Originally posted by richispsychoFrom a scientific perspective, there definitely seems to be a dimension which we call 'time' which is different from the other dimensions (geometrically it has opposite signature to the others with respect to relativity, and also there are some things which only work in one direction, especially entropy). So I don't think it's any more subjective than space or matter.
Does time exist? As a thing on its own? Or is it completely a subjective experience?
Your thoughts please...
The passage of time is another matter - the idea that we are somehow in the present and not the past or future, and that the universe is changing. So far, our instinctive notions are not incompatible with what we know scientifically, and as long as this remains the case, the jury remains out on the matter. For example, one question to ask is: does the future exist already, and does the past still exist? This is something that we could answer immediately if we knew of time travel, but as it is there is no way of knowing.
Isnt the very basis of relativity the idea that time must have a positive value (the fitzgerald-lorenz contraction) and that nothing in our universe can therefore travel back in time without taking an imaginary value? Wouldnt anything traveling faster than light have to be an imaginary object when at rest?
Originally posted by AcolyteYeah............ right.............. that's what I was going to say!!!???
From a scientific perspective, there definitely seems to be a dimension which we call 'time' which is different from the other dimensions (geometrically it has opposite signature to the others with respect to relativity, and also there are some things which only work in one direction, especially entropy). So I don't think it's any more subjective than s ...[text shortened]... we could answer immediately if we knew of time travel, but as it is there is no way of knowing.
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Originally posted by frogstompSpecial Relativity just rules out objects with mass reaching the speed of light. Particles that travel permanently faster than the speed of light (called tachyons) are theoretically possible.
Wouldnt anything traveling faster than light have to be an imaginary object when at rest?
Time certainly does exist, in the same way any kind of measuement exists, e.g feet, pints, meters, gallons, pecks, etc. The question, therefore, is whether or not times flows from one moment to the next. If it does, the the future has yet to be created, and the past is gone. If it does not, then it is all there already, and we are merely cursed to experience it in an order that keeps our sanity intact.
In my opinion, all of time exists already, and that the feeling of time flowing is just an illusion. My reasoning behind this is the obvious (to me) lack of natural randomness. What I mean by this is that everything in our reality is caused by something else. The ball rolls because it was struck or pushed by something else. It rains because the clouds were too heavy with water. My wife shoots me bacause I spend too much time on the computer. In other words, every effect has a cause. This being true, the future is already mapped out because it's substance has already been supplied by the past. No slice of time can exist without the rest of it, for it is all tied together; therefore all of time exists as a block. Our feeling of time flowing can be nothing more than a personal data pointer.
Originally posted by SiskinYes , and so are Gossemer wings. The basic point Einstein made was if we cant measure it ,,it's not in our universe. Otherwise we would be posting on the existance of the Ether.
Special Relativity just rules out objects with mass reaching the speed of light. Particles that travel permanently faster than the speed of light (called tachyons) are theoretically possible.
Originally posted by thesonofsaulOk.... I think Stang contradicts you but does no justify his conclusion.
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In my opinion, all of time exists already, .... My reasoning behind this is the obvious (to me) lack of natural randomness. What I mean by this is that everything in our reality is caused by something else. This being true, the future is already mapped out because it's substance has already been supplied by the past. No slice of time can exi ...[text shortened]... s as a block. Our feeling of time flowing can be nothing more than a personal data pointer.
If the future is deterministic (already decided by the past) we should be able to know everything that is going to happen (predict). However we cannot because we do not know (and cannot know) everything about the present state of the environment. Doesn't this make the future as good as random (at least to us)....
Originally posted by thesonofsaulDoesn't Heisenberg's Uncertainty Principle contradict this view?
Time certainly does exist, in the same way any kind of measuement exists, e.g feet, pints, meters, gallons, pecks, etc. The question, therefore, is whether or not times flows from one moment to the next. If it does, the the future has yet to be created, and the past is gone. If it does not, then it is all there already, and we are merely cursed to ex ...[text shortened]... s as a block. Our feeling of time flowing can be nothing more than a personal data pointer.
Originally posted by STANGI disagree. Consider the following as a way of getting round the idea of indeterminacy:
Randomness is proof that time exists.
Let X be the set of all possible worlds (which includes all the space and time in those worlds). We live in one of these, let's call it x, but x is fixed and always has been.
We can narrow down X by conditioning on worlds that are consistent with our observations of our past and present, and this gives a set Y.
Let's say some observation is coming up, say we are going to observe the spin of a particle. We can now quotient Y by the following equivalence relation: a~b if in both a and b, the particle has the same spin.
The observable is 'random' if Y/~ has more than one element. We then say the probability of a given result (eg that the particle has spin -1) is the measure m of the corresponding equivalence class in Y, where m(Y) is 1. But since we don't know what X is, or what the measure is, from our point-of-view the probability is something we have to guess at by reference to the past. It may in fact be that the equivalence classes are unmeasurable, in which case even our notions of events having probabilities are wrong.