Discussion in 'General Science & Technology' started by Farsight, Nov 8, 2006.
1st post. Woot.
The OP is almost word for word Rovelli's hypothesis isn't it?
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2nd post. Never mind. I see you made some significant additions/changes.
Whoo boy. I think the answer to the question you are asking does indeed lie in the nature of time. I don't really see what you did though.
Folks here are creating confusion. Time is a fundamental concept. It should not be defined or described using more complex concepts.
Many posts back, I posted the following, which seems to have been ignored or misunderstood by many here. There is no need to make ithe concept more complex that what is described below.
Einstein once wrote something like the following about time, which I think is very succinct and pretty much describes it.
When an individual ponders his experiences, he can order the events in his life using the criteria of before and after. He can assign a number to each event in such a way that events assigned a lower number occurred before events assigned a higher number.
It is convenient to use a device called a clock to provide a consistent set of numbers for use in ordering events.
In describing the laws of physics using the language of mathematics, it is convenient (if not necessary) to use a continuous variable called time. This variable similarly orders events based on the criteria of before and after.
There is little (if anything) more that can be said relating to time.
The above is not a quote: It is a paraphrase based on my not infallible memory. I Think it is from the preface to one of his books or essays on Relativity. I have read several articles containing very lengthy & confusing verbiage which did not seem to describe the concept of time any better than the above.
It is interesting that Albert used bold or italics for before & after, implying that they should be considered primitive terms. not definable via the use of simpler terms or concepts.
Note that an axiomatic system requires undefined primitive terms to avoid various problems associated with circular definitions.
It is interesting that Albert did not mention the concept of the flow of time from past through the present into the future, which does seem to be a construct (illusion?) of the human mind rather than an objective process associated with reality.
All of the natural laws that we have painstakingly derived from our observations of the natural universe are predicated on the assumption that time flows. However, it would (presumably) be just as easy to derive those laws if we assume that time flows in the opposite direction.
Possibly the most glaring casualty would be our notion of entropy. On the other hand, at a moment about twelve billion years in the "future," the universe will collapse in on itself and disappear! Does that qualify as maximum order, or maximum disorder?
Fraggle Rocker: What makes you believe the following?
With few (if any) exceptions, the laws of physics apply to events. In this context an event is said to occur at (x, y, z, t) using some convenient coordinate system, where (x, y, z) specify a position in space and t is a variable indicating the order of 2 or more events.
Consider events occurring at various coordinates.
(1, 1, 1, 0), (2, 2, 2, 1), & (3, 3, 3, 2). These coordinates could be associated with a moving particle. One does not claim that the x-distance flows from 1 to 2 to 3. Similarly, one should not claim that the Time-variable flows from 0 to 1 to 2.
(1, 1, 1, 0), (2, 2, 2, 1), & (1, 1, 1, 2). These coordinates could also be associated with a moving particle (perhaps a ball which hit a wall at (2,2,2, 1) & bounced to (1, 1, 1, 2). Would one say that the distance variables flowed backward? I suppose that such a statement would have meaning, but most would say that the ball bounced backward.
What about (1, 1, 1, 0), (2, 2, 2, 1), & (3, 3, 3, 0), or (2, 2, 2, 0) ? Most would state that these coordinates cannot be associated with the motion of a particle, although they could be associated with two particles. This might be related to claims that time does not flow backward.
Philosophers (as compared to physicists & mathematicians) tend to be vague in their use of language when not using formal logic. They use statements like Time flows. Similarly Eastern mystics sometimes come up with statements like: The sound of one hand clapping. In the absence of further desription, I tend to think that such statements are clever bulls**t rather than erudite or wise statements.
I would be interested in some description of the semantics implied by: Time flows. Might it merely be an alternative say of saying: The time variable associated with particle motion or other physical processes always increases algebraically. ? If this is what is meant, Time flows is surely a simpler phrase & useful if understood to mean the longer, more precise phrase.
BTW: I think there are some misunderstandings about the fact that there is time-order ambiguity associated with some sets of events. If shown photos of billiard ball movements or atomic-level particle movements, it is not always possible to determine which are the earlier & which are the later events.
I have always considered such statements to relate to ignorance (or lack of pertinent data), preventing the assignment of a time order to such events. I have never interpreted such statements to be claims that the micro events are actually time-reversible. I always assumed that the statements indicated that in different contexts, seemingly same sets of events could have a different time ordering.
In context, such events can readily be ordered with respect to a time variable. Consider the particle level events associated with breaking an egg or dropping a marble into a pail of water. It might not be possible to assign a time order to any group of 2-3 particle level events associated with these processes. I have seen it stated that at the particle level, small sets of events associated with these processes are time reversible. I have never seen any claim that such compete processes are time-reversible.
In theory, one could bombard the sides of the pail with air molecules & the bottom with dirt molecules in such a manner that the marble would pop up from the bottom of the pail, waves would flow from the edge to the center, & the marble would become airborne. Similarly (in theory) one could reverse the process of breaking an egg by dropping it on the kitchen floor.
I have never heard anyone I respected claim that such overall processes could be reversed in practice. I suspect that the Uncertainty Principle & quantum capriciousness would prevent the reversal of such processes even in theory.
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