HDTenEightyP/NetNews huggingface dataset:
From: fc03@ns1.cc.lehigh.edu (Frederick W. Chapman)
Newsgroups: sci.math
Subject: Mathematics vs. Sex
Date: 4 Jan 93 16:08:54 GMT
Organization: Lehigh University

In honor of the recent thread on why there is no Nobel prize in
mathematics, and the subsequent questions probing the sexual/asexual,
moral, etc. character of mathematicians, I have decided to update my
.signature file.  :-)

-- 

o ------------------------------------------------------------------------- o
|  Frederick W. Chapman, User Services, Computing Center, Lehigh University |
|    Campus Phone:  8-3218     Preferred E-mail Address:  fc03@Lehigh.Edu   | 
o ------------------------------------------------------------------------- o
|             Ecstasy is transitory, but a theorem is forever!              |
o ------------------------------------------------------------------------- o
From: andrew@rentec.com (Andrew Mullhaupt)
Newsgroups: sci.math
Subject: Re: Value of the US Dollar
Date: 12 Jan 93 16:02:32 GMT
Organization: Renaissance Technologies Corp., Setauket, NY.

In article <1993Jan11.180318.6541@cs.unca.edu> snodgras@cs.unca.edu (Ryan Snodgrass) writes:
>How do I compute the value of the US dollar?  Or what is used to figure
>
>it out?  ANY input would be helpful,

Value in what terms? People often consider various indications of relative
worth of the US dollar. For example you can consider the 'purchasing power'
which is done by tracking the price of a basket of consumer goods, or
the relative strength to other currencies (compute an average exchange
rate against major currencies like the Pound, Yen, Deutschmark and others)
or against its historical value (using all sorts of things based on the
yield curve).

But this is not very difficult _mathematically_. A few minutes with a
friendly economist will help magnify this problem to its true, intractable
size...


Later,
Andrew Mullhaupt
Newsgroups: sci.math
From: nissim@mary.fordham.edu (Leonard J. Nissim)
Subject: Re: term for the "angle" of a complex number
Organization: Fordham University
Date: Tue, 12 Jan 1993 21:40:00 GMT
News-Software: VAX/VMS VNEWS 1.41    
Distribution: usa
X-Posted-From: mary.fordham.edu
NNTP-Posting-Host: sol.ctr.columbia.edu

In article <C0rFC2.A8@smsc.sony.com>, markc@smsc.sony.com (Mark Corscadden) writes...
>A complex number Z can be expressed in these ways:
> 
>rectangular -   X + Yi         where X and Y are real
>polar -         R  exp(Ai)    where R>=0 and A are real (A is not unique)
> 
>Terminology for these quantities:
> 
>X - the real part of Z
>Y - the imaginary part of Z
>R - the magnitude of Z or the absolute value of Z
>A - ???  I have no idea ???
> 
>What do you call "A"?  Ideally this would be a term that you could expect
>to be recognized in a discussion about quantum field theory, for example.
> 
>Mark Corscadden
>markc@smsc.sony.com
>work: (408)944-4086

Most textbooks (and in particular, "Complex Variables and Applications"
by Churchill, Brown, and Verhey, which I used the last time I taught it)
call it: 
          the *argument* of Z, abbreviated arg(Z)
-------------------------------------------------------------------------------
Leonard J. Nissim  (nissim@mary.fordham.edu)   
Disclaimer:  "I speak only for myself."
-------------------------------------------------------------------------------
Newsgroups: sci.math
From: duentsch@dosuni1.rz.uni-osnabrueck.de (Ivo Duentsch)
Subject: Aliquot chains
Organization: University of Osnabrueck, FRG
Date: Thu, 7 Jan 1993 08:08:00 GMT

The targets of aliquot chains with starters <= 200,000 are now
available in the package aliquot.zip via anonymous ftp to
 
           tethys.rz.uni-osnabrueck.de (131.173.17.10)
 
in the directory pub/msdos/math. About 15% of the start numbers
have not been resolved.
 
Aliquot is a utility to compute and process aliquot chains. Comments
and bug reports are welcome.
From: Interested
Newsgroups: sci.math
Subject: Re: High Prices of Math Books. I am pissed.
Date: 10 Jan 93 18:07:02 GMT
Reply-To: addamax!watson@uxc.cso.uiuc.edu
Distribution: sci.math
Organization: University of Notre Dame

In article <1993Jan09.202015.19777@eng.umd.edu> clin@eng.umd.edu (Charles  
Lin) writes:
> 
>     I have heard (and seen) paperbacks sold in India (and possibly  
Taiwan)
> which are sold for a fraction of the cost in the US.   I suspect these
> countries have pretty lax copyright laws, and no one could really afford
> the equivalent of a thirty dollar American book in rupees, anyway.  The
> two combined means that companies that want to make any money on the  
book,
> have to sell it dirt cheap.   The paper quality is usually not quite as
> good though.
	I would not like to comment on Taiwan, but in India, pirated 
version of US books are not available. What is available are asian 
editions printed in New Delhi/Singapore/etc which have a low list price
(I assume it is due to the lower production costs). If one wishes to
obtain books with US editions, they cost as much as they do here.

Acharya
Newsgroups: sci.math
Subject: Re: Cantor set problem
From: a_rubin@dsg4.dse.beckman.com (Arthur Rubin)
Date: 6 Jan 93 00:09:02 GMT
Organization: Beckman Instruments, Inc.

In <C0EB3o.Kzy@undergrad.math.waterloo.edu> cmspring@undergrad.math.waterloo.edu (Colin Springer) writes:


>I'd be interested in any solutions or references anyone might find for the
>following problem which I've been thinking about recently.

>Problem:  Consider the subset of the plane formed by starting with the Cantor
>set placed on the interval [0,1], and for any two points a, b in this set
>we construct the circle centered at a passing through b.  Does this set have
>measure zero?

Probably not.  I see no reason why it should have measure 0.

--
Arthur L. Rubin: a_rubin@dsg4.dse.beckman.com (work) Beckman Instruments/Brea
216-5888@mcimail.com 70707.453@compuserve.com arthur@pnet01.cts.com (personal)
My opinions are my own, and do not represent those of my employer.
My interaction with our news system is unstable; please mail anything important.
Newsgroups: sci.math
From: misar@rbg.informatik.th-darmstadt.de (Walter Misar)
Subject: Re: Fermat's Last Theorem
Date: Wed, 6 Jan 1993 10:54:38 GMT
Organization: TH Darmstadt

In article <1993Jan6.092212.9851@bradley.bradley.edu>, pwh@bradley.bradley.edu (Pete Hartman) writes:
 
[some stuff deleted]

> Hinging on that, it seems apparent that if we go to N = 3, we are
> dealing with normal 3-D volumes, and it's also apparent that the
> two lesser volumes would sum to less than the third.  For N = 4,
> we have hypercubes with edges adjacent to the right triangle, and
> it seems sensible that the two lesser 4-D volumes would be even
> smaller than the third.  Etc.  Is there some way to formalize
> this proof?  Is it really a proof?

NO.
What you are showing is: if a^2+b^2=c^2 holds true then it follows
that a^3+b^3=c^3 is false (trivial cases like a=b=c=0 excluded).
Or more generally, that there are values a,b,c for which a^N + b^N = c^N
isn't true (N>2). But Fermat claimed that there are no integer values
satisfying the equation.


[some more stuff deleted]

> area1^3 + area2^3 + area3^3 = area4^3.  Does this really sound
> feasable to someone who isn't an utter layperson like me?  If
> so, is it "interesting"?  Has it been demonstrated already?
> Does it have any use?  Does anyone care?

Also there is no geometrical representation in euclidian space, there
are examples of this (3^3 + 4^3 + 5^3 = 6^3), and there are methods of
systematically getting all those values. Related to this, there is
conjecture of Euler : There aren't any n<N integers, such that the sum
of this integers each raised to the Nth power is equal to another integer
raised to the Nth power. But this was proven to be wrong, and an 
example of four 5th powers that some to another 5th power was given.

Anyone know the numbers and who this did ?
 
> Any comments, criticisms, etc, are welcome.  Just my own little
> shot in the dark....

Before posting a proof of FLT, just check with a local mathematician (or
however this word is spelled, sorry).

-- 
Walter Misar                                | It is impossible to enjoy
misar@rbg.informatik.th-darmstadt.de        | idling thoroughly unless
                                            | one has plenty of work to do.
Newsgroups: sci.math
From: graham@cs.sfu.ca (Graham Finlayson)
Subject: Linear combinations of Vector Spaces
Keywords: Vector Spaces
Organization: CSS, Simon Fraser University, Burnaby, B.C., Canada
Date: Tue, 5 Jan 1993 22:29:42 GMT


(SECOND POSTING - I typed my email address incorrectly 1st time around)

I was wondering if anyone has come across the following problem:

Given 2 mXn matrices A and B, where m>n. The columns of A and B span
n-dimensional subspaces of m-space. What are the properties of the
subspaces spanned by linear combinations of A and B.
 
For example, given a 3rd mXn matrix C how can you check if there exists
a linear combination of A and B such that the space defined by (a*A+b*B)
intersects  the space spanned by C in 
at least 1 dimension?

Any pointers you can give would be appreciated.

Please email responses to 

	graham@cs.sfu.ca
	----------------
	----------------


Graham

(If there is any interest I will post a summary)
From: bumby@dimacs.rutgers.edu (Richard Bumby)
Newsgroups: sci.math
Subject: Re: Euclidean Domain
Date: 10 Jan 93 14:44:57 GMT
Organization: Rutgers Univ., New Brunswick, N.J.

steele@isis.cgd.ucar.edu (Alfred Steele) writes:


>In article <HAMMOND.93Jan3134111@annemarie.albany.edu>, hammond@csc.albany.edu (
>William F. Hammond) writes:
>|> In article <Jan.3.02.05.44.1993.24643@spade.rutgers.edu>
>|>    cadet@spade.rutgers.edu (Uniquely TiJean) writes:
>[....]

>|>If someone can answer the question:
>|>Why there are not other candidates for the Euclidean function?

>I have asked the very same question and do not know the answer....
>Any information netters know about this, I would be interested in hearing
>about.  What is the "folklore" on the subject?

This should be a FAQ.  T. S. Motzkin, "The Euclidean Algorithm", Bull.
Amer. Math. Soc. 55(1949), 1142-1146, gave a simple analysis of the
properties of any Euclidean Algorithm in an integral domain.  The idea
is to work backwards, starting with the set consisting only of zero,
and applying the following construction.  The derived set of a set, S,
consists of all elements of the domain which have a complete set of
residues in S.  This construction may be extended transfinitely if
necessary by taking unions at limit ordinals.  In order to have a
Euclidean Algorithm, you must be able to exhaust the domain in this
way.  For quadratic number rings, there are only finitely many units.
The derived set of {0} consists only of units.  If all proper ideals
have index greater than the number of units (only 2 except for some
rings that are already Euclidean for the norm), the process stops
there.

Another major article on Euclidean Algorithms is P. Samuel, "About
Euclidean Rings", J. Algebra 19 (1971), 282-301.  It would appear that
the next major exposition is due this year.
-- 
R. T. Bumby **  Rutgers Math ||   Amer. Math. Monthly Problems Editor
bumby@math.rutgers.edu       || P.O. Box 10971 New Brunswick, NJ08906-0971
bumby@dimacs.rutgers.edu     || Phone: [USA] 908 932 0277 * FAX 908 932 5530
Newsgroups: sci.math
From: chappell@symcom.math.uiuc.edu (Glenn Chappell)
Subject: Re: Let's add some sci.math.* groups
Organization: Math Dept., University of Illinois at Urbana/Champaign
Date: Mon, 11 Jan 1993 21:18:41 GMT

In article <1993Jan11.194822.665@stsci.edu> kimball@stsci.edu (Timothy Kimball) writes:
>Robert D. Silverman (bs@gauss.mitre.org) wrote:
>: I *might* vote for a split into sci.math, and sci.math.recreational,
>: as well as keeping sci.math.research.

>This sounds like a good idea.
>Not everyone who reads this group is a mathematician by trade,
>and over-dividing sci.math will ruin its eclectic nature.

Agreed, but I would suggest a different sort of split (if there is to be
a split at all). After all, what is "recreational" math, anyway? How do
you draw the line between that and "ordinary" math?

It appears to me that a much clearer dividing line is the one between
discussions about mathematics and discussions about people & society.
In the latter category are topics like teaching, textbook prices,
innumeracy, US vs. Japan, the job market, mathematical personalities,
who won the Fields Medal, etc....

				GGC  <><
Newsgroups: sci.math,alt.flame
From: matmcinn@nuscc.nus.sg (brett mcinnes)
Subject: Re: Frankly,my dear......was: Fermat's Last Theorem
Organization: National University of Singapore
X-Newsreader: Tin 1.1 PL4
Distribution: usa
Date: Sat, 9 Jan 1993 03:13:39 GMT

gjm11@cus.cam.ac.uk (G.J. McCaughan) writes:
: >I disagree. :)  My point is that if the proof were easy, nobody would have
:            ^^^^^
: On what grounds do you say this? Just saying that you don't happen to find it
: exciting isn't enough, of course.
Yes, it is. Or rather,to be more precise: there is an admittedly tenuous
consensus that some results are profound, others not. I suggest that the
continuing popularity of FLT is a historical accident.:
: 
: You haven't answered either of my main points: namely, that FLT is interesting
: on its own account, and that it is connected quite intimately with other areas
: of mathematics, and has given rise to work which is clearly important.
: 
Astrology and alchemy also gave rise to important things. Actually, you
almost seem to be agreeing with me: FLT is of historical interest only.   :
: 
: Perhaps I'll understand better if you tell me what you think of some other
: famous conjectures. What do you think of:
:  * the twin prime conjecture?
:  * the Goldbach conjecture?
I try to think of them as little as possible.                            
 :  * the four-colour problem?                                           
 Amusing and entertaining, but not the stuff of Fields Medals.          
  :  * the Poincare conjecture?                                          
 Now you're talking. This is really significant, and would be so even if
it had no applications.                                                  
:  * the Riemann hypothesis? :  : -- 
Utterly boring in itself, like FLT; but unlike FLT, it is important
because you need it to prove things that are interesting. Just imagine the
sensation if it turns out to be wrong.
From: wsadjw@rw7.urc.tue.nl (Jan Willem Nienhuys)
Newsgroups: sci.math
Subject: Re: probability = 0
Date: 6 Jan 93 10:24:38 GMT
Reply-To: wsadjw@urc.tue.nl
Organization: Eindhoven University of Technology, The Netherlands

In article <9301051655.AA22441@aplpy.jhuapl.edu> louis@aplpy.jhuapl.edu (Louis Vasquez) writes:
>Hello,
>	My friend and I got in a debate about the probability of 
>something happening.  The event was that another friend of ours
>could win the superbowl.  Not that he would play on a winning team
>in the superbowl but that he would win it.

[rest deleted]

Strictly speaking, there's hardly a way that you can define the probability
of such an event.  If you want to discuss the probability of a certain
*type* of event, you must have some kind of well-defined universe of
possibilities and some kind of known or plausible chance mechanism.
If the situation leading up to the "event" can be experimentally
reproduced (in principle) then you would have (in principle) a way
to check whatever you say about the probability.

In most cases such "probabilities" only are defined in suitably chosen
models of the situation.  So the throw of a coin is simplified to 
*postulating* that both sides have equal chance.  The possibility that
the "throw" consists of initializing the coin as spinning very rapidly
around a vertical axis on a very smooth surface is left out from the
model.  Similarly the unequal mass distribution (due to the different 
numbers of pips) of a die is left out in the model.

However in the case of the poster, where hypothetical changes of
rules are envisaged, there is no clear model. I'd say that for
all practical purposes the chance is 0.  If you were to bet, then
1 cent would be the lowest stake. But there is also a highest stake,
namely the amount you can credibly raise in case you lose.  I guess
that in each credible model of the situation, the chance of the event
is much less than the ratio between the lowest and highest stake. 
So from a theoretical point of view there's no probability (because
a clear model is lacking) and from a practical point of view (rational
betting) the probability is zero.

JWN
From: rme59719@zach.fit.edu (Tony Witkowski /ADVISOR Nansteel)
Newsgroups: sci.aeronautics
Subject: Canard Design Project
Date: 12 Jan 93 17:21:46 GMT
Distribution: usa
Organization: Florida Institute of Technology, Melbourne USA


I am a senior at the Florida Institute of Technology
and am studying Aerospace Engineering. For a senior
design project, we have decided to build a radio
controlled model of a canard style airplane.

Could anyone tell me of reference books (Nasa papers,
text books, etc.) that would be direclty
aplicable to canard airplanes, particulary
in the areas of stability and aerodynamics. 

A main wing will be mounted in the aft section of the
model, with rudders mounted on the wing tips for 
directional control. The forward canard will serve as
a lifting surface as well as for pitch control.

Thank you in advance for any sources of information
you can provide.

Tony Witkowski
e-mail:  rme59719@zach.fit.edu
From: fiddler@concertina.Eng.Sun.COM (steve hix)
Newsgroups: sci.aeronautics
Subject: Re: Unflattering descriptions
Date: 7 Jan 93 20:28:16 GMT
Organization: Sun
NNTP-Posting-Host: concertina

In article <1993Jan7.020155.26211@massey.ac.nz> news@massey.ac.nz (USENET News System) writes:
>In article <lkmemtINNe38@appserv.Eng.Sun.COM> fiddler@concertina.Eng.Sun.COM (steve hix) writes:
>>Grumman AgCat.
>>
>Well, there is a re-engined AgCat that operates from the field I often fly from
>that sports a turbine up front. The long pointy nose looks a lot better than the
>fat lump that graced the front before surgery. It's a lot quieter too.
>
>The worlds first (turbo) jet biplane?

There is a turbojet-powered biplane made in Russia (and perhaps under
license in Poland).  Designed for dusting those wheatfields that
extend for (literally) miles in every direction.

--
-------------------------------------------------------
| Some things are too important not to give away      |
| to everybody else and have none left for yourself.  |
|------------------------ Dieter the car salesman-----|
Newsgroups: sci.aeronautics
From: gcr8829@aw2.fsl.ca.boeing.com (Gustav C. Rettke)
Subject: Re: Unflattering descriptions
Organization: fsl
Date: Thu, 7 Jan 1993 20:18:25 GMT

From article <bob1.726333584@cos>, by bob1@cos.com (Bob Blackshaw):
> In <alien.026m@acheron.amigans.gen.nz> alien@acheron.amigans.gen.nz (Ross Smith) writes:
> 
>>I'm trying to compile a list of the more, shall we say, unflattering
>>descriptions that have been applied to various aircraft over the years.
>>Does anyone know any good ones? The short list I've been able to recall
>>myself goes something like this ... sources omitted to protect the
>>guilty :-)
> 
>>F-15 Eagle : "Living proof of the American theory that even a brick will
>>fly if you hang enough engines on it."

At Luke AFB, the F-15 "Flying Eagle" got abridged to "Fleagle"

>>Any more? (The above are all military planes, but I'm interested in civilian
>>examples too.)

How about the venerable DC3 "Gooney Bird"


Gus Rettke			| Programming - the key to understanding and
				|		utilizing the computer.
From: gabriele@aero.org (Mark Gabriele)
Newsgroups: sci.aeronautics
Subject: Re: Kidney Transplant Information Needed -- NOT HERE!!
Date: 5 Jan 93 17:24:03
Organization: The Aerospace Corporation, El Segundo, CA
NNTP-Posting-Host: solecism.aero.org
In-reply-to: ramin@crchh775.BNR.CA's message of Tue, 5 Jan 1993 20:20:22 GMT

I think this about tears it....

I do NOT typically play the role of net.cop, but this is getting
ridiculous.  We don't do kidney transplants on sci.aeronautics.  Nor
is this the appropriate place for clever aircraft nickname
discussions, nor "what's the ugliest / prettiest plane you ever saw?",
nor any of that stuff.  Please, please, please, take those topics to
the other groups - rec.aviation.military would be a good place for
most of it.
 
This group should be used for the discussion of serious aeronautic
issues.  By all means, ask questions here.  But please, before asking
a question here, ask yourself "is this a serious aeronautic question?"
and then, if the answer is yes, try to look up the answer in a
textbook.  If you have no luck with those methods, by all means, post
here.
 
I'm sorry if the above sounds rather facist, and I apologize in
advance for the addition of yet another tidbit of noise to this group.

And now, back to sci.aeronautics...

=Mark
(gabriele@aero.org)
From: ghee@vision.larc.nasa.gov (Terry A. Ghee)
Newsgroups: sci.aeronautics
Subject: Re: Teach-Yourself-AERO books etc.. (was Re: Helicopter Aerodynamics)
Date: 11 Jan 1993 12:40:12 GMT
Organization: NASA Langley Research Center, Hampton, VA  USA
Distribution: world
NNTP-Posting-Host: vision.larc.nasa.gov

From Dan Sharpes who could not post this:

  Just to close the loop on this continent, I've attached the response I
sent Roger on Saturday:

  While Anderson's text (I'm not familiar with his series) is a good
introduction to the subject, I believe it is not at all helpful in
creating an algorithm to do the analyses you desire.  I used Bertin &
Smith's "Aerodynamics for Engineers" (1979, Prentice Hall, Englewood
Cliffs, New Jersey) as a starting point for my Master's thesis on v-tail
aircraft aerodynamics.

  Bertin & Smith pick up where Anderson leaves off on page 267 (1984
printing), and expands Anderson's equation 5.76 into a comparitively
easy-to-follow planar wing analysis, complete with a sample problem the
student can work through.  I used this as the starting point for my work
(which involved looking at a wing in three dimensions).  Once I got the
three-dimensional equations right, the rest was comparitively easy.
Similarly, the equations in B&S should be fairly straight forward to
program (I used FORTRAN 77).

  The Navier-Stokes and Euler-Lagrange codes are not only way over my
head, but they could be overkill on the sail design aspect of your
problem.  I believe they would be most appropriate for looking at the
hull design.  The trouble, as I see it, with these codes is the vast
amount of time required to mathematically define the hull.  Also, the
type of workstation required to interpret the results graphically place
it far out of my league.  HOWEVER, I have a friend who may know the
individuals who supported the America's Cup competitor from your part of
the globe a few years back (please pardon my spelling!! the Kokabora II,
was it?)  If you like, I could try to find the names of the individuals
involved.

  Anyway, good luck and all success to your ventures!

Dan Sharpes

Note: Dan asked me to send this to you as his net bounced him.
I found the author of the book I have and it is a guy by the
name of Marchaj.  A previous poster didn't like this reference
much, but I still think its a good text.  The publishing company
is International Marine Press, Camden, Maine, USA.  Good luck.


Newsgroups: sci.aeronautics