I've decided we're going to time travel. It precipitates the question though- is that even possible? Let's put it to the people of PMS to decide.
There's two obvious categories. Forward, and backwards. Do you think we can do either of these? Why might it be impossible or possible? After at least one post (unlikely enough as it is to even get one post) I'll come back and try to answer too.
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Well if forward time travel wasn't possible, then we'd sort of have a problem moving and all.
But aside from that, I do think that faster forward time travel is possible, for example that whole thing where traveling near the speed of light makes you be older than your twin as time travels slower for you than he when you're going so fast.. Not sure about backwards, though. If it is its probably way unintuitive.
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I thought I saw upon the stair a little man who wasn't there.
He wasn't there again today. Oh how I wish he'd go away.
So, is the theory that travelling the speed of light would cause you not to age at all?
I think forward "time travel" in the sense of going extremely fast is possible but sounds like it'd be costly and not altogether that "worth it". Backwards... I just can't see happening.
Yes you can, though I'm not allowed to say how I know.
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"...you should try reading my posts being getting all emo." --FoxMetal
So, is the theory that travelling the speed of light would cause you not to age at all?
Something like that. Except my understanding is that you can't actually reach the speed of light, just approach it, so you can approach not aging, but you'll actually age. And really, time will feel normal for you, but in reality it will be moving at a slower rate for you than everyone else, which leads to the effect of time travelling faster for them than for you, meaning if you wanted to see the world in 100 years, you'd just have to go fast enough and you could get there in a short period of time.
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I thought I saw upon the stair a little man who wasn't there.
He wasn't there again today. Oh how I wish he'd go away.
Right-o, I've read a bit about time dilation. Well, from wikipedia. I don't quite understand it yet, but the idea seems to be that as one moves faster in relation to another, time "slows" for the faster moving individual, relative to the individual who is not moving (well, you're moving if you're on the Earth, since it's moving, but eh)
So I suppose, if we engineered a way to go super fast we could travel vast distances without much aging.
In reverse though? I just don't know. It doesn't make sense to me. You can't go slower than an object that isn't moving, so time dilation doesn't help. Going back in time would alter the world in such a grand way, possibly without even doing anything if you went back far enough (introducing new microbes to the area, displacing the environment you land in, all of these things are good enough for a butterfly effect) that you'd probably become undone in the future.
I suppose if you considered that you weren't going backwards, so much as just bring the past to the front, then you could avoid that paradox problem... for example...
2007 2008 2009 2010
If we're in 2010, and then go back to 2007, we'd be going back through all of the years and altering our own future, thus possibly endangering us in a paradox. So it just can't be.
But, if we're in 2010 and duplicate 2007... sort of copy/paste if you will, it'd look more like this.
2007 2008 2009 2010 2007 2008' 2009' 2010'
Where the ' after the successive years denotes that those years will likely not be identical to their counterparts, because you're interacting with them and changing them.
So... you don't "undo" history. History has always been the same, it's just that only you and any other time traveler knows about it. Thus you undo the paradox, because you haven't gone back in time, you've brought back in time to you.
Still, I don't know how that would be done, and I think it's probably impossible.
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Well, I did read a description of how it might be done, but it has a ton of contingencies, primarily having a stable wormhole and being able to move one "mouth" but not the other. The idea involves moving one mouth close to the speed of light, desyncing it in time from the other. Then if you go from one to the other, you'll either jump forward or backward in time, but the furthest you can travel backward is to the day that they were first desynched, if I understand correctly.
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I thought I saw upon the stair a little man who wasn't there.
He wasn't there again today. Oh how I wish he'd go away.
Notice that we aren't overrun by tourists from the future, and Hitler was never assassinated by a time traveller.
http://www.viruscomix.com/page382.html
So either backwards time travel will never be invented, or going back in time creates a new timeline.
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Many real-world problems are contingency problems, because exact prediction is impossible. For this reason, many people keep their eyes open while driving.
Ah, but aren't wormholes only hypothetical so far? Not that I'm saying just because something is hypothetical means it can't be.
Amusing but insightful observation, Mimir. Though I suppose there could have been 100 Hitlers and 99 of them were assassinated and we would never know about it.
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Oooh ooh! I totally watched a Stephen Hawking special on this subject!
There are multiple viable ways--wormholes are definitely out of the question simply because of laws of thernodynamics and the fact that having a wormhole would effectively be violating the law of entropy. The other possibilities are to travel quickly around some massive object (say...just outside of the event horizon of a black hole) or to travel very quickly in space.
It may sound very out there to say that time flows differently at different places and velocities, but there's pretty solid evidence for it--for example, satellites that orbit earth, no matter how accurate their clocks are, always end up a few milliseconds ahead of earth time after orbiting a few months.
Also, I love Stephen Hawking.
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"A period"
~~This is what I like to add to the end of almost every sentence.~~
http://www.youtube.com/watch?v=wjtgN0jfA2E
Someone already figured out how to travel through time to the future.
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Holy **** we're in the Matrix? - Willis