Outside of sentient observers, time is entropy.

Without the concept of time, Einstein could not describe his theory.

Time is entropy, nothing more. Entropy can go forward, entropy can go backward (I imagine) - but the universe only seems to tolerate it going forward.

Going backwards in time and then returning from whence you came without change is impossible, considering you tamper with the past. If you change the past, the present from which you left ceases to be. It's much like Back to the Future II and one of it's biggest plot holes. Biff could not have stolen the Almanac, taken it to 1955 and then returned the DeLorean to the time he came from -- he changed everything when he took the almanac to the past!

We can travel backwards, but maybe not manipulate the past. I mean, the sunlight we view right now is about 6 minutes old. Let's apply that to a larger scale -- Alpha Centauri would be able to view our past, just as we view the Sun's past (light). For instance, from Alpha Centauri (if they had a big enough telescope) they could witness the Battle of Hastings here on Earth (I did the Math a long time ago, can't remember but it came out around the year 1066 with all the light year conversions) and with the right technology we could narrarate it for them!

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"The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom."
Isaac Asimov

That brings in the theory of multiple time lines. The idea that every possible event is already existing along different paths and we go down those paths like forks in a road. That is a rather convenient way to deal with paradox. It would mean that no matter what you do in the past, when you get back, nothing changes because all you've done is created a new timeline.

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chicken butt

Yeah, but the problem I see is that with multiple timelines I don't think there is ever a way to get back to the "original" timeline. Even if you "fix" what you changed, it's still not the same thing.

Say you go back in time and run over a cat on accident. That sets off a chain of events, and so on. Now, if you go back in time and kill yourself before you run the cat over but somebody sees you do this, it sets off another chain (though you arguably "fixed" the problem).

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"The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom."
Isaac Asimov

Long ago I heard a very interesting theory that photons, while appearing to move in a straight line, actually have an infinitesimally small bend to their trajectory.
A photon fired at right angles to the trajectory of the Sun would indeed have a two-dimensional (bent) trajectory.
Just as you could capture the image of the Battle of Hastings at the distance of Alpha Centauri, if photon trajectories are bent, then at some time they will eventually return to their point of origin.
An observer present at that site would see a star that really isn't there.

Observation can be downright deceiving.

Perhaps that Sun we see is actually just a harmonic of a star that no longer exists - a phantom!

But still - where does the matter for that extra you come from?

I hereby officially coin the term "Ghost Stars". You saw it here first.

Say you go back in time and run over a cat on accident. That sets off a chain of events, and so on. Now, if you go back in time and kill yourself before you run the cat over but somebody sees you do this, it sets off another chain (though you arguably "fixed" the problem).


Naw, what I'm saying is let's say a cat jumps in front of your car. Two timelines exist already(and presumably always existed since the Big Bang). One in which you hit the cat and one in which you don't. You will go down one of those timelines and continue on, just as if you chose the right fork in a road. If you go back in time, you can choose the left fork, but you haven't changed anything but your own direction. The road never changed.

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chicken butt

Ah, so you view time as a road that has different turns and roads that are predestined and sitting to be chosen (whether by way of fate or multiple universes coexisting). That could very well be true. I see it sort of similarly but looking at my explanation, I guess I view it as a continual road (or roads) which is being paved for a person individually by each persons actions.

By your analogy, I believe (in terms of time travel to the past) different roads can be created, but after a change it's a set of lanes in which one tends to erase itself once you switch lanes. By that I mean it is irrelevant once you've changed lanes (or the a mistake in the past), because the one you're on is now your reality. Ay...time travel. My avatar captures how I feel after an hour long discussion of time travel.

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"The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom."
Isaac Asimov

Ah, so you view time as a road that has different turns and roads that are predestined and sitting to be chosen (whether by way of fate or multiple universes coexisting). That could very well be true. I see it sort of similarly but looking at my explanation, I guess I view it as a continual road (or roads) which is being paved for a person individually by each persons actions.


I don't view it that way, I just noticed that it solves the paradox problem nicely. Theoretically, if you travel back in time, no matter what you do, when you get back it'll be as if you never did anything, since all you did was change the "roads" you travelled. When you get back at your original point, you're back exactly where you started.

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chicken butt

I thought that the new Biff (with almanac) was changed. Didn't he have a ton of money. It has been a while since I've seen the movie, but I thought things did change. As far as the article I read goes, the guy was saying that when Biff went back and gave himself the almanac, he created another dimension. He would return to his unchanged present, but the Biff with the Almanac would exist in a different dimension where he was rich from winning all the bets. I'm pretty sure that if someone did figure out time travel, we wouldn't hear about it anyways. The government would keep it secret, in the interest of national security, and then run amuck with it.

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Neither am I the means to any end others may wish to accomplish. I am not a tool for their use. I am not a servant of their needs. I am not a bandage for their wounds. I am not a sacrifice on their altars. ... I owe nothing to my brothers, nor do I gather debts from them. I ask no one to live for me, nor do I live for others. I covet no mans soul, nor is my soul theirs to covet.

Ayn Rand, Anthem.

But according to the multiple universes theory, you can never change the past. You can only see what's down different causality paths.

What makes that cool is that it would transform history into a true science. You could experiment. Want to see what would happen if Hitler hadn't declared war on the US? Travel down that pathway and see. Alternative histories would no longer be speculative.

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chicken butt