If I saw that book "End of time" I would want to look into it, because it's the first time I've heard of someone who attempted to exclude time from physics. If the author was a recognized figure in academia then I wouldn't be so skeptical, but we all know of ideas that were once outlandish that later become mainstream so I will withold judgement. That link to the encyclopedia entry on time has alot of good detail, thanks for posting it.

An article on "time" from "The Internet Encyclopedia of Philosophy" www.iep.utm.edu

"Time ripens all things. No man is born wise."

Thanks N_N for ur precious comments."Time is at once the most valuable and the most perishable of all our possessions."

NB: Aristotle said that the concept of time is paradoxal itself. To summarize what he said: the past disapears as soon as it appears, the future is unknown until it appears, and the present is what is between them. How can one think about something which is between what disappears as soon as it appears and what exists only in our imagination (i.e. the future) ?
So intuitively, one can say that time is just an artifact and doesn't exist. I highly recommend reading the book of Barbour.

An interview of E. Klein: www.quantumphil.org

IF you understand French, there is an article at www.quantumphil.org
(the experiement which killed time)

A summary of the book of Etienne Klein, "Les tactiques de Chronos" www.cerncourier.com


Time is an elusive concept and presents itself in manifold and disparate guises. As a result, dictionaries mention it in relation to fields as varied as choreography, economics, horse-riding, linguistics, liturgy, seafaring, sports, forestry, hunting and, obviously, physics. In his book Les tactiques de Chronos (Chronos's tactics), Etienne Klein sheds some light on the ideas each of us have of the disconcerting parameter that is time.
With his considerable store of philosophical and scientific knowledge, the author sets out to help the reader understand the concept of time. However, the meaning of time remains ambiguous and the book warns of the difficulties in providing a definition. The reader is reminded of the words of Saint Augustine: "What, then, is time? If no one asks me, I know what it is. If I wish to explain it to him who asks, I do not know."
Klein attempts to assist Saint Augustine. He begins with a summary of the various philosophies put forward over the ages, before introducing the concept of physical time with Galileo, who included time as a variable in dynamic equations. The concept of time was revolutionized by relativity theory and lost its absolute quality. Quantum mechanics suggests that going back in time is like crossing over into the world of antimatter. Klein goes on to discuss the "arrow" of time, which stipulates the irreversibility of macroscopic phenomena, and is illustrated by effects such as entropy and the evolution towards more probable states. This brings him to a discussion of CP violation, which implies T violation, in microscopic phenomena. The author does not shy away even from the most speculative of concepts, such as discontinuous time or time with several dimensions as a possible consequence of superstring theory. On the anecdotal side, the reader learns who wrote the article on time in Diderot and d'Alembert's encyclopaedia. It was J J Rousseau. We also find out to whom the phrase "eternity is long, especially towards the end" can be attributed - a list that over the years has included Franz Kafka, French humorist Pierre Dac and Woody Allen - and about S B Preuss, the physicist who put his name to just one article, albeit alongside Albert Einstein's.
While reading the book, which is a pleasure, it becomes clear that physics has made an important contribution to our understanding of time. It also becomes evident that a subjective time exists that is distinct from physical time, or if you prefer an individual time that is superimposed on universal time. Is not subjective time evidence of our relationship to physical time? This question is addressed in the final chapter of the book, entitled "Has physics forgotten about death?". Life still transcends the laws of physics, and it may be that man's concept of time is defined by his awareness of his own mortality. This hypothesis remains unanswered and the book is rounded off with a comprehensive bibliography of the sources used by the author.
Having finished the book, the physicist is left with the feeling of being closer to the philosopher, and maybe the philosopher will be better able to understand the need to take into account the major advances in physics in order to provide a more complete picture of the human experience.

I like the topic of "time", and i have been reading a little about it. There is a French Astrophysicst who wrote a lot about it, his name is Etienne Klein.

Regarding the topic itself, the evolution of the concept of time was gradual in physics: time is absolute (Newton), time is relative (Einstein)- both Newton and Einstein were for not using time in the laws of physics and for having them formalized as a pure geometric concepts (i.e. indepedent of time). And now, there are some physicists who question the existence of time itself. There is one book which talks about it: The End of Time:The Next Revolution in Physics by Julian Barbour. The author is a physicist who made a modification of general relativity in order to do not deal with time.
www.amazon.com s=books& n=507846

"Time present and time past
Are both perhaps present in time future,
And time future contained in time past."
T.S. Eliot,
Four Quartets
"Burnt Norton"

Simple answer of course time is real we use it all the time. Time is the great equalizer, we all have 24 hours a day to work with, but we achieve tremendously different results based on how we wisely we use time.

Mathematically, you can think of the time dimension just like you would one of the spatial dimensions. So, let's say you have an x-axis (1 dimension) and you would call that the "position" dimension. Is position directional? No, position is scalar. If position varies wrt some other variable however, then you can draw out a rate vector pointing one of two ways on the x axis. There is a clear distinction between "change of position" and "position" but people use the word "time" to represent single time values (like position), a range of time values (like distance), and just the progression of time in general. Obviously the first two cases are scalar (those were the ones I was referring to originally), but I think you're refering to just the last case. The reason why I'd represent the last case as a scalar is mathematical: if you have sec/sec as a rate the units cancel and you have a number with no associated unit or dimension. If you can define rate of time as change of time wrt some other dimension, then a vector representation would be more meaningful.

Time can be considered as the infinite progress of existence and how it affects us and our surroundings. However, we are not aware of the changes takg place around us. Sometimes we dont even c them.Time also alters our memory and way of thinking!

Salaam Omar. Exactly. It culdnt have been expressed in a better way. It can only be claimed that time is a scalar qty since it is added algebraically. If time constitutes a separate dimension, does it mean that time is directional but that this direction is not taken into account as time cannot be controlled? Is it the reason to treat it as scalar?

Is time an awareness of things changing-interactions happening, a comparison of our memory with new observations? It will be very useful indeed if we know how a gold-fish understands time!

Salaam, that is the special thing about the time dimension compared to the other three commonly known dimensions of space. We are within the dimensions of space-time (the four commonly known dimensions), and time is a dimension we have no control over, unlike the 3 positional dimensions where we can easily go to any point as we choose. Although we don't have control over real time, we have control over time in computer simulations and in reviewing recordings of events up until the present (as with the TiVo recorders used with TVs). In reviewing those you can play with the rate of "unreal" time wrt real time and you can jump around in time. If that rate is -1, then you go back 1 sec in "unreal" time for every sec of the real time which you have no control over. You can pause and the rate would be 0, but real time proceeds just the same. Muslims believe God is outside of spacetime, and so is not limited to see different points in our real time at once. We can see a whole range of x,y,z coordinate values all at once when looking at an object, but God can see the same including time, since He is outside of time, and to the whole extent of the universe. He can see and comprehend the beginning of spacetime and the end of spacetime, and all that is in between, all at once. And God knows best.

Salaam. I was using "flow" literally, meaning that time glides along a stream. But if u take "flow" in the world of physics, rate itself means with respect to time. I'd think that flow of time shld be with respect to itself. However, the flow cannot be controlled. Could it be that it is equal to infinity?

Well, if you are considering time as a quantity of measurement, as in x seconds, this doesn't have any direction associated with it. Another definition of time (t) is a dimension of space that is independent of spatial directions (x,y,z). When you represent time on paper as an axis then right and left would represent going forward and back in time. However, that's just a representation and time doesn't flow in any physical direction. I couldn't think of a good definition for the flow of time, because when we talk about rates, flows, etc in the physical world we're talking about change with respect to time. A flow is a kind of rate, but flow of time would be change of time with respect to what?

What abt past, present and future?The time axis suggests that time does have a direction. Without past, there is no present and without present, there is no future.Time flows from left to right.

I'd think it is a scalar, just like mass, because it represents a quantity without direction.