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#### mabus

##### Guest

To set it up, it seems fairly common sense to imagine that the universe has a finite span of time. We imagine it beggining x number of years ago in the big bang, and (assuming the big crunch model is correct) ending at some finite time in the future. Of course it may go on expanding for an eternity, this is not the point, the point is that if it has a final end, it will end at a determinable amount of time in the future. It's life history can be accurately dated and timed. While we may age at different rates based on time dilation, surely the universe ages at a finite set pace. Right?

So the thought occured to me, what if we had a clock in the universe from the moment it emerged from the big bang to the moment it died in the big crunch. Would we not then, have a finite defined amount of time elapsing which we would recognize as the duration of the universe. It certainly seems reasonable to me anyway, but time dilation presents a bit of a problem to, what otherwise seems like a rather common sense conclusion. Let's set the experiment up so I can show you what I mean, and hopefully someone can show me where I'm in error.

So let's assume that at the moment of the big bang (which we are going to assume is the origin of the universe for the purpose of this experiment) an atomic clock emerged. Yes I know atoms had not formed yet, much less clocks, but we will dismiss that objection for the purpose of this experiment. This clock will measure the duration, or the elapsed time of the universe from the moment of the big bang, until the big crunch (which we are going to assume will be the end of the universe for the purpose of this experiment)

Now, atomic clocks measure time by detecting the vibrations of electrons inside atoms (feel free to correct me if I am mistaken), so such a clock, emerging with the big bang, and ending with the big crunch, would measure the exact finite number of vibrations of electrons in the universe throughout the entire existence of the universe.

Now, imagine we were to build a second newer atomic clock, several million years after the big bang.

We would now have two atomic clocks. One measuring the elapsed time from the moment of the big bang, and one that began to measure time several million years later.

We've already established that the electrons in the universe would (according to the original atomic clock) have a finite number of vibrations. Just for simplicities sake let's call this 1X.

The second clock measures the vibrations as 1X - 1MillionY

That is to say, whatever finite number of vibrations in the lifespan of the universe is, minus the amount in 1 million years.

Here's where time dilation causes a problem.

If we place the original clock on a rocket, and leave the second newer clock on earth, then the original clock will see time elapse more slowly than the clock back on earth. In other words, the clock back on earth will see time pass quicker, or said another way, it will age more quickly.

If you do this long enough, you could bring the original clock back down, and set it next to the newer clock and compare the two. If you did so, the newer clock, created millions of years after the universe, would actually be OLDER than the universe. It would have seen more vibrations than the original clock which measures the entire life of the universe. How could this be possible?

My first thought is that the original clock, while having emerged at the same time as the universe, is WITHIN the universe and moving around within it. The moment it does so it becomes ensnared in relativity, and ceases to be a universal measurement of the universe (despite having been there from the very beggining).

This seems to make sense, but then here's the question. Can we ever truly measure the age of the universe? Aren't we really only measuring it from a reference frame? What age would the universe be from the perspective of the universe itself, rather than from something (or someone) measuring it from within.

Anyway, Like I said, it's a fairly kooky thought experiment, but it led me to a certain appreciation for the locality of time. It seems, from the way that the "old clock" behaves in this thought experiment that time seems to lose any meaning the moment you take up a position WITHIN the universe. My sense is that time must be the way we experience the difference in the way matter behaves locally within the universe, and that it would cease to exist on a larger (universal) scale.

This really feels like the single dumbest post I've ever written, but anyway there it is

Any thoughts?