How many years will it be until we are capable of time travel into the past?
Assume humans dont go extinct first.
@cobratbq To a certain extent isnt that all quantum mechanics? Just random interactions that average out to having a bias?
@freemo well, sure, but you're approaching it statistically now. Looking at the theories there's all the juggling with fields and particles, force-carriers, etc. There such a comprehensive framework.
Julian Barbour mentioned in a recent presentation that I watched with a casual "letting the information flow" kind of attitude, that his recent work may have removed the need for wave function collapse. Now I have only very superficial idea but I know his ideas make a lot of things simpler.
@freemo it's like having a alternative view to not get stuck in the hype too much.
@cobratbq The interpretation leaves a lot to be desired. but the math predicts reality and that makes it correct as much as any other model is correct. So long as it makes consistently valid predictions then the model is right, even if our understanding or interpretation is not.
@freemo sure, of course. If the math works for it, then you can use it. I'm just saying that there are some alternatives that sound interesting that may just work because it turns out to be a simplification of a subset of the math formulas involved. It's not unthinkable, and I'm just left with the idea that the current mainstream models seem complicated. Also, different math could end up approximating just slightly better/worse. (I'm a CS guy, so no physics background, just casual interest.)
@freemo again, I'm not arguing the current models are wrong.
@cobratbq sure a simpler model that is as complete is certainly possible. Someone may create a whole new form of math that makes this stuff trivial to calculate.
the wave function collapsing is an oversimplification inhow we describe it, but i dont think the underlying facts any less true.
What we call wave function collapse is just entanglement from the perspective of the thing being entangled.. We are just idiots and most people dont recognize "observation" is just a fancy term for "I entangle myself with the system". The wave function never really collapses in any absolute sense (as in someone not entangling themselves with the system).
@freemo sure, I see your point. But has the question of "what constitutes an observation" been solved? Same with the double slit experiment, .. I read something about this pilot wave idea which sounded nice, but I keep hearing how there are theories but nothing really is solved.
I get your reference of entanglement. I probably don't have a good understand of it on every level, so I'm guessing I'm missing significant parts of your comment. But I get where you're going with this.
@freemo okay, maybe to clarify with another perspective: I read this thing about the Schrödinger's cat experiment but now there were more (nested) levels with the office and a next-door office with see-through mirror. Also a thought experiment. So there is this recursive notion of observation. That's why I mentioned that it's all not quite clear / clarified, as I understand it.
@freemo oh, to summarize, even if just for myself. So if gravity would be just a 'bias' of the mass, i.e. the gravitational effects, and time doesn't really exist, but because of the bias, interactions are no longer reversible, then you've got your arrow of time because the bias is enough to ruin an otherwise perfectly (symmetrical?) reversible situation.
@freemo You can't come out the other end of a machine that doesn't exist yet.
@LouisIngenthron That makes the assumption that a machine must exist on the receiving end at all.
Two counter possibilities... 1) your timemachine moves through time with you, like a car it doesnt need to exist at your destination 2) it "throws" you into the past, you just land there, with no machine anywhere to be seen. A bit like getting shot out of cannon.
@freemo The delorean method, maybe, but the terminator method seems exceedingly unlikely.
Even so, the only way it could possibly exist is with each travel backward forming a new timeline.
If there was only one timeline, then time travelers in our past or present would definitely leave some pretty obvious clues (hyper-resistant future illnesses, for one), even before you consider the timeless human need to be a shithead.
@freemo Also, I have a separate concern with both methods: What happens to the matter that used to be where you appear? When it's just air, nobody thinks about it, but landscapes change over time, so it won't always be just air.
I feel like we would have seen some time travelers fossilized halfway into a mountain by now.
@LouisIngenthron A portal would , it is a 1d surface that weakly interacts, by crossing through the portal you displace the air on the other side as you normally move.
@freemo Do you mean 2D? Struggling to picture how you'd cross a 1D barrier.
@LouisIngenthron sorry yes 2D
If ever possible It would be a newer time that looked like the past Well, a possible past
@freemo what definition of "time travel" would not be self-contradicting?
@freemo please don't answer. But I recommend the tv series "12 Monkeys".
I have thought about that alot and can see a way that every framework imagined for framework can be non-contradictory with some additional characteristics.
Since you said don't answer I wont go into detail unless youa sk though. But i find it a fun thought experiment.
@freemo it's always fun to think about it. I deeply enjoyed the 4 seasons of 12 Monkeys. Many other people did. I don't want you to miss out!
@mjambon I watched it... I liked it more than most shit on tv... wasnt like something im raving about, but i enjoyed it. The original movie is a classic too.
@freemo Julian Barbour researches this idea where time is just changes in configuration space.
I have been (casually) wondering for quite a while: what if gravity is a consequence of some sort of bias in interactions, i.e. out of number of viable interactions the bias determines the actual interaction that takes place. As-in, gravity is such a subtle force that I wonder if it is a subtle side-effect of something else. (It would reduce the whole time-space-mass thing by a lot.)