Researcher Discusses Whether Time Travel Could Prevent a Pandemic (popularmechanics.com) 145
University of Queensland student Germain Tobar who worked with UQ physics professor Fabio Costa on a new peer-reviewed paper "says he has mathematically proven the physical feasibility of a specific kind of time travel" without paradoxes, reports Popular Mechanics:
Time travel discussion focuses on closed time-like curves, something Albert Einstein first posited. And Tobar and Costa say that as long as just two pieces of an entire scenario within a closed time-like curve are still in "causal order" when you leave, the rest is subject to local free will... In a university statement, Costa illustrates the science with an analogy
"Say you travelled in time, in an attempt to stop COVID-19's patient zero from being exposed to the virus. However if you stopped that individual from becoming infected, that would eliminate the motivation for you to go back and stop the pandemic in the first place. This is a paradox, an inconsistency that often leads people to think that time travel cannot occur in our universe. [L]ogically it's hard to accept because that would affect our freedom to make any arbitrary action. It would mean you can time travel, but you cannot do anything that would cause a paradox to occur...."
But the real truth, in terms of the mathematical outcomes, is more like another classic parable: the monkey's paw. Be careful what you wish for, and be careful what you time travel for. Tobar explains in the statement:
"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."
"Say you travelled in time, in an attempt to stop COVID-19's patient zero from being exposed to the virus. However if you stopped that individual from becoming infected, that would eliminate the motivation for you to go back and stop the pandemic in the first place. This is a paradox, an inconsistency that often leads people to think that time travel cannot occur in our universe. [L]ogically it's hard to accept because that would affect our freedom to make any arbitrary action. It would mean you can time travel, but you cannot do anything that would cause a paradox to occur...."
But the real truth, in terms of the mathematical outcomes, is more like another classic parable: the monkey's paw. Be careful what you wish for, and be careful what you time travel for. Tobar explains in the statement:
"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."
12 Monkeys (Score:5, Insightful)
Re: 12 Monkeys (Score:2)
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Terry Gilliam always makes brilliant films. They have a claustrophobic style and sometimes require repeated viewings but not in a bad way.
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Or the four season series from 2015-2019. It was great.
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The series almost completely abandoned the paradox-free principle, and therefore was unwatchable (at least to me).
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you mean the soap opera with time travel? it sucked.
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You are walking through a red forest, and it doesn't suck.
Primer is a better example of paradox free. (Score:3)
Primer's timeline is confusing to everyone. But the actual method of time travel used in the story is based on the one and only example we have in physics of paradox free time travel. Thus primer is the only movie about time travel in which the time travel itself introduces no paradoxes and doesn't require a multi-world escape hatch.
In physics a photon can decompose into a particle and antiparticle. And then some time later the particle and anti-particle can recombine creating a new photon. It turns out
Hmm (Score:3)
Obviously not.
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Re:Hmm (Score:5, Insightful)
Because the pandemic already happened and no time traveler stopped it.
Re: Hmm (Score:2)
No, but many soothsayers from the WHO told the Chinese government that if they didn't shut down the wildlife trade, this would happen.
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For a _much better_ model of tme travel and its consequences, I'll recommend the Terry Pratchett stories involving the time monks, including Small Gods, Thief of Time, and Night Watch. The stories have become more meaningful as I've become more expert in my fields. The time monks are the hidden forces of the really _skilled_ engineers who make systems work behind the scenes, who sometimes fix disasters with very small changes made with insights long before disasters occur.
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Why not? A guy in January 2020 takes a sample of the Covid and goes back to 2018 so that they have time to develop a vaccine. That being said, if that kind of time travel was possible, a Covid pandemic wouldn't be the top priority.
Let me see: Prevent COVID or prevent Trump? COVID or Trump...?
Hmmm.
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Prevent Trump for a number of reasons. First, preventing COVID, even if you could skip though time easily and had massive resources on your hands, might be impossible - a ton of bats are probably carrying it and you'd just be kicking the can down the road to the next unfortunate bat/human encounter. On the other hand, if you could prevent Trump from being elected once, which would be relatively very easy, it's likely nothing like it would happen again in the foreseeable future - Trumpism is the violent deat
Physics not Maths (Score:2)
Why not?
Because maths can describe things that are not real so saying that it is "mathematically proven" does not mean it is going to happen. I can mathematically prove the amount of time taken for a stone to fall under gravity through the centre of the earth and emerge on the other side but if I drop a stone it is just going to hit the ground and lay there because my maths did not include the electromagnetic interactions between the stone and the rest of the planet.
Re: Hmm (Score:4, Insightful)
The entire point of this scientist's proof is that in a single non-branching timeline, paradox-free time travel is self-consistent. If you want to discuss other models of time travel, feel free, but be aware that you are doing so, and that this scientist isn't interested in your discussion.
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The entire point of this scientist's proof is that in a single non-branching timeline, paradox-free time travel is self-consistent.
It's probably impossible. One might be able to somehow look back, but probably not to GO back, because causality is a thing. The idea that to go back you must have always gone back is self-limiting. And isn't this concept the whole reason for imagining a branching universe where everything happens? Which, BTW, I also think is cockery. It's a convenient belief if you want to make a whole bunch of probably impossible things possible.
On the other hand, if this is just a simulation, "anything" is possible. Then
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You DEFINITELY didn't read the article.
It totally discusses all that.
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Why would I? I want to know what's new. If I read all the articles linked from Slashdot stories I'd be pissed off, I'd want most of that time back.
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Trump is just a symptom of the larger problems that have been building up over decades. A blue wave and super majority isn't going to save us anymore then a red wave would.
Douglas Adams hsd it all figured out (Score:2)
"The past," they say, "is now truly like a foreign country. They do things exactly the same there."
Who's to say (Score:3, Interesting)
Who's to say COVID isn't the result of someone from the future coming back here to unleash it on purpose for some greater good that they perceive?
It's all foolishness.
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Who's to say COVID isn't the result of someone from the future coming back here to unleash it on purpose
Occam's Razor says that the simplest explanation is correct.
This is certainly a simple explanation, so, therefore, it must be true.
Re: Who's to say (Score:2)
"Who's to say COVID isn't the result of someone from the future coming back here to unleash it on purpose for some greater good that they perceive"
Watch what you say because we have an endless of mental cases in the world who will take what you said here to heart and feel the need to blather this 'conspiracy' throughout the world. This behavior is largely fueled by the rampant hard drug use that is all too common these days.
Remember, you can't trust people to be mentally balanced. :|
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Yeah this is why we don't allow people to use the time machine to kill Hitler. We learned our lesson when we tried to prevent the deaths of 500,000, then 1,250,000, and 3,000,000 Jews in the futures we created and you know how that we- shit I shouldn't have said that.
Re:Who's to say (Score:4, Insightful)
Yeah this is why we don't allow people to use the time machine to kill Hitler.
I thought that everyone knew that time traveling to kill Hitler results in Stalin trying to conquer the world.
Re: Who's to say (Score:2)
I read a claim that Churchill ordered no assassination attempts on Hitler to be carried out, because âoeHitler did as much for the British war efforts as Britainâ(TM)s top six generals.â
Enjoy outer space (Score:2)
Problem with time travel is that the planet moves at a considerable speed, so you need to catch up or sit in empty space where earth is going to be in x years..
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Why?
Seriously.... when you are simply standing in one spot on the planet and not trying to move, does the planet suddenly move away from under you?
So, why would it do so if you were in a time machine that didn't move itself through space either?
Yes, its obvious that travelling through time means travelling through space, but either way the earth is just going to carry you along with it, so as far as the immediate environment is concerned, you don't actually seem to move at all.
Re: Enjoy outer space (Score:5, Interesting)
Re: Enjoy outer space (Score:4, Insightful)
Well if one can manipulate time then it would stand to reason you could also manipulate space.
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Well if one can manipulate time then it would stand to reason you could also manipulate space.
That's a completely random assertion. It's equivalent to "if one can manipulate space then it would stand to reason you could also manipulate time." Our ability to move about in the first three dimensions hasn't helped us move in the fourth at all.
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Welcome to Special Relativity.
Re: Enjoy outer space (Score:4, Funny)
If you travel back in time by six months and don't change position or velocity the earth will be about 300000 miles away on the othe side of the sun
You sure know a lot about something that doesn't exist.
I came back through time to tell you that time travel works by opening a wormhole through time that's attracted by the matter around it, so when you walk through that wormhole through time, you still end up in the same place on Earth that you started. Your worst problem would be a tree or building being there instead, but that will just block the exit so just means that you can't get through.
Re: Enjoy outer space (Score:2)
"Your worst problem would be a tree or building being there instead, but that will just block the exit so just means that you can't get through"
Or you end up trapped in a void in the
material created by the 'exit gate' and become entombed in the wall, suffocating to death. Or perhaps your atoms will become fused with the wall's.
If we ever develop "Timegate technology", I hope the system has sensors that can see what's on the other side before anybody steps through.
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This happened in real life.
Almost all of the Navy sailors (all but 2) became enmeshed / "fused" with the ship's metal floors / walls /etc.
Research The Philadelphia Experiment.
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Re: Enjoy outer space (Score:4, Funny)
When you travel through Time, you must also adjust your Relative Dimensions In Space.
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Similarly, when you travel intercontinentally you need to adjust your relatively position and velocity wrt. the starting location, otherwise you'd be sideways or even upside down when you get off the plane. Luckily planes compensate for this motion by slowly adjusting the orientation of the vehicle during the flight. Perhaps, once we are advanced enough to build time machines, we'll be able to build time machines to work the same way?
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You seem quite certain that you won't be affected by gravitational forces during a time jump.
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If you travel back in time by six months and don't change position or velocity the earth will be about 300000 miles away on the othe side of the sun
That's only if the solar system stayed still and our galaxy didn't move. I really hate this kind of stupid science fiction--even if it's dressed up as a paper by a student who's locked in during the pandemic--because it never accounts for why a society which could teleport to position x,y,z, at time (whatever) wouldn't have already been dramatically changed by the ability to teleport to position x,y,x. Really, what would that look like? What happened if that ability arose NOW? Would it make a difference dep
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It is much worse than that, the whole solar system will be far far away.
However, if we go with the rather speculative theories for time travel that could perhaps work... Those involve travelling to a region with very strange geometry, perhaps next to a black hole, and then back again. It will also be a continuous process, not a teleport-like jump. Any problems relating to the position of the Earth are insignificant compared to those of getting to the black hole and back.
Teleport-like time travel would seem
Re: Enjoy outer space (Score:2)
The time machine is travelling at 88mph amortized over a 30 year period.
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If you travel back in time by six months and don't change position or velocity the earth will be about 300000 miles away on the othe side of the sun
Even if you ignore the motion of our solar system in our galaxy, and our galaxy in the universe, your math is off by about 620x.
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does the planet suddenly move away from under you?
Yes, with about 30km/s or 20miles per second.
On top of that the whole solar system moves with a few thousand km per second thought the universe.
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Re: Enjoy outer space (Score:3)
Oddly enough, the other day I was thinking
about Doc Brown's remark in BTTF3 of "It could've been worse, I could have ended up in the Dark Ages where I would've been burned at the stake for being a heretic".
Scince his time machine clearly ends up in the exact place regardless of where Earth is at in space, he would've still been in what would become the Southwestern United States. There were no Europeans inhabiting that part of the country at the time, and there may not have been any Native Americans in that
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Actually, according to general relativity, the ground is accelerating towards you at 9.8 m/s^2, as if the planet was inflating rapidly. The reason the planet isn't really inflating is because space itself is contracting at the same rate.
So if you were only moving through time and not through space, you would find yourself somewhere in space, falling towards the earth. With no external forces, you would crash on earth at the exact time and location you started your time machine.
I don't know where you would h
Logical Inconsistent (Score:2)
Problem with time travel is that the planet moves at a considerable speed
That's solvable - we already know how to move in space. The problem with the argument they make is that, like almost all time travel, it is logically inconsistent. If the universe will always ensure that events remain the same the only way to do that is to prevent time travel in the first place. Thus time travel is impossible and their argument for it also becomes the argument against it.
Possibly (or not) (Score:4, Insightful)
"Say you travelled in time, in an attempt to stop COVID-19's patient zero from being exposed to the virus. However if you stopped that individual from becoming infected, that would eliminate the motivation for you to go back and stop the pandemic in the first place. This is a paradox, an inconsistency that often leads people to think that time travel cannot occur in our universe. [L]ogically it's hard to accept because that would affect our freedom to make any arbitrary action. It would mean you can time travel, but you cannot do anything that would cause a paradox to occur...."
If the many worlds interpretation of quantum mechanics is correct, the act of travelling back in time (and indeed all actions) would branch off a new temporal reality without affecting the one you left. This would also mean that time travel paradoxes cannot occur. I would like to think that the universe is so nice and orderly but there is no way that we can know.
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I was thinking about the same thing, as a matter of fact I had been considering this for a long time. A Multiverse with infinite parallel dimensions, from close twins where a single subatomic particle might be the difference, to wildly different universes (say, antimatter ones versus matter ones). Traveling back in time creates another universe where the only difference is you, and you can't go back to the original one. With an infinite number of Universes, there's a very high chance we never were, or never
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The "many worlds" interpretation is not proven and, for now, cannot be proven.
In any case, world-hopping simply magnifies the paradox.
Leaving one has its consequences and so does entering another.
The laws of conservation are screaming at you but the language is not native to you.
It's in physics books.
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If you haven't mastered reading comprehension, I somehow doubt you have mastered quantum physics.
Even then it seems unlikely (Score:3)
If the many worlds interpretation of quantum mechanics is correct, the act of travelling back in time (and indeed all actions) would branch off a new temporal reality without affecting the one you left.
True but even with this model I would argue that time travel is unlikely. If there are many alternative worlds and time travel is possible then what are the odds that we just happen to be in a reality where nobody has even travelled into the past and done something noticeable?
If time travel ever becomes possible then surely there would be millions of people travelling back to stop a loved one being hit by a bus or telling their earlier selves what stocks to buy etc. This would create huge numbers of rea
Yeah sure. (Score:2)
Call me when the tickets are for sale.
If Time Travel Were Real (Score:3)
Then someone would have come back to tell us from the future. We can't be so arrogant to think we are the end players now can we?
All I want to know is can I have some research money for some bullshit like this?
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Then someone would have come back to tell us from the future.
Did you read the summary? It is all explained. There is a magic time travel fairy that prevents any paradoxes or inconsistencies.
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I had my way with her once. She is a liar.
Re:If Time Travel Were Real (Score:4, Interesting)
It's like Quantum Leap where you can only travel within your own lifetime. Or something.
I remember reading another theory about this that stated that information could be sent back in time but a receiver was required, so until we build the receiver we can't get any messages from the future.
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Sad, not arrogant (Score:2)
We can't be so arrogant to think we are the end players now can we?
Arrogant? I'd call that sad since if we are the end players it means something has to stop us developing further.
Comment removed (Score:4, Interesting)
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Or maybe when you travel back in time, any alterations done in the past instantly forks the universe.
The git pull on that would be HUGE, but an "unlimited" network plan might help ...
I wonder what kind of "cloud" storage hosts the Universe.
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Or maybe...
all possible moments and all possible variations are happening all at once. There are infinite universes.
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Said no one in the field.
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That's the parallel universes theory in a nutshell.
You get pushed into "a parallel universe where you appeared from nowhere" instead of your own past.
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It's not a theory, it's a hypothesis. Theories are testable.
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Indeed indeed.
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The laws of conservation do not allow for missing persons.
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Yep.
Hitler paradox, grandfather paradox, bootstrap paradox.
If we went back and killed Hitler, he would be unknown for his dastardly deeds before we felt compelled to do so.
If we go back and kill our grandfather, we would not be born to do so.
We could go back in time and clue Einstein in before he even thought of the problem, but then it wouldn't be his work, so where did it come from?
A dodge is to invoke a parallel universe where a person could do all those things and really fuck stuff up in there , but th
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The real problem (Score:2)
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This is less ridiculous than psychology research (Score:2)
And millions of animals wouldn't be tortured to death in the name of pseudoscience.
Make for a great TV show (Score:3)
They could call it Doctor When or something snappy along those lines, and then explain this same line of research in, like, four hundred plus episodes over the next sixty years.
Because, you know, without a show like that we'd have to come up with shiny new research on the topic.
Sorry, no! (Score:2)
It would let you jump in one of the different universes where the pandemic doesn't happen, while all others one would keep on suffering it.
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That would only work if something from the other universe came our way.
Conservation is a thing.
Misleading headline (Score:3)
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The answer is: no (Score:2)
If time travel was possible this pandemic was either caused by it, or it could not be prevented. Simply because we have this pandemic now. The future might have been able to stop it, but in that case the pandemic was clearly needed for something.
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Many bad things that can be prevented, aren't. Mostly because of the effort required.
There is no reason to assume that a future with time travel can be bothered to make lives better for people who are by then long dead. Good luck getting funding for such a project.
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Unintended consequences.
Perhaps the pandemic killed a future Hitler.
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This is bullshit (Score:2)
Whenever a scientific paper includes the words "free will" then you know it's bullshit because free will doesn't exists.
IIUC, this isn't new. (Score:2)
Robert Forward explained just that principle in SF novel "TimeMaster", and in an appendix claimed that it was standard physics.
It could work for COVID-19, but... (Score:2)
Are charmed quarks tasty? (Score:2)
Covid 19 is perfect. (Score:3)
Covid 19 is the perfect warning shot humanity needed. Not only is it a dressed rehearsal for Ebola 22 or something similar, it's also very good for showing us that we can show down economic throughput without the sky falling. We're decommissioning 747s. That's a good thing for the environment too.
know if I would prevent Covid 19 of I could.
Re: Covid 19 is perfect. (Score:2)
Behold the Man (Score:2)
"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."
In Michael Moorcock's "Behold the Man", Karl Glogauer travels through time in order to find the historical Jesus of Nazareth. When he realizes that the actual Jesus can't be the Biblical Jesus, he becomes the Biblical Jesus and fulfills the Biblical accounts.
Why would the universe bother (Score:2)
Alternate theory (Score:2)
Where I went to school, I had a professor who did work on this kind of thing, and I think his theory makes more sense.
In his theory, you can't travel back in time. You could send information back in time (so in this example you could send a cure for Covid or a warning about it) but this wouldn't do anything to your timeline - the second you do that, you create a new and entirely separate timeline. So while it would be possible to create a timeline where Covid never happens, it wouldn't do anything to this o
there is no past (Score:2)
Time Travel is Possible (Score:2)
Now I just need to figure out how to go backwards.
Explain the paradox (Score:2)
I drop a tennis ball in the backyard.
Winter comes and goes, and the ground swallows the tennis ball in the usual way.
It's springtime, and my puppy wants his ball.
He sniffs around, and digs up his ball.
I see a hole in the ground, so I fill it up.
But now there's no ball in the ground, and hence there's no motivation for the puppy to dig up the ball. There's no evidence left that the ball was ever in the ground. Nor is there any evidence that it ever happened or that we ever did any terraforming.
We don't cal