1 comments about Telling Time: How to Tell Time on Digital and Analog Clocks.

1. Our almost 6 year old has been wanting to be able to tell time for the past year. We've tried many different manipulatives with not much luck past the o'clocks and X:30. After reading this book just once, she's now actually telling time on analog clocks. It's slow going, but she really gets it now. Our daughter LOVES the poem at the end. It also covers calendar time - from one day to a millenium.

   The book is VERY interactive in the way it's written when the parent reads to the child. My only complaint is that it's never explained about what hour it is when the hour hand is between numbers or almost on the next number.

1 comments about What Time Is It? (Math Learn to Read).

1. Kids love it and can read it easily.

2 comments about Splitting the Second : The Story of Atomic Time.

1. I think a better subtitle would have been, "The Constant Search for Time," because only a third of the book is devoted to atomic clocks. The development of increasingly stable and accurate clocks is covered in detail, thankfully without dwelling on Harrison's efforts (already well covered in other books).

   As better clocks were built, measurements showed increasingly subtle causes for variations in the length of the day ranging from a non-circular orbit, to tidal effects, to crust movements, and down to atmospheric effects on the rotation rate. All these are covered in detail.

   The most convenient source of time with nanosecond accuracy is now the GPS satellites. Jones describes how special and general relativity affect their timekeeping and how these effects are compensated.

   He also goes into great detail about the international organizations responsible for managing UTC and the complex methods used to average the time from the primary standards and hundreds of secondary standards to produce UTC. Jones manages to do this without losing the reader's attention.

   Although the book avoids any math or advanced physics, it does not condescend in any way, and is directed to the mature reader. There are explanations of cesium and rubidium frequency standards, hydrogen masers, and also the latest developments: laser cooling and cesium fountains.

   It would have been nice if the author had included a bibliography, but this is compensated by providing the URLs for all the major world timekeeping organizations and also links to a number of web sites devoted to time.




2. Tony Jones has crafted an excellent history of time keeping from basic astronomy to pendulum and quartz clocks to modern atomic clocks. The problems and successes at each level are clearly explained. The text is at the early undergraduate level and is unencumbered with mathematics. Precision time has become imbedded in the activities of modern civilizations and it is interesting to see how the determination and dissemination of time has become complex as the accuracy has improved.

1 comments about Me Counting Time: From Seconds to Centuries (Me).

1. Not as good as _Me on the Map_, yet a good jumping off point to introduce concepts of time.

No comments about The Becoming of Time: Integrating Physical and Religious Time.

4 comments about Time Series Analysis: Forecasting & Control (3rd Edition).

1. This book shows the basic developments, and also allow users to get deeper in time series theory. In this revised edition, some discutions about ARMA models, models choice, and calibration of parameters are done. This book is of special interest for hydrologic engineers working in forecasting, planning, an modelling of water resources.



2. Box-Jenkins is THE definitive, foundational text in time series analysis. Mastery of this volume requires extensive graduate level understanding of mathematical statistics. While difficult even for intermediate statistical practitioners, this text is necessary for any professional who examines time series data and well worth the considerable effort to acquire mastery.



3. In the early 1970s I was working on practical forecasting methods to apply to the U.S. Army supply depot workloads. Exponential smoothing was the commonly used "automatic" technique (once smoothing constants have been determined) that had great advantages over the informal methods used by the Army. Then someone told me that Box-Jenkins techniques were more general and powerful. I got a copy of the first edition published in 1970 and found that I could read and understand it even though I had little statistical training. I had a bachelors degree in mathematics. I got to appreciate the book even more when I took a short course from George Box, George Tiao and David Pack based on the book. I began to grasp some of the key ideas of stationary and nonstationary time series and learned about model selection, diagnostic checking and estimation. This started my interest in becoming a statistician and gave me the practical side of time series analysis first. I later specialized in it and got a Ph.D. in statistics.

   Gwilym Jenkins died many years prior to this edition and Box's colleague Greogory Reinsel took on the task of helping to revise and update it.

   It retains its original flavor. It is an applied book with many practical and illustrative examples. It concentrates on the three stages of time series analysis: modeling building, selection, estimation and diagnostic checking and how to iterate the process toward a good solution. The ARIMA time series models are what are considered. The theory of stationary and nonstationary time series is introduced to motivate interpretation of autocorrelation and partial autocorrelation in the model identification phase. Operator notation is introduced and used throughout the book to simplify equations. For me it helped simplify things and illuminate some concepts. But many readers found it difficult and confusing. the book is very systematic and practical. Many of the examples are real examples from Box's work in the chemical industry and his consulting during his career at the University of Wisconsin and also the consulting experience of Gwilym Jenkins in England.

   The publishers and some amazon reviewers say that this edition is a major revision. The second edition published in 1976 was criticized for being essentially a reprint of the first. Although there is a new chapter 12 on intervention analysis and outlier detection it mainly is an expansion of ideas already discussed in the first edition. Theoretical results are kept aside in appendices as in previous editions.

   This is not an up-to-date text on the theory of time series. It deals strictly with the time domain approach and does not include recent advances including nonlinear and bilinear models, models with non-Gaussian innovations and bootstrap or other resampling methods.

   To get a balanced approach that includes the theory for frequency and time domain approaches the book by Shumway, the latest edition of the Brockwell and Davis text and the latest edition of Fuller's text are appropriate. For a graduate course I taught at UC Santa Barbara in 1981 I used the first edition of Fuller's book. Anderson provides a thorough account of the time domain theory. Excellent texts that specialize in the frequency domain approach are Bloomfield's second edition and the two volume book by Priestley. Brillinger's text is also worthwhile for those interested in spectral theory (frequency domain statistics).

   Although there are many things that is text does not cover, it remains the classical text on a rich class of time domain methods that are still very practical. This is a text I bought for reference even though I still have the first edition.




4. In the early 1970s I was working on practical forecasting methods to apply to the U.S. Army supply depot workloads. Exponential smoothing was the commonly used "automatic" technique (once smoothing constants have been determined) that had great advantages over the informal methods used by the Army. Then someone told me that Box-Jenkins techniques were more general and powerful. I got a copy of the first edition published in 1970 and found that I could read and understand it even though I had little statistical training. I had a bachelors degree in mathematics. I got to appreciate the book even more when I took a short course from George Box, George Tiao and David Pack based on the book. I began to grasp some of the key ideas of stationary and nonstationary time series and learned about model selection, diagnostic checking and estimation. This started my interest in becoming a statistician and gave me the practical side of time series analysis first. I later specialized in it and got a Ph.D. in statistics.
   Gwilym Jenkins died many years prior to this edition and Box's colleague Greogory Reinsel took on the task of helping to revise and update it.
   
   It retains its original flavor. It is an applied book with many practical and illustrative examples. It concentrates on the three stages of time series analysis: modeling building, selection, estimation and diagnostic checking and how to iterate the process toward a good solution. The ARIMA time series models are what are considered. The theory of stationary and nonstationary time series is introduced to motivate interpretation of autocorrelation and partial autocorrelation in the model identification phase. Operator notation is introduced and used throughout the book to simplify equations. For me it helped simplify things and illuminate some concepts. But many readers found it difficult and confusing. the book is very systematic and practical. Many of the examples are real examples from Box's work in the chemical industry and his consulting during his career at the University of Wisconsin and also the consulting experience of Gwilym Jenkins in England.
   
   The publishers and some amazon reviewers say that this edition is a major revision. The second edition published in 1976 was criticized for being essentially a reprint of the first. Although there is a new chapter 12 on intervention analysis and outlier detection it mainly is an expansion of ideas already discussed in the first edition. Theoretical results are kept aside in appendices as in previous editions.
   
   This is not an up-to-date text on the theory of time series. It deals strictly with the time domain approach and does not include recent advances including nonlinear and bilinear models, models with non-Gaussian innovations and bootstrap or other resampling methods.
   
   To get a balanced approach that includes the theory for frequency and time domain approaches the book by Shumway, the latest edition of the Brockwell and Davis text and the latest edition of Fuller's text are appropriate. For a graduate course I taught at UC Santa Barbara in 1981 I used the first edition of Fuller's book. Anderson provides a thorough account of the time domain theory. Excellent texts that specialize in the frequency domain approach are Bloomfield's second edition and the two volume book by Priestley. Brillinger's text is also worthwhile for those interested in spectral theory (frequency domain statistics).
   
   Although there are many things that is text does not cover, it remains the classical text on a rich class of time domain methods that are still very practical. This is a text I bought for reference even though I still have the first edition.

No comments about Chronotypes: The Construction of Time.

2 comments about Cycles of the Sun, Mysteries of the Moon: The Calendar in Mesoamerican Civilization.

1. Vincent Malmstrom has written a wonderfully entertaining book stuffed full of facts on the Mesoamerican systems of calendrical accounting. I had no idea the history of their calendars went so far back, nor that they were so widely used by such a great number of civilizations. His theories fill in where the facts leave off, as most studies on ancient cultures must, and the facts support his hypotheses. Malmstrom's theories on the origin of the calendar are quite different in some aspects than those of scholars before him -- one major difference is that he does not believe the Olmec developed the calendar. I don't want to ruin any surprises for a reader -- and there are some for those who accept the commonly supported theories of the Olmec as the "father" of all subsequent Mesoamerican civilizations -- so I will stop with just one more comment: If you have any interest in Mesoamerica or the cultures of the Zoque, Olmec, Zapotec, Maya, Mixtec, Toltec or Aztec, GET THIS BOOK!



2. The author never jumps to conclusions, but slowly, gathering the clues to lay out a history of the Mayan calendar. It is up to you to decide whether his logic is correct, I could not find any flaws. As the book goes you pick up plenty of astronomical, geographical and historical facts. Very engaging.
   The book has gone out of print, but is now posted in a digital format on the author's website. Still it is sad that it did not get wider attention.

1 comments about Eternity and Time's Flow (S U N Y Series in Philosophy).

1. Robert C. neville explores the metaphysical foundations of modern scientific concepts in a tradition that goes back to the great writings of continental philosopy such as Hegel, Husserl and Bergson. But, being an American in the end of the twentieth century, Neville uses the process philosophy of Alfred North Whitehead and the metaphysical concepts of the ontology of Martin Heidegger, together with contemporary quantum physics theory and the big-bang theory, to give us an holistic account of the concept of time as examined through the context of Eternity, that is complimentary to Christianity thought, Buddhizm and Zen. No other book that I have read deals with such a deep philosophical question concerning time in such a broad context. You can never tell if neville is more faitefull to modern science, continental philosophy, religion or eastern thought. Neville is a modern theologian, a briliant scholar, that does not forget modern science, and treat it with due respect, like he treats continental philosophy and metaphysics. Although he deals with religion, metaphysics, moral philosophy, philosophy of science, physics and zen philosophy, Neville never fails the temptation to write in a popular way or in indoctrinical voice. He truly take the imposible task to write a complete metaphysic of time and Eternity, in the same context that Hegel judged Descartes, Spinoza, Liebnitz, Lock, Berckly and Hume to have their own metaphysics. Because Neville's book borrows from three main systems, that is from Bergson, Whitehead and Heidegger, and synthesise them together in order to find the answear to the question of time as this concept is used in physics, western culture, Budhism, Judaism and Christianity, it is not too exaggerated to claim that it is an original thought that have its place as one of western culture keystones - but still, only intellectualy, since this book is very rarly known in philosophical circles and university departments. The only flaw of this book is the trust that Neville feels (to my mind) towards the western modern sciences of astronomy, chemistry, physics and astrophysics. It seems to me that in bringing science into philosophy Neville have made this book a waste in a hundred years from now: it will be old instead of immortal. As science change, it will make this book redundant. For now, this book have a superb analysis of self-will and self-responsibility, that is based on its excellent understanding of the meaning of time (and subjective time) as related to the concept of Eternity.

5 comments about Seize the Daylight: The Curious and Contentious Story of Daylight Saving Time.

1. I never realized that Daylight Saving Time (DST) had such a controversial and turbulent history. I believe that the author has done an excellent job in detailing DST's evolution, often in excruciating detail, right up to the current, yet still fluctuating, situation. The writing is clear and engaging making the book very easy to read. The book also contains many caricatures that were published over the years clearly expressing people's views on this most contentious issue. I highly recommended this book to anyone, especially those interested in recent history. The fact that this subject has recently made the news makes this book very timely.



2. Prerau has done a fine job chronicling the history of DST. Every reader is certain to find something here he didn't know (Example: Having been overseas 1973-75, I was completely unaware that the U.S. had ever experienced a period of year-round DST!) I'd prefer he had spent more time exploring the available evidence of DST's "advantages" and "disadvantages," which he comes to rather late in the book.
   
   New legislation in 2005 will extend the period of Daylight Saving Time in the U.S. considerably, so this topic is "timely" in more ways than one. Whether you love or hate DST, this book provides a useful foundation of history and fact as the controversy bubbles on.



3. I grew up hearing as an explanation for Daylight Saving Time that it was "good for the farmers." It turns out that this is a widespread misconception, and it also turns out not to be true: farmers have in fact historically opposed the adoption or expansion of DST because of the inconveniences it imposes on them. Another childhood illusion put to bed, if decades late.
   
   Since 1986 the U.S. has observed DST from the first Sunday of April to the last Sunday of October. Beginning in 2007, DST is to be expanded by three weeks (in accordance with the Energy Policy Act of 2005). It will now begin on the second Sunday of March and extend until the first Sunday of November. Given this change I figured it was high time for me to find out what Daylight Saving Time is all about.
   
   I review below David Prerau's Seize the Daylight: The Curious and Contentious Story of Daylight Saving Time. It's the first of two DST-related books that have been weighing down my TBR shelves. Both books were published in 2005--the idea of exploring DST apparently being very much in the air in the first years of the new millennium.
   
   ---
   
   Benjamin Franklin proposed in 1784, when he was serving as the American minister to France, that Parisians conserve energy--in the form of candle wax and tallow--by changing their habits, rising with the sun rather than sleeping in with their shutters closed against the daylight. The idea never caught on, and it is at any rate impractical as it would depend on the alteration of individual habits on a large scale for it to have any chance of working for a community. Over a hundred years later, in 1905, a certain William Willett devised an alternative plan for increasing the number of usable daylight hours during England's summer months. His plan, what we now call Daylight Saving Time, called for setting the nation's clocks forward in the spring (he initially imagined the time being changed in 20-minute increments on each of four successive Sundays) and back in the fall, thus not relying on people to alter their sleep patterns on an individual basis. His idea didn't catch on either, at least not immediately. In his book Seize the Daylight: The Curious and Contentious Story of Daylight Saving Time author David Prerau, who has coauthored government reports on the effects of DST, traces the complex history of DST from Willett's tireless campaigning on behalf of its adoption to the modern era. Prerau also provides a chapter on the two artificial adjustments to natural sun time that men adopted prior to the introduction of DST. (Mean solar time was adopted starting in the late 18th century. It differs from apparent solar time in that the length of a day is a constant throughout the year rather than depending on the amount of daylight in any given day, which varies throughout the year. The second artificial adjustment was standard time, adopted in the late 19th century, which is when a single mean time is recognized over a large area.)
   
   The history of DST has been, as Prerau's subtitle asserts, a highly contentious one, the case for and against its adoption taken up over the years by a variety of special interest groups--the railroads, theater operators, purveyors of sporting goods, golfers and farmers and concerned parents and religious purists. Political cartoonist jumped to portray its inconveniences. Presidents and prime ministers came to recognize its merits as an economizing measure. And scientists and astronomers were divided on the question of implementing it. The editors of the scientific journal Nature, for example, ridiculed DST early on by equating the time change with the artificial elevation of thermometer readings in the winter:
   
   "'It would be more reasonable to change the readings of a thermometer at a particular season than to alter the time shown on the clock, which is another scientific instrument.' They wondered if perhaps another bill would be proposed 'to increase the readings of thermometers by ten degrees during the winter months, so that 32∘F shall be 42∘F. One temperature can be called another just as easily as 2 A.M. can be expressed as 3 A.M.; but the change of name in neither case causes a change of condition.'"
   
   It's surprising just how many people have had an axe to grind one way or another on the DST issue.
   
   The implementation of DST was neither a quick affair nor a straightforward one. Initially adopted in the U.S. during World War I, for example, it was repealed in 1919, retained in pockets of the country between the Wars, adopted again and expanded during Wold War II, and repealed again by Truman after the War. It remained in use by local option in the decades following, and wasn't adopted as national law until 1966. Even now its implementation is not entirely regular, as certain states and territories have opted not to observe DST. In short, the history of Daylight Saving Time is a confusing mess. Transforming the complex story of its adoption in the U.S. and England and elsewhere in the world into a readable narrative is a great accomplishment.
   
   Prerau's book is packed with information, some of which certainly surprised me. I'd had no idea, for example, that it was standard as late as the 19th century for communities to determine their time locally, so that the time from town to town would vary by minutes depending on how the communities were situated from one another longitudinally.
   
   "As long as travel and communications were relatively slow, it didn't much matter that, for instance, in the United States when it was 12:00 noon in Chicago it was 12:31 in Pittsburgh, 12:24 in Cleveland, 12:17 in Toledo, 12:13 in Cincinnati, 12:09 in Louisville, 12:07 in Indianapolis, 11:50 in St. Louis, 11:48 in Dubuque, 11:39 in St. Paul, and 11:27 in Omaha. The relaxed pace of travel, the lack of instant communications, the inherent inaccuracy of contemporary clocks, and the less frantic pace of life all made minor time variations unimportant."
   
   What a strange world our great-grandparents inhabited.
   
   Prerau sometimes errs on the side of including too many details in his book, but for the most part the story he tells is fascinating, and the book well written. Seize the Daylight is a nice example of a type of book that I particularly enjoy, one that is as informative as it is interesting to read, one that sheds light on a convention or invention that quietly informs our daily lives but which few of us bother to investigate on our own. Seize the Daylight definitely rewards the reading.
   
   Debra Hamel -- author of Trying Neaira: The True Story of a Courtesan's Scandalous Life in Ancient Greece (Yale University Press, 2003)



4. This book really opened my eyes to the story of "Daylight Saving Time".
   It was a fast read and I recommend it to anyone who is involved in DST.
   :)
   
   Highly recommended.



5. Everybody talks about Daylight Savings Time. This book tells an interesting story about it and timekeeping.