How Mechanics Shaped the Modern World

407 Pages·2014·21.94 MB·English

by  David H. Allen (auth.)

David H. Allen
How
Mechanics
Shaped the
Modern World
How Mechanics Shaped
the Modern World
David H. Allen
How Mechanics Shaped
the Modern World
123
David H.Allen
Civil EngineeringDepartment
Texas A&MUniversity
College Station, TX
USA
ISBN 978-3-319-01700-6 ISBN 978-3-319-01701-3 (eBook)
DOI 10.1007/978-3-319-01701-3
SpringerChamHeidelbergNewYorkDordrechtLondon
LibraryofCongressControlNumber:2013946340
(cid:2)SpringerInternationalPublishingSwitzerland2014
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To my wife Claudia, who, despite the fact
thatsheisneitherascientistnoranengineer,
read this entire manuscript repeatedly,
providing valuable insight and much-needed
encouragement
Preface
Thisbookwasbornfrommylifetimeofstudyofthescientificfieldofmechanics.
I feel fortunate to have had a fulfilling career in such a challenging and enlight-
ening field of study.
I was born in 1950 in the United States, the son of a World War II Army Air
Corpsveteran.MyfatherwaseducatedinEngineeringatCalTech,andhewasin
every sense of the word an ‘‘engineering nerd.’’ I was somehow endowed by him
with sufficient talents to follow in his footsteps, thus I subsequently enrolled in
Engineering in college, and over a 12-year span of time that included three and a
half years in the U. S. Air Force, I obtained degrees in Aerospace Engineering
(B.S.), Civil Engineering (M.E.), and Aerospace Engineering (Ph.D., focus on
Engineering Mechanics) at Texas A&M University. Somewhat serendipitously,
Ialsostudiedmeteorologyforayearingraduateschoolinpreparationformytime
in the Air Force as a weather forecaster. I would not realize until much later how
important that experience would be to my understanding of mechanics. I have
subsequently spent my entire career as a Professor (until recently), teaching at a
number of universities both in the U.S. and abroad.
Now, as I look backwards in time, I find myself to have been exceedingly
fulfilledbymyprofessionalcareer.Nonetheless,Ifeeltheneedtoimpartmytake
on the history of my discipline. I say ‘‘my take,’’ because it would not be
appropriatetocallthistextahistorybook.Itisrathermyownpeculiarviewofthe
universe,onepredicateduponmyexperiences,whichareadmittedlybiasedbymy
longandsomewhatnarrowlyfocusedviewofmyownfieldofstudyanditsimpact
ontheworld.Imustthereforeapologizeinadvancetothosewhofinderrorwith,or
worse,areoffendedby‘‘mytake.’’Insomecasesthereareclearlyenormousgaps
in the history of mechanics found within the pages of this text. In other cases,
Ihavechosentodiscussdetailsthatmayseeminsignificanttosomereaders.Such
is the nature of each person’s view of what is important to this subject. In that
sense ‘‘my take’’ is surely highly idiosyncratic, but hopefully not offensive. For
those who seek a more technical and in-depth coverage of the history of
mechanics, I refer you to the excellent book entitled A History of Mechanics, by
René Degas (Dover 1988).
I’m abigfan ofCarl Sagan. Iwon’tgo intohis life orhis achievements, since
through one of the miracles of modern science and technology you can simply
Googlehisnameandfindouteverythingyoueverwantedtoknowandmore.But
suffice it to say this—at the time that he was writing, Dr. Sagan brought the
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wonders of science to more people than anyone else in the history of this planet.
Yes,hewasabrilliantscientistaswellasaprolificauthor.Andyes,hewastaken
fromusfartoosoon(attheageof62).ButasfarasIamconcerned,itishisskillat
making science accessible to so many that is his enduring legacy.
YoumayaskwhyIchoosetoelevate‘‘showmanship’’tosuchaloftypedestal.
Noonecan doubtthatCarlSagan wasashowman,andabrilliant oneatthat.His
New York accented way of saying ‘‘billions and billions’’ became a trademark
phrase for a generation of Americans. It has even been whispered that Dr. Sagan
was passed over for election to the National Academy of Science because his
showmanship crossed over the boundaries of science. I will not dispute this
conjecture.
WhatimpressesmeiswhatDr.Sagan clearlyknew,andwhathewastryingto
do with that knowledge. I have learned so much from him. And this is what
I learned—I learned the importance of education. I learned that education of our
speciesisthedrivingforcebehindoursuccessonthisplanet.Idonotbelievethat
IwouldhaveevercompletelyunderstoodthatfacthaditnotbeenforCarlSagan.
Henotonlyunderstoodit,he‘‘puthismoneywherehismouthwas,’’sotospeak.
To be sure, he never stopped doing important scientific work during his lifetime,
but he devoted a substantial part of his time here on Earth to imparting that
wisdomtotherestofhisfellowhumans.Heunderstoodthatwithouteducationwe
arenothing.Withouteducationwewouldstillbeforagingforfoodalongwiththe
otherspecies.Withouteducation,almosteveryonealiveonthisplanettodaywould
neverhavebeenborn.Andsohedevotedhislifetoeducation.AsIsaid,I’mabig
fan of Carl Sagan.
In this book my intention is to explain how the science of classical mechanics
hasaffectedourworldinwaysthatarecommonplaceandaccessibletotheaverage
person as opposed to scientists and engineers. As such, it should be considered
non-technicalincontent.Nonetheless,Ihopethatthesetwolattergroupswillfind
pleasure in my somewhat purposefully simplified exposition of the subject.
Satisfying all of these disparate groups simultaneously is a difficult challenge,
and it is at least in part for this reason that I have chosen to restrict my views to
classical mechanics. This term is intended to imply that field of mechanics that
developed prior to the advent of quantum mechanics, thus encompassing the
pervasivefieldofNewtonianmechanics.Furthermore,Iwillnotdelvedeeplyinto
thesubjectofeitherspecialorgeneralrelativityinthisbook.Similarly,becauseit
doesnotfallunderthecognomenofclassicalmechanics,Iwilleschewthesubject
of quantum mechanics. These all-important subjects are amply explained in a
numberofexemplaryvolumespublishedinrecenttimes,somuchsothatIfearmy
coverage of these developments would fail to measure up. Thus, as I said, I will
confine my coverage to the subject of classical mechanics and henceforth in this
book when I utilize the term mechanics, it is implied to be synonymous with the
term classical mechanics.
The perceptive reader may ask exactly what is meant by the title of this book.
Thisisindeedanexcellentquestion.Ihavepurposefullychosenaduplicitoustitle,
and for good reason. There are in fact two objectives that I have set for myself
Preface ix
herein, and the title of this text bridges both. First, it is my aim to explain in
layman’s terms how mechanics played a role in the development of so many
achievementsthroughoutthehistoryoftheuniverseasweknowit.Insomecases
wedonotreallyknowhowthishappened,butasthereaderwillsoondiscover,this
willinnowayhindermefromconjecture.Second,andperhapsmoreimportantly,
itisalsomyintentiontodescribethemoreobviousmeaningwithinthetitle—how
specific developments that involved mechanics actually served to shape our
modernworld.Thislattergoalisindeedaloftyambition.Withthisinmind,Ihope
that ‘‘my take’’ does not disappoint.
I may be reaching high, but it is my desire that the admittedly unusual per-
spective contained within this book will somehow accomplish the same thing for
mechanics that Dr. Sagan did for Astronomy, Astrophysics, and whatever else he
chosetowriteabout—toenlightennotonlythosefamiliarwithmydiscipline,but
also those who may not be well-versed in the subject and are simply curious to
know more about mechanics. If so, then my aim is indeed not too high, but has
squarely struck my intended mark. And so, dear reader, I wish you both an
enlightening and enjoyable read.
David H. Allen
Acknowledgments
Iwouldliketothankallthosewhohelpedtomakethistextbookcometofruition.
I am especially indebted to my Editor at Springer, Michael Luby, who made
valuable suggestions that improved the final text, and his assistant Merry Stuber,
who patiently answered any and all of my questions. In addition, I would like to
thankthosewhoreviewedandcritiqued themanuscript.Theircarefulandselfless
efforts contributed significantly to the quality of the final manuscript.
xi
Contents
1 Mechanics and Our Ancestors . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Early Developments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
The Egyptians. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Pyramids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Mummies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Obelisks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
The Seven Ancient Wonders of the World . . . . . . . . . . . . . . . . . . . 31
2 The Greeks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
The Dawn of Mechanics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Thales of Miletus (c. 624–546 BCE) . . . . . . . . . . . . . . . . . . . . . 38
Pythagoras of Samos (c. 570–495 BCE). . . . . . . . . . . . . . . . . . . 38
Democritus (c. 460–370 BCE). . . . . . . . . . . . . . . . . . . . . . . . . . 39
Aristotle (384–322 BCE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Euclid of Alexandria (3??–2?? BCE) . . . . . . . . . . . . . . . . . . . . . 41
Aristarchus of Samos (310–230 BCE) . . . . . . . . . . . . . . . . . . . . 42
Archimedes (287–212 BCE) . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Eratosthenes of Cyrene (276–195 BCE) . . . . . . . . . . . . . . . . . . . 49
Hipparchus of Nicaea (190–120 BCE) . . . . . . . . . . . . . . . . . . . . 51
Claudius Ptolemy (c. 90–168 AD) . . . . . . . . . . . . . . . . . . . . . . . 51
Other Greek Mechanists. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Archeology of Greece. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3 The Romans. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
The Roman Arch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Roman Roads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Massive Roman Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4 Mechanics in the Middle Ages . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Economic and Cultural Collapse . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Gothic Cathedrals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Universities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Torture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
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