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On Measurement and Numbering

Rory Fox

in Time and Eternity in Mid-Thirteenth-Century Thought

Published in print:
2006
Published Online:
May 2006
ISBN:
9780199285754
eISBN:
9780191603563
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/0199285756.003.0007
Subject:
Philosophy, Philosophy of Religion

This chapter examines 13th century views on issues of measurement, particularly temporal measurement. It shows that 13th century thinkers distinguished between a variety of ways in which the word ... More


Time error due to air pressure variations

Robert James Matthys

in Accurate Clock Pendulums

Published in print:
2004
Published Online:
January 2010
ISBN:
9780198529712
eISBN:
9780191712791
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780198529712.003.0030
Subject:
Physics, History of Physics

The rate of a pendulum clock is affected by air pressure. As the air pressure increases, the clock slows down, and vice versa. The basic cause is that the pendulum floats in a sea of air, and when ... More


Accurate Clock Pendulums

Robert J. Matthys

Published in print:
2004
Published Online:
January 2010
ISBN:
9780198529712
eISBN:
9780191712791
Item type:
book
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780198529712.001.0001
Subject:
Physics, History of Physics

The Shortt clock, made in the 1920s, is the most famous accurate clock pendulum ever known, having an accuracy of one second per year when kept at nearly constant temperature. Almost all of a ... More


Physical Relativity: Space-time structure from a dynamical perspective

Harvey R. Brown

Published in print:
2005
Published Online:
September 2006
ISBN:
9780199275830
eISBN:
9780191603914
Item type:
book
Publisher:
Oxford University Press
DOI:
10.1093/0199275831.001.0001
Subject:
Philosophy, Philosophy of Science

This book explores the nature of the distinction at the heart of Einstein's 1905 formulation of his special theory of relativity: that between kinematics and dynamics. Einstein himself became ... More


The Physics of Coordinate Transformations

Harvey R. Brown

in Physical Relativity: Space-time structure from a dynamical perspective

Published in print:
2005
Published Online:
September 2006
ISBN:
9780199275830
eISBN:
9780191603914
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/0199275831.003.0002
Subject:
Philosophy, Philosophy of Science

This chapter discusses the physics of coordinate transformations. Topics covered include coordinatization of space-time, inertial coordinate systems, the linearity of inertial coordinate ... More


Variations on the Einstein Theme

Harvey R. Brown

in Physical Relativity: Space-time structure from a dynamical perspective

Published in print:
2005
Published Online:
September 2006
ISBN:
9780199275830
eISBN:
9780191603914
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/0199275831.003.0006
Subject:
Philosophy, Philosophy of Science

This chapter begins with a brief discussion of Einstein's operationalism. It then discusses the clock hypothesis, the conventionality of distant simultaneity, David Malament's 1977 result, the ... More


Rate adjustment mechanisms

Robert James Matthys

in Accurate Clock Pendulums

Published in print:
2004
Published Online:
January 2010
ISBN:
9780198529712
eISBN:
9780191712791
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780198529712.003.0014
Subject:
Physics, History of Physics

The usual coarse adjustment for trimming a pendulum's clock rate is a threaded nut beneath the bob, which moves the whole bob up and down the pendulum rod. The surface of the thread is somewhat ... More


Position sensitivity along the pendulum rod

Robert James Matthys

in Accurate Clock Pendulums

Published in print:
2004
Published Online:
January 2010
ISBN:
9780198529712
eISBN:
9780191712791
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780198529712.003.0024
Subject:
Physics, History of Physics

Every clock's pendulum needs a fine trim to adjust its rate to the desired value. This is frequently done by adding small weights to a weight pan, which is usually located about one-third of the way ... More


Pendulum air movement: A failed experiment

Robert James Matthys

in Accurate Clock Pendulums

Published in print:
2004
Published Online:
January 2010
ISBN:
9780198529712
eISBN:
9780191712791
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780198529712.003.0028
Subject:
Physics, History of Physics

A previous experiment showed that the walls of a pendulum clock case can slow down the pendulum via air drag by about 1 second per day. The pendulum has a 2-second period. This chapter describes an ... More


An electronically driven pendulum

Robert James Matthys

in Accurate Clock Pendulums

Published in print:
2004
Published Online:
January 2010
ISBN:
9780198529712
eISBN:
9780191712791
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780198529712.003.0032
Subject:
Physics, History of Physics

An electromagnetically driven pendulum is more accurate than a mechanically (escapement) driven pendulum. This is because a pendulum is disturbed less by an electromagnetic drive pulse than by ... More


Check your clock against WWV

Robert James Matthys

in Accurate Clock Pendulums

Published in print:
2004
Published Online:
January 2010
ISBN:
9780198529712
eISBN:
9780191712791
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780198529712.003.0035
Subject:
Physics, History of Physics

In the United States, WWV is the obvious time standard to check a clock against. WWV's claimed time accuracy as transmitted in Boulder, Colorado is 10 microseconds short term, and 1 second in 3,000 ... More


Introduction: Rupert T. Gould

Jonathan Betts

in Time Restored: The Harrison timekeepers and R.T. Gould, the man who knew (almost) everything

Published in print:
2006
Published Online:
January 2010
ISBN:
9780198568025
eISBN:
9780191718144
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780198568025.003.23
Subject:
Physics, History of Physics

This introductory chapter presents a background on Rupert T. Gould. Gould possessed an exceptional mind; he was a veritable polymath, and his extraordinary knowledge and his dissemination of it in ... More


The earliest fossil record of the animals and its significance

Graham E. Budd

in Animal Evolution: Genomes, Fossils, and Trees

Published in print:
2009
Published Online:
September 2009
ISBN:
9780199549429
eISBN:
9780191721601
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780199549429.003.0001
Subject:
Biology, Evolutionary Biology / Genetics, Developmental Biology

The fossil record of the earliest animals has been enlivened in recent years by a series of spectacular discoveries, including embryos, from the Ediacaran to the Cambrian, but many issues, not least ... More


Animal phylogenetics

Alessandro Minelli

in Perspectives in Animal Phylogeny and Evolution

Published in print:
2008
Published Online:
May 2009
ISBN:
9780198566205
eISBN:
9780191713866
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780198566205.003.0002
Subject:
Biology, Animal Biology, Evolutionary Biology / Genetics

The single main root of phylogenetics is Hennig's reformulation of the comparative method, but the empirical basis has increased enormously in recent years with the availability of an exponentially ... More


The Photoperiodic Pathway of Floral Induction

Beverley J. Glover

in Understanding Flowers and Flowering: An integrated approach

Published in print:
2007
Published Online:
January 2008
ISBN:
9780198565970
eISBN:
9780191714009
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780198565970.003.0005
Subject:
Biology, Plant Sciences and Forestry

Long day plants and short day plants experience photoperiodic induction of flowering, and so flower in certain daylengths. This chapter considers the photoperiodic regulation of flowering in ... More


Molecular clock and estimation of species divergence times

ZIHENG YANG

in Computational Molecular Evolution

Published in print:
2006
Published Online:
April 2010
ISBN:
9780198567028
eISBN:
9780191728280
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780198567028.003.0007
Subject:
Biology, Evolutionary Biology / Genetics

This chapter focuses on statistical methods for testing the clock hypothesis, and on likelihood and Bayesian methods for dating species divergence events under global and local clock models. In such ... More


Ancestral sequence reconstruction as a tool to understand natural history and guide synthetic biology: realizing and extending the vision of Zuckerkandl and Pauling

Eric A. Gaucher

in Ancestral Sequence Reconstruction

Published in print:
2007
Published Online:
September 2008
ISBN:
9780199299188
eISBN:
9780191714979
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780199299188.003.0002
Subject:
Biology, Evolutionary Biology / Genetics

The perspective on natural history and medicine by Emile Zuckerkandl combined with the chemical expertise of Linus Pauling generated many novel ideas concerning molecular evolution. These included ... More


Biological Circuit Components

Richard M. Murray

in Biomolecular Feedback Systems

Published in print:
2014
Published Online:
October 2017
ISBN:
9780691161532
eISBN:
9781400850501
Item type:
chapter
Publisher:
Princeton University Press
DOI:
10.23943/princeton/9780691161532.003.0005
Subject:
Biology, Biochemistry / Molecular Biology

This chapter describes some simple circuit components that have been constructed in E. coli cells using the technology of synthetic biology and then considers a more complicated circuit that already ... More


Photoperiodic Flowering in the Long-Day Plant Arabidopsis thaliana

Joanna Putterill, Christine Stockum, and Guy Warman

in Photoperiodism: The Biological Calendar

Published in print:
2009
Published Online:
May 2010
ISBN:
9780195335903
eISBN:
9780199775446
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780195335903.003.0001
Subject:
Biology, Animal Biology

This chapter provides an overview of the theoretical models proposed to explain the mechanisms by which photoperiodic time measurement is achieved and our current understanding of the molecular basis ... More


Photoperiodic Control of Flowering in the Short-Day Plant Oryza sativa

Takeshi Izawa

in Photoperiodism: The Biological Calendar

Published in print:
2009
Published Online:
May 2010
ISBN:
9780195335903
eISBN:
9780199775446
Item type:
chapter
Publisher:
Oxford University Press
DOI:
10.1093/acprof:oso/9780195335903.003.0002
Subject:
Biology, Animal Biology

This chapter summarizes the progress made in understanding photoperiodic flowering in rice. Over the last decade, major questions regarding the photoperiodic control of flowering in plants have been ... More


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