3 comments about Comprehensive Hebrew Calendar.

1. A great reference for holiday dates, candle lighting times, Torah & Haftarah portions, etc. Well laid out and easy to access. If you're looking for a scholarly book on the origin of the Hebrew Calendar, buy something else. Though it's not intended as anything but a reference book, the introduction to the Hebrew Calendar in this book is well-written, concise, informative, and useful.



2. Everything I ever wanted in a book-calendar - the order of the Haftarahs, the date and holidays are all clarified either, in the beginning with tables, or in the calendar itself. The introduction is so informative, clear and useful that it precludes many other detailed books.
   
   Be sure to obtain Leo Levi's halachic times for home and travel. It is an excellent supplement to this calendar, that I continue to use for barmitzvahs, yahrtzeits and everything else related to the calendar.



3. It's just a tabulated thing showing english next to hebrew calendar. For about a hundreds years.
   
   It's pointless nowadays, when we have computers.
   programs like aishluach or kaluach.
   
   I can't believe anybody would rate such a book so highly. Or not make clear what the book is in their reviews.
   
   I did once see a book with a similar cover that explained the calendar. That was what I was looking for. This was very misleading.

3 comments about The Deconstruction of Time (SPEP).

1. This book is a fascinating reflection on the possibility of thinking time outside of the traditional metaphysical logic of
   representation. David Wood shows that the contemporary
   deconstructions of time lead to opening a sense -- and a future -- of philosophy as event, and performativity.
   This is an important and original work, and a brilliant demonstration of what it might mean to speak of time, and thinking, as event. It also performs new interpretations of the works of Nietzsche, Husserl, Heidegger, and Derrida.



2. The Deconstruction of Time is a necessary read for anyone interested in phenomenology or deconstruction--and David Wood shows clearly why an interest in one requires an interest in the other. He does so by tracing the central importance of the concept of time in works by Nietzsche, Husserl, Heidegger and Derrida. In each case, Wood analyzes the treatment of time with a clarity that makes the book accessible by nonexperts, and a rare sensitivity that will undoubtedly appeal to the well-versed reader as well. Taking the question of time as its axis, The Deconstruction of Time shows what is at stake in practicing phenomenology or deconstruction, illuminating along the way the fundamental tendencies, limitations, and values of each. In addition to his lucid analyses, Wood also offers sophisticated problematizations of the texts and positions he treats, submitting phenomenology to deconstruction, and holding deconstruction to a sort of phenomenological standard--he walks a fine and cautious line between the dominant impulses of these two ways of thinking about time, and he does so with grace and wit. Highly recommended!



3. The Deconstruction of Time is a necessary read for anyone interested in phenomenology or deconstruction--and David Wood shows clearly why an interest in one requires an interest in the other. He does so by tracing the central importance of the concept of time in works by Nietzsche, Husserl, Heidegger and Derrida. In each case, Wood analyzes the treatment of time with a clarity that makes the book accessible by nonexperts, and a rare sensitivity that will undoubtedly appeal to the well-versed reader as well. Taking the question of time as its axis, The Deconstruction of Time shows what is at stake in practicing phenomenology or deconstruction, illuminating along the way the fundamental tendencies, limitations, and values of each. In addition to his lucid analyses, Wood also offers sophisticated problematizations of the texts and positions he treats, submitting phenomenology to deconstruction, and holding deconstruction to a sort of phenomenological standard--he walks a fine and cautious line between the dominant impulses of these two ways of thinking about time, and he does so with grace and wit. Highly recommended!

1 comments about Time Dependent Problems and Difference Methods (Pure and Applied Mathematics: A Wiley-Interscience Series of Texts, Monographs and Tracts).

1. This book must be placed at the eye-level in the bookshelf of any scientist, mathematician, and practitioner who uses numerical techniques in his/her work. I was introduced to this book a few years ago when I was working on my Ph.D. dissertation, and I have kept it handy and close by ever since. The chapters are well written and well ordered, and the techniques are universal. The methods presented can be utilized to apply not only to finite difference schemes, which was the intention of the authors, but also to other numerical techniques such as finite elements, finite volumes, or spectral. I highly recommend this book.

No comments about What Is Time?: The Classic Account of the Nature of Time.

No comments about History of the Hour: Clocks and Modern Temporal Orders.

2 comments about Chronos: How Time Shapes Our Universe.

1. Commencing in 2007 the Hadron collider at CERN (in Switzerland) will be set to open and do what the US Congress declined to back in 1993...provide an appropriate facility for testing some of the more gross predictions of cosmic string theory.
   
   In so doing cutting edge contemporary research may yet provide additional material that -- obviously logically -- was unavailable when this book was originally written two years ago.
   
   That being said, this book is for the most part a serviceable discussion of the main issues regarding understanding time. As can be gleaned from a reading of the book, an arrow of time exists at a number of levels (including perceptual, thermodynamic and subatomic...all nested in that order) and its interesting to see the correspondences and disconnects between the various levels.
   
   Sadly, when discussing the perceptual arrow of time, Klein chose to use Freud as an authority...an example of what happens when someone chooses to write outside their profession.
   
   Perhaps a better book on this topic is Paul Davies About Time.



2. If you're in seventh grade and know very little about time, this is your book. If you're an adult who has had any interest in the subject whatsoever, you've seen more information on the subject in Scientific American. This is a very good book for children. It is not for scientifically literate adults.
   For a philosophical discussion of time, try Hans Reichenbach The Direction of Time (Dover Books on Physics) or The Philosophy of Space and Time.
   For a more general adult level discussion, try Paul Davies About Time: Einstein's Unfinished Revolution and How to Build a Time Machine.
   Chapter 11 gives a brief description of some standard science fiction books on time travel - again, if you have any interest in the subject, you're already familiar with the material.

No comments about Cycles of Time and Meaning in the Mexican Books of Fate (Joe R. and Teresa Lozano Long Series in Latin American and Latino Art and Culture).

3 comments about Sundials: History, Art, People, Science.

1. You are used to seeing a sundial in the middle of a garden, and if you are like me, you look at the shadow, then compare the time to a wrist-borne chronometer, and note that the sundial is off by however many minutes. In _Sundials: History, Art, People, Science_ by Mark Lennox-Boyd I learned that this is at least doubly wrong. The author quotes Hilaire Belloc: "I am a sundial and I make a botch / Of what is done much better by a watch." He complements the wit of the couplet, and shows the errors. Firstly, he points out, sundials tell time perfectly well; they simply measure time differently than watches do, but neither of them is objectively "right". Secondly, sundials are not merely garden ornaments, and only one in this profusely illustrated and colorful book is from that category. The dials shown here are often scientific instruments and elaborate works of art that sometimes do not look like sundials at all. Not only are many styles of sundial illustrated here, but the science and history of making them is summarized; the reader will come away with a much better idea of how the solar system runs from the contemplation of these not-so-humble instruments.
   
   Lennox-Boyd (or actually Sir Mark, since he has been, besides a Patron of the British Sundial Society, a Member of Parliament and a Foreign Office Minister), says that the association of the dial with the garden began in the Renaissance, not because the dials were ornaments, but because teachers of the time often used the garden as a place where lessons of science could be delivered. There are pictures here of artwork and architecture that one would not expect to be sundials at all. The Sundial Bridge across the Sacramento River in California is a suspension bridge, suspended on one side of the river from a huge, slanted support. The support just happens to be slanted at the correct angle to make it a gnomon, and its huge shadow sweeps along the ground beneath. The huge sundial at Jaipur in India has a gnomon that is big enough to walk up, fifty steep stairs. A Dutchman has designed beer glasses that you turn until the sunbeam through a circle on one side of the glass hits the date line on the other side; you can then tell if the time is after 5 p.m., the time when the inventor says the glass ought to be filled. There is a picture of a spherical sundial invented by Thomas Jefferson. The Disney World offices in Florida are "entertainment architecture", and part of the fun is that a central room is shaped like a truncated cone and has gigantic sundials visible on the outside and the inside, with quotations about time on marble plaques from such notables as Albert Einstein and Donald Duck. Sir Mark himself designs sundials, some of which are shown here. The most ambitious is one in Oliveto, Italy, within the stair tower of a house; a system of mirrors sends a sunbeam during different times of the day to different walls of the stairwell, each intricately crisscrossed with lines to read time, date, times of sunrise and sunset, and more.
   
   Sir Mark points out that since we now have clocks accurate to more than one second in fifteen million years, sundials ought to be obsolete, but they are not. There has been a resurgence of interest in them, both in the historical forms and the modern ones which come in strange and undial-like shapes. "There is a particular symbolism in an object that does something helpful but requires no power and performs indefinitely," he writes. He is clearly fascinated with his subject, and this lovely and colorful book conveys the fascination perfectly.



2. This is an excellent book for the layman as well as for an accomplished sundial expert. It shows the evolution of humankind's interest in the passage and the marking of time. And if you look on page 123 you will see photographs of Kate Pond's contemporary sun-aligned public sculptures.



3. After having purchased almost all of Amazon's collection on sundials, I eagerly awaited this book's delivery. From the first page, I regretted not having bought it before as Sir Mark Lennox Boyd has produced a masterpiece. Anyone who has an appreciation for gnomonics should get this book. Although it contains technical information, it's the historical journey which is most engaging.

5 comments about Calendrical Calculations.

1. The book explains the structure of 14 calendars, and gives easily comprehensible formulae for the conversion of a date in any of these calendars into a day count, and back to the calendar date. It also includes many holidays for these calendars.

   Rather than on the history of calendars or their cultural background, the focus is on a lucid, correct, and complete exposition of their functional principles. Extensive bibliographic references are given to the primary sources for each calendar.

   A highlight is the complete specification of several calendars depending on fairly precise timings of astronomical phenomena (Chinese calendar and some Hindu religious calendars).

   To make it self-contained, the book explains the necessary mathematical and astronomical background. The astronomical models are taken from the classic 1991 book "Astronomical Algorithms" by Jean Meeus.

   I especially like the presentation of the calendrical formulae in an essentially non-algorithmic manner, using normal mathematical notation. This makes it easy to further analyze these formulae.

   For instance, if one wants to know how good an approximation to the spring equinox is March 21 in the Gregorian calendar, one finds from the formula on page 36 in the book that midnight of March 21 in Gregorian year Y is exactly

   Y·365.2425 - (Y mod 4)·97/400 + (floor(Y/4) mod 25)·3/100 - (floor(Y/100) mod 4)/4

   days after midnight of March 21 in Gregorian year 0, which ranges from Y·365.2425 - 1.4775 up to Y·365.2425 + 0.72. Thus, even assuming the Gregorian approximation of 365.2425 days to the tropical year, spring equinoxes are distributed over at least three dates in March in the Gregorian calendar.

   Such reasonings would be very difficult if the book specified the calendars only in terms of programming language code.

   The formulae are designed so that it is easy to incorporate them into code written in the programming language of your choice. This use is further supported by a set of test dates in an appendix. Another appendix lists an example implementation of all the formulae, in the programming language Common Lisp. This code (intended for personal use) can also be downloaded from the internet.

   But this book is much more than a collection of programming recipes for many calendars -- it makes you understand the structure of those calendars. Ambitious readers can even find the data and the methods to construct their own calendrical formulae.

   What would I like to be changed in the book? Not much. Some of the calendrical formulae could be further simplified, the astronomical terminology could be modernized in places, and perhaps some additional historical information could be added. And, of course, even more calendars! For instance, some of the proposed reformed calendars, a more widespread version of the Persian calendar, or an historic Japanese calendar.

   This book is a must for everybody wanting reliable and highly readable information on the functional principles of the world's calendars.

   Michael Deckers




2. An excellent book on the history and workings of various calendars. But don’t use the source code! The licensing agreement is a trap. Use the code in GNU Emacs from the Free Software Foundation distributed under the General Public License. It does everything the authors code does (except for two obscure calendars) and it's free and always will be.



3. The reason why these people use the code in Emacs is that they wrote it. The authors virtually created the field of computerised calendaring, and then published the algorithms in two landmark papers in SPE in 1990 and 1993.



4. This is an interesting little book that provides a unified algorithmic presentation for more than two dozen calendars of current and historical interest. The book gives precise descriptions of each calendar and makes accurate calendar algorithms available for computer programmers. The complete workings of each calendar are described in verbage and then mathematically. Working computer programs are included in an appendix and on the accompanying CD.
   
   The one thing I didn't care for was the choice of Lisp as the implementation language in appendix B. However, this isn't too big of a problem since equivalent Java programs are on the book's website along with the Lisp implementations. Also, since the mathematical equations of conversion are clearly given, you can choose your own implementation language with few problems. The following is the table of contents:
   
   1. Introduction
   
   Part I. Arithmetical Calendars:
   2. The Gregorian calendar
   3. The Julian calendar
   4. The Coptic and Ethiopic calendars
   5. The ISO calendar
   6. The Islamic calendar
   7. The Hebrew calendar
   8. The Ecclesiastical calendars
   9. The Old Hindu calendars
   10. The Mayan calendar
   11. The Balinese Pawukon calendar
   12. Generic cyclical calendars
   
   Part II. Astronomical Calendars:
   13. Time and astronomy
   14. The Persian calendar
   15. The Baha'i calendar
   16. The French Revolutionary calendar
   17. The Chinese calendar
   18. The modern Hindu calendars
   19. The Tibetan calendar
   20. Astronomical lunar calendars coda
   
   Part III. Appendices:
   A. Function, parameter, and constant types
   B. Lisp implementation
   C. Sample data.



5. I am amazed by the clarity and "simplicity" of the text in the book.
   Calendars are not simple at all, but the approach taken by the authors makes the algorithms involved very accessible. I also appreciated the decision to focus on clarity rather then performance.

1 comments about Chimp Math: Learning about Time from a Baby Chimpanzee.

1. Chimp Math is a story of a baby chimp who was born at the zoo and his mother would not take care of him. Human doctors took over and the book shows photographs of the chimp named Jiggs as he grows. As the story unfolds it features pages showing clocks, calendars, time lines and other ways of keeping time records based on Jiggs growth and development.

   I liked the full color photographs of Jiggs. He�s funny. He does lots of things that real babies do like wear diapers, play with toys and crawls.

   I would recommed this to kids who enjoy stories about monkeys because this one is really neat.