# Paradox-Free Time Travel is Mathematically Possible

#### Drone

Try as you might to create a paradox, the events will always adjust themselves, to avoid any inconsistency. This research suggests that anyone eventually designing a way to meaningfully travel in time could do so and experiment without an underlying fear of ruining the world—at least not right away.

#### the54thvoid

##### Moderator
Staff member
From the article:

“In the coronavirus patient zero example, you might try and stop patient zero from becoming infected, but in doing so you would catch the virus and become patient zero, or someone else would. No matter what you did, the salient events would just recalibrate around you. Try as you might to create a paradox, the events will always adjust themselves, to avoid any inconsistency.”
i find this troublesome. It infers the 'fate' of time-based reality would adapt, which infers a conscious level correction. To reduce the COVID argument to something more linear; I go back in time to stop my father dying of an aneurism (which he did die of) - but the paper suggests he will die anyway. But this avoids the situation of what he actually died of, which did in fact change time. Also, what manner of death would be applied to inflict the suffering on my mother (who gave futile and desperate CPR - true story)?

I think applying mathematics to such things is naive when the changes in format for an event to occur must also be rectified. Now, I am not a mathematician and I cannot pretend to understand the complexity of the theories but to suggest outcome 'A' which happened via incident 'B', will be auto-regulated to occur by a new incident 'C', sounds like a reach to me. I'd love to hear the thoughts of the theory author on the multi-branch side effects of altering the causal stream to arrive at the same outcome. Changing the cause leads to a vast disparity of timeline anomalies. In fact, it would look like this:

(Particle decay from atom smashing).

I figure time travel is a luxury of the sub-atomic realm.

Rei

#### Vayra86

Supporter
I think that as long as we do not have absolute certainty that everything is bound and organized by mathematics and logic (the absence of chaos), we have no certainty on how a time travel paradox would actually work. Its just a wild guess, really. We haven't mapped and organized 'everything' to begin with. It would be arrogant to say anything about time travel really. Its also more philosophical of nature I think than anything else.

As with all things I feel like we try to make the inexplicable fit within our frame of reference, with these ideas.

#### Rei

Try as you might to create a paradox, the events will always adjust themselves, to avoid any inconsistency. This research suggests that anyone eventually designing a way to meaningfully travel in time could do so and experiment without an underlying fear of ruining the world—at least not right away.
I prefer the theory that we cannot change the future cuz we already changed the past. In other words, the future is already set in stone, even by changing the past. I think there was this one scene in Harry Potter film that does this. I forgot which episode though. All I know is that they were using a time pendant?

#### trickson

##### OH, I have such a headache
One thing we as humans have is free will. and having this surprises GOD. As he knows every thing and every possible out come of all things, Save one, Our free will. We surprise GOD every day with it.

#### xman2007

Try as you might to create a paradox, the events will always adjust themselves, to avoid any inconsistency. This research suggests that anyone eventually designing a way to meaningfully travel in time could do so and experiment without an underlying fear of ruining the world—at least not right away.
A paradox isn't a certainty that you would ruin the world, take Predestination for example, the main character was it's own mother and father and the events will happen again and again until the end of time in a loop with no ending, that's a paradox, going back in time and killing hitler when he was a child to stop WW2 from happening isn't a paradox in and of itself.

Rei

#### Rei

One thing we as humans have is free will. and having this surprises GOD. As he knows every thing and every possible out come of all things, Save one, Our free will. We surprise GOD every day with it.
Is it truly free will though or is it actually god's will making us think that we have free will? As you said: It is omniscience & knows every possible outcome of everything... including our free will. You sound like a believer but you are underestimating god itself. Well, this is out of topic...
A paradox isn't a certainty that you would ruin the world, take Predestination for example, the main character was it's own mother and father and the events will happen again and again until the end of time in a loop with no ending, that's a paradox, going back in time and killing hitler when he was a child to stop WW2 from happening isn't a paradox in and of itself.
By "Predestination" you mean that if I go back in time to impregnate my mother so I could be born so he(me) could go back in time as well & repeat the loop? That's a time paradox right?

#### xman2007

Is it truly free will though or is it actually god's will making us think that we have free will? As you said: It is omniscience & knows every possible outcome of everything... including our free will. You sound like a believer but you are underestimating god itself. Well, this is out of topic...

By "Predestination" you mean that if I go back in time to impregnate my mother so I could be born so he(me) could go back in time as well & repeat the loop? That's a time paradox right?
No not really, unless you are your mother also , if you havent seen it I dont have enough time to explain it to you though it's a fairly simple/very complicated idea lol which pretty much sums up time travel. BTW one of my most favourite sci-fi subjects, and I recommend watching predestination, primer, time crimes, donnie darko, 12 monkeys, about time, the time travellers wife etc for very well done (imo) time travel and paradoxical movies if you havent already.

#### Drone

I prefer the theory that we cannot change the future cuz we already changed the past. In other words, the future is already set in stone, even by changing the past.
I know what you mean. It's basically Novikov self-consistency principle but the other way around:

If an event exists that would cause a paradox or any "change" to the past whatsoever, then the probability of that event is zero. It would thus be impossible to create time paradoxes.
It's got to do with closed timelike loops and parallel timelines. Zeldovich, Hawking and Kip Thorne wrote lots of papers on that subject. I got all the maths but lots of physics and logic is just waaaaaaaay over my head.

Rei

#### Bones

Is it truly free will though or is it actually god's will making us think that we have free will? As you said: It is omniscience & knows every possible outcome of everything... including our free will. You sound like a believer but you are underestimating god itself. Well, this is out of topic...

By "Predestination" you mean that if I go back in time to impregnate my mother so I could be born so he(me) could go back in time as well & repeat the loop? That's a time paradox right?
That's Himself not itself for proper context.

We are indeed given the gift of freewill to choose but not for our own sake.
For example a tool is just that, has no desire to do anything and serves no purpose on it's own. It cannot choose what it's function will be when made, how to perform it's function or for how long.
It also cannot determine whether it's still useful..... Simply put, without freewill we are just automatons with no ability to feel, care or even love and God wants us to choose him out of choice of our own freewill - Not simply because it's "Our function" and nothing else.

With freewill we DO get to choose all that and more but it's also a double-edged sword.
If a bad choice is made we have to deal with the consequenses of such a choice as well, a simple tool does not.

That's my view of how basic freewill works and why.

Related to timetravel, I do hope all that math didn't have an error creep in somewhere and get carried along to the final computation.

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#### Vya Domus

I am fascinated all of these discussions still focus on debating the practicality of time travel for our own interests when that essentially means nothing. Trying to change past events ? What does that even mean, these "events" are identified as such by us not by any mathematical constructs. So what exactly do you even go back to ? The state in which all particles had a specif location, velocity, charge, etc ?

Say you make the time machine and you set it up such that you go back in time only if a photon hits a sensor, your goal being that, in the case the particle hits the sensor, you go back and change it's path so that doesn't happen.

The universe will somehow rearrange itself such that the particle always hits the sensor, right ? That makes no sense because the location of the particle was a quantum event anyway, your chance of making it back was a random event and so is the one where you are trying to prevent that. How can events rearrange themselves to converge towards a random event to maintain consistency ? Consistency of what, the event itself is a superposition of outcomes.

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#### Rei

No not really, unless you are your mother also , if you havent seen it I dont have enough time to explain it to you though it's a fairly simple/very complicated idea lol which pretty much sums up time travel. BTW one of my most favourite sci-fi subjects, and I recommend watching predestination, primer, time crimes, donnie darko, 12 monkeys, about time, the time travellers wife etc for very well done (imo) time travel and paradoxical movies if you havent already.
I think I understand... I guess...
I have seen Primer, Donnie Darko & 12 Monkeys. The latter 2 is good & 12 Monkeys was what I meant in my first comment. Primer is a complex movie & I was only 7 years old... You can imagine how that went for that kid...
That's Himself not itself for proper context.
Depends on who you're talking to. God shouldn't be identified with any gender or as a person, at least by my standards. But then again, you are talking to a guy who isn't religious.
I know what you mean. It's basically Novikov self-consistency principle but the other way around:

It's got to do with closed timelike loops and parallel timelines. Zeldovich, Hawking and Kip Thorne wrote lots of papers on that subject. I got all the maths but lots of physics and logic is just waaaaaaaay over my head.
Much appreciate the straight & proper definition. Thank you.

#### Bones

Depends on who you're talking to. God shouldn't be identified with any gender or as a person, at least by my standards. But then again, you are talking to a guy who isn't religious.
That's my belief as what you posted is yours and I have no problem respecting that - It's a matter of freewill and choice as said before.

Now..... With all the randomness how does any mathematical equasion even begin to account for and compute all the variables?
No way it can be done.
All that is dependent on accurate, complete information being available to be included within the equasion - Which we'll never have it all to provide anyway.
And just because math "says" it's possible still doesn't make it reality, only that it's possible.

Not arguing about being "Possible" as the article says but I'm keeping in mind it's just that and no more.

Rei

#### mtcn77

How can events rearrange themselves to converge towards a random event to maintain consistency ?
There are two layers, we are seeing the manifestations of those that are irrational. Our rational mindset only sees the destination, not the journey.
One possible use of this knowledge is that it would make great 'pun' jokes, like the "It always was" meme.
The other is point at the torment of being bullied by a rational world, like suffering due to events that come to pass no matter what. It gives no reprieve.
Perhaps, we are just at the surface of macrocosm while our resolution is looking at the microcosmic modifications like stopping the time, not changing it. Changing it causes vibrations that set chain reactions whereas tuning them should be our focus.

#### Drone

Much appreciate the straight & proper definition. Thank you.
No problem. What is time? Nobody knows anyway lol
What we do know is that light (photons) do not experience time. They don't care if it's fraction of a second or infinity. Time exists only when mass is around.

And just because math "says" it's possible still doesn't make it reality, only that it's possible.
That article states exactly that. But if spacetime is infinite (or if there're other dimensions) anything that's mathematically possible has a chance to become reality. What really matters is that back in the day sceptic scientists would say "oh come on, time travel is bullshit" but now they take it kinda seriously.

Rei

#### jayseearr

Doc Brown and Marty Mcfly already proved that all you need is a delorean

#### trickson

##### OH, I have such a headache
Time travel is completely impossible.
We can dream about it and even create a reality in witch one could in theory travel through time.
We are linear beings in the physical realm.
Unable to effectively change past events once you have made the "choice" in time to do whatever it is, You can NOT go back and change it.
I just do not see it happening. Not a chance.

Doc Brown and Marty Mcfly already proved that all you need is a delorean
The Flux capacitor Marty!

#### R-T-B

Supporter
One thing we as humans have is free will. and having this surprises GOD. As he knows every thing and every possible out come of all things, Save one, Our free will. We surprise GOD every day with it.
The Frog God is never surprised, just hungry.

#### Bones

The Frog God is never surprised, just hungry.
You need to hook him up with the Lord of Flies - Or on second thought...... Maybe not.