New Professor F. B. Farquharson AKA Herr Richard, Maple Support, Scientific Computers GmbH

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Vladimir Bondarenko

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Mar 13, 2005, 4:49:06 AM3/13/05
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On July 1, 1940, the Tacoma Narrow Bridge at Puget Sound in the
state of Washington was completed and opened to traffic. From the
day of its opening the bridge began undergoing vertical
oscillations, and it soon was nicknamed "Galloping Gertie."
Strange as it may seem, traffic on the bridge increased
tremendously as a result of its novel behavior. People came from
hundreds of miles in their cars to enjoy the curious thrill of
riding over a galloping, rolling bridge. For four months, the
bridge did a thriving business. As each day passed, the
authorities in charges became more and more confident of the
safety of the bridge - so much so, in fact, that they were
planning to cancel the insurance policy on the bridge.

Starting at about 7:00 on the morning of November 7, 1940, the
bridge began undulating persistently for three hours. Segments of
the span were heaving periodically up and down as much as three
feet. At about 10:00 a.m., something seemed to snap and the bridge
began oscillated wildly. At one moment, one edge of the roadway
was twenty-eight feet higher than the other; the next moment it
was twenty-eight feet lower than the other edge. At 10;30 a.m. the
bridge began cracking, and finally, at 11:10 a.m. the entire
bridge came crashing down. Fortunately, only one car was on the
bridge at the time of its failure. It belonged to a newspaper
reporter who had to abandon the car and its sole remaining
occupant, a pet dog, when the bridge began its violent twisting
motion. The reporter reached safety, torn and bleeding, by
crawling on hands and knees, desperately clutching the curb of the
bridge. His dog went down with the car and the span - the only
life lost in the disaster.

There were many humorous and ironic incidents associated with
the collapse of the Tacoma bridge. When the bridge began heaving
violently, the authorities notified Professor F. B. Farquharson of
the University of Washington. Professor Farquharson had conducted
numerous tests on a simulated model of the bridge and had assured
everyone of its stability. The professor was the last man on the
bridge. Even when the span was tilting more than twenty-eight feet
up and down, he was making scientific observations with little or
no anticipation of the imminent collapse of the bridge. When the
motion increased in violence, he made his way to safety by
scientifically following the yellow line in the middle of the
roadway. The professor was one of the most surprised men when the
span crashed into the water.

One of the insurance policies covering the bridge had been
written by a local travel agent who had pocketed the premium and
had neglected to report the policy, in the amount of $800,000, to
his company. When he later received his prison sentence, he
ironically pointed out that his embezzlement would never have been
discovered if the bridge had only remained up for another week, at
which time the bridge officials had planned to cancel all of the
policies.

A large sign near the bridge approach advertised a local bank
with the slogan "as safe as the Tacoma Bridge." Immediately
following the collapse of the bridge, several representatives of
the bank rushed out to remove the billboard.

After the collapse of the Tacoma Bridge, the governor of the
state of Washington made an emotional speech, in which he declared
"We are going to build the exact same bridge, exactly as before."
Upon hearing this, the noted engineer Von Karman sent a telegram
to the governor stating "If you build the exact same bridge
exactly as before, it will fall into the exact same river exactly
as before."


-- Martin Braun
-- Differential Equations And Their Application

Springer, 4th ed, 1992, 578 pp.


Book

http://www.amazon.com/exec/obidos/tg/detail/-/0387978941/103-2904260-8139031?v=glance


More details about Takoma Bridge

http://www.engineering.com/content/ContentDisplay?contentId=41009025


Theodore von Karman

http://www.ceemast.csupomona.edu/nova/vonK.html
http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Karman.html
http://www.nas.edu/history/members/karman.html
http://aerodyn.org/People/vonKarman.html
http://www.siam.org/prizes/vonkar.htm
http://www.vki.ac.be


Search also for

Born-von Karman lattice model (crystallography)
von Karman street (flow past cylinder)
von Karman integral equation (boundary layers)
Karman-Pohlhausen parameter (boundary layers)
von Karman-Tsien compressibility correction
von Karman ogive (supersonic aerodynamics)
Karman-Treffz transformation (airfoil theory)
Karman-Nikuradse correlation (viscous flow)
Prandtl-von Karman law (velocity in open channel flow)
Chaplygin-Karman-Tsien approximation (potential flow)
Falkowich-Karman equation (transonic flow)


von Karman (vortex) street

http://www.ai.mit.edu/projects/im/broch/pics/vk_time_lapse_cam8.gif
http://iacweb.ethz.ch/staff/schwierz/vorlesung_fd/pics/soapfilm_street.jpg
http://www.aceflyer.com/images/kvelocity.jpg
http://www.cps.unizar.es/~ghauke/ESP/investigacion/comp-incomp.htm
http://earth.esa.int/workshops/ers92/ATSRM/00771/
http://www.space.com/scienceastronomy/planetearth/vortex_street_001213.html
http://climate.gsfc.nasa.gov/~cahalan/KarmanVortices.html


http://www.mcef.ep.usp.br/staff/jmeneg/cesareo/Cesareo_Page3.html

Since ancient times, it has been known that wind causes vortex
induced vibration of the wires of an Aeolian harp. According to
Rabbinic records, King David hung his kinnor (kithara) over his
bed at night where it sounded in the midnight breeze. In the
fifteenth century, Leonardo da Vinci sketched a row of vortices in
the wake of a piling in a stream. In 1878, Strouhal found that the
Aeolian tones generated by a wire in the wind were proportional to
the wind speed divided by the wire thickness. He noticed that the
sound greatly increased when the natural tones of the wire
coincided with the Aeolian tones. In 1879, Lord Raleigh found that
a violin string in a chimney draft vibrated primarily across the
flow, rather than with the flow. The periodicity of the wake of a
cylinder was associated with vortex formation by Benard in 1908
and with the formation of a stable street of staggered vortices by
von Karman in 1912. (ref.: Flow-Induced Vibration, Robert
D.Blevins).


Parametric resonance

http://monet.physik.unibas.ch/~elmer/pendulum/parres.htm
http://www.enm.bris.ac.uk/teaching/projects/2002_03/ca9213/Parametric_Resonance.htm


History of the Tacoma Narrows Bridge

http://www.lib.washington.edu/specialcoll/tnb/


Takoma Bridge Movie [mov, 11 MB]

http://maxwell.ucdavis.edu/~cole/phy9a/tacoma_narrows.mov


Takoma Bridge Movie [avi, 43 MB]

http://mech2.pi.tu-berlin.de/schoop/lehre/Tacoma.avi


Art of the Bridges Continues

http://www.wsdot.wa.gov/TNBhistory/Art/art3.htm

RockyLake

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Mar 13, 2005, 2:38:46 PM3/13/05
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Vladimir Bondarenko wrote:
> On July 1, 1940, the Tacoma Narrow Bridge at Puget Sound in the
> state of Washington was completed and opened to traffic. From the
> day of its opening the bridge began undergoing vertical
> oscillations,
. . ., etc., etc., etc.

Vladimir:

What in the world are you trying to do with this posting?

This posting comes across as a small-minded and petty personal attack
on the integrity and intelligence of an individual ("Herr Richard" in
your subject header) who has made many substantive postings to this
newsgroup. It appears as though you are attempting to equate some
errors from 80 years ago with judgements being made by an individual
today. If you are trying to be cute: you are not. If you are trying
to be clever: you are not. If you are attempting to use metaphor to
state your unhappiness with Maple and your astonishment that some of us
find it useful in spite of its flaws, you are, sadly, being repetitious
and tiresome. You have already made your views on these subjects very
clear. Your views on these matters do not give you license to attack
another person, even when you choose to do so using a metaphorical
club.

If you have just discovered the Tacoma Narrows Bridge and wish to share
with others your discovery, why in the world are you posting
information about it to this news group? Perhaps you could have
included some maple worksheets that analyzed the motions and made it
relevant. Absent such information, that posting clearly steps beyond
the focus of this group.


Your passion for sharing information is laudable, but your tendency to
post lengthy and irrelevant material to this newsgroup does both it
and you a disservice. This tendency detracts from the positive
impression that you are an intelligent and capable person with
mountains of energy. I hope that what appears to be a descent into
personal attack on a valuable contributor to this newsgroup is either a
misunderstanding or else a temporary bout of poor judgement.

RockyLake

unread,
Mar 13, 2005, 2:47:09 PM3/13/05
to
Vladimir Bondarenko wrote:
> On July 1, 1940, the Tacoma Narrow Bridge at Puget Sound in the
> state of Washington was completed and opened to traffic. From the
> day of its opening the bridge began undergoing vertical
> oscillations,
. . ., etc., etc. etc.

Vladimir:

What in the world are you trying to do with this posting?

This posting comes across as a small-minded and petty personal attack
on the integrity and intelligence of an individual ("Herr Richard" in
your subject header) who has made many substantive postings to this
newsgroup. It appears as though you are attempting to equate some
errors from 80 years ago with judgements being made by an individual
today. If you are trying to be cute: you are not. If you are trying

to be clever: you are not. If you are trying to express your
displeasure with Maple and your astonishment that anyone could find it
useful in spite of its flaws you are being repetitious and tiresome.
You have already made your views on these subjects well known.
However, your views do not give you license to attack another person
whose views differ from yours, even when you choose to use a blunt
metaphor as the club.

Vladimir Bondarenko

unread,
Mar 13, 2005, 7:29:32 PM3/13/05
to
RockyLake:

Thank you for direct sharing of your honest opinion. Let me also
express you my sheer gratitude for invariable balance of your
judgements. It's really enjoying to see that you rather ask
me what could be the explanation of my actions than instantly
claim that I'm an egregious wrong-doer, Mr Baddie-The-Brainless
and the blackest arch-villain :)

RL> What in the world are you trying to do with this posting?

I already explained this twice to the extent I could afford.
For example,

http://groups-beta.google.com/group/sci.math.symbolic/msg/e771119732cc7071

[...]

VB> Let me recur to a comparison. A championship in chess is in
VB> full swing. Kasparov and his opponent, with intense eagerness,
VB> are bent their heads at the checkerboard trying to decipher
VB> each other's designs. The winner takes all!

VB> Now an elegant newspaperwoman is walking onto the stage, and
VB> she is addressing Kasparov politely, Dear Grand Master, could
VB> you please disclose publicly your ideas on account of what are
VB> your next moves, as well as your far-reaching designs?

VB> ;-)

[...]

I do believe that you cannot understand a hidden meaning of some
my actions. This not necessarily means that my action are weak or
meaningless. This is also not bad (for me), this is, to an extent,
my intention. My opponents are too mighty that I could afford to
disclose Cyber Tester's offensive/defensive warfare plans without
running a risk to lose the whole battle.

To this I can only add, with none of hard feelings on my parts or
any intention to make you upset, that on your side, you are free
absolutely to just ignore all my posts, that's all there is to it.

Actually, there is a set of certain tasks Cyber Tester is going to
resolve, and part of them (sure not all) is enumerated here

http://maple.bug-list.org/objectives.php
http://www.cybertester.com/goal.php

but one of the Cyber Tester's top priorities is here

http://www.cybertester.com/intro.php

As for Maple, over years, Maple quality gets worse and worse, and
now we have calculated a huge data base bearing Maple bugs showing
that it looks like Maple developers are no longer in control over
Maple development.

This might ends in a very bad way for the Maple customers, well,
for example, Maple XI or Maple XII will not be released at all.
Or their quality could become even worse at the moment of release
than the shameful so to say quality of Maple 9.

So we decided to make a kind of fire alarm.

Other CASs are also not holy but with Maple the whole business
looks especially black... while these gents orate loudly about
'standards'... this is frozen limit and brainwashing to use
the mildest words.

Personally, I am not sure that making Maple bugs public will
dehypnotize the Maplesoft leaders... but I am 100% sure that
if all the Maple users will follow a policy of non-resistance
to evil, then in 2-3 years we all will be in a real plight.

But at any rate my theme song is 'human testing is obsolete and
cumbersome and costly and unproductive and must be brought to
(virtually) nought'. In other words, instead of, say, today's
100 'software testers' there should be 1 person weaponed with
a high-performance environment. (You might think that it is not
possible but I announce in advance that I am not going to enter
ANY discussion on the topic. Wait and see. Or ignore my postings)

And sure I need a public example to demonstrate my viewpoint.

And if I succeed in demesmerizing Maplesoft leaders, and they
will get down to business (Maple bug fixing) then you and me
and millions Maple users would have a better Maple - is this
a bad goal or a wrong direction?

To sum up, I have no idea to impress (or don't impress or make
indifferent) you, in any way.

RL> If you are trying to be cute: you are not. If you are trying
RL> to be clever: you are not.

Oh it looks like you have a toolkit for measuring cuteness and
cleverness?! It's zero cool! ;) If you however do not have such
an objective toolkit let me please ignore this particular remark
of yours.

Also, I am afraid that I need not too much grounds to trying to
*look* cute and/or clever as over 25 years quite a number of
persons from different countries (financially independent from
me and not women :) already conveyed to me their opinion that
they I *am* clever and cute (sure when I need to produce such
an impression :-)

If you are still in doubt, you may wish to look at a fairly
small fractions of such info at

http://www.cas-testing.org/index.php?list=3

and the links there.

Also, just for info, for what it is worth, my Eysenck's number
is 164. So if some my remarks seem to be stupid the reason not
necessarily might be hidden within myself ;-)

RL> If you are trying to express your displeasure with Maple and
RL> your astonishment that anyone could find it useful in spite
RL> of its flaws you are being repetitious and tiresome.

Let me indulge yet another self-quotation.

VB> Could I remind you that you are absolutely free to ignore
VB> all my messages... or read them... Well, or read part of
VB> them. Or read on Sunday, and ignore the rest of days etc.
VB> In a word, there seems to be quite a number of choices.
VB> Aha, I came near forgetting, or attempt solving my harder
VB> challenges coming.

VB> Please do as you wish.

VB> [more decisive action from me.]

VB> All in good time.

VB> If however you like playing chess you realize that there
VB> is stuff like positional game and combinative game, there
VB> is stuff like opening, endgame, gambit etc

Yet another your remark.

RL> irrelevant material

At least you have such an impression. I cannot help you here.
Also, in my obvious opinion, it looks like now you are catching
the ball before the bound.

RL> If you have just discovered the Tacoma Narrows Bridge

I know about TB for about 20 years.

RL> Absent such information, that posting clearly steps beyond
RL> the focus of this group.

I hardly think so, and maybe you will see this in just a day,
too, from my next postings.

I convey info about CASs and their quality to many actual and
potential CAS professional users and amateurs. Is this really
out of focus?

RL> Absent such information, that posting clearly steps beyond
RL> the focus of this group.

First, Cyber Tester is a NEW phenomenon. You never encounter
any organization with our goals. Sure, this might disturb you.
People often fear unknown, and this is fairly normal. This is
just the instinct of self-preservation.

RL> Absent such information, that posting clearly steps beyond
RL> the focus of this group.

At least you think so. Unlike me, you do not see (and are not
able to see now) the full majestic tapestry. This might be a
reason you find a speck of tapestry to be alien, extraneous,
strange, foreign.

We keep working, and hopefully, save not an act of God, in a
year or so you will see clearly more of the whole tapestry,
and would decide that all the cogs are fine-cut and well-set.

RL> Absent such information, that posting clearly steps beyond
RL> the focus of this group.

You visit Michelangelo toiling on the Sistine after a half
a year he had started his masterpiece.

Dust. Sand. Adam's front is quarter-created. Burnt and slaked
lime all over the Cappella. Scaffolds. Paints passim. Artistic
disorder. Not much interesting for a casual passer-by.

RL> I hope that what appears to be a descent into personal
RL> attack on a valuable contributor to this newsgroup

Herr Richard has NONE real experience in automated testing
of computer algebra systems (in manual testing, I believe
his experience is much poorer then mine is).

Herr Richard, however, decided to go beyond the verge of his
real top-notch expertise which is Maple PROGRAMMING but not
automated testing, and claim that Maple quality is better and
better with time.

This is a baneful, destructive, detrimental myth.

This is just silly puffing out his (and Maplesoft's) cheeks.

Neither Herr Richard nor Maplesoft has the huge stock of Maple
bugs we have at Cyber Tester. Nobody has.

If however, I am not right and Maplesoft HAS all these bugs
this means only one thing, that they are swindlers.

Do you propose me to consider Maplesoft to be swindlers?

RL> is either a misunderstanding or else a temporary bout of
RL> poor judgement.

I am a person with stable mind, very cheerful at that. Also,
almost always, I think carefully before doing anything.

Not a vestige of hope for an idea of 'temporary bouts' :)


Best wishes,

Vladimir Bondarenko

VM and GEMM architect
Co-founder, CEO, Mathematical Director
Cyber Tester, LLC

http://www.cybertester.com/
http://maple.bug-list.org/
http://www.CAS-testing.org/

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