was: Meitner and Hahn)
Date: 29 Sep 92 08:30:03 GMT
Reply-To: aw3@ukc.ac.uk (Alan Wilson)
Organization: Chemical Laboratory, University of Kent at Canterbury, CT2 7NH, UK

In article <rl.717712058@cgl.ucsf.edu> rl@socrates.ucsf.edu (Robert Langridge) writes:
>jac@ds8.scri.fsu.edu (Jim Carr) writes:
>[...discussion of Hahn/Meitner...]
>>
>>Not nearly as clear-cut a case as in the DNA story, where Rosalind (?) 
>>Franklin actually made the measurements and the correct interpretation 
>>of the measurements.  The excuse there is that she had died by the 
>>time the award was made, and was thus not eligible, but begs the 
>>question of why others who did not make the real discovery were 
>>considered eligible! 
>
>There is certainly a case to be made that Franklin, if she had lived,
>should have shared the Nobel Prize with Crick, Watson and Wilkins.
>This would have given the Nobel Committee serious problems since the 
>award is restricted to no more than three individuals.  As jac says,
>no award is made posthumously, but to say that the three who got the
>award did not make the real discovery is utter nonsense.  As in much of
>science, no one person deserves the credit.
>
>Robert Langridge			Phone: +1 415 476-2630, -1540, -5128
>Computer Graphics Laboratory		               FAX: +1 415 476-0688 
>926 Medical Sciences
>University of California	                    E-Mail: rl@cgl.ucsf.edu
>San Francisco  CA  94143-0446 

Can I add my 2p worth, before this thread takes off? This subject was
discussed some six months ago in sci.chem - perhaps some kind individual
who kept all the posts can summarise (I read a few, then headed for the
KILL file......)

Alan
--
Dr. Alan Wilson        (Approved by Morrissey, the consumer monkey)

" That was MY idea "
=================================================================
From: vancleef@ohstpy.mps.ohio-state.edu
Newsgroups: sci.physics
Subject: Re: TIME HAS INERTIA
Date: 27 Sep 92 02:31:58 EDT

In article <1992Sep26.004832.20400@athena.mit.edu>, rx1@athena.mit.edu (Stanley H Thompson) writes:
> In article <abian.717352315@pv343f.vincent.iastate.edu> abian@iastate.edu (Alexander Abian) writes:
>>    
>>    Neither the notion of Time nor its properties nor its nature are satis-
>>factorily treated in Classical or Relativistic or Quantum Physics.
>>    
>>    I say that
>>      
>>         TIME HAS INERTIA AND SOME ENERGY IS IRRETRIEVABLY DISSIPATED
>>                          ON MOVING TIME FORWARD
>>
>>    For instance, the total energy  E(t) of the Universe at time  t  can be
>>expressed as:
>>
>>(1)           E(t) =  E(0)  exp (-At)     for some constant  A > 0
>>
>>    Thus, when  t --> infinity   there will be less and less energy left in
>>the Universe.  However, something will always remain in the Universe since
>>t  will never be equal to infinity.
>>    
>>As (1) shows, the Principle of Conservation of Energy must be rejected.
>>
>>    Also, as (1) shows, the  energy and mass  are more directly related to Time
>>than to each other.  In fact
>>
>>(2)   E = mcc  (Einstein)   may be replaced by   E = m exp(-At)  (Abian)
>>  
>>  The Universal time is obtained by taking the natural log from both sides of 
>>(1) as:
>>
>>(3)   t = (1/A) log (B/E(t))   
>>
>>where  E(t) = the total energy of Universe at t=t.  
>>
>>Dr. Alexander Abian
>>Professor of Mathematics
>>Iowa State University
>>Ames, Iowa 50011, USA
>>
>>
>>
>>
>>
>>
>>
> 
>>	E(t) = m exp (-At)
> 	I am only lowly undergraduate, but do the units of the above 
> equation even check?
> 
> 						-Stan
> 
> ---
> Stan Thompson 		I'm only an undergraduate--what's your excuse?
> rx1@athena.mit.edu

The units are pedagocial. Lets hear more on this idea :|

:)

-Garrett
From: ralf@ark.abg.sub.org (Ralf Stephan)
Newsgroups: sci.physics
Subject: Re: Eastern Philosophy
Date: 28 Sep 92 12:58
Organization: Magick Shoppe, Gurth City

mitsu@nic.cerf.net (Mitsuharu Hadeishi) writes:
> [...]  Of course, this
> is all getting rather silly, but for fun (since we two seem to be
> the only ones left reading this topic anyway), I'll continue with
> my arguments.

Not at all!

But I have to throw in an observation of mine that IMO shows a difference
between Taoism and Zen Buddhism that at least is important for Western
people:  I have the impression that Taoism in its roots rejects the idea
of technical progress while Zen Buddhism behaves indifferently in this regard.
If I remember correctly, Taoism was partly a "back-to-nature" counter-movement
when new machines (like draw wells) were invented and supported by
Confucianist people.

What do you say?  --ralf
From: amnell@klaava.Helsinki.FI (Marko Amnell)
Newsgroups: sci.physics
Subject: Re: Number of elementary particles in visible universe?
Date: 5 Oct 92 10:28:47 GMT
Organization: University of Helsinki

In article <1992Oct5.010024.7629@hellgate.utah.edu> 
tolman%asylum.cs.utah.edu@cs.utah.edu (Kenneth Tolman) writes:

>What is the approximate number of elementary (I mean proton, electron,
>neutron) particles in the visible universe?  Is it around 10^40, or 
>way higher?  

It's way higher.  More like ~10^80 (in a typical cosmological model).
On p. 1216 of MTW there are two 'big numbers' listed of about the size
you mention.

10^40 ~= 10^28 cm/10^-12 cm  (radius of universe at maximum
                               expansion)/(`size' of elementary particle)

10^40 ~= e^2/GmM             (electric forces)/(gravitational forces)

Maybe you were thinking of one of these.

-- 
Marko Amnell
amnell@klaava.helsinki.fi
Graduate Student in Philosophy
From: johno@sdd.hp.com (John Ongtooguk)
Newsgroups: sci.physics
Subject: Re: How do you draw a straight line?
Date: 5 Oct 1992 21:44:49 GMT
Organization: Hewlett-Packard, San Diego Division
Distribution: world
NNTP-Posting-Host: hpsdlg10.sdd.hp.com

In article <HAGERMAN.92Oct5161957@rx7.ece.cmu.edu>, hagerman@ece.cmu.edu (John Hagerman) writes:
|> In article <1992Oct5.154211.21663@ecrc.de> micha@ecrc.de (Micha Meier) writes:
|> > 
|> > Although we can make a circle as precise as we want, I think we
|> > cannot make a really precise straight line - every straight line is
|> > made from another one or from a tool that has been made using some
|> > older straight lines ..............Although we have precise 
|> > instruments and tools, we can only make better and better lines 
|> > but IMHO there is no process to create a straight line directly. 
|> 
|> How about laser milling ? 

   Laser milling usually involves moving a laser head around on the 
   straight lines of a machine...which gets you back to square one. 
   As someone else recently posted you can use a laser to calibrate
   a machine or setup but generating a line is something different. 
   I've never used a laser over a long distance but it seems that it
   would be affected by mirage or 'seeing' the same way a long distance 
   shooter or telescope user is. 

   I seem to recall that the Mormans used long trays of water when
   laying out the pitch of their irrigation systems and that it was
   remarkably accurate over a long distance. Some early astronomers
   also used trays of water to test their flats. A chalk line works
   well as does a plumb line but like most (all?) generated figures,  
   circles included, some error is always present. With some types 
   of setups one can rotate the figure 180 degres in a plane or around
   an axis and regenerate or remeasure the line in an attempt to cancel
   out some error. Usually one is forced to say that this line is
   straight in this plane or space to within some value at some level  
   of confidence, as one has to account for 'four dimensional' error 
   where each time it is measured you get a different answer.   

   John Ongtooguk (johno@sdd.hp.com)