Time Travel: some thoughts - Page 1
Forum section: electronics / general

author: Bicurico
author_rank: Super Contributor
timestamp: April 30, 2022, 12:25:23 pm
content: Hi,I was wondering that time travel does not exist or at least won't exist in the forseeable future, because otherwise someone would have traveled back in time and killed SOMEONE when it was easy enough to do so and before he could do harm.Since we don't have such a present, either there will be no time travel or, when changing the past, a new parallel universe emerges, thus fixing any inconsistencies or paradoxes.What are your thoughts?Regards,VitorMODERATOR EDITED TO MAKE POLITICS FREE AS POSTER CLAIMED TO DESIRE

author: Brumby
author_rank: Unknown
timestamp: April 30, 2022, 01:20:06 pm
content: At this stage of our technological development, this is more a philosophical question than anything else.I don't see that changing - but I'd love to be proven wrong.

author: TimFox
author_rank: Super Contributor
timestamp: April 30, 2022, 01:42:38 pm
content: A problem with the classic "go back 70 years and kill your own grandfather" paradox is that the situation would be oscillatory: Yes-No-Yes-etc.(edited to fix typo)

author: daqq
author_rank: Super Contributor
timestamp: April 30, 2022, 01:46:19 pm
content: Going down that line of thought you immediately get a few problems:1. Paradoxes - depending on how time travel or the Universe works/would work, then: X is bad, you go back in time, kill X (or set him on a nicer path where he finishes art school and becomes a mediocre artist instead of legendary baddie), problem caused by X is no longer. This sets the world on a completely different course where odds are that you were never born and even if you were, you don't know about the problem X caused, since it never happened. As such you have no reason to go to the past and kill/reeducate X. Grandfather paradox.2. Is it reasonable to roll the dice? All that has led up to any point in history is a series of events that had some chance to not happen. Even if you go back in time, and do literally nothing but have history unfold again, will it unfold in the exact same way? Step on the wrong bug, it won't eat a tick in the forest that will in 1673 bite and infect some kid that will eventually grow up to be Super X.Also, any single noble act can have absolutely devastating consequences. Killing X can, in the short run have a good impact (war doesn't happen), in the long run, have an absolutely catastrophic effect (tensions erupt in a different way and instead of X rising to power, Y rises to power in a different country and creates a dystopian horror state that will encompass the whole world and last for 10000 years).Butterfly effect. This also likely destroys your civilization. Assuming that you have access to time travel technology, odds are that civilization is fairly advanced. Are you going to risk that when you have no way of knowing how even the tiniest change will affect stuff?3. Ethical concerns - your reasons for altering the past may be noble, but someone's won't be. If time travel was invented, it would immediately become the most secreted and regulated technology. The amount of damage that can be done by someone going 5 years back is immense. 50 years is world changing.There's more, but these are a few quick ones I can think of.

author: gabiz_ro
author_rank: Regular Contributor
timestamp: April 30, 2022, 01:47:26 pm
content: Starting from that,even is more SF thing,that thing maybe already happened.But at time when this was done a new timeline spawned.We are living on initial branch,but author of time travel who fixed "putin" incident live in new timeline branch.As result we are unaware of this fix.edit:Could be a paradox if time travel was a result of that.Also any little change can have unexpected results.As for ethical concerns ... we can't be aware of that,that is for us.We live now.

author: magic
author_rank: Super Contributor
timestamp: April 30, 2022, 01:52:08 pm
content: Quote from: Bicurico on April 30, 2022, 12:25:23 pmGood job so farQuote from: Bicurico on April 30, 2022, 12:25:23 pmEither that or I will invent it. I have already promised to take care of Steve Jobs and Mark Zuckerberg before even considering the Usual Suspects That Shall Remain Nameless

author: Brumby
author_rank: Unknown
timestamp: April 30, 2022, 03:44:23 pm
content: Quote from: gabiz_ro on April 30, 2022, 01:47:26 pmMarty McFly:Nice shot Doc! You're not going to believe this, we have to go back to 1955.Doc:I don't believe it!

author: Black Phoenix
author_rank: Super Contributor
timestamp: May 01, 2022, 12:05:25 pm
content: Quote from: daqq on April 30, 2022, 01:46:19 pmA good movie (in terms of setting, not really in terms of story and acting since it is average to say the minimum) that touches such concept of changing the present by knowing the future is Ben Affleck and Uma Thurman`s Paycheck.Small synopsis: Michael Jennings (Ben Affleck) is a top-notch reverse engineer. Corporations pay him to crack the secrets of their competitors' products. When the job is done, he has his memory of it erased. Rethrick (Aaron Eckhart), head of a company called Allcom, hires Jennings to reverse-engineer a secret government device. After the job, Jennings wakes from the memory erasure to find himself being chased by various agencies. He soon realizes that the fate of the entire world may be in his hands.

author: themadhippy
author_rank: Super Contributor
timestamp: May 01, 2022, 12:27:14 pm
content: Not sure about time travel,but traveling at faster than the speed of light is certainly possible ,and most dog owners will have seen it.Your hound is sound asleep upstairs when you open the fridge door,but before the light in the fridge has come on ,said hound already has there snout in the butter.

author: CJay
author_rank: Super Contributor
timestamp: May 01, 2022, 01:08:14 pm
content: Quote from: Bicurico on April 30, 2022, 12:25:23 pmHow do you know someone hasn't already traveled back in time and killed someone?It's not as if you'd have any idea when/where/how the timeline changed or the reason for killing said person.I seem to have mastered the art of time travel to the future, now if only I could work out how to slow it down?

author: CJay
author_rank: Super Contributor
timestamp: May 01, 2022, 01:12:59 pm
content: Quote from: Black Phoenix on May 01, 2022, 12:05:25 pmAnd on Netflix too, nice recommendation for my Sunday evening watching, thank you.

author: Black Phoenix
author_rank: Super Contributor
timestamp: May 01, 2022, 02:16:29 pm
content: Quote from: CJay on May 01, 2022, 01:12:59 pmTone down your expectations OK, it's average at best in my opinion. Story wise is a good sci-fi, but the original source for adaptation was better.https://en.m.wikipedia.org/wiki/Paycheck_(novelette)

author: eugene
author_rank: Frequent Contributor
timestamp: May 01, 2022, 04:12:20 pm
content: Magic and mysticism aside, time travel is easiest to understand when you realize that we are all traveling forward through time continuously. Forward is the only direction that makes sense; you can't unstir coffee or uncook eggs. However we could travel forward at different speeds. By slowing down time for myself I can let the rest of the world go far forward. Then when I speed back up it would be as if I traveled forward in time. But you can never go back...

author: CJay
author_rank: Super Contributor
timestamp: May 01, 2022, 05:41:23 pm
content: Quote from: Black Phoenix on May 01, 2022, 02:16:29 pmEnjoyable enough for a Hollywood treatise, I wasn't expecting high art or deep and meaningful philosophical insight. A pleasant way to spend some time.

author: Bicurico
author_rank: Super Contributor
timestamp: May 01, 2022, 07:13:55 pm
content: Of course, time travel does not make any sense, if you consider determinism.if everything is preconditioned to physical laws, in an expanding universe, there would be no free will for anyone to make decisions and hence no room for time travel "to correct things".On the other hand, if you consider that any decision taken throughout the time line will generate a new parallel universe (one for when I turned left, another if I had turned right), then there would be an infinite amount of parallel universes. But... where would they be stored?Just some thoughts for the end of a lazy sunday.Cheers,Vitor

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 01, 2022, 07:19:55 pm
content: We have enough trouble handling time as it flows.

author: Black Phoenix
author_rank: Super Contributor
timestamp: May 01, 2022, 07:21:44 pm
content: Quote from: CJay on May 01, 2022, 05:41:23 pmThen great you enjoyed and find your time well spent. I like it, but I'm not that cinema guru most people are.If a movie basically makes me stay glued to the screen without wanting to stop it or pause it to so someting or get annoyed because something made me have to rewind it its a good movie in my book.The last part is important. Even with YouTube videos or music I see myself rewinding some seconds (music normally is back to the start of the track) if a loud noise or someone call me and distract me from the experience I'm having.Reason really I don't know why, but I get really annoyed if such happen. Same as with books, if I'm reading something and for some reason stop for a while, I have to read from the start of that chapter (or if the stop does go for a long time from the beginning).

author: Bicurico
author_rank: Super Contributor
timestamp: May 01, 2022, 08:02:05 pm
content: When you rewind, you are going back in time!

author: Simon
author_rank: Unknown
timestamp: May 02, 2022, 03:50:49 pm
content: well do we know what is beyond the edge of the universe? I remember pondering this at something like 8 years old, it occurred to me that everything exists alongside similar things in a bigger entity that in turn is with similar entities contained in a bigger unit and so on, this stops with the universe, what is the universe in? what else is with the universe in what the universe is in. my 8 year old mind put a temporary hold on dilemma's progression this by imagining it must be a hug white space with other universes in it too and I managed to not worry about what contained the big white space of black universes as I was already into the unknown of multiple universes...... I didn't know about the big bang yet.

author: Bicurico
author_rank: Super Contributor
timestamp: May 02, 2022, 07:19:42 pm
content: My current interpretation is that nothing exists.Our universe, all that is in it, is just an infinitely small disturbance in the nothingness, a singularity. To compensate this positive singularity, somewhere else there is a symmetric negative singularity. Both cancel each other out and the nothingness is perfect, except for this glitch.Since time is relative, the millions of years it took from the big bang up to now is nothing in the infinite scale os nothing. It does not count.It's like a positive quantum and a negative quantum emerged from nothing and disappeared again after a billionth of a nanosecond. Doesn't really count.Are we that complex? Just because we have the notion of ourselves? Seems important to us, but again in the eternal and infinite nothingness, it is unremarkably unimportant. We are just a bunch of atoms that got together for a period of time.I am not starting a religion nor do I want to convince anyone. This just happens my current state of belief. I would be grateful for ideas to believe in something better.

author: eugene
author_rank: Frequent Contributor
timestamp: May 02, 2022, 07:41:31 pm
content: When the subject of time travel comes up, I have to ask myself "what would Rick say?"

author: Bicurico
author_rank: Super Contributor
timestamp: May 02, 2022, 07:55:43 pm
content: Never watched this show (Ricky & Morty, right?).Is it good?

author: eugene
author_rank: Frequent Contributor
timestamp: May 03, 2022, 03:31:28 pm
content: Yeah, it's entertaining. The character Rick is a scientist and the "smartest man in the universe." He evidently has strong opinions about time travel but has never articulated them. He just thinks it's bullshit and not worth talking about.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 03, 2022, 07:44:46 pm
content: I saw where they now offer a new series of TTL devices. I picked up a couple to try. Time travel logic. A years ago, we would have never thought rise times this fast were possible. I'm already working on a DAS system based on them and have applied for a patent.

author: free_electron
author_rank: Super Contributor
timestamp: May 03, 2022, 08:08:51 pm
content: wait.. what ? are you telling me none of you visit the annual time travellers conference ?You're in luck ! Registration opens tomorrow. It will be held 23/24 February of this year.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 03, 2022, 08:11:58 pm
content: Quote from: free_electron on May 03, 2022, 08:08:51 pmI already attended that one.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 03, 2022, 08:19:38 pm
content: I worked on a system where we used a bucket brigade delay line to store our analog data long enough that we could then bring it back into phase with the present data to subtract it out. With the time traveling wave, we no longer have to store the delayed signal but rather can work with the live data before it happens. I am working on a patent now for my new noise cancellation system based on this technique. We not only plan to apply it to audio but for fully active suspension. I'm also working on a similar project for collision avoidance. Now days, taking on several long term projects like these is no big deal.I heard MS is working on a new schedule system to replace MS Project to handle it.

author: free_electron
author_rank: Super Contributor
timestamp: May 03, 2022, 09:56:38 pm
content: Quote from: joeqsmith on May 03, 2022, 08:19:38 pmyou could make a data compression system with this. compress everything down to 1 bit. then replay the compression backwards in time to get the original data...kind of like this.phase 1 compress adjacent numbers3+4 +5 +6 : 7 + 11repeat:18phase 2 : compress adjacent digits9phase 3 convert to binary and do the same based of bits1001 ->1111 ->1done.not that you cannot skip steps and simply go "1".. you need to go backwards in time to expand.1 -> 11 -> 1001 ->9 -> 18 ->7 11 -> 3 4 5 6try it. if you film yourself while doing this and then play in reverse you will see the algorithm works !

author: joeqsmith
author_rank: Super Contributor
timestamp: May 03, 2022, 11:29:03 pm
content: As long as we can go forward and backwards, time itself is the compression and storage.

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 04, 2022, 01:40:57 am
content: I don't know for sure about going backwards, but we all eventually end up getting compressed in some way.

author: free_electron
author_rank: Super Contributor
timestamp: May 04, 2022, 03:04:40 am
content: Quote from: SiliconWizard on May 04, 2022, 01:40:57 ammany people can be replaced by very small scripts.. some so small the compiler optimizes them away completely.

author: Rick Law
author_rank: Super Contributor
timestamp: May 04, 2022, 10:56:00 pm
content: I have reservations about participating in this discussion. This is more about philosophy than electronics, but it is a discussion that promotes understanding and interest of science and technology. I will share some thoughts. This is a mind twister to write,I hope it is as interesting to read as it is to write.1. Space Time vs Space and TimeMcFry looks at time travel as rather like spatial travel. You can go back to 1955 and then return to 1985 as if you can go to Boston for dinner then head back to New York. They treat the past as if it is a place and that it still exists.Now let say you can indeed travel in an enclosed machine in your basement and you go back exactly one day. You will not find yourself in your basement one day back - Earth is not in the same place as it was one day ago. You will find yourself in that machine alone, in space, with Earth at a distance about 1.6 million miles away as Earth orbits the Sun. If you travel further back in time, you will find yourself closer to other stars than to our Sun.You can receive information from the past - if you travel faster than light away from earth to about 50 light years, you could receive TV broadcast of the Apollo 11 launch and the first moon-landing. But the world of 1969 no longer exists today. World of 1969 is not a place you can go to, not any more. It doesn't exist any more. The world of 2069 is yet to be, so there is no there to go.I will however attempt to contradict myself later.2. Rewinding the clock or fast-forward the clockHow would one control every single particles in the universe to modify their time vector?3. Wormholes, the most promisingThis isone theory yet to be debunked by Science in-so-far as I know. Reading published scientific paper is a rare event for me so I could be wrong here. You can in theory create a wormhole with one end anchored to the north pole of the Moon and the other end at the south pole of the moon of different time. In theory, you can also find wormholes elsewhere connecting some other spatial locations and some other times,Current theory is, there must be something to prevent the "Grand Father Paradox". But who knows if that is indeed the case, or not.Note that current theory is, you can't go back father than the creation time of the wormhole -- that is if you can indeed travel through a wormhole without it collapsing. That said, wormholes is the most viable way of time travel (viable as in not yet debunked). Again, I could be out of date with my knowledge here.4. Trying to contradict myself.Let say you have a chess board with three chess pieces only, one Bishop, one Knight, and one Queen, and you randomly put the three chess pieces onto your chess board squares. Lets also say everyone on Earth will do the same thing. Will you find your placement position of Bishop, Knight, and the Queen on one of the other 8 billion chess boards done by others? Possibly so!If you limit the chess board's size to 3 squares by 3 squares (9 spots) and again 8 billion people on earth each doing the same random placement of 3 pieces on 9 spots on their chess boards.Statistically, it is a near-certaintythat you will find the exact same placement of the 3 chess pieces as yours on one of those 8 billion chess board done by others.As space expands, star that was visible to us reduce because those stars are so far away. With so much space between us and those stars, they are receding from us faster than the speed of light - they are beyond our cosmic horizon. We will never see them, ever.Let's call what is within our cosmic horizon ourlocal universefor short.What happen within our local universe can not affect elsewhere, and what happen elsewhere cannot affect our local universe.There is a limited number of particles within our local universe. A very big number but limited none the less. I'll call that P for now. Light and Forces are particles as well, so they are included in P. For that matter, you can add the particles property and count each property into P so P is all inclusive of particles and its properties. So our local universe has P particles andP is a very big numberbut not infinite.If the entire universe issufficiently large, it can have many local universes, lets call that N. N is the number of local universes out there.Now you know where I am going. While the permutation of P is huge, if N issufficiently large, one will statistically find every permutation of P within one of the N's. So if the universe is sufficiently large, every single arrangement of a local universe should exist. So, you may well find a local universe arranged exactly as 1955 Earth would have it!So, indeed, if the universe is sufficiently large, we could have every moment of our local universe represented on some other local universe!Well, even if it is out there on another local universe, how do you find it and get there is another matter.---------------------------------EDIT: PerEugene's suggestion/request, added one that omitted at first, click link below.Quote from: Rick Law on May 06, 2022, 12:58:40 am

author: eugene
author_rank: Frequent Contributor
timestamp: May 05, 2022, 01:13:42 am
content: You left out the only example of time travel that was predicted by physics more than 100 years ogo, and was actually demonstrated experimentally 50 years ago! Where have you guys been? I think I'll call each of you Rip Van Winkle from now on.The dilation of time according to Einstein's Relativity was shown in theHafele–Keating experimentin 1971. They sent two cesium-beam atomic clocks 275 nanoseconds into the future. Well, it was the future as far as the clocks were concerned, and it shows that anyone, including you, can go on a similar journey through time simply by flying around the world in an airplane.

author: Rick Law
author_rank: Super Contributor
timestamp: May 05, 2022, 01:32:43 am
content: Time dilation is not time travel as the term time travel is commonly used. You are moving forward in time, just at difference pace, and there is no possibility of returning to the "start time".Heck, you don't even need an airplane. Just be near something massive (like a pyramid), the added gravity would change the rate of your clock.

author: eugene
author_rank: Frequent Contributor
timestamp: May 05, 2022, 04:37:17 am
content: I get that. I'm just surprised that it didn't make the list of things to think about. It's the only thing with any basis at all in science that suggests time travel in any form might be possible.

author: TimFox
author_rank: Super Contributor
timestamp: May 05, 2022, 01:34:52 pm
content: Some recent news about replacing cesium-beam clocks with another process at an ever higher frequency mentioned that the slight difference in frequency between several cesium clocks at NIST in Colorado were due to different altitudes of the systems.

author: MikeK
author_rank: Super Contributor
timestamp: May 06, 2022, 12:47:21 am
content: Quote from: Bicurico on May 02, 2022, 07:19:42 pmI don't see how our universe can be infinite when we know to high precision how old it is. It's very likely that our universe is one among countless. Also likely that our universe was created by a black hole in another universe...The Big Bang *was* a singularity and a black hole *contains* a singularity.As far as I know, time travel is not possible because it violates entropy. Time moves in one direction only.

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 06, 2022, 12:58:05 am
content: While "traveling backwards", as in being physically present at some point in the past while being in the present, is a contradiction in itself and can probably only be solved through some kind of metaphysics, observing the past is almost trivial. When you look at someone 1m away from you, what you see of them is already 3.33ns in the past.

author: Rick Law
author_rank: Super Contributor
timestamp: May 06, 2022, 12:58:40 am
content: Quote from: eugene on May 05, 2022, 04:37:17 amYou are right, I should include that - I omitted it because of my own bias. For one reason or another, somehow, I just consider Tachyon (complex mass) too far a stretch.So, per request, here is my thought on it3a. Time travel by time dilationPer Einstein's relativity, we know and have confirmed that we each have our own personal clock. My one second is not the same as your one second.If I travel fast enough, one second for me could be 2 seconds or even years for the rest of the people on Earth.This is a way to time travel to the future Earth - get into a space craft and accelerate to incredible speed to return to Earth with your time being an hour later but Earth time being a years later.It is quite possible in theory, but I don't know of any practical way to accelerate anything other than elementary particles to a speed for meaningful time travel(meaningful as in 1 second for you but wrist watch measurable > 1 second for others).Interesting note:Current theory is light speed (c) is the universe's speed limit. There is actually a complication here that is important to point out. Say the plan route is just a bit (say 1km) under 2 light seconds away. On Earth, the observer saw me cover that 2 light second (minus 1km) distance in 2 seconds. Earth observers saw me traveled almost two light seconds in 2 seconds and traveled at speed below c. All Laws of Physics are obeyed and all is well. I am the traveler and my clock ran slow, so I could cover that Earth-observer measured 2 light seconds (-1km) in my 1 second. It would seem I observed myself traveled almost 2x light speed and broke the Laws of Physics. Not so. From my traveling frame of reference, Relativity say distances in my direction of travel is compressed accordingly. My observations is actually myself traveled the distance of 1 light second (minus 0.5km) in 1 second, almost at light speed but not 2x light speed.Current theory sayonly objects with zero mass can travel as the speed of light (c). We have mass, and in fact our mass increase as our speed increase. The closer we approach light speed, the closer our mass increased to near infinity. So we can't get near light speed with conventional means. If we could travel at light speed, our clock will stop relative to the rest of the folks on Earth. We can go anywhere and since our clock doesn't move, we got there instantly.Interesting note:For a photon and photons always move at light speed, the moment of it's birth and it's death is the same moment. For us, we can see that photon being emitted, travel to the moon, 1.3 seconds later, it hit and bounce on the mirror left by our Astronauts and return to earth another 1.3 seconds later and absorb by our photo detector. For that photon, the birth, the bounce, the death (re-absorption) are all the same moment. No time has passed in-so-far as the photon is concerned.To go back in time, we need to travel faster than light speed. For something to go faster than light speed, it will need to havecomplex mass- that is, it's mass is an imaginary (complex) number. Imaginary as in theimaginary number square root of -1. Tachyon is the name given to the imaginary object (field) with imaginary mass. Can we use it? I rather doubt that. To know more, we have to study Tachyon, but to study it, we have to find it or make it. Thus far, the possibility exists only in the mathematics.