DOCSLIB.ORG

Metrology for Non-Metrologists

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Metrology for Non-Metrologists METROLOGY FOR NON-METROLOGISTS Rocío M. Marbán Julio A. Pellecer C. 2002 iii To contact the authors: 2001 Producción y Servicios Incorporados S.A. Calzada Mateo Flores 5-55, Zona 3 de Mixco Guatemala, Centro América Tel.: (502)431-0662 Fax: (502)434-0692 email: [email protected] ISBN 99922-770-1-7 © OAS, 2002 iv This English version of the second revised edition is pub- lished under the sponsorship of SIM. The Interamerican Metrology System, SIM (Sistema Interamericano de Metrología, Normalización, Acreditación y Calidad) is the regional organization for metrology in America, comprising national metrology institutes from the 34 member nations represented at the Organization of the American States, OAS, which acts as its Executive Sec- retariat. The opinions stated in this document are not necessarily opinions of the OAS, its bodies or its staff. v vi CONTENTS Acknowledgements ix Presentation xi Introduction 1 What we measure and how 11 Characterization of metrology 19 Vocabulary 21 Applications - what is measured and what for 27 Length 27 Mass 28 Temperature 29 Time and frequency 30 Electricity and magnetism 31 Photometry and radiometry 32 Acoustics and vibrations 33 Ionizing radiation 34 Chemistry 35 Standards and reference materials Introduction 37 Length 39 Mass 45 vii INTRODUCTION The initial concept of metrology derives from its etymology: from the Greek metros - measure, and logos - treaty. This concept is certainly as old as human beings: “I have nothing”, “I have something”, “I have much”; these expressions reflect a primi- tive comparison that is still valid and presently we can say that metrology is the science of mea- surements and that to measure is to compare with something (a unit) which is taken as the basis for comparison. Measurements for primitive human beings began with the ideas of: near-far, fast-slow, light-heavy, clear-dark, hard-soft, cold-hot, quiet-noisy. At first these were personal perceptions, but experi- ence and life in common gave rise to comparisons between persons and, through the ages, to gener- ally accepted bases for comparison. Thus, after several millennia, it is easy to think of bases for comparison of personal concepts - in other words: measurements and their units. 1 Metrology for non-metrologists Some of these measurements and units are basic: MEASURE UNIT length metre (meter) mass kilogram time second temperature kelvin intensity of light candela electric current ampere amount of substance mol For other purposes, not covered by the above, it is often necessary to use other measurement units, called derived units because they use or are based on the base units. That is, using mathematical al- gorithms, a unit is expressed algebraically in terms of other units. To enter the realm of units based on one or more fundamental units, is to enter a world of scientific algorithms for specific purposes, which is why de- rived units are more numerous. A unit is a value in terms of which a quantity may be described. It must be stressed that, qua unit, it must not be broken down into its elements. Mul- 2 Introduction tiples and sub-multiples are used to express quan- tities larger or smaller than those of the unit per se. We will see later on that in the International Sys- tem of Units multiples and sub-multiples are deci- mal, that is, they use powers of 10. We mentioned using something with which to com- pare; this something is known as a measurement standard or simply a standard. Originally, a standard was considered to be a rep- resentation or physical embodiment of a unit. It was necessary to stress that the standard was a trust- worthy representation of the unit only under a set of precisely defined conditions, to make sure it was independent of environmental influences such as temperature, humidity, atmospheric pressure, etc. Because of their characteristics, physical standards were not used to directly take measurements. In- stead they were the basic reference point for the manufacture and calibration of the instruments that are used for such purposes. Today, thanks to scientific advances, we have more exact and reliable definitions for the units, based on universal physical constants, and now a stan- dard can be defined as: a materialized measure, 3 Metrology for non-metrologists measurement instrument, reference material or measurement system, whose purpose is the defi- nition, materialization, conservation, or reproduc- tion of a unit, or one or several known values of a quantity, for transmission by comparison to other measurement instruments (2). It is also important that the procedure used to mea- sure give reproducible results and, in fact, there are precise instructions on how to carry out the pro- cedure, which units to use and which standard. In the real world, we usually measure following this sequence: - we decide what we are going to measure, - we select the unit according to the measure, - we select the measuring instrument (calibrated), - we apply the accepted procedure. Before going into details of the main measures, let us have a brief, very brief look, at the history of measurement. Archeological finds show that very ancient civiliza- tions had well-defined concepts of weighing and measuring. Trade, land division, and taxation, 4 Introduction among others, must have required very soon the uniformity of measurements. The appearance of weights and measures systems goes far back into time. We know little of what was done in the Far East; however, there is no doubt that they existed in the Mesopotamian civilizations and - clearly - it is obvious that the construction of pyramids in Egypt (3000 to 1800 BC) required elaborate systems of measurement. We know, and in some countries we still use, some of the linear measurements of current usage in ancient Egypt (the span, the foot, the pace, the fathom, the cubit). Also in Egypt, scales were used to weigh precious metals and gems. Later on, when coins began to be used as elements of trade, they were simply pieces of gold or silver, stamped with their weight. They gave birth to a monetary system that spread throughout the whole Mediterranean area. The way we measure time is based on the sexagesimal system developed in Mesopotamia, and our calendar is derived from the original 365 days Egyptian calendar. 5 Metrology for non-metrologists Roman conquest of a large part of the European continent contributed to disseminate the systems of weights and measures. By the beginning of the second millennium AD, the different measures in use had mutiplied uncontrol- lably. There were, for instance, different measures for capacity according to the product, be it wine or beer, wheat or barley. Measures could also vary from province to province or from town to town. England used Anglo-Saxon measures and gradu- ally tried to improve and simplify its system. For many centuries, the pound-foot-second system was the preferred system in English-speaking coun- tries as well as worldwide for some commercial and technical uses; to date it has not been totally dis- carded and is still used for many activities in many countries. France created and developed a simple and logi- cal system, based on the most advanced scientific principles known at the time (the end of the eigh- teenth century) - the decimal metric system, which first came in use during the French Revolu- tion. It owes its name to the use of the decimal system for multiples and sub-multiples and to its 6 Introduction base unit: the metre, mètre in French, which is it- self derived from the Greek metron, meaning mea- sure. In its first version, the metre was defined as one ten-millionth of the length of a quadrant of the earth’s meridian (i.e. one ten-millionth of an arc representing the distance between the Equator and the North Pole) and it was determined by measur- ing an arc of meridian between Dunkerque, in France, and Barcelona, in Spain. The history, vi- cissitudes, development and application of this sys- tem are amply documented (1,18). Metrologists are very active and there are con- stantly important changes and improvements in all aspects of measurements. Growing cooperation between metrologists from different countries is also helping to establish internationally accepted work procedures. There are now uniform methods of measurement so we can all work on the basis of the same known quantity or unit, and the results of any calibration, verification and test, in any labora- tory or enterprise, are a guarantee of compatibility and quality. In consonance with the global approach, more and more countries are adopting the International Sys- tem of Units (SI) based on the decimal metric sys- 7 Metrology for non-metrologists tem, with the subsequent adoption of the corre- sponding standards and measurements tech- niques. Forty-eight countries have subscribed the Metre Convention, that adopted the International System of Units (SI). The Convention gives authority to the Conférence Générale des Poids et Mesures (CGPM - General Conference on Weights and Mea- sures), the Comité International des Poids et Mesures (CIPM - International Committee on Weights and Measures) and to the Bureau Inter- national des Poids et Mesures (BIPM - International Office of Weights and Measures), to act interna- tionally in matters pertaining to metrology. CGPM is constituted by representatives of the member countries and it holds meetings every four years in Paris, France for: discussion and exami- nation of agreements for the improvement and dis- semination of the International System of Units (SI), validation of advances and results of new funda- mental metrological determinations, scientific inter- national resolutions, and decisions pertaining to the organization and development of the BIPM. 8 Introduction In search of a world-wide unification of physical measurements, the BIPM: - establishes fundamental standards and scales for the main physical quantities, - carries out and coordinates determinations related to physical constants, - preserves international prototypes, - coordinates comparisons with standards kept at the National Laboratories of Metrology, - ensures coordination of the measurement techniques.
Load more

Recommended publications
  • Business Unit Newsflash
    No.2 2017 PDC Center for High Performance Computing Business Unit Newsflash Welcome to the PDC Business Newsflash! The newsflashes are issued in the PDC newsletters or via the PDC business email list in accordance with the frequency of PDC business events. Here you will find short articles about industrial collaborations with PDC and about business events relevant for high performance computing (HPC), along with overviews of important developments and trends in relation to HPC for small to medium-sized enterprises (SMEs) and large industries all around the world. PDC Business Unit Newsflash | No. 2 – 2017 Page 1 HPC for Industry R&D PRACE Opens its Doors Further for Industry from world-leading research conducted over the last decade by a team of researchers at the KTH Royal Institute of Technology in Stockholm. Their project, called “Automatic generation and optimization of meshes for industrial CFD”, started on the 1st of September 2017 and will continue for one year. In early 2017 PRACE opened up a new opportunity for business and industrial partners to apply for both HPC resources and PRACE expert-help through what are known as Type-D PRACE Preparatory Access (PA Type-D) Meanwhile other Swedish SMEs continue to be applications. The objective of this was to allow active within the PRACE SHAPE programme. For PRACE users to optimise, scale and test codes on example, the Swedish SME Svenska Flygtekniska PRACE systems. Type-D offers users the chance Institutet AB was successful with an application to start optimization work on a PRACE Tier-1 called “AdaptiveRotor”. The project is expected system (that is, a national system) to eventually to start soon and will last six months.
    [Show full text]
  • Named Units of Measurement
    Dr. John Andraos, http://www.careerchem.com/NAMED/Named-Units.pdf 1 NAMED UNITS OF MEASUREMENT © Dr. John Andraos, 2000 - 2013 Department of Chemistry, York University 4700 Keele Street, Toronto, ONTARIO M3J 1P3, CANADA For suggestions, corrections, additional information, and comments please send e-mails to [email protected] http://www.chem.yorku.ca/NAMED/ Atomic mass unit (u, Da) John Dalton 6 September 1766 - 27 July 1844 British, b. Eaglesfield, near Cockermouth, Cumberland, England Dalton (1/12th mass of C12 atom) Dalton's atomic theory Dalton, J., A New System of Chemical Philosophy , R. Bickerstaff: London, 1808 - 1827. Biographical References: Daintith, J.; Mitchell, S.; Tootill, E.; Gjersten, D ., Biographical Encyclopedia of Dr. John Andraos, http://www.careerchem.com/NAMED/Named-Units.pdf 2 Scientists , Institute of Physics Publishing: Bristol, UK, 1994 Farber, Eduard (ed.), Great Chemists , Interscience Publishers: New York, 1961 Maurer, James F. (ed.) Concise Dictionary of Scientific Biography , Charles Scribner's Sons: New York, 1981 Abbott, David (ed.), The Biographical Dictionary of Scientists: Chemists , Peter Bedrick Books: New York, 1983 Partington, J.R., A History of Chemistry , Vol. III, Macmillan and Co., Ltd.: London, 1962, p. 755 Greenaway, F. Endeavour 1966 , 25 , 73 Proc. Roy. Soc. London 1844 , 60 , 528-530 Thackray, A. in Gillispie, Charles Coulston (ed.), Dictionary of Scientific Biography , Charles Scribner & Sons: New York, 1973, Vol. 3, 573 Clarification on symbols used: personal communication on April 26, 2013 from Prof. O. David Sparkman, Pacific Mass Spectrometry Facility, University of the Pacific, Stockton, CA. Capacitance (Farads, F) Michael Faraday 22 September 1791 - 25 August 1867 British, b.
    [Show full text]
  • Edmond Halley (1656 – 1742)
    Section 1: Science in the Early 18th Century 1 Lessons 1-15: Science in the Early 18th Century Lesson 1: Edmond Halley (1656 – 1742) The 17th century was a time of great progress in the way natural philosophers understood the heavens. With the help of Kepler’s Laws, Newton had produced his theory of gravity, which explained why the planets in the solar system orbit the sun. There was still a lot left to explain, but Newton had provided an incredibly important insight into how the solar system works. Towards the end of that century, a young natural philosopher by the name of Edmond Halley (hal’ ee) visited Newton to discuss some details regarding the way the planets orbit the sun. While he didn’t contribute a lot to our understanding of the planets, this young natural philosopher did help us figure out something else about what is seen in the heavens. Halley was the son of a very successful English soap merchant who was also named Edmond. Because his father was wealthy, he had the best education money could buy. At an early age, he This portrait of Edmond Halley was painted by Scottish became interested in astronomy, and his father artist Thomas Murray. purchased some very expensive equipment to help him observe the heavens. This allowed him to make some keen observations of Mars as the moon passed between it and the earth. He published those observations in a scientific paper at the ripe old age of 20! He continued to observe the heavens as much as he could.
    [Show full text]
  • Lesson 1 the Nature and History of Temperature
    Lektion 1 Sidan 2 av 5 © Pentronic AB 2017-01-19 ---------------------------------------------------------------------------------------------------------------------------------------------------- However, the thermometer had no real practical use until 1714, when the German physicist Daniel Gabriel Fahrenheit developed a temperature scale that made it possible to take comparative measurements. He is also considered to be the inventor of the mercury thermometer as it is today – that is, mercury inside a closed glass tube. It is worth pointing out that the glass thermometers containing mercury that may still be in use are being used by special exemption. Mercury is a stable substance but it becomes dangerous out in the environment. Today we use other liquids such as coloured alcohol. The temperature scales Fahrenheit Fahrenheit created a 100-degree scale in which zero degrees was the temperature of a mixture of sal ammoniac and snow – the coldest he could achieve in his laboratory in Danzig. As the upper fixed point he used the internal body temperature of a healthy human being and gave it the value of 100°F. In degrees Celsius this scale corresponds approximately to the range of -18 to +37 degrees. With this issue Pentronic begins its training in Becausetemperature it can be awkwardmeasurement to achieve .the We upper will fixed start point , he apparently introduced the more practical fixed points of +32°F and +96°F, which were respectively the freezing point of lesson 1 with a historical review and then continuewater and with the temperaturethermodynamics, of a human being’sheat armpittransfer. and quality assurance with calibration. Only after that will we move on to temperature sensors – primarily thermocouples and Pt100s.Fahrenheit’s scale was later extended to the boiling point of water, which was assigned the temperature value of +212°F.
    [Show full text]
  • How Cold Is Cold: What Is Temperature?
    How_Cold_is_Cold:_What_is_Temperature? Hi. My name is Rick McMaster and I work at IBM in Austin, Texas. I'm the STEM advocate and known locally as Dr. Kold because of the work that I do with schools in central Texas. Think about this question. Was it cold today when you came to school? Was it hot? We'll come back to that shortly, but let's start with something that I think we would all agree is cold, ice. Here's a picture of a big piece of ice. An iceberg, in fact. Now take a few minutes to discuss how much of the iceberg you see above the water, and why this happens. Welcome back. The density of water is about 0.92 grams per cubic centimeter, and sea water about 1.025. If we divide the first by the second, you see that about 90% of the iceberg is below the surface, something for a ship to watch out for. Why did we start with density and not temperature? Density is something that's a much more common experience. If something floats in water, it's less dense than water. If it sinks, it's more dense. That can't be argued. Let's take a little more time to talk about water and ice because it will be important later. So why is ice less dense than water? The solid form of water forms hexagonal crystals with the Hydrogen atoms shown in white, forming bonds with neighboring Oxygen atoms in red. With the water molecules no longer able to move readily, the ice is less dense and the iceberg floats.
    [Show full text]
  • The Links of Chain of Development of Physics from Past to the Present in a Chronological Order Starting from Thales of Miletus
    ISSN (Online) 2393-8021 IARJSET ISSN (Print) 2394-1588 International Advanced Research Journal in Science, Engineering and Technology Vol. 5, Issue 10, October 2018 The Links of Chain of Development of Physics from Past to the Present in a Chronological Order Starting from Thales of Miletus Dr.(Prof.) V.C.A NAIR* Educational Physicist, Research Guide for Physics at Shri J.J.T. University, Rajasthan-333001, India. *[email protected] Abstract: The Research Paper consists mainly of the birth dates of scientists and philosophers Before Christ (BC) and After Death (AD) starting from Thales of Miletus with a brief description of their work and contribution to the development of Physics. The author has taken up some 400 odd scientists and put them in a chronological order. Nobel laureates are considered separately in the same paper. Along with the names of researchers are included few of the scientific events of importance. The entire chain forms a cascade and a ready reference for the reader. The graph at the end shows the recession in the earlier centuries and its transition to renaissance after the 12th century to the present. Keywords: As the contents of the paper mainly consists of names of scientists, the key words are many and hence the same is not given I. INTRODUCTION As the material for the topic is not readily available, it is taken from various sources and the collection and compiling is a Herculean task running into some 20 pages. It is given in 3 parts, Part I, Part II and Part III. In Part I the years are given in Chronological order as per the year of birth of the scientist and accordingly the serial number.
    [Show full text]
  • Kemivandring ‐ Uppsala]
    Uppsala Universitet [KEMIVANDRING ‐ UPPSALA] En idéhistorisk vandring med nedslag i kemins Uppsala och historiska omvärld i urval. Karta: 1. Academia Carolina, Riddartorget 2. Gustavianum 3. Skytteanum 4. Fängelset vid domtrappan 5. Kungliga vetenskaps‐societeten 6. St. Eriks källa, akademikvarnen 7. Starten för branden 1702 8. Celsiushuset 9. Scheeles apotek (revs 1960) 10. Gamla kemikum, Wallerius/Bergman 11. Carolina Rediviva 12. Nya Kemikum/Engelska parken 13. The Svedberg laboratoriet 14. BMC, Uppsala Biomedicinska centrum 15. Ångströmlaboratoriet Uppsala Universitet [KEMIVANDRING ‐ UPPSALA] Uppsala universitet: kort historik[Karta: 1‐4] Uppsala universitet grundades 1477 av katolska kyrkan som utbildningsinstitution för präster och teologer. Det är nordens äldsta universitet och var vid tidpunkten världens nordligaste universitet. Domkyrkorna utbildade präster men för högre utbildningar var svenskar från 1200‐ talet och framåt tvungna att studera vid utländska universitet i till exempel Paris eller Rostock. Den starkast drivande kraften för bildandet av Uppsala universitet var Jakob Ulvsson som var Sveriges ärkebiskop mellan år 1469‐1515 och därmed den som innehaft ämbetet längst (46 år). Vid domkyrkan mot riddartorget finns en staty av Jakob Ulvsson av konstnären och skulptören Christian Eriksson. Statyns porträttlikhet med Ulvsson är förstås tvivelaktig eftersom man inte vet hur Jakob Ulvsson såg ut. Konstnären studerade i Paris tillsammans med Nathan Söderblom och det sägs att Eriksson hade honom som förebild för Ulvsson statyn och som därmed fick mycket lika ansiktsdrag som Söderblom. (Nathan Söderblom var ärkebiskop i Uppsala 1914‐ 1931, grundade den Ekumeniska rörelsen och fick Nobels fredspris 1930). Till en början bestod undervisningen vid Uppsala universitet främst av filosofi, juridik och teologi. Någon teknisk eller naturvetenskap utbildning fanns inte vid denna tidpunkt.
    [Show full text]
  • Thermodynamics Test
    International Academy Invitational Tournament Keep the Heat Test 2-4-2012 Team Name ________________ Team Number _____________ Predicted Water Temp ____________________C Circle the all of the correct answer to the below questions. One or more of the answers can be correct, if more than on one answer is correct, circle all correct answers. 1) Temperature is a measure of ____ of the particles in an object. a) the difference between the potential and kinetic energy b) the sum of the potential and kinetic energy c) the average potential energy d) the average kinetic energy 2) An increase in heat in a system __________. a) has less kinetic energy b) increases entropy c) decreases entropy d) reduces temperature 3) The specific latent heat of melting for lead is 22.4 kJ/kg and that of oxygen is 13.9 kJ/kg. This means: a) Lead melts at a higher temperature. b) More energy is needed to heat lead than is needed to heat the same mass of oxygen by the same amount. c) More energy is needed to melt lead than is needed to melt oxygen. d) Less energy is needed to heat lead than is needed to heat the same mass of oxygen by the same amount. e) Lead melts at a lower temperature. 4) Convert the temperature of -32 oC to degrees Rankline a) -485 oR b) -445 oR c) 371 oR d) 434 oR e) 474 oR 5) Convert the temperature of 50 oC to degrees Rankline a) -338 oR b) -400 oR c) 455 oR d) 518 oR e) 582 oR 6) Convert the temperature of 100 oF to degrees Celsius a) 24 oC b) 38 oC c) 88 oC d) 122oC e) 148 oC 7) An Object starts at 70 C, energy is added until the temperature increases to 80 C for a total ∆T of 10 C.
    [Show full text]
  • Fahrenheit(F)
    Fahrenheit(F) It was named after the German physicist Daniel Gabriel Fahrenheit. He based his scale on three reference points of temperature. In his initial scale (which is not the final Fahrenheit scale), the zero point is determined by placing the thermometer in brine (mixture of ice, water and salt). This is a frigorific mixture which stabilizes its temperature automatically: that stable temperature was defined as 0 °F (-17.78 °C). A mixture of ice and water also stabilizes, either freezing or melting at 32 °F. The second point, 100 degrees, was the horse body temperature, said at the time to be more stable than that of a human. The third point, 96 degrees, was approximately the human body temperature, then called "blood-heat." According to a letter Fahrenheit wrote to his friend Herman Boerhaave, his scale was built on the work of Ole Rømer, whom he had met earlier. In Rømer’s scale, brine freezes at 0 degrees, ice melts at 7.5 degrees, body temperature is 22.5, and water boils at 60 degrees. Fahrenheit multiplied each value by four in order to eliminate fractions and increase the granularity of the scale. He then re-calibrated his scale using the melting point of ice and normal human body temperature (which were at 30 and 90 degrees); he adjusted the scale so that the melting point of ice would be 32 degrees and body temperature 96 degrees, so that 64 intervals would separate the two, allowing him to mark degree lines on his instruments by simply bisecting the interval six times (since 64 is 2 to the sixth power).
    [Show full text]
  • DOE-HDBK-1122-99; Radiological Control
    DOE-HDBK-1122-99 Module 1.02 Unit Analysis & Conversion Instructor’s Guide Course Title: Radiological Control Technician Module Title: Unit Analysis & Conversion Module Number: 1.02 Objectives: 1.02.01 Identify the commonly used unit systems of measurement and the base units for mass, length, and time in each system. 1.02.02 Identify the values and abbreviations for SI prefixes. 1.02.03 Given a measurement and the appropriate conversion factor(s) or conversion factor table, convert the measurement to the specified units. 1.02.04 Using the formula provided, convert a given temperature measurement to specified units. References: 1. "Health Physics and Radiological Health Handbook"; Scinta, Inc; 1989. 2. DOE-HDBK-1010-92 (June 1992) "Classical Physics" DOE Fundamental Handbook; US Department of Energy. 3. "Nuclides and Isotopes"; Fourteenth Edition, General Electric Company; 1989. 4. "Chemistry: An Investigative Approach"; Houghton Mifflin Co., Boston; 1976. 5. "Introduction to Chemistry: sixth ed.; Dickson, T. R.; John Wiley & Sons, Inc.; 1991. 6. "Physics"; 2nd ed.; Giancoli, Douglas C.; Prentice Hall, Inc.; 1985. 7. "Modern Physics"; Holt, Rinehart and Winston, Publishers; 1976. 8. NIST Special Publication 330; "The International System of Units" National Institute of Standards and Technology; 1991. Instructional Aids: 1. Overheads 2. Overhead projector/screen 3. Chalkboard/whiteboard 4. Lessons Learned 1.02-1 DOE-HDBK-1122-99 Module 1.02 Unit Analysis & Conversion Instructor’s Guide I. MODULE INTRODUCTION A. Self Introduction 1. Name 2. Phone number 3. Background 4. Emergency procedure review B. Motivation A knowledge of the unit analysis and conversion process is a necessity for the RCT.
    [Show full text]
  • Thermodynamic Temperature
    Thermodynamic temperature Thermodynamic temperature is the absolute measure 1 Overview of temperature and is one of the principal parameters of thermodynamics. Temperature is a measure of the random submicroscopic Thermodynamic temperature is defined by the third law motions and vibrations of the particle constituents of of thermodynamics in which the theoretically lowest tem- matter. These motions comprise the internal energy of perature is the null or zero point. At this point, absolute a substance. More specifically, the thermodynamic tem- zero, the particle constituents of matter have minimal perature of any bulk quantity of matter is the measure motion and can become no colder.[1][2] In the quantum- of the average kinetic energy per classical (i.e., non- mechanical description, matter at absolute zero is in its quantum) degree of freedom of its constituent particles. ground state, which is its state of lowest energy. Thermo- “Translational motions” are almost always in the classical dynamic temperature is often also called absolute tem- regime. Translational motions are ordinary, whole-body perature, for two reasons: one, proposed by Kelvin, that movements in three-dimensional space in which particles it does not depend on the properties of a particular mate- move about and exchange energy in collisions. Figure 1 rial; two that it refers to an absolute zero according to the below shows translational motion in gases; Figure 4 be- properties of the ideal gas. low shows translational motion in solids. Thermodynamic temperature’s null point, absolute zero, is the temperature The International System of Units specifies a particular at which the particle constituents of matter are as close as scale for thermodynamic temperature.
    [Show full text]
  • Bill Nye - Biography, Facts and Pictures
    5/9/2016 Bill Nye - Biography, Facts and Pictures Home List of Scientists Blog Bill Nye Search Famous Scientists SEARCH Scientist of the Week André Marie Ampère: Founded electromagnetic theory Recent Scientists of the Week Jane Goodall: Discoveries in chimpanzee behavior James Hutton: Founded modern geology Harold Urey: Deuterium and the building blocks of life Andreas Vesalius: Founded modern anatomy Niels Bohr: Quantum mechanics & the atom Barbara McClintock: Jumping genes & crossing chromosomes Francis Bacon: The Scientific Method “The Science Guy.” William Sanford Nye who goes by his more popular moniker Anaximander: An ancient scientific revolution Bill Nye is a science educator who began his career in science as one of Boeing’s mechanical engineers. He is most popularly known as Bill Nye the Science Guy Heinrich Hertz: Discovered radio waves and photoelectric effect where he hosts the Disney/PBS science show for children. Bill Nye is also a Charles Darwin: Evolution by natural selection comedian, actor, scientist, and a writer. He has gained popularity for his many Robert Boyle: The birth of chemistry appearances in today’s media as a fun to watch science educator. Srinivasa Ramanujan: The purest mathematics Ernest Lawrence: Invented the cyclotron; founder of big science Early Life and Education Rudolf Virchow: Discovered diseases strike by attacking cells Irene Joliot­Curie: The first artificial radioactive elements Hans Christian Oersted: Discovered electromagnetism Bill Nye was born in November 27, 1955. His mother was a codebreaker named Jack Horner: New horizons in dinosaur research Jacqueline, and his World War II veteran father was named Edwin Darby. His father had experienced being a prisoner of Japanese war camps, and this made Ronald Fisher: Statistician; and greatest biologist since Darwin? him an enthusiast of sundials.
    [Show full text]