Space, Time and Stuff 5.
Okay, let’s have a look at the idea of time as a dimension and I’ll try to explain why I have problems with the concept, though perhaps it’s just my tired old brain, a lack of knowledge or a lack of imagination.
Anyway, if time is a dimension, then obviously it stretches from the beginning to the end. But what if time is eternal? No, we’ll ignore that possibility for now, and assume time begins with the Big Bang and progresses into the future. Does it have an end—possibly the end of the universe? If time is part of the universe, then surely the end of the universe would mean the end of time.
Could the universe come to an end? If it had a beginning …
Now, time isn’t a spatial dimension, but if we are going to consider it as a fourth dimension, then surely it must contain the three spatial dimensions. And if those dimensions are infinite, then time must be spatially infinite as well. Still, we won’t worry about that possibility, and simply consider it as part of ‘our’ universe. Even then, it means it must contain every particle of the universe, not just us humans, but every moon, planet, star, galaxy and nanoparticle in the universe.
If we consider time as a dimension, then it must include every unit of whatever is the smallest unit of time. My research tells me that is Planck time, but it is only a hypothetical unit, as is the next smallest, a yoctosecond. The smallest unit actually measured is a zeptosecond—0.000000000000000000001second, I think. Actually, if time is a dimension, then it is continuous. These units are simply the concepts we use for measurement and don’t really exist except as a concept.
As we move forward in time, I guess there are two possibilities. One would be that another unit of time forms behind us, but that seems ridiculous, as it would mean every unit was simply a still frame. The far more likely possibility is that every unit moves forward behind us, and at the beginning of time another unit of Planck time is squeezed out.
Personally, I don’t consider time travel is possible. Science-fiction writers love stories of time travel and finding the paradoxes that would exist. I loved the TV series Futurama and the episode where Fry basically became his own grandfather. But really, isn’t the first paradox the fact that the characters are even there? You don’t need to find another one.
Now, we’re in the present heading towards the future. But wait a minute! Don’t the people 200 years behind us believe that they’re in the present? And wouldn’t the people 200 years behind them believe the same thing? Etc, etc, etc. In actual fact, they might as well be actors in a film simply acting out what has already happened.
And what if we also only THINK we’re in the present. What if, like those behind us, we’re simply actors in the past. Could the actual present be far ahead of us? Could it even be just seconds away from the end of the universe?
No, we won’t think about that possibility, but if time exists as a dimension …
Perhaps the past is more of a spiritual quality. Now I’m beginning to get a headache, thinking of all those spirits behind us, and wondering what happened to the landscape around them.
Is there another explanation of how the past could still exist?
Okay, if time began with the Big Bang and only exists in our universe, what if we’re actually part of a multiverse? Would that mean that each universe has its own time dimension? Now I really do have that headache, but if a time dimension does exist, surely it must be part of the entire universe or multiverse.
While I understand that the idea of time simply not existing is difficult for many of us to accept, I have to say that I personally find it easier to accept than the idea of time as a dimension.
Yep, Just my thoughts. Nope, not much research.
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