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Originally Posted by Doctordick
But, my point is that Einstein's picture “is making those bad assumptions” by his definition of time; and it does indeed lead to some subtle problems.
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I think Einstein's definition leads to problems with your world view. His definition has never led to problems of agreement with observation.
Quote:
Originally Posted by Doctordick
Consider a world where clocks accurate enough to be used as “the definition of time” were small enough to wear as wrist watches by everyone. Then everyone would know exactly what time it was (by definition) and no two people would agree as to what time it is.
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Time is relative. What's the problem here?
Quote:
Originally Posted by Doctordick
Add to that the fact that things can only physically interact when they exist at the same time and “time” seems to have failed in its purpose.
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You want Einstein's definition of time to fail in its purpose which would then support your personal philosophy of anti-realism. However, such a thing cannot be managed. Relativity is one of the most successful theories of all time. It has yet to disagree with observation. The only way to attack such a theory is to make a better one that makes better predictions with better theoretical structure. Your sentence above doesn't accomplish that.
Quote:
Originally Posted by Doctordick
That is why I say “time is not a measurable variable” and it only has meaning along the evolving path of an entity. It is a useful parameter for describing the phenomena impacting the evolution of that entity and any additional properties can not be defended.
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By this reasoning length is not a measurable variable. The front and back of a train have spacetime separation and therefore a train has no length. That's not useful.
Quote:
Originally Posted by Doctordick
My definition of time stands! The past is "what we know" and the future is "what we do not know". The present then becomes the boundry (of our knowledge).
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This is not a definition of time. I appreciate that it has meaningful constraints that are related to time. But, taken literally "the future is "what we do not know"" means anything we do not know is in our future. This is untrue because what we "know" is not an exact way of describing our past lightcone.
Perhaps you meant to say "we can only know things from our past".
Quote:
Originally Posted by Doctordick
The fact that we find it convenient to think of what we know (the past) as a collection of "presents" for the purpose of ordering our world view (and the evolution of specific phenomena) does not make time a measureable variable.
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Yet there is something (some concept) that distinguishes two past events that are exactly the same in every way except for 'time' that separates them. Your definition makes no allowance for that. It is therefore incomplete at best.
Quote:
Originally Posted by Doctordick
That is an unjustifieable leap of faith enjendered by the success of Newtonian mechanics. He introduced the idea that the future could be known if the past were known and Einstein's picture is soundly based upon that erroneous illusion. That is precisely the source of the problems between general relativity and quantum mechanics.
Have fun -- Dick
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I agree that the usefulness of the concept (and the normal definition) keeps it alive and kicking.
~modest
