1 comments about The Nick of Time: Politics, Evolution, and the Untimely.

1. I first became interested in this book after seeing it in a bookshop. Having read some Darwin and a fair bit of Bergson I was interested. It is rare indeed nowadays to see any work at all on the concept of time in any other form than the typical linear classical physics/relativity idea. This posits time as something that either acts as a medium through which matter moves or in the case of relativity as another dimension much like the three known space dimensions. In both cases time is strongly spatialised i.e. thought of in the same way that space is.
   
   Time is of course strongly linked to change whether it is the idea of change prevalent in ancient times e.g. Plato and Aristotle, Heraclitus or the more modern versions used in science. Grosz has studied time's presence through three well known figures Charles Darwin, Friedrich Nietzsche and Henri Bergson. Darwin's concern was how organisms evolved over time, Nietzsche how the human being uses the "Will to Power" to become more and Bergson was interested in both. That is in how organisms evolved and what duration (time) actually is, especially in comparison to space.
   
   Grosz analyses all of them in turn. She does something unexpected with Darwin, she suggests that natural selection is in fact a positive "force" rather than a purely negative influence on species. I did not find myself believing this, it makes more of natural selection that it is originally posited to be. In turn she considers the ideas of Nietzsche who did foresee Bergson to some degree in that he proposed "The Will to Power" which can be recognised a little in Bergson's elan vital. Finally she discusses Bergson's ideas on time/duration, evolution, intelligence, instinct and so on. She studies Bergson far more deeply than either of the other two.
   
   She also relates these concepts to politics especially those of feminism, racism and other forms of political struggle. Her discussion of Bergson is deep and she understands his work well. At times I found myself impressed at her whole grasp of Bergson's issues. She locates a kind of complete whole within his work which eluded me. I had read Creative Evolution, Time and Free Will and The Creative Mind but have not as yet covered Duration and Simultaneity or Mind-Energy.
   
   I find that she takes the most from Bergson and relates it at the highest level to much else in our current cultural and political reality. However I did not feel convinced by her study of Darwin and the earlier parts of the book felt a little disjointed. Some parts, especially those on Bergson flowed well together. A good piece of work with more potential.

4 comments about The Direction of Time (Dover Books on Physics).

1. If you didn't know, this book is hard. I am a first year engineering student, and I felt lost through most of it. I gather it was intended for full-fledged physicists, but I was intrigued to read it anyway because of a philosophical thread running through the work. But beware--get ready for some Immanuel Kant and Einstein in only the introduction. This book is as much about the physics of time as the philosophy concerning subjectivity of time. Even though I didn't understand a lot of the probability or almost any of the quantum mechanics math, I still got some pleasure out of some of the more bizzare conclusions of the book. Did you know that for an isolated system (one not interacting with any others), time can't be said to have any direction? Furthermore, time as we know it is just a statistic. Another interesting fact is that on the quantum mechanical level, there is no such thing as time! If these things intrigue you (and you know what a double Riemann sum is) go for this book. Otherwise, be very afraid...



2. It is a beautiful but exterememly difficult book. It covers the concept of time and direction of time from the beginning up to current thinking. Author, being one of the founding fathers of philosophical quantum theory first introduces a good understanding of Thermodaynamics and Statiastical Physics and defines the order of events to lead into statistical definition of arrow of time. A lot of difficult concepts from Classsical Statistical Physics, Probability Theory, Relativity and Mathematical Logic as well as a good understanding of Quantum Physics is assumed to be in the bag of the reader, after all this book is not a Popular Science book. Although the author claims that knowledge of derivations of the formulas used are not critical to understand this study yet time to time the language and logic becames exteremely difficult. This is a must read book in this subject, may be many times or time and time over after increasing the understanding in other subjects that only tools in this book.



3. H.Reichenbach is undoubtly one of the most remarkable scientists that the world has ever witnessed. The interested mind is to be very strongly urged to read the book 'The direction of time' by him. Time is an essential concept to every physics student, as without it nature would be meaningless, and therefore the study of nature would be an empty pursuit. Whenever we wish to understand why we are in the 'world', say rather than in the planet MARS we have to understand thoroughly what actually happenned in the past, beginning from The Big Bang, that is, from the beginning of time. The book gives us a clear understanding into this inquiry ('TIME') developing both classical and quantum mechanical content of the concept of time starting from the first principles. The book carefully clarifies many confusing conceptions about time. For instance, the author clearly explains the contradictions lying in the famous Zeno's paradox which attemts to prove that time does not exist, in such a way that the physics student is now much more confident with such essential concepts as displacement and velocity. Also in the book, another essential concept of statistical physics ENTROPY is developed in a very systematic way and through this concept the direction of time is decisively established. Moreover, the issue of DETERMINACY or INDETERMINACY , an issue which is simply ignored in the text books or mentioned briefly in a few sentences as if it is self-evident and therefore does not need further elaboration, is discussed in depth, so both theoretical and experimental physicists have now a strong ground in arguing their proposals. I, as a physicist of 18 years of university lecturing experience, strongly recommend it to every single physics student or actually every single mind (student or not) who cares about the future, and who needs a decisive explanation (justification) for their potential steps to save (before being too late) our home THE WORLD WHICH WE NOW LIVE IN, only home only home and only home for us and for our childeren including of course our organic bodies, the animals and the plants. The direction of time and equally of The ENTROPY are the key concepts to understand what technology actually is, and to understand why it is inevitable to face more and more polluted environment as technology advances.



4. I can't believe that everyone didn't rate this with 5 stars!
   I had to write this because this was one of those really great books that changed my understanding of something that seems so basic, so obvious, time.
   Well well worth the 5 bucks.

1 comments about Flat and Curved Space-Times.

1. This is one of the best introductions to the subject that I've read. The explanations are transparent with ample illustrations and examples. There are also many exercises to help the reader enforce what he has learned. There is also a very helpful annoted bibliography (actually the Afterword) which guides the reader to more advanced reading.

   It is really a shame that this book is not quoted more often. Overall, this is a very fine book.

No comments about On Space and Time.

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.

No comments about The Discovery of Time.

5 comments about Mapping Time: The Calendar and Its History.

1. Designing calendars is one of the more difficult tasks that human beings have set themselves. You first needed to -determine- the lengths of the cycles of the solar year and the lunar month. This was not an easy task, and it was not achieved until well into recorded history.
   
   The various cycles don't fit into each other particularly easily, either. With a solar year of just under 365.25 days, and a lunar month of just over 29.5 days, you aren't going to get it to come out even in the short run. You can stick with the sun and ignore the moon --- the solution of the Roman calendar fixed by Julius Cæsar. You can go with the moon, and leave the seasons to fall where they may --- as Muhammad, the desert-dwelling prophet of Islam, chose.
   
   Or you can try to keep the moon and sun tied together, necessarily loosely. This requires a number of cumbersome kludges, as the Babylonians, the Jews, the Chinese, and the Christians who fixed the date of Easter all discovered. These calendars took a lot more thought than the ones that simply discarded one or the other heavenly lights, and rank among the most intricate and intriguing works of ancient astronomy.
   
   This book contains a complete listing and description of the several solutions people have come up with to this seemingly intractable problem of arithmetic.



2. One of several books written in anticipation of the millennium, "Mapping Time: The Calendar and Its History" by E. G. Richards suffers from an especially heavy burden of typographical errors. As can be seen on the author's own web page, the address of which also is incorrect, there are hundreds of errors, some of which affect the accuracy of the account. For example, on page 208, January 1 came to mark the beginning of the Roman civil year in 153 BC, not 158 BC, and was in response to the Second Celtiberian War in Spain. Rather than wait until the middle of March for consuls to assume office, the new year was moved to the first of January so the Roman commander could depart with his legions that much sooner. It is a pity that so many errors compromise an otherwise informative history. Until they can be corrected, a better introduction to the calendar is "The Oxford Companion to the Year."



3. This is a nice examination of the different calendars and methods of mapping time that humans have employed over the centuries. On the surface it has the air of a dusty reference book, but inside the author is often witty and amusing as he covers the histories and backgrounds of different dating systems. I'm especially impressed by his inclusion of the different algorithms used to calculate dates, of Easter for example, which are marvelously complex. Most readers will never have occasion to use these algorithms, but its nice to know they're there. I also appreciated the charts and the glossary of the more obscure calendrical terms.



4. If expanded, this would make a good reference text. As a leisure read, it's weighed down by a fact-heavy writing style that makes it read like a bulleted list. While the information is great (if occasionally slightly inaccurate) and the additional reference material is useful for context, it lost my interest pretty early on, and I only finished it out of a grudging desire to just be done with it.
   
   Great reference material; not very re-readable.



5. nice, documented, interesting compilation/essay on the most important topics in the study of calendars. good place to start if you are interested in the topic. apparently started as the author wanted to build algorithms to program a computer to switch between dating systems.
   
   a few places i had to scratch my head and wonder about what he was saying, a bit more explanation in those contexts would have helped. the glossary in the back is a very good idea, i used it several dozen times. a bit more diagrams and hand holding would have improved the book for me.
   
   makes what could be a dull and boring subject, interesting, flowing and a worthwhile read. probably a bit advanced for the average person at places, but don't get discouraged, keep reading and struggling with the material.

3 comments about Clocks and Culture: 1300-1700.

1. This is a great book on the evolution of time measuring machines. But its real value is in the large amount of bibliographic references.



2. This book was a real surprise - the title doesn't sound very promising, but it was fascinating. The development of reliable time-keeping devices had a revolutionary impact on society, and we're unlikely to grasp the significance from our perspective on this side of the revolution without a book like this. It was a good read, and an enlightening one.



3. My dad's always been interested in clocks; when I saw this book, I bought it for him for his birthday.
   
   I've received TWO emails telling me how much he's enjoyed it. :)

2 comments about Four-Dimensionalism: An Ontology of Persistence and Time (Mind Association Occasional Series).

1. This book should be required reading for anyone interested in analytic metaphysics. Not only is the book interesting in its own right, it also provides a model for what rigorous argumentation and clear presentation can be. I recommend it most highly!



2. Hud Hudson, in a review of Ted Sider's book, says, "This is simply a superb book in metaphysics - handsomely written, cleverly argued, and exceedingly clear." Of course, Hudson happens to agree with almost every thesis Sider defends in the book. But I don't. In fact, I happen to disagree with almost every position defended in Sider's book. So what do I think of the book? I think it is simply a superb book in metaphysics - handsomely written, cleverly argued, and exceedingly clear. And I think it is notable that both friends and foes of the views defended in the book will find it to be extremely valuable. That is a real mark of distinction in philosophy, and my hat is off to Sider for producing such an outstanding work.

   What is the book about? Mainly the question of whether physical objects have temporal parts. A temporal part of x is, roughly, an object that exists for a shorter time than x but that exactly overlaps x throughout its existence. Sider believes, for example, that you have a temporal part that exists (only) from noon to 1pm today, and that perfectly overlaps you throughout that time. His view allows him to give neat and clean solutions to all manner of metaphysical problems (including the problem of how a time traveler who meets his former self could be both sitting and standing at the same time), and to do various other wonderful things.

   Although this is primarily a work for academic philosophers, it is clear enough that non-philosophers will be able to follow it, and to benefit from a careful reading of it. I highly recommend Four-Dimensionalism to professional philosophers, philosophy students (both graduate and undergraduate), and anyone else who is interested in questions about time and space.

No comments about From Sundials to Atomic Clocks: Understanding Time and Frequency, Second Revised Edition.