Collage 263               H u m o u r N e t               15 MAY 96

Talk about an oversight....

<Reuter news service>

LONDON, May 9 - A faulty mathematical equation used by aircraft
designers may have caused mistakes for more than 50 years and may
have caused heat tiles to fall off the space shuttle, a report
published on Thursday said.

(Interesting how journalists can consider equations to be "faulty."
The average engineer or mathematician would generally use an
adjective like "inaccurate" -- pretty much the same way we'd
describe the average journalist. :-)

The equation is supposed to calculate how much force is exerted on
an aircraft's wing, but it was never verified in experiments, New
Scientist magazine reported.

(This is going to be bad news for my complex-variables professor
from college -- apparently, my answer to the Joukowski airfoil
problem wasn't as far off as he thought. I wonder if they'll fix
grades twelve years after the fact....)

It quoted mathematicians and engineers as saying the equation
underestimated how much pressure passing air put on a wing. But this
probably does not mean planes are unsafe.

(Uh, Mr. Reuter, could you please clarify "probably"?)

Alexandre Chorin of the University of California at Berkeley said
aeronautical engineers never relied exclusively on the equation and
added in a safety margin when designing wings.

(Yeah, they added in a "safety margin," all right -- floatable seat
cushions.)

</Reuter>

Okay now, let me just see if I have my events ordered correctly here:

 9 May: Reuter reports that the fluid-flow calculation is incorrect
10 May: Two helicopters inexplicably collide at Camp Lejeune
11 May: ValuJet aircraft plummets from the sky; no explanation

Coincidence? Your guess is as good as mine. But I'm going to
Albuquerque in two weeks, and I'm seriously considering driving. ;-)

Okay, I'm kidding (lest anyone be inclined to explain to me that
there really is no link between the Reuter report and the aircraft
incidents -- you'd be surprised what some people will take seriously).

To be sure, the fact that this escaped notice by the engineers
isn't surprising; that it escaped notice by the mathematicians
*is*, however. You see, mathematicians have a slightly different
perspective on these things -- and this Collage attempts to
illustrate that difference through some simple examples:

"Understanding Mathematics (Take One)" comes to us from Simone in
Massachusetts,

"Understanding Mathematics (Take Two)" is provided by your HumourNet
moderator (this joke goes waaaaaay back),

"Understanding Mathematics (Take Three)" appears here with thanks to
Lord Ian in South Africa,

"Understanding Mathematics (Take Four)" was contributed by Randy
Cassingham of the highly-recommended (by your moderator) "THIS is
TRUE" list (see Collage 239),

"R U a Computer Geek?" and "More Geek Humor" come to us from Neil in
Massachusetts,

"Understanding Engineering Professors" appears courtesy of Igor at
Cornell University,

"Perhaps You Should Consider Finding a New Hobby If" was contributed
by Ric in California, and

"Bear Transformations" appears courtesy of (once again) Simone in
Massachusetts.

A big thanks to this issue's contributors -- and an extra big thanks
to Randy Cassingham for the Reuter news story.

It's another "Geek Humor" Collage. Enjoy!

- Vince Sabio
  HumourNet Moderator
  HumourNet@telephonet.com
____________________________________________________________________
          Opener (above) Copyright 1996 by Vincent Sabio
  Permission is hereby granted to forward or post this "Collage";
  please observe the guidelines stated at the end of the message.
____________________________________________________________________

SUBJ: Understanding Mathematics (Take One)

"In testing primality of very large numbers chosen at random, the
chance of stumbling upon a value that fools the Fermat test is less
than the chance that cosmic radiation will cause the computer to
make an error in carrying out a 'correct' algorithm. Considering an
algorithm to be inadequate for the first reason but not for the
second illustrates the difference between mathematics and
engineering."

-- Harold Abselon, "Structure and Interpretation of Computer
Programs"

========================[ H U M O U R N E T ]=======================

SUBJ: Understanding Mathematics (Take Two)

A psychologist unwittingly makes the mistake of testing a
mathematician and an engineer.

He sets up a room with a table, a chair, and a stove, and places a
pot of water on the table.

First, he sends the engineer into the room with instructions to
"boil the water." The engineer takes the pot of water from the table,
places it on the stove, and lights the burner.

"Very good," says the psychologist. He places the pot back on the
table, and sends in the mathematician with instructions to "boil the
water."

The mathematician moves the pot from the table to the stove and
lights the burner.

"Very good," says the psychologist. He then places the pot of water
onto the chair, and sends the engineer back into the room with
instructions to "boil the water."

The engineer takes the pot of water from the chair, places it on the
stove, and lights the burner.

"Very good," says the psychologist, who obviously studied positive-
feedback techniques when he was in college. Once again, he places
the pot of water on the chair, and sends the mathematician back into
the room, with instructions to "boil the water."

The mathematician takes the pot off the chair, places it on the
table, and says, "The solution is simple from there."

========================[ H U M O U R N E T ]=======================

SUBJ: Understanding Mathematics (Take Three)

Assume a guy and a girl start on opposite sides of a room. Once a
minute, they halve the distance between them.

To the mathematician, they will never meet.

To the engineer, they will get close enough for practical purposes.

========================[ H U M O U R N E T ]=======================

SUBJ: Understanding Mathematics (Take Four)

A Mathematician, a Biologist and a Physicist are sitting in a street
cafe watching people going in and coming out of the house on the
other side of the street.

First they see two people going into the house. Time passes. After
a while they notice three persons coming out of the house.

The Physicist: "The initial measurement wasn't accurate."

The Biologist's conclusion: "They have reproduced."

The Mathematician: "If now exactly 1 person enters the house, it
will be empty again."

========================[ H U M O U R N E T ]=======================

SUBJ: R U a Computer Geek? Take This Simple Test

Q: Why do programmers always get Christmas and Halloween mixed up?
A: Because DEC (25) = OCT (31)

Q. What happens to programmers when they die?
A: They get deallocated? Their values become undefined? The get
re-intialized? Their structures break down? They become WORM food?
They start dropping bits. They branch to a new address!

Q. What do you get when you cross 200K of apples and lots of garbage?
A. A core dump

----------[ H U M O U R N E T ]----------

SUBJ: More Geek Humor

Have you heard about the new Cray? It's so fast, it executes an
infinite loop in 6 seconds.

Have you heard about the new Cray? It's so fast, it requires TWO
halt instructions to stop it.

My sister Cecilia opened a computer store in Hawaii.
She sells C shells by the seashore.

If God had intended Man to program, we would be born with serial I/O
ports.

Earth is 98% full ... please delete anyone you can.

To define recursion, we must first define recursion.

Hardware: The parts of a computer system that can be kicked.

If a train station is where the train stops, what is a work station?

God is Real, unless explicitly declared Integer...

========================[ H U M O U R N E T ]=======================

SUBJ: Understanding Engineering Professors
By Anson Mayers and Howard Sanders, Cornell University

This is the 1996 collection of faculty humor from the Engineering
Physics Department at Cornell University. Never let it be said that
engineering professors have no sense of humor; they simply don't
*realize* that they're amusing.

"The simplest macroscopic example of tunneling I know of is in the
A&EP office, when late homeworks manage to make it into the box
after the office is closed."
-- Prof. Wise

"Laplace Transforms are the vegetables of mathematics. Nobody likes
them, but you've got to have them."
-- Prof. Kusse

"How many of you take more than 8 hours to do a homework? Almost
all of you, huh? Oh well, you're young."
-- Prof. Kusse

"Dirac says it's OK."
-- Prof. Wise

"It has no batteries, and is very good for scratching your back."
-- Prof. Lovelace on the slide rule

"I thought you wanted a cross product ... I delivered."
-- Prof. Lovelace

========================[ H U M O U R N E T ]=======================

SUBJ: Perhaps You Should Consider Finding a New Hobby If ...

Your bookmarks file takes 15 minutes to scroll from top to bottom.

You get a tuner card so you can watch TV while surfing.

You and your friends get together regularly on IRC, even though all
of you live in the same city.

Your eyeglasses have a web site burned in on them.

You find yourself brainstorming for new subjects to search.

You refuse to go to a vacation spot with no electricity and no
phone lines.

You finally do take that vacation, but only after buying a cellular
modem and a laptop.

You spend half of the plane trip with your laptop on your lap ...
and your child in the overhead compartment.

========================[ H U M O U R N E T ]=======================

SUBJ: Bear Transformations

Is a polar bear is a rectangular bear after a coordinate transform?

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</collage263>