Perfectly Simple and Simply Perfect, Horological Journal Feb. 2009
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Pendulum Time" Lesson Explores How the Pendulum Has Been a Reliable Way to Keep Time for Centuries
IEEE Lesson Plan: P endulum Time Explore other TryEngineering lessons at www.tryengineering.org L e s s o n F o c u s Lesson focuses on how pendulums have been used to measure time and how mechanical mechanism pendulum clocks operate. Students work in teams to develop a pendulum out of everyday objects that can reliably measure time and operate at two different speeds. They will determine the materials, the optimal length of swing or size of weight to adjust speed, and then develop their designs on paper. Next, they will build and test their mechanism, compare their results with other student teams, and share observations with their class. Lesson Synopsis The "Pendulum Time" lesson explores how the pendulum has been a reliable way to keep time for centuries. Students work in teams to build their own working clock using a pendulum out of every day materials. They will need to be able to speed up and slow down the motion of the pendulum clock. They sketch their plans, consider what materials they will need, build the clock, test it, reflect on the assignment, and present to their class. A g e L e v e l s 8-18. Objectives Learn about timekeeping and engineering. Learn about engineering design and redesign. Learn how engineering can help solve society's challenges. Learn about teamwork and problem solving. Anticipated Learner Outcomes As a result of this activity, students should develop an understanding of: timekeeping engineering design teamwork Pendulum Time Provided by IEEE as part of TryEngineering www.tryengineering.org © 2018 IEEE – All rights reserved. -
White Paper: the KCC Scientific Model 1900W-UNV Clock Winder for Standard Electric Clocks Ken Reindel, KCC Scientific Updated 1-26-13
White Paper: The KCC Scientific Model 1900W-UNV Clock Winder For Standard Electric Clocks Ken Reindel, KCC Scientific Updated 1-26-13 The purpose of this White Paper is to help provide some background on Standard Electric Time master clock, what a Model 1900W-UNV Clock Winder can do for it, and how the Model 1900W-UNV works. Historical Perspective. From the 1880s and beyond, inventors became interested in applying the principles of telegraphy to horology. The idea of a battery-wound master clock which would drive multiple slave clocks, effectively communicating the time signal to them, began to take shape. Additionally, it became fascinating to inventors that the “slave” clocks could be very simple with no escapements or springs, no internal batteries, and requiring little if any maintenance. Charles Warner, who founded the Standard Electric Time Company in 1884,1 was one such inventor. Very early on, Standard Electric borrowed heavily from the Self Winding Clock Company for the design of its master clock movements. Master clocks would have the characteristics described above and relied on special contacts to drive the slaves. Later on, this same concept would be extended to driving program wheels and punched tape ribbons within the clocks themselves, to provide bell timing and other electrical sequences to businesses, schools, etc. For example, many such clocks have been found in schoolhouses and were at one time responsible for ringing bells at the proper times throughout different parts of the building to send students to the next class, as well as driving classroom slave clocks. Standard Electric’s master clock movements eventually took a shape similar to that of the slave clocks: simple, elegant minute impulse ratchet designs for winding the 60, 72, or 80 beat pendulum movements. -
SETTING up and MOVING a PENDULUM CLOCK by Brian Loomes, UK
SETTING UP AND MOVING A PENDULUM CLOCK by Brian Loomes, UK oving a pendulum This problem may face clock with anchor the novice in two different Mescapement can ways. Firstly as a clock be difficult unless you have that runs well in its present a little guidance. Of all position but that you need these the longcase clock to move. Or as a clock is trickiest because the that is new to you and that long pendulum calls for you need to assemble greater care at setting it in and set going for the very balance, usually known as first time—such as one you have just inherited or bought at auction. If it is the first of these then you can attempt to ignore my notes about levelling. But floors in different rooms or different houses seldom agree Figure 1. When moving an on levels, and you may eight-day longcase clock you eventually have to follow need to hold the weight lines through the whole process in place by taping round the of setting the clock level accessible part of the barrel. In and in beat. a complicated musical clock, Sometimes you can such as this by Thomas Lister of persuade a clock to run by Halifax, it is vital. having it at a silly angle, or by pushing old pennies or wooden wedges under the seatboard. But this is hardly ideal and next time you move the clock you start with the same performance all over again. setting it ‘in beat’. These My suggestion is that you notes deal principally with bite the bullet right away longcase clocks. -
Relativity and Clocks
RELATIVITY AND CLOCKS Carroll 0. Alley Universityof Maryland CollegePark, Maryland Sumnary be mentioned. In this centennial year of the birth of Albert The internationaltimekeeping communityshould Einstein, it is fittingto review the revolutionary takegreat pride in the fact that the great stabil- andfundamental insights about time whichhe gave ity of cont-mporaryatomic clocks requires the us inthe Restricted Theory of Relativity (1905) first practical applications g Einstein's General and in the conseqences of the Principle of Equiv- Theory of Relativity.This circumstance can be ex- alence (l'. .The happiest thought of my life.. .") pected to produce a better understanding among whichhe developed (1907-1915) into histheory of physicists andengineers of the physical basis of gravityas curved space-time, the General Theory of gravity as curvedspace-time. For slow motions and Relativity. weak gravitational fields, such as we normally ex- perience on the earth, the primary curvature is It is of particularsignificance that the ex- thatof &, notspace. A body falls,according traordinary stability ofmodern atomicclocks has to Einstein's view, not because of the Newtonian recentlyallowed the experimental Study and accur- forcepulling it tothe earth, but because of the ate measurement of these basic effects of motion properties of time: clocksrun slower when moving and gravitationalpotential on time. Experiments andrun faster or slower, the higher or lower re- with aircraft flights and laser pulseremote time spectively they are in the earth's gravity field. comparison(Alley, Cutler, Reisse, Williams, et al, 1975)and an experiment with a rocketprobe (Vessot,Levine, et al, 1976) are brieflydes- Some Eventsin Einstein's cribed. Intellectual Development Properunderstanding and allowance for these Figure 1 shows Einstein in his study in Berlin remarkableeffects is now necessary for accurate several years after he hadbrought the General global time synchronization using ultrastable Theoryof Relativity to its complete form in 1915. -
Remembering the First Battery-Operated Clock
© 2015 Antiquarian Horological Society. Reproduction prohibited without permission. ANTIQUARIAN HOROLOGY Remembering the first battery-operated clock Beverley F. Ronalds* Francis Ronalds invented a reliable electric clock in 1815, twenty-five years before Alexander Bain’s patent. It was powered by dry piles, a modified form of battery that has extremely long life but the disadvantage that its electrical properties vary with the weather. Ronalds had considerable success in creating regulating mechanisms for his clock to ensure accurate time-keeping in all meteorological conditions. He did not go on to commercialise his ideas, although others made and sold comparable timepieces on the Continent. This year marks the bicentenary of the with the electrically dissimilar metals. The publication of the first battery-operated dry pile was found to have an electric clock. It was rediscovered in the 1970s by potential difference or voltage across its two Charles Aked, Council member of the ends but, unlike Volta’s pile, did not exhibit Antiquarian Horology Society and first an electric current when the terminals were Chairman of the Electrical Horology Group, joined in a circuit. Its potential difference and further information has since come to was also maintained in use whereas a voltaic hand.1 pile ceased to work after a while.3 The clock was created by a prolific Two of the scientists in England who inventor named (later Sir) Francis Ronalds developed and improved the dry pile were FRS (1788–1873); he lived on the Upper Jean-André de Luc (1727–1817) and Mall in Hammersmith, London, at the time George Singer (1786–1817). -
Oscillations[2] 2.0.Pdf
Team ______________ ______________ Oscillations Oscillatory motion is motion that repeats itself. An object oscillates if it moves back and forth along a fixed path between two extreme positions. Oscillations are everywhere in the world around you. Examples include the vibration of a guitar string, a speaker cone or a tuning fork, the swinging of a pendulum, playground swing or grandfather clock, the oscillating air in an organ pipe, the alternating current in an electric circuit, the rotation of a neutron star (pulsars), neutrino oscillations (subatomic particle), the up and down motion of a piston in an engine, the up and down motion of an electron in an antenna, the vibration of atoms in a solid (heat), the vibration of molecules in air (sound), the vibration of electric and magnetic fields in space (light). The Force The dynamical trademark of all oscillatory motion is that the net force causing the motion is a restoring force. If the oscillator is displaced away from equilibrium in any direction, then the net force acts so as to restore the system back to equilibrium. Definition: A simple harmonic oscillator is an oscillating system whose restoring force is a linear force − a force F that is proportional to the displacement x : F = − kx . The force constant k measures the strength of the force and depends on the system parameters. If you know the force constant of the system, then you can figure out everything about the motion. Examples of force constants: k = K (mass on spring of spring constant K), k = mg/L (pendulum of length L), k = mg/D (wood on water, submerged a distance D). -
CLOCKS – TIMERS ASTROTECH QUARTZ CHRONOM E TERS SUPERCLOCK from a Fine Quality Instrument to Satisfy All Cockpit Clock/Timer Needs
CLOCKS – TIMERS ASTROTECH QUARTZ CHRO NOM E TERS SUPERCLOCK FROM A fine quality instrument to satisfy all cockpit clock/timer needs. 12 or 24 hour clock, 24 hour elapsed timer with time- ELECTRONICS INTERNATIONAL Displays local and Zulu time. May be set to display in a 12 out or hold feature, month and date. Will operate on internal or 24-hr format. A 10-year lithium battery keeps the clock CM battery for 2 years or can be connected to electrical system. running even if the aircraft battery is removed. Displays an 12 or 28V DC operation. Up Timer. This Timer will start running when the engine Part no. Model Description Price is started. In this manner the Timer acts as an automatic Flight Timer. 10-15508 LC-2 Panel Mount Aircraft Powered 14/28V . The Up Timer may be started, stopped or reset. A Recurring Alarm may 10-15515 LC-2 Aircraft Powered Panel Clock 28V . be set to alert you at appropriate time intervals. Example: If the alarm is WP 10-15512 LC-2A-5 King Air, 28 volts . set for 30 minutes, you will get an alarm at 30 minutes, 60 minutes, 90 10-15513 LC-2A-6 Beechcraft 28V Clock . minutes, etc. This alarm can be used to remind you to check your fuel 10-15514 LC-2E Embaraer 5V CLOCKClock . level or switch tanks at set time intervals. Displays a Down Timer. This 10-15507 LC-2P Central Wheel 14V A/C Powered . Timer counts down from a programmed start time. The Down Timer may NOTE: For Aircraft Application Information on Astrotech Chronometers visit be started, stopped or reset. -
Celestial, Flow, and Mechanical Clocks
recalibration Michael A. Lombardi First in a Series on the Evolution of Time Measurement: Celestial, Flow, and Mechanical Clocks ime is elusive. We are comfortable with the concept of us are many centuries older than the first clocks. The first -in time, but in many ways it defies understanding. We struments that we now recognize as clocks could measure T cannot see, hear, or touch time; we can only observe intervals shorter than one day by dividing the day into smaller its effects. Although we are unable to grasp time with our tra- parts. ditional senses, we can clearly “feel” the passage of time as we Most historians credit the Egyptians with being the first civ- watch night turn to day, the seasons change, or a child grow up. ilization to use clocks. Their first clocks were probably nothing We are also aware that we can’t stop or reverse the continuous more than sticks placed in the ground that indicated time by flow of time, a fact that becomes more obvious as we get older. both the length and direction of their shadow. As early as 1500 Defining time seems impossible, and attempts to do so by phi- BC, the Egyptians had developed a more advanced shadow losophers and scientists fall far short of their goal. clock (Fig. 1). This T-shaped instrument was placed in a sun- In spite of its elusiveness, we can measure time exception- lit area on the ground. In the morning, the crosspiece (AA) was ally well. In fact, we can measure time with more resolution set to face east and then rotated in the afternoon to face west. -
Time in the Theory of Relativity: on Natural Clocks, Proper Time, the Clock Hypothesis, and All That
Time in the theory of relativity: on natural clocks, proper time, the clock hypothesis, and all that Mario Bacelar Valente Abstract When addressing the notion of proper time in the theory of relativity, it is usually taken for granted that the time read by an accelerated clock is given by the Minkowski proper time. However, there are authors like Harvey Brown that consider necessary an extra assumption to arrive at this result, the so-called clock hypothesis. In opposition to Brown, Richard TW Arthur takes the clock hypothesis to be already implicit in the theory. In this paper I will present a view different from these authors by taking into account Einstein’s notion of natural clock and showing its relevance to the debate. 1 Introduction: the notion of natural clock th Up until the mid 20 century the metrological definition of second was made in terms of astronomical motions. First in terms of the Earth’s rotation taken to be uniform (Barbour 2009, 2-3), i.e. the sidereal time; then in terms of the so-called ephemeris time, in which time was calculated, using Newton’s theory, from the motion of the Moon (Jespersen and Fitz-Randolph 1999, 104-6). The measurements of temporal durations relied on direct astronomical observation or on instruments (clocks) calibrated to the motions in the ‘heavens’. However soon after the adoption of a definition of second based on the ephemeris time, the improvements on atomic frequency standards led to a new definition of the second in terms of the resonance frequency of the cesium atom. -
Some Multi-Pendulum Clocks
Double Pendulum Resonance Clocks John Kirk 1 Topics • Introduction • Resonance • Early Makers • Janvier’s Clocks • Breguet’s Clocks • Modern Clocks • “Reproductions” 2 Topics • Introduction • Resonance • Early Makers • Janvier’s Clocks • Breguet’s Clocks • Modern Clocks • “Reproductions” 3 Introduction • While there are three and four pendulum clocks, most multi-pendulum clocks have two pendulums – Clocks with more than two pendulums will be the subject of another presentation • Resonance clocks have two or more pendulums locked to each other in rate, which aids rate stability and can compensate for disturbances 4 Topics • Introduction • Resonance • Early Makers • Janvier’s Clocks • Breguet’s Clocks • Modern Clocks • “Reproductions” 5 Resonance (1 of 4) • Two mechanical oscillators, such as balance wheels or pendulums, can influence each to become resonant • For this to happen, – The oscillation of one must be detected mechanically by the other, such as two pendulums on a common slightly soft mounting – The two oscillators must have close to the same period of oscillation 6 Resonance (2 of 4) • When two pendulums influence each other of almost the same frequency, the two will trade energy until they swing in anti-phase • This occurs because swinging in anti-phase has the lowest system energy level – All resonant systems “relax” total system energy to the lowest level – This lowest level also requires the least energy to keep both oscillators in the system oscillating 7 Resonance (3 of 4) • The “Thursday Mystery” is well-known among repairers -
Variable Time and the Variable Speed of Light Edward G
Variable Time and the Variable Speed of Light Edward G. Lake Independent Researcher August 14, 2018 [email protected] Abstract: Einstein’s Special and General Theories of Relativity state that time is a variable depending upon motion and gravity. The theories also state that the speed of light is variable. Einstein’s theories are being verified virtually every day. Yet, a few physicists still argue that time does not vary, and many physicists appear to inexplicably argue that Einstein’s theories state that the speed of light is invariable. This is an attempt to clarify what Einstein wrote and show how experiments routinely confirm that the speed of light is variable. Key words: Speed of Light; Time; Time Dilation; Relativity; Einstein. I. Measuring the speed of light. The fact that the speed of light is variable is demonstrated almost every day. No matter where you measure the speed of light, if you measure it correctly, you will get a result of 299,792,458 meters per second. Does this mean that the speed of light is the same everywhere? No. It means the speed of light per second is the same everywhere. And, according to Einstein’s Theories of Special and General Relativity, the length of a second can be different almost everywhere. That means that if you measure the speed of light to be 299,792,458 meters per second in one location, and if you also measure it to be 299,792,458 meters per second in another location, if the length of a second is different at those two locations, then the speed of light is also different. -
030-125-501 at & Tco Standard Issue 4, February 1979 BUILDING MASTER CLOCKS PRECISE TIME SETTING
BELL SYSTEM PRACTICES SECTION 030-125-501 AT & TCo Standard Issue 4, February 1979 BUILDING MASTER CLOCKS PRECISE TIME SETTING CONTENTS PAGE 2.02 Compare the master clock daily with one of the following references: 1. GENERAL 2. METHOD Operating Company precise time announcement 1. GENERAL machine 1.01 This section covers the method of setting Boston 617 637-1234 Eastern Time all building time reference sources to precise time. Newark 201 936-8181 Eastern Time 1.02 This section is being reissued to change the -+New York 212 936-1616 Eastern Time +- reference telephone number for the precise time announcement machine in Chicago and New Wash., D.C. 202 844-1212 Eastern Time York. Revision arrows are used to indicate the change. This reissue does not affect the Equipment -+ Chicago 312 936-3636 Central Time +- Test List. Detroit 313 472-1212 Eastern Time 1.03 All building time reference sources, such as master clocks and customer call timing devices, U.S. Bureau of Standards must be accurate at all times. Boulder, 303 499-7111 Greenwich 2. METHOD Colo. Mean Time 2.01 Designate one electric clock as a building master clock. Choose a clock with a sweep second hand and preferably one that is not affected by office routine emergency power transfers. Affix Note: Allowance must be made if your local a tag or plastic tape to the master clock stating: time zone differs from the above time zones. Choose a time reference geographically close Caution: Reset per Section 030-125-501. to your office. NOTICE Not for use or disclosure outside the Bell System except under written agreement Printed in U.S.A.