Foucault Pendulum Research Articles

The driving mechanism for a Foucault pendulum (revisited)

The driving mechanism for a Foucault pendulum (revisited)

Drawing and displaying the trajectories of some pendulums

This paper presents a way to deal with the trajectories of some pendulums, such as thesimple pendulum, the conical pendulum, and the Foucault pendulum. With asimulator designed by us for displaying the behaviour of the Foucault pendulum, it issimple and convenient to obtain such a trajectory on a piece of paper; this isuseful and helpful for students and teachers engaged in college physics courses.

Foucault pendulum through basic geometry

We provide a thorough explanation of the Foucault pendulum that utilizes its underlying geometry on a level suitable for science students not necessarily familiar with calculus. We also explain how the geometrically understood Foucault pendulum can serve as a prototype for more advanced phenomena in physics known as Berry’s phase or geometric phases.

Bound Motion of Bodies and Paticles in the Rotating Systems

The Lagrange theory of particle motion in the noninertial systems is applied to the Foucault pendulum, isosceles triangle pendulum and the general triangle pendulum swinging on the rotating Earth. As an analogue, planet orbiting in the rotating galaxy is considered as the giant galactic gyroscope. The Lorentz equation and the Bargmann-Michel-Telegdi equations are generalized for the rotation system. The knowledge of these equations is inevitable for the construction of LHC where each orbital proton “feels” the Coriolis force caused by the rotation of the Earth.

New age in Serbia, Zoran Simjanovic: New ideas symphony

?New age? was a trend which appeared in the music of the 1980?s, bringing a new dimension to art music in general, especially in its reception. At first its development was stimulated by technological inventions, ?the technological craze?, by new carriers of sound, simultaneously globalizing art and making it widely accessible. This new trend includes quite disparate categories. It does not distance itself from subculture, and in art music it gravitates towards cosmopolitism while being permeated with other musical trends such as pop, rock, jazz and other phenomena of show business and popular art. This trend was originally found in the large number of occult writing which flooded book markets all over the world, to which Umberto Eco gave an important base (Foucault's Pendulum and others). In his essay on the music of the eighties, Peter Niklas Wilson, one of the most significant theoreticians of this movement, researches into all elements of those novelties, not hesitating to call this art eclectic, commercial and the like. Examples of Serbian music get into such style directives. The New Ideas Symphony by film score composer Zoran Simjanovic, was performed in the open air at Kalemegdan fortress in 2006, before an audience of about one thousand people. Since then the recording has often been broadcast on television and radio channels. In its combination of folklore and film models, traces of rock, pop, and jazz can also be found, in a score with all symphonic characteristics. This attempt is a fascinating item for research as well as a pleasure to be listened to.

The Mysterious Flame of Queen Loana: A Postmodern Historiographic Illustrated Novel of a Generation

In his fifth novel, The Mysterious Flame of Queen Loana, the world renowned narrator semiotician directs his encyclopedic fiction once again to several levels of readers. In many ways similar to the case of Foucault's Pendulum Eco here directs his narration to a particular generation of readers. Underneath the beautiful illustrations that accompany this unusual and brilliant hybrid hypetextual historical fiction can be detected some postmodern neorealistic strategies in revisiting the fascist eras of the thirties and early forties. Eco's narration of cultural and political hegemony and his familiar treatment of intertextuality are examined along with his personal stories and the central and underlying motif of the novel: storing and retrieving memories.

Buffalo's Foucault pendulum gets its swing back

Buffalo's Foucault pendulum gets its swing back

A machine-vision system to measure the parameters describing the performance of a Foucault pendulum

We describe a machine-vision system that makes real-time measurements of the kinematics of a Foucault pendulum. Images are taken from a downward-facing camera placed close to the pendulum suspension point. The bob is detected via background subtraction and located by fitting circles to the resulting contour segments. The bob trajectory is then modelled by fitting ellipses to recent positions. Parameters are improved through Kalman filtering. Experimental results are shown. Our implementation is a robust and accurate tool for visualization of the pendulum kinematics as well as troubleshooting and maintenance of the mechanical elements.

The Foucault pendulum with an ideal elastic suspension string

It is interesting and instructive to compare the precession of a Foucault pendulum, which has an inextensible suspension string, to the precession of an ideal elastic pendulum, for which the string force is proportional to string length (a harmonic oscillator). For the latter case, a simple derivation is presented of the bob trajectories as seen by the local observer on the rotating earth. It is shown that the initial precession rate is equal to the precession rate of the Foucault pendulum, and that the precession period is equal to the rotation period of the earth. The different precession period of the Foucault pendulum may therefore be seen as a cumulative effect of its inextensible suspension string, which constrains the motion of the bob. It is also shown that the initial angular acceleration of the oscillation plane of the ideal elastic pendulum is opposite for opposite initial azimuth angles. If any such difference were observed for a real Foucault pendulum, it might indicate the presence of effects due to elasticity of the suspension string. Another interesting application of the present derivation would be to the precession of the spring-mass oscillator.

Observations of the Performance of Pendula at the Time of the 2002 December 4 Solar Eclipse in South Australia

SummaryIt has been claimed that pendula exhibit anomalous behaviour at the time of solar eclipses. The claims have been that Foucault pendula deviate from the regular motion of their plane of oscillation and that pendula, more generally, change their oscillatory period. At the time of the 2002 December 4 solar eclipse, we made observations of the operation of a Foucault pendulum and a pendulum clock at the University of Adelaide. We were able to set an upper limit of one degree on the deviation of the oscillatory plane of the Foucault pendulum at eclipse time when compared to observations immediately before and after the partial eclipse phases. Our limit on any change of pendulum time periods associated with the eclipse was one part in one hundred thousand.

A Mathematician's Look at Foucault's Pendulum

(2005). A Mathematician's Look at Foucault's Pendulum. Math Horizons: Vol. 12, No. 3, pp. 19-32.

What Makes the Foucault Pendulum Move among the Stars?

Foucault’s pendulum exhibition in 1851 occurred in an era now known by development of the theorems of Coriolis and the formulation of dynamical meteorology by Ferrel. Yet today the behavior of the pendulum is often misunderstood. The existence of a horizontal component of Newtonian gravitation is essential for understanding the behavior with respect to the stars. Two simple mechanical principles describe why the path of oscillation is fixed only at the poles; the principle of centripetal acceleration and the principle of conservation of angular momentum. A sky map is used to describe the elegant path among the stars produced by these principles.

On Mach’s critique of Newton and Copernicus

By maintaining the relativity of all motion, especially rotational motion, Mach denied the existence of absolute motion and of absolute space. Accordingly, he maintained the equivalence of the Ptolemaic and the Copernican systems and the equivalence of rotating-system/fixed-universe and universe-rotating/fixed-system situations. An analysis of the Foucault pendulum shows that Mach’s relativity principle implies that there cannot be a fixed bucket in a rotating universe. Also, Mach’s views violate the physics that he espoused: noninertial experiments, for example stellar aberration and electromagnetic effects, distinguish between a rotating bucket in a fixed universe and a fixed bucket in a rotating universe, between a Copernican universe and a Brahean or Ptolemaic universe, and establish that one cannot ascribe all pertinent observations solely to relative motion between a system and the universe.

A Topological Look at the Quantum Hall Effect

The amazingly precise quantization of Hall conductance in a two-dimensional electron gas can be understood in terms of a topological invariant known as the Chern number.

The Past is Now

(One Hundred Thousand Billion Poems, Composition no. 1, Hopscotch). Some of them offer scandalous stories (Story of the Eye, Story of 0); others retain the power to shock, long after they have been appropriated and enshrined in the canon (Against Nature, Ubu Roi, Naked Lunch). As much as it pains me to admit it, some perfect books are maddeningly-and without a doubt intentionally-obscure (The Making of Americans, Tomb for Five Hundred Thousand Soldiers). Others persuade us that conspiracies are afoot, and preferably phony ones (Foucault's Pendulum, Dump This Book While You Still Can!, Fourbi). Perfect books must be perfectly reflexive (The Counterfeiters, Doctor Faustus, Ficciones, How I Wrote Certain of My Books, Why I Have Not Written Any of My Books). Perfect books should offer us perfect moments. For me (if perhaps not for the Anny of Nausea) the most perfect expression of the perfect moment is when Perceval gazes, transfixed, at the three drops of blood in the snow. Why aren't there more moments like that in the books I read? Perfect books should assure us that too much is never enough (Under the Volcano, The Ginger Man, Fear and Loathing in Las Vegas, The Dark Night of the Soul). Perfect books should tell us that it's OK to say no (Bartleby the Scrivener), and they should persuade us that there's nothing wrong in spending a day, a week, a month or longer flat out on our couch (Oblomov, The Bathroom). Finally, some perfect books must be perfectly obsessional, perfectly tailored for perfectly obsessed readers (The Confessions of Zeno). Should the existence of such a breed one day be confirmed, that is. As a reader (and I am first and foremost, in my present incarnation, a reader), I have always looked for books that combine each and every one of those qualities in perfectly resonant harmony. And some day soon, I fervently hope to come upon just such a book. Or perhaps-mirabile dictu!-a whole shelf of such books. Is that truly too much to ask? University of Colorado

Lawrence Nathan Hadley Jr

Lawrence Nathan Hadley Jr, a member of the physics faculty at Colorado State University for more than 45 years, died on 26 January 2002 in Fort Collins, Colorado, of age-related complications. His lifelong research interest was in optical properties of materials with an emphasis on thin films.Lawrence was born on 14 October 1916 in Valley Center, Kansas. His skill at problem solving was first revealed when, as a boy, he and his father wired their home after electricity had first come to Kansas. They had holes beneath the floor in outside walls and at opposite sides of the house. The problem was to get wire from one side to the other. It was lunchtime, but Lawrence had an idea: He tied a piece of twine to the collar of one of the farm cats and tied the other end to a small board. He placed the cat in the space under the floor on one side and placed the board over the hole. After lunch they returned to find the cat on the other side of the house and it was then easy to pull the wire with the twine.Lawrence received an AB degree in physics from Friends University in Wichita, Kansas, in 1937 and an MS in physics from the University of Oklahoma in Norman in 1939. His PhD dissertation, “Reflection and Transmission Interference Filters,” was completed at the University of Michigan, Ann Arbor, in 1947 under the supervision of David Dennison.While at Michigan in 1942, Lawrence worked on the proximity fuse project for the US Navy, which included firing test objects. On occasion, retrieval was complicated when the objects landed in patches of poison ivy.After serving briefly as an assistant professor of physics at Colorado A&M (later Colorado State University) in the spring of 1947, he was appointed as an assistant professor of physics at Dartmouth College that same year. There, he enlisted a roomful of students using essentially all of Dartmouth’s early mechanical calculators to compile the 147-page document “The Transmittance and Reflectance Versus Thickness/Wavelength for Thin Films.”Lawrence returned to Colorado A&M as associate professor of physics in 1955, and was promoted to full professor in 1958. He served as the chair of Colorado’s physics department for three years, beginning in 1965. Even after his official retirement in 1987, Lawrence continued to interact with faculty and students and was a regular attendee at the weekly physics colloquium.In addition to teaching introductory physics to literally thousands of students in more than 10 000 lectures, Lawrence contributed in many other ways. He was active in the formation of the Colorado State University Research Foundation and served as both chairman of the board and as president from 1960 to 1964. Typical of Lawrence’s dedication to physics and education were his enthusiasm and skill when he guided students through a new course called “Flying Circus of Physics.” Students discussed topics ranging from “What is a water bell?” to “Why do sand dunes squeak?” In 2000, a new Foucault pendulum at Colorado State University was dedicated in Lawrence’s honor.In his spare time, Lawrence enjoyed carpentry and built several items for his house and yard. He played the organ, piano, and cello for relaxation. Lawrence will be remembered as an educator, scientist, gentleman, and gentle man.Lawrence Nathan Hadley JrPPT|High resolution© 2002 American Institute of Physics.

Hands-On Earth Rotation

A Foucault pendulum equipped with a low-cost computer interface is described. It allows one to measure the precession rate of the plane of oscillation due to Earth rotation within a few minutes. A graphic interface (PC tablet) serves as a frictionless two-dimensional position sensor. By using standard software tools it is possible to record the position of the pendulum up to 50 samples/s. Although the sensor provides only rather coarse-grained data, the method is remarkably precise due to statistical analysis of the data.

Indirect Analytic Representation of Foucault's Pendulum

A complex representation of the equations of motion of the Foucault's pendulum is considered and the inverse problem is solved to derive an indirect analytic representation. Both real LR(i) and imaginary LI(i) parts of the derived complex valued Lagrangian are found to reproduce the equations of motion via the Euler-Lagrange equations. The expressions for LR(i) and LI(i) are not connected by a gauge term thereby forming a set of inequivalent Lagrangians. In an appropriate limit LI(i) is found to reproduce the Lagrangian obtained by implementing the usual Coriolis theorem while in some other limit LR(i) and LI(i) give the indirect and the direct analytic representations for a set of two uncoupled harmonic oscillators.

Vortex pairing in an unstable anticyclonic shear flow: discrete subharmonics of one pendulum day

Observations of the downstream evolution of an oceanic zonal horizontal shear flow at a Reynolds number of about 1011, formed as the westward North Equatorial Current passes the island of Hawai‘i, reveal finite-amplitude anticyclonic vortices resulting from instability of the shear. The initial orbital period of the vortices is exactly one pendulum day (3.1 days at this latitude), centrifugal instability presumably inhibiting stronger vortices from forming. As they move downstream, they appear to pair and merge into successively larger vortices, in a geometric sequence of longer orbital periods; three subharmonic transitions are suggested with final orbital periods near 6, 12 and 24 days.

Umberto Eco: Philosophy, Semiotics and the Work of Fiction by Michael Caesar (review)

MLR, 96. I, 2001 UmbertoEco: Philosophy,Semioticsand the Workof Fiction. By MICHAELCAESAR. (Key Contemporary Thinkers) Cambridge: Polity Press. i999. x + 198 pp. [45 (paperbound I3.99). This is another in Polity's'Key ContemporaryThinkers'series and it is interesting to speculateon the briefthe authorwas given by the editors(John Thompson, who began the series, is not credited here, except in the acknowledgements).Michael Caesar decided to go for the hard and the mainstream,and well over half his book is on Eco and semiotic theory, about which he writesvery competently, but a little dourly, as though it were not an area he feels relaxed in. His concentration on this, as central to Eco's work, makes it very professional,but also means that he cannot find space to write about other parts of Eco that are not so mainstream. I miss discussionof Travels inHyperreality, Eco's book on America:not so much the workof a key contemporary thinker, but as interesting as Baudrillardon the same topic. Eco's workonJames Bond isjust alluded to, but as it also shows off Eco at his best, it is a pity that it was missedout. There isnothing on Eco's relationshipwith Borges, where the affinitiesand culturaldifferencesrun deep. What is witty and on the side of the transgressivein Eco, not least the aspect of his semiotics that sees it as the theoryof the lie, is missedout. Caesar'sapproach, beginning with Croce and Pareyson,necessitatesleaving out much of the changesin criticaltheorytakingplace in Francein the I96os and 1970s: these are reduced to occasional references, but they matter, as does Eco's relationshipwith them: for example, why did he staywith structuralistapproaches afterpost-structuralism? Though Caesarrefersto the 'cultureindustry'(p. 39), he is silent on Adorno from whom the phrase comes, and does not relate Eco's work on the popular to other debates. At one point (p. Io8) he quotes Roger Scruton's irritationwith semiotics as making all cultural forms 'equally legitimate forms of inquiry';noting that Eco does not reply to that specifically,Caesar does not either, and remains content with close descriptionof what Eco's theory of semiotics does, without taking up the argument. Caesar cites others on Eco in general terms: Jonathan Culler's'interesting'discussion(p. 72), or Michael McCanles's 'trenchant review' (p. I03). But here the problems with Caesar's approach set in. His critical termsare inadequatefor seeing that a review in Diacritics (thatof McCanles) means a specificallynuanced criticaldebatefromwhich neitherEco nor he can be isolated. Referringto Eco'sApocalittici eintegrati (1964), his studyof intellectuals'relationship, (apocalypticor integrated)to popularculture,he notes how Eco feels able to situate both, but thisposes the question:the intellectualwho can situateothers,fromwhat point of vantage does he write himself? What blindness gives him the insight to divideup intellectualsin thatway?Which intellectualpositions,apartfromhis own, is he missing out? In reacting to essays such as David Robey's as 'closely argued', (p. 46), the compliment disguisesthe point thatCaesar'sbook,valuableon so much, fails to ask about the basis for his own and his subject'sjudgements about politics and culturalpractices;there is no recognition of the role of ideology either in Eco's workor as a topic that semioticsis inseparablefrom. I miss in both Eco and this book, a sustainedtreatment of the unconscious, and of Freud,and of Kristeva, though a discussionof these things begins and breaksoff through reference to Teresa De Lauretis (pp. Io6-07); similarly, the question of gender,whose relationshipto semioticsshouldneed no arguing,isbarelymentioned. Lastly,I thinkCaesarshould have trustedhimselfmore to write about Eco'sfiction, where he spends roughly only ten pages. As exasperationa hundredpages before I stopped reading meant I could not finish Foucault's Pendulum, I would have liked I45 Caesar to have told me whetherI was rightor wrong, but he is much too evasive to give a clue on thismatterto the reviewer. UNIVERSITY OF HONG KONG JEREMY TAMBLING Travel Writing andEmpire.Ed. by STEVE CLARK. London and New York:Zed Books. I999. viii + 264 pp. $65 (paperbound $22.50; 1I4.95). This collection of fifteenessaysoffersfreshperspectiveson travelwritingin the light of a number of contemporarytheories.Collectivelythey argue conclusivelythat the very notion of an innocent travel narrativeis an impossibilityand that travellers' 'textspromote, confirmand lament the exercise of imperialpower' (p. 3...