#time paradoxes

[hurtcomforted]

i love when time travel media is like "you're trying to change the past but you need to understand that everything you do has already happened. you have already been here. you have already tried and you have failed and you will fail again."

[sailorsol]

Do you think Marty McFly ever tries to share an inside joke with his siblings, only to realize that they don't get it? That it was a relic of a childhood his siblings no longer remember? Do you think he regrets it when he realizes that his entire family is basically now strangers to him, with no shared life experiences?

Or do you think his memories of that first past start to fade in time, written over by a childhood he never actually experienced?

How much did Marty seemingly change overnight, to his friends and family? Did they wonder why he changed, how he changed? Talking about things that never happened and places that don't exist? It's always been Lone Pine Mall, Marty, why would you think it was Twin Pines? Clayton Ravine? You don't mean Eastwood Ravine, do you? That's the only ravine in town.

Or do they chalk it up to teenage imagination? He sure takes after his father, that famous sci-fi writer George McFly.

How do you live in a world where you're never quite sure anymore which memory is real? Where everyone you knew is a stranger and you're a stranger to them?

[frank-olivier]

Physics, Philosophy, and the Fabric of Time: An Examination of Asymmetry

The human perception of time is fundamentally asymmetric, marked by a clear distinction between past and future, and an irreversible flow of events. This inherent asymmetry starkly contrasts with the time-reversal symmetry of fundamental physical laws, from Newton’s mechanics to quantum mechanics and relativity. Delving into this paradox reveals a complex interplay between philosophical inquiry and physical explanation, highlighting the challenges of reconciling our macroscopic experiences with the symmetric laws governing the microscopic realm.

At the heart of this dilemma lies the paradoxical coexistence of time-reversal symmetric physical laws with our asymmetric experience of time. While microscopic laws are indifferent to time’s direction, macroscopic phenomena—such as the second law of thermodynamics’ entropy increase and our disparate access to past and future—unequivocally demonstrate time asymmetry. Ludwig Boltzmann’s statistical mechanics offers a partial explanation through entropy, but this is complicated by the time-reversal symmetry of microscopic laws, suggesting equal probability for a process and its reverse.

The “Past Hypothesis,” proposing a universe initiated in a low entropy state, may provide a framework for understanding observed time asymmetries. Combined with statistical mechanics, this hypothesis explains why physical processes appear asymmetric and why our knowledge of the past exceeds that of the future. It also touches upon our belief in influencing the future, not the past, with profound implications for causality, free will, and the nature of time.

Pursuing a physically grounded explanation, rather than definitional or grammatical interpretations, is crucial. The limitations of current laws in accounting for the arrow of time highlight a knowledge gap, necessitating innovative insights at the intersection of thermodynamics, quantum mechanics, and statistical mechanics.

Further understanding may emerge from exploring quantum mechanics’ probabilistic nature and its influence on our understanding of time, as well as examining the universe’s initial conditions and evolution in setting the arrow of time. An interdisciplinary approach, integrating philosophical and physical theories, promises to address causal and knowledge asymmetries, potentially reconciling symmetric physical laws with our asymmetric experience of time.

Resolving this conundrum promises not only to illuminate the nature of time but also to contextualize human existence within the universe’s unfolding narrative, highlighting the profound interconnectedness of human perception, physical laws, and the cosmos. As we navigate the complexities of time asymmetry, novel perspectives may transform our understanding of the universe and our place within it.

Prof. David Albert: A Masterclass on Time‘s Arrow (Robinson Erhardt, December 2024)

Tuesday, December 17, 2024

[markerofthemidnight]

Time Travel Paradoxes Are Objectively Cool (aka An Essay Where A Lame Bitch Gives You Ideas For Resolving Time Travel Paradoxes In Your Writing)

Hey guys, it’s me, ranting again. This time I wanted to try talking about time travel. Or, more specifically, time travel paradoxes.

I’ll go in-depth about what the paradox is, how it’s caused, where things get complicated, and potential “solutions” to it, all for the sake of your reading entertainment… or mainly just to give you a really hyperspecific form of writing advice.

I’ll talk about both ones I came up with myself and old-timey ones we’re all familiar with. Speaking of which:

The Grandfather Paradox

This one’s simple. Like, probably the simplest one on the list.

If you go back in time to kill your grandfather before he has any children (for whatever reason), you cease to exist as well, which means your grandfather exists since you are no longer around to kill him, which means that you exist since he’s around to eventually bring rise to you, which means that he doesn’t since you killed him, and so on and so forth.

This is, like I said, a simple problem with multiple simple solutions. For example:

Killing your grandfather is downright impossible up until he conceives one of your parents: wether because of horrible, reverse-Final Destination-style luck getting in the way or whatnot (the thread of time has to have self-preservation instincts, after all)

The most common solution: when you kill your grandfather, you create an alternate reality where you were never born, but since you’re from Reality A and not Reality B, both you and your grandfather are fine

My favourite solution: you succeed in killing your grandfather, but then your grandmother goes on to get with another man, who is now your new grandfather

The Bootstrap Paradox

Just barely lagging behind The Grandfather Paradox as the simplest one on this list.

The Bootstrap Paradox is what happens when an event causes itself. Let’s say you go back in time and give your grandmother (dear god why do these always have to do with grandparents) an item that she will later give to you in the present.

This is obviously a problem because it raises questions on how the item originally got there. (This isn’t limited to just items, of course, but let’s use that as an example-) Not only that, but also that, if the cycle started, how will it ever be broken? Can it be broken?

The reason why this is ranked as not being as simple as the Grandfather Paradox, if you ask me, is the lack of immediately obvious solutions. Granted, it’s not really something that needs to be solved: it’s just confusing.

Regardless, the item had to get there somehow. Someone, whether third party or not, gave it to one of you at some point. But if your grandmother truly was the original recipient, and you gave her an item that someone else was supposed to give to you, is there now a copy of it somewhere around there? Does she have both, and the reason why she gave it to you is because she already has a spare?

Oh, and speaking of copies:

The Time Travel Clone Paradox

You all knew this was coming, didn’t you?

This one doesn’t really need an explanation. If you travel back in time and meet your past self, what happens?

Well… probably the simplest solution I can come up with is just “nothing”.

There’s no grand cosmic plan in this universe. No one person has to always be in the same place at the same time: if that was the case, then why is time travel even possible?

There’s no reason for them to not be able to both exist at the same time. So why can’t they? Well… that’s a deceptively simple solution, so let’s just say that the, like… Gods of Time or whatever can’t allow that. Here’s a few other, more complex solutions:

The Futurama solution, where the time traveler is doomed to die if they don’t get out of there quick enough

Time travelers, for whatever reason, can only travel to points in time where they aren’t alive, preventing this problem altogether

When people make eye contact with their past selves, they’re instantly sent back to the present: there’s a timeline out there missing a person, after all

And when you think about it… this trope doesn’t only apply to people, does it? What if instead of seeing your future self… you saw your fate?

The Prophecy Problem

Now, THIS is what I made this entire essay for.

I know what you’re thinking. Prophecies of your own future can’t count as time travel paradoxes: most of the time they don’t even involve time travel!

And to that I say… do they? It’s a character making decisions based off of information that, at that point in their lives, they shouldn’t have. That’s time travel in a sense, don’t you think?

And sure, this is pretty boring when applied to the old “self-fulfilling prophecy” trope. But when it isn’t… well, here’s a situation I thought up.

A man is approached by an… entity of chaos, let’s say, who tells him that he will die later today. It tells him one small decision he makes later today that will inevitably result in his death… and nothing else. Not when he dies, not how he dies, it just tells him one thing he can do to potentially prevent it and then leaves.

Assuming that he, for some reason, knows that this isn’t a trick and believes it instantly, what does he do? The entity only told him one thing that could prevent it potentially, but he still doesn’t know how or when it happens, just that it does.

A man often meets his destiny on the road he takes to avoid it. Even if he tries to avoid his fate, he might still meet it nonetheless. But if the entity knew that- which it likely did- why did it even bother telling him about his future?

Here’s how I would take this: It’s not like Futurama and its doomed temporal clones where any attempts for you to make a new timeline instantly go to waste. The new timeline has the potential to be both better and worse than the original: but regardless, it’s never going to be easy for you.

After all, you are making decisions based off of information you shouldn’t have. That alone leaves a major hole in the space-time continuum.

That’s All, Folks

Honestly, I didn’t put much thought into this essay before making it. There’s not a lot more I have to say… except for two last things:

No, I’m not including the Free Will Paradox. Its entire point is that everything you do was always destined to happen and that nothing you do matters: it doesn’t have a solution, it’s just incredibly confusing.

I considered including time loops as well, but really it depends on how it’s taken. If it’s a Majora’s Mask loop, it’s inevitable that it’ll be solved if you try hard enough. If it’s a Groundhog Day loop, it’s up to you to figure out the not immediately obvious solution, assuming it even has one.

[egophiliac]

can't believe that skeleman has turned on us, and Halloween Prom is tomorrow.

(what a top-tier UM...we are about to be just totally obliterated in the absolute silliest way. what possible use could this power have outside of bringing us to the brink of utter holiday disaster.)

[calista-222]

BLAZE 🔥🔥🔥!!!

[nenoname]

always thinking about mabel causing high fives to be invented 100 years early which meant the stan twins got to use high sixes as kids....

[spines-tvo]

(one of) you asked for it, so here it is!

So, exactly one vote came from my poll on whether or not I should talk about this time paradox, and that vote was yes! I did not vote on it, so here's what you asked for. (This will probably be long.)

This is something that I call the "apple tree paradox." It probably has an official name, but I thought of it once in the shower, so here it goes.

So imagine there's an apple tree that you love. You've spent your life under it, relaxing. Then one day, it drops an apple on your head. You feel so betrayed that you decide to build a time machine to chop it down. Once you have, the version of you from that timeline never feels the need to build a time machine to chop the tree down, so you never do, causing the original timeline to resurface where you decide to go back and chop the tree down, etc. etc. Basically, it's an infinite loop of "chops" and "doesn't chop."

So... What happens? You've essentially created two parallel timelines that both exist at once. I've come up with three possibilities.

The universe blows up. Basically, two timelines would be in the same place, so atoms would collide everywhere. The change isn't big enough to move everything away, so everything would blow up. It's a really simple outcome.

One timeline would emerge victorious. Basically, in order to prevent an all-encompassing disaster, the universe would choose one timeline and stick with it.

Schroedinger's tree. Essentially, the two timelines would combine into one to create one timeline where the tree is both there and not there at the same time.

Now, these all ignore the possibility of the two timelines coexisting, but I find these more interesting.

[zhukzucraft]

@dei-lab-assistant ordered a Kakashi so here he is!

and here he is again minus the weird shading experiment!

[iknowicanbutwhy]

"and the universe said the darkness you fight is within you and the universe said the light you seek is within you and the universe said you are not alone and the universe said you are not separate from every other thing and the universe said you are the universe tasting itself, talking to itself, reading its own code and the universe said I love you because you are love." - End poem, Julian Gough

ho lds. g ently ,,,

[poorly-drawn-mdzs]

Luo Binghe? Sorry, I only know Binghorse now.

[tardis-technician]

Man I don’t know if any official Doctor Who artists know Doctor Who like Alice X. Zhang knows Doctor Who. Like lots of people are technically skilled but hot damn Alice X. Zhang always understands the assignment.

God the fucking emotion in all of these pieces.

[cringefail-clown]

i think dirk would give up on his evil masterplan like one week into the journey if those three ganged up on him. hed turn the ship back in tears and, once returned, begged dave on his knees to never make him sit in a room alone with those fuckers. thats the seer power for you

[homoqueerjewhobbit]

I just can't get with Christianity because the age gap and power imbalance between God and Mary is so problematic.

[eightdoctor]

just because YOU don’t know why the eighth doctkr is half human doesn’t mean it’s dumb or bad. there’s literally a reason explicitly given in canon and yet every body is always like “ohh it was a dumb joke” “everybody ignored it anyway” “it wasn’t brought up again”. just say you’re uninformed it’s okay. i promkse you. go read interference books one and two and then you can join the discussion. maybe the blue angel too

[isbergillustration]

Haunted by Judgement (holiday themed)