Atomic Clocks
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Measurement of Time
Measurement of Time M.Y. ANAND, B.A. KAGALI* Department of Physics, Bangalore University, Bangalore 560056 *email: [email protected] ABSTRACT Time was historically measured using the periodic motions of the sun and stars. Various types of sun clocks were devised in Egypt, Greece and Europe. Different types of water clocks were assembled with ever greater accuracy. Only in the seventeenth century did the mechanical clock with pendulums and springs appeared. Accurate quartz clocks and atomic clocks were developed in the first half of the twentieth century. Now we have clocks that have better than microsecond accuracy. This article gives a brief account of all these topics. Keywords: Sun clocks, Water clocks, Mechanical clocks, Quartz clocks, Atomic clocks, World Time, Indian Standard time We all know intuitively what time is. It can be civilizations relied upon the apparent motion of roughly equated with change or motions. From these bodies through the sky to determine the very beginning man has been interested in seasons, months, and years. understanding and measuring time. More We know little about the details of recently, he has been looking for ways to limit timekeeping in prehistoric eras, but we find the “damaging” effects of time and going that in every culture, some people were backward in time! preoccupied with measuring and recording the Celestial bodies—the Sun, Moon, planets, passage of time. Ice-age hunters in Europe over and stars—have provided us a reference for 20,000 years ago scratched lines and gouged measuring the passage of time. Ancient holes in sticks and bones, possibly counting the Physics Education • January − March 2007 277 days between phases of the moon. -
Grade 6 Quarter 1 Lessons Ycsd.Pdf
Name__________________________________________________________________ th 6 Grade - Grading Period 1 Overview Ohio's New Learning Standards Minerals have specific, quantifiable properties. (6.ESS.1) Igneous, Metamorphic, and Sedimentary rocks have unique characteristics that can be used for identification and/or classification. (6.ESS.2) Igneous, Metamorphic, and Sedimentary rocks form in different ways. (6.ESS.3) Clear Learning Targets "I can": 1. _____ follow a laboratory procedure and work collaboratively within a group using appropriate scientific tools. 2. _____ work individually, with a partner, and as a team to test a scientific concept, change a variable, and record the experimental outcome. 3. _____ use the engineering design cycle to develop a solution with a predictable outcome. 4. _____ cite specific text or online resource to support a proposed design solution. 5. ____ identify minerals by testing their properties 6. ____ use mineral properties, to use in testing and identifying minerals. 7. ____ use the rock cycle to describe the formation of igneous, sedimentary and metamorphic rocks. 8. ____ identify the unique characteristics to classify rocks. 9. ____ describe the formation of igneous, metamorphic, and sedimentary rocks 10. ____ use the unique characteristic of sedimentary rocks to identify and classify sedimentary rocks. 11. ____ identify the characteristics/classify metamorphic rocks. 12. ____ describe how metamorphic rocks form. Name_________________________________________________________________ th 6 Grade - Grading -
Deep Space Atomic Clock
National Aeronautics and Space Administration Deep Space Atomic Clock tion and radio science. Here are some examples of how one-way deep-space tracking with DSAC can improve navigation and radio science that is not supported by current two-way tracking. Ground-based 1. Simultaneously track two spacecraft on a atomic clocks are downlink with the Deep Space Network (DSN) the cornerstone of at destinations such as Mars, and nearly dou- spacecraft navigation ble a space mission’s tracking data because it for most deep-space missions because of their use no longer has to “time-share” an antenna. in generating precision two-way tracking measure- ments. These typically include range (the distance 2. Improve tracking data precision by an order of between two objects) and Doppler (a measure of magnitude using the DSN’s Ka-band downlink the relative speed between them). A two-way link (a tracking capability. signal that originates and ends at the ground track- ing antenna) is required because today’s spacecraft 3. Mitigate Ka-band’s weather sensitivity (as clocks introduce too much error for the equivalent compared to two-way X-band) by being able one-way measurements to be useful. Ground atom- to switch from a weather-impacted receiving ic clocks, while providing extremely stable frequen- antenna to one in a different location with no cy and time references, are too large for hosting on tracking outages. a spacecraft and cannot survive the harshness of space. New technology is on the horizon that will 4. Track longer by using a ground antenna’s en- change this paradigm. -
Atomic Clocks: an Application of Spectroscopy in the Last Installment of This Column (1), I Talked About Clocks As the First Scientific Instrument
14 Spectroscopy 21(1) January 2007 www.spectroscopyonline.com The Baseline Atomic Clocks: An Application of Spectroscopy In the last installment of this column (1), I talked about clocks as the first scientific instrument. What do clocks have to do with spectroscopy? Actually, the world’s most accurate clocks, atomic clocks, are based upon a spectroscopic transition of cesium or other elements, making spectroscopy a fundamental tool in our measurements of the natural universe. David W. Ball ime is one of the seven fundamental quantities in Originally, a second was defined as part of a minute, nature. I made a case in the last installment of this which was part of an hour, which was in turn defined as T column (1) that mechanical devices for measuring part of a day. Thus, 1 s was 1/(60 ϫ 60 24), or 1/86,400 time — clocks — might be considered the world’s first sci- of a day. However, even by the 17th century, defining the entific instruments. Clocks are ubiquitous because the day itself was difficult. Was the day based upon the position measurement of time is a fundamental activity that is im- of the sun (the solar day) or the position of distant stars portant to computer users, pilots, and lollygaggers alike. (the sidereal day)? At what latitude (that is, position toward the north or south) is a day measured? Over time it was rec- The Second ognized that measuring time accurately was a challenge. Quantities of time are expressed in a variety of units that In 1660, the Royal Society proposed that a second be de- we teach our grade-schoolers, but the IUPAC-approved termined by the half-period (that is, one swing) of a pendu- fundamental unit of time is the second (abbreviated “s” not lum of a given length. -
Splash Proof Atomic Clock with Outdoor Temperature/Humidity
SPLASH PROOF ATOMIC CLOCK WITH OUTDOOR TEMPERATURE/HUMIDITY MODEL: 515-1912 DC: 092419 TABLE OF CONTENTS 3. Power up 3. Buttons 3. Atomic Time 4. Settings Menu 5. Custom Display Views 6. Timer 7. Search for Outdoor Sensor 7. Low Battery 7. Specifications 8. We’re Here to Help 8. Join the Conversation 8. Warranty Info 8. Care and Maintenance 8. FCC Statement 8. Canada Statement Atomic Digital Clock Page | 2 POWER UP 1. Insert 2-AA batteries into your Outdoor Sensor. 2. Insert 2-AA batteries into your Atomic Clock. 3. Configure basic Settings. 4. Once the sensor is reading to your clock, place sensor outside in a shaded location. Watch sensor mounting video: bit.ly/TH_SensorMounting TX191TH AA Outdoor Sensor AA AA AA 515-1912 Atomic Clock BUTTONS TIMER +PLUS (+) MINUS- (-) SET Hold: Set Timer duration Hold: Search for Press: Change Hold: Set Time Press: Start, Pause or Outdoor Sensor Display Press: Search for Restart Timer Press: Adjust Values Atomic Time Signal ATOMIC TIME • The clock will only search for the WWVB Atomic Time Signal at UTC 7:00, 8:00, 9:00, 10:00, and 11:00. • The Atomic Time Indicator will flash while searching, and will remain solid on screen when connected. • From the normal time display, press the SET button to search for the WWVB Atomic Time Signal. Atomic Digital Clock Page | 3 SETTINGS MENU Daylight Saving Time Options: DST ON- Clock gains 1 hour in spring and loses 1 hour in the fall DST OFF- Clock remains in Standard Time all year long DST ALWAYS ON- Clock remains in Daylight Saving Time all year long Settings order: • Beep ON/OFF • Atomic ON/OFF • DST (Daylight Saving Time) o DST ON o DST OFF o DST ALWAYS ON • Time Zone TIME ZONES AST = Atlantic • Hour EST = Eastern • Minutes CST = Central • Year MST = Mountain PST = Pacific • Month AKT = Alaska • Date HAT = Hawaii • Fahrenheit/Celsius To begin: 1. -
Governing the Time of the World Written by Tim Stevens
Governing the Time of the World Written by Tim Stevens This PDF is auto-generated for reference only. As such, it may contain some conversion errors and/or missing information. For all formal use please refer to the official version on the website, as linked below. Governing the Time of the World https://www.e-ir.info/2016/08/07/governing-the-time-of-the-world/ TIM STEVENS, AUG 7 2016 This is an excerpt from Time, Temporality and Global Politics – an E-IR Edited Collection. Available now on Amazon (UK, USA, Ca, Ger, Fra), in all good book stores, and via a free PDF download. Find out more about E-IR’s range of open access books here Recent scholarship in International Relations (IR) is concerned with how political actors conceive of time and experience temporality and, specifically, how these ontological and epistemological considerations affect political theory and practice (Hutchings 2008; Stevens 2016). Drawing upon diverse empirical and theoretical resources, it emphasises both the political nature of ‘time’ and the temporalities of politics. This chronopolitical sensitivity augments our understanding of international relations as practices whose temporal dimensions are as fundamental to their operations as those revealed by more established critiques of spatiality, materiality and discourse (see also Klinke 2013). This transforms our understanding of time as a mere backdrop to ‘history’ and other core concerns of IR (Kütting 2001) and provides opportunities to reflect upon the constitutive role of time in IR theory itself (Berenskoetter 2011; Hom and Steele 2010; Hutchings 2007; McIntosh 2015). One strand of IR scholarship problematises the historical emergence of a hegemonic global time that subsumed within it local and indigenous times to become the time by which global trade and communications are transacted (Hom 2010, 2012). -
18 TK Client DS
SECURE ENTERPRISE TIME SYNC WHITEPAPER SERIES TimeKeeper’s Competitive Survey Introduction The TimeKeeper® suite of products are more accurate, more reliable and far more capable than CAPEX-free open source alternatives. TimeKeeper has a lower OPEX than alternatives, but more importantly, TimeKeeper has features found nowhere else. These features include the ability to verify time is correct, compare against many time sources, report when time is incorrect or when time sources fail, and much more. Standard logging and integration provide guarantees of accuracy whenever proof is needed in the future. Some TimeKeeper customers previously built large in-house projects to try to make alternative solutions fit their needs. These expensive and very limited solutions were abandoned once they saw TimeKeeper gave them all they needed and more out of the box, saving valuable time and resources. TimeKeeper in use TimeKeeper hardware and software is in use by financial institutions of all sizes, from exchanges and very throughout Wall Street & large investment banks to small “prop shops”. TimeKeeper is there because after rigorously evaluating the globally product, customers found it gave them capabilities they simply could not get anywhere else. In addition, TimeKeeper support is far better than any of the competition. A few comments from our customers: “KCG has been using TimeKeeper Client and Server Software for two years in our trading environment with great success. TimeKeeper delivers accurate time, and has helped us to reduce operational risk with its built-in failover and event notification. We use TimeKeeper Client Software on our servers, using NTP or PTP to sync them to our GPS Based TimeKeeper Servers.” – Steve Newman, Managing Director, Corporate IT and Infrastructure, KCG “Technology is readily accessible for synchronizing to the microsecond, and there is no excuse for not having this in place today. -
Proposal of Atomic Clock in Motion: Time in Moving Clock
Proposal of atomic clock in motion: Time in moving clock Masanori Sato Honda Electronics Co., Ltd., 20 Oyamazuka, Oiwa-cho, Toyohashi, Aichi 441-3193, Japan E-mail: [email protected] Abstract: The time in an atomic clock in motion is discussed using the analogy of a sing around sound source. Sing around frequency is modified according to the motion of the sing around sound source, using the Lorentz transformation equation. Thus, if we use the sing around frequency as a reference, we can define the reference “time”. We propose that the time delay of an atomic clock in motion be derived using the sing around method. In this letter, we show that time is defined by a combination of light speed and motion. PACS numbers: 03.30.+p Key words: Atomic clock in motion, Lorentz transformation, Michelson-Morley experiment, special relativity, sing around 1. INTRODUCTION The derivation of the Lorentz transformation equation was clearly described by Feynman et al. [1]. The Doppler shift equation was observed to be different between acoustic wave and light, thus we determined the reason for this difference [2]. We pointed out that the frequency of a sound source should be modified according to its motion. We proposed a sing around sound source whose frequency changes with its velocity, as is suggested by the Lorentz transformation equation. We discussed the reference frequency of a moving sound source with respect to the Lorentz transformation equation. The sing around sound source moving in air exhibits a decrease in frequency. If the modified frequency is used as a reference frequency, the time delay in a moving frame can be explained [2]. -
Best Practices for Leap Second Event Occurring on 30 June 2015
26 May 2015 Best Practices for Leap Second Event Occurring on 30 June 2015 Sponsored by the National Cybersecurity and Communications Integration Center in coordination with the United States Naval Observatory, National Institute of Standards and Technology, the USCG Navigation Center, and the National Coordination Office for Space-Based Positioning, Navigation and Timing. This product is intended to assist federal, state, local, and private sector organizations with preparations for the 30-June 2015 Leap Second event. Entities using precision time should be mindful that no leap second adjustment has occurred on a non- holiday weekday in the past decade. Of the three leap seconds implemented since 2000, two have been scheduled on 31 December and the most recent was on Sunday, 1 July 2012. Please report operational challenges you experience to the following organizations: GPS -- United States Coast Guard Navigation Center (NAVCEN), via the NAVCEN Website, http://www.navcen.uscg.gov/ under "Report a GPS Problem" Network Timing Protocols (NTP) -- Michael Lombardi at NIST, Boulder, Colorado at 303-497- 3212, or [email protected]. ============================================= 1. Leap Second Introduction The Coordinated Universal Time (UTC) time standard, based on atomic clocks, is widely used for international timekeeping and as the reference for time in most countries. UTC is the basis of legal time for most of the world. UTC must be adjusted at irregular intervals to maintain its correlation to mean solar time due to irregularities in the Earth’s rotation. These adjustments, called leap seconds, are pre-determined. The next leap second will occur on 30 June 2015 at 23:59:59 UTC. -
DS1284/DS1286 Watchdog Timekeepers Are
DS1284/DS1286 Watchdog Timekeepers www.maxim-ic.com GENERAL DESCRIPTION FEATURES The DS1284/DS1286 watchdog timekeepers are . Keeps Track of Hundredths of Seconds, self-contained real-time clocks, alarms, watchdog Seconds, Minutes, Hours, Days, Date of the timers, and interval timers in a 28-pin JEDEC DIP Month, Months, and Years; Valid Leap Year and encapsulated DIP package. The DS1286 Compensation Up to 2100 contains an embedded lithium energy source and a . Watchdog Timer Restarts an Out-of-Control quartz crystal, which eliminates the need for any Processor external circuitry. The DS1284 requires an external . Alarm Function Schedules Real-Time-Related quartz crystal and a VBAT source, which could be a Activities lithium battery. Data contained within 64 8-bit . Embedded Lithium Energy Cell Maintains registers can be read or written in the same manner Time, Watchdog, User RAM, and Alarm as byte-wide static RAM. Data is maintained in the Information watchdog timekeeper by intelligent control circuitry . Programmable Interrupts and Square-Wave that detects the status of VCC and write protects Outputs Maintain JEDEC Footprint memory when VCC is out of tolerance. The lithium . All Registers are Individually Addressable via energy source can maintain data and real time for the Address and Data Bus over 10 years in the absence of VCC. Watchdog . Accuracy is Better than ±1 Minute/Month at timekeeper information includes hundredths of +25°C (EDIP) seconds, seconds, minutes, hours, day, date, month, . Greater than 10 Years of Timekeeping in the and year. The date at the end of the month is Absence of VCC automatically adjusted for months with fewer than . -
A Measure of Change Brittany A
University of South Carolina Scholar Commons Theses and Dissertations Spring 2019 Time: A Measure of Change Brittany A. Gentry Follow this and additional works at: https://scholarcommons.sc.edu/etd Part of the Philosophy Commons Recommended Citation Gentry, B. A.(2019). Time: A Measure of Change. (Doctoral dissertation). Retrieved from https://scholarcommons.sc.edu/etd/5247 This Open Access Dissertation is brought to you by Scholar Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. Time: A Measure of Change By Brittany A. Gentry Bachelor of Arts Houghton College, 2009 ________________________________________________ Submitted in Partial Fulfillment of the Requirements For the Degree of Doctor of Philosophy in Philosophy College of Arts and Sciences University of South Carolina 2019 Accepted by Michael Dickson, Major Professor Leah McClimans, Committee Member Thomas Burke, Committee Member Alexander Pruss, Committee Member Cheryl L. Addy, Vice Provost and Dean of the Graduate School ©Copyright by Brittany A. Gentry, 2019 All Rights Reserved ii Acknowledgements I would like to thank Michael Dickson, my dissertation advisor, for extensive comments on numerous drafts over the last several years and for his patience and encouragement throughout this process. I would also like to thank my other committee members, Leah McClimans, Thomas Burke, and Alexander Pruss, for their comments and recommendations along the way. Finally, I am grateful to fellow students and professors at the University of South Carolina, the audience at the International Society for the Philosophy of Time conference at Wake Forest University, NC, and anonymous reviewers for helpful comments on various drafts of portions of this dissertation. -
Table of Contents
TABLE OF CONTENTS SECTION I ACCESS THE KRONOS TIMEKEEPER I-1 SECTION II POST ABSENCE/ATTENDANCE CODES IN KRONOS II-1 A. Absence Reports II-1 B. Absence/Attendance Pay Codes II-2 C. Teacher’s Full Time Equivalency (FTE) II-8 D. Absences Posted to an Employee in the Full Screen Editor II-10 E. Employee's Balances Viewed from the Full Screen Editor II-19 F. Absences Viewed from the History Module II-21 SECTION III EDIT TIME IN TIME EDITOR III-1 A. Time Editor II-1 B. Editing a Punch or Absence Record III-4 C. Add an In and Out Punch III-6 D. Insert a Single Punch or a Transfer Punch III-9 E. Delete a Line Item III-11 F. Delete a Single Punch III-13 G. Forcing Overtime / Comp Time III-15 H. Editing Student Activities Records III-17 I Viewing Available Positions III-19 J. View Time Clock Punch Detail in History Inquiry III-21 Reference Pages Options in the Time Editor III-23 Function Keys in the Time Editor III-24 Help Screens Within the Column Headings III-25 SECTION IV RUN REPORTS FROM REPORT MODULE IV-1 A. Employee Master IV-2 B. Punch Detail IV-4 C. Punch Detail with Exceptions Only IV-8 D. Punch Detail Summary by Position Number IV-12 E. Punch Detail by Pay Codes IV-15 F Time Card Report IV-18 G. Total Hours IV-22 H. Approaching Overtime Report IV-24 I. Employee Accrual Report IV-26 Section II-1 Revised 7/23/2015 Revised SECTION V PRINT REPORTS FROM WORK SPOOL FILE V-1 A.