Time Travel (part 2)
So it doesn't make any sense to talk about time 'travel', because there's nothing called time to travel IN. There's nothing called space to travel in either; to recap from last time, if I walk from this side of the room to the other side of the room, one way to describe this would be that it takes me a certain amount of time to cover the space between here and the other side of the room. But you can't really properly define either of those things without the other, they're two sides of the same thing - you can't really talk about the time to get to the other side of the room without talking about the space ("it took me 5 seconds to walk over there"), and you can't really talk about the space of that walk without talking about the time ("it's not far, only takes a few seconds to get from here to there").
And again try to find something called space or something called time, separate to the chairs and floor and walls and carpet etc. in that room. It's a fiction, there are just chairs and floor and walls and tables - no space or time. If you reckon they're there, please send a picture.
There's another interesting way to see the fiction of space and time. Part of that fiction is that time 'passes', which I mentioned in part 1. Like a river flowing along. If I sit here from 9am until 10am, I could say an "hour has passed".
The flow of time is (apparently) from past, to present, to future. Time's arrow. But if you think about any moment, any present moment, like right now as you read this (assuming anyone does of course). Are you in the present? Common sense says yes, but if you think about it how does the present ever become the past? And how does the present ever become the future? If you're in the present right now, and in a second you're in another present, how did time get from that one present to the next? Time must be both 'now' and 'then', at the same time, it must be passing at the same moment it's now, if it's ever to become past. Otherwise it would never pass. Similarly the future would never get here unless in each present moment it was already arriving. Unless time is passing and arriving at the same time as the present, you'll be stuck in an eternal, unchanging moment.
About a century ago Henri Bergson looked at all of this and scratched his head. Something was obviously wrong in the way people understood time. He realised the only way past, present and future could all be happening at the same time, in each moment, was if past, present and future actually always happen at the same time. Sounds bizarre, but Bergson added that past, present and future have a different form or state in each moment. An example may make it easier to follow.
Say you sneeze. You get a feeling which tells you a sneeze is about to happen (the "ahh" moment in the "ahhh-choo"). In that 'present' moment that feeling is the future (you sneezing, the "choo") - the feeling is the presence of that future moment (the sneeze) in this present moment. You may instinctively start to make movements, say of your hands to find a tissue, as you get that feeling. That instinct is the past at work, in that present moment, your body/mind remembering what you've done for sneezes in the past. The past and future are both already there as you sneeze, in other words, but they're not 'there' in quite the same way as the sneeze itself - they're there as feelings and memories (and memories can also be physical, like learned bodily habits).
For Bergson memory isn't remembering something in the way we usually think of, like some photograph of something that's happened but is now gone. It's not something stored up in our brain cells, as if our brains are like photo albums. Memory is the past itself, which never leaves us, coming forward again to re-animate the present. The past is always just there, it doesn't 'pass'. And the future isn't pre-determined, it's always something new and unexpected, but it's there in each present moment, just not fully formed - it always has a trace there of some kind, like a feeling, telling you what's coming.
Past and future are as real as the present, in each moment, they just have a slightly different form or state to the more 'solid' present. Similar to how water can be either solid, liquid or gas. They always exist, they're always real, they're just 'potential' rather than actually 'there'. Not potential as in fully formed and just waiting to pop into existence, like unwrapping a package, but potential like a tree is potential in its seed - there's no mini-tree in there, but a potential (Bergson would say "virtual") tree. The tree is there in the seed, but not like a little miniature tree you just add water to.
Reading Bergson for the first time can be a "wow" sort of experience, everything you may have taken for granted in a common sense way about space and time goes out the window. And not because he replaces common sense with some abstract ideas, but because he shows how the common sense ideas about space and time are actually ridiculously abstract, and don't hold up for more than about 5 seconds when you look at them. One of the reasons the potential or virtual aspects of reality don't get much press is because common sense again assumes things either exist, or they don't. Something is either here, or not here. But in reality lots of things are somewhere between here and not here. That's common sense too, we all know what it means to say something has 'potential', for example. Potential is real, it's just a different kind of real to the sort of real we usually think of, like a rock or a chair. If a child is a potentially good athlete, it means there's something about the way their body works which could develop into a champion athlete. That potential is already there, in their body, just like a tree is in a seed, but it's not developed yet. But that potential is real, and here in the present.