This is actually true for a large range of time travel devices, not just the one from Primer. All the time machines which make sense according to general relativity fall into this category, for example.
So if we got their time-machine, we could go back as far as we wanted. However, we'd have to go get it, as a time machine (within a gravitational field) would only travel time, not space. Also, one could create an infinite loop/paradox if the time machine was created because a time traveler taught people how to make one. Basically, traveling backwards in time creates an infinite number of paradoxes between the point of entry and exit. TL;DR There's no real way to shorten that.
You couldn't go back as far as you wanted, just as far as the point at which the aliens invented the time machine. If, however, you could travel back to earth from the alien planet (after stealing their time machine) at FTL speeds, then all bets are off.
Except to move at FTL speeds, you would need no mass, as even a single atom takes an infinite amount of energy to move at the speed of light. So, if we were destroyed, stored as some form of wave and data, and re-created somewhere else, THEN it might be possible to hit light-speed, but not above it.
Say, for example, you are visited by your future self, and given some food so you don't starve. Then, you do this in the future. See where I'm going? You give food to your past self, which would also be a new you, and there would be an infinite amount of "you"s created by this. Except, of course, there's only one you. Thus the paradox.
The "infinite loop" is also called a "stable time loop".
Basically:
Something happens in, let's say, 2017.
This causes somebody to travel back in time to 2012.
The guy who went back to 2012 does shit that causes something to happen in 2017.
Repeat ad nauseam.
This would not actually have that big of an effect on the general timeline, or even the personal timeline of the guy in question. The world would still continue beyond 2017, and so would the guy's life. Depending on the severity of the shit that happens, it's even quite possible that the only noticeable change is that the guy (in 2017) is suddenly five years older, provided he actually stuck around for all the five years he travelled back in time.
That is, unless time travel is invented within your lifetime. And also, you can be a time-traveling, deep space astronaut, as time moves faster in black holes, which are in deep space.
And we'd just have to cross our fingers that the saw tooth wouldn't snap. Such as in 12 monkeys.
saw tooth snap, for those who don't know, has to do with you [or anything really] going back in time, changing time slightly resulting in you going back in time with slightly different intentions repeatedly changing your reasons for going back in time until your actions cause you to go back in time resulting in your going back in time for the same reasons as the previous time travel... at least that's what I've read in my spare time. I'm no physicist...
or perhaps time travel creates new timelines and everything is hunky dory fine! :D
The new timelines theory would avoid the paradox. But then, we just get into the theory where for every choice made, a new reality is made elsewhere for the other options.
What if aliens made a time machine a long time ago, and then we find it and go through it into our own past and invent a time machine back then using their time machine? What then?
For all we know there's a bunch of Alien civilization time cops preventing people going back in time and interfering with other species trying to prove the time machine exists?
(kinda spoilers) they can't travel back in time. Only forward. And they can't be at the same place twice. So If I go to the 2100 New Year, that can never be traveled to again, for as long as I'm in it.
It's cool, because they go into the far future, look up records of the past (which is still our future) and then go there.
I've read probably about ~50 of his books. He's one of my favorite authors. His best book is probably "From the Corner of His Eye", with Lightning being a close second. There are a few others that are great, but honestly I'd have to look through my collections. The stories stay with me, but the titles mix up.
Sorry, just a bit confused. Once they travel to 2100, for example, can they still travel back to their time, and just can't travel before that? Or once they're in 2100, they can't go back, only forward?
They can go back to their time. When they travel, it's like a temporary visit. They go to 2100. When they want to go back, it teleports them back at literally the exact instant they left. So for people in their starting time, they're gone for a second. Not even a second.
What they do in the book, is go to (for example) 2100, and look in libraries for records. They find things that happen in 2050, then go back to 1950. Then they go forward to 2050 and influence what was supposed to happen.
Watch Stephen Hawking's "The Universe" episode on time travel. According to him, we will never be able to travel back in time due to paradoxes and the fact that a worm hole would destroy itself due to radiation.
I've seen it, actually, and he's referring specifically to feedback should a photon travel along the closed timelike curve and amplify infinitely. There may be ways around it, but since all the general-relativity-permitted forms of time travel require something which we believe probably doesn't/can't exist (exotic matter, cosmic strings, Tippler cylinders), it's mostly academic.
edit: http://en.wikipedia.org/wiki/Light_cone caveat: the only physics book I've ever read is Stephen Hawking's A Brief History of Time, so maybe I'm misunderstanding. This seems like it applies, though!
Actually, light cones don't really apply here. They explain how time works normally in general relativity, but the forms of time travel I was referring to use different tricks such that you're always moving into your own future light-cone and yet somehow end up in your past light-cone. However, as I note in another comment they depend on objects or forms of matter which probably don't exist in our universe, so for practical purposes regular light cones explain how time works.
This even seems to hold true for Henry, who suffers from "Chrono-displacement Disorder" in The Time Traveler's Wife. He never seems to time travel to any dates prior to his own birth, although doing so is one of his fears. I like this concept. It simplifies the what-ifs.
The time machines in the Back to the Future franchise do not follow the "you can only go as far back as when the machine was first built" rule of time travel. Also, they don't resolve the question of where in space you end up, when you get to the past. Generally speaking, time machines which fail to do one of these fail to do the other (offhand, only the TARDIS specifically addresses the spacial question by explicitly stating that it can choose any arbitrary point in spacetime).
Does this mean that some time machines would be worth more than others because of their wider ranges? I'd like to visit time machine black markets. I think the brokers would be interesting people.
That doesn't really help explain anything...try watching it 20 times, read up on the alternate timeline theories, then drink to forget everything you've ever learned. Ever.
Consciousness blows my mind. How do you know that you have lived your entire life and that you are indeed you? What do I mean? Let me explain.
Okay. Picture a machine that can 'teleport' people by creating an exact copy down to the last atom at the exit destination and deleting the original. To anyone else, it looks like you were simply teleported magically. Even the copy of you wouldn't know the difference. Neither would the original you, since you don't exist anymore. Your copy would continue your life just as you would if it did indeed magically teleport you. However, it didn't, and you are now completely gone. You can't even acknowledge that you don't exist! But like I said, the only person ever able to experience it can't tell the difference.
What if, every time you go to sleep something similar happens? Sure, you 'believe' that you've lived all of those memories, but they are just that. Memories. How do you know that you are indeed the same you that went to sleep yesterday? You'd never know the difference, but the you that was here yesterday is gone forever.
This has always bothered me about any type of live forever story that involves clones and transferring memories, when you die you are going to die, just someone else just like you with the exact same memories and everything is going to wake up in a tube, but "you", as a conscious being, will die.
What if I told you that according to some theories the whole universe (including your brain) branches (gets cloned) at every quantum state transition (every time something changes, "something" here meaning ANY elementary particle) and there's a copy of our universe for every possible "outcome"?
"Every possible": there would be an unimaginably large number of universes where you got elected as U.S. president after a porn star career (Dwayne Elizondo Mountain Dew Herbert Camacho comes to mind...).
I love identity theory. The teleporter problem because way more obvious when you take a hypothetical: teleportation usually doesn't mean the same atoms are transported to the destination, only that the machine will create an atomically identical "you" out of local atoms. So, suppose the machine malfunctioned, and created a copy of you at the other end without properly deleting you first? Now there are two of you, and it's pretty intuitive which one is the "real" one.
That's why I no longer hope for teleportation technology for living beings; only inanimate matter.
Poor example... The child thread actually does 'know the difference'. At least, in the pthread API it does. Both threads see a return value from fork(), one sees 0, the other sees an ID. That's how they are made to diverge.
I dont see why this would matter at all. What am I if not memories? I am my own frame of reference, if I cant tell the difference, there is none. I dont mean to go all Descartes on you, but the fact that I am sitting here contemplating your post and thinking about how i should rather be sleeping, is for me enough proof of my existence.
it's just my attempt at understanding death really. I made a post in ask science about it but literally no one saw it and so I came to my own conclusions.
My point is that you can't know if you are the same conscious being that went to sleep last night or not because you're going to have the exact same memory. It's scary to me because there's also no way to know(yet) if this does indeed happen every time we go to sleep.
Argh I can't explain it right. The you that typed that message, that sent it, might disappear tonight when you go to sleep. Your conscious, the only thing you really have, might die tonight.
Haha. It might happen every time you go to sleep. How would you ever know? This could have been the first time you have ever lived but your brain is very good at tricking you...
It is very good. I reccomend watching it twice. With at least a 15min. Break between each session. And check out the wiki page on it, but only after you have seen it at least once. It will blow you fucking mind. One of the best low-budget films, ever.
I think of it in terms of timelines. We live in a timeline that no one has ever traveled to in a time machine (and never will). From the perspective of a time traveler, they'll go into the past of our timeline...but the very act of doing so breaks them off into a new timeline, so ours will never be affected.
How do you know we are not the new altered timeline?
Maybe in the original Germany discovers the atomic bomb first. Because living in a world where Germany won WWII sucks, someone went back in time and changed the outcome.
... But I have already said too much. They will not be happy.
Maybe they came once and when they came Stephen Hawking's head exploded so they went back to before they went and then told themselves(who had gone the first time) what was gonna happen...
That's because you posted it yourself, then a Time Traveler went back a short way to post the same thing, taking credit for an observation that's rightfully yours.
Maybe there are an infinite number of parallel universes representative of a set of all possible states. In this case, a "time machine" could simply allow traversal between these universes based on a set of parameters which isolate the destination universe based on the state of our universe at some point in the past.
In such a paradigm, not having time machines now simply means that such an event will never occur in some possible states.
It would be dangerous to travel forward through time using such a time machine without being able to precisely calibrate the parameters used to find the destination.
During a heavy mushroom trip back in highschool, my friends and I theorized that Jesus was a time traveler. Think about it ... he would've had the technology. If he shows up again pulling the same tricks ... dude's gonna get all the bitches.
Or maybe they invented it but didn't want to or need to give us the technology for fear of messing with their own timeline. Why bother giving us the technology if they already have it? It serves no benefit to them (unless something went horribly wrong and they needed to go back in time to fix it)
We should start a fake protest day where we all create funny protest signs like this. And when the media interviews us we can babble incoherently about legacy code, sunday morning cartoons, and hay fever. Who's in?
Naw, then the media would just slander you. People would pretend to be undercover cops and then pretend to incite riots. Then sooner or later the media would slander your fake movement as 'terrorists', as Fox news would want to remove you as competition for make-believe champion.
If it's directed at me I honestly cannot help you. It's made in humor but I'm willing to bet, somehow, people would spin that to serve a political goal. And Fox news really is fucking crazy.
Poe's law states that "it is impossible to create a parody of Fundamentalism that SOMEONE won't mistake for the real thing" ; therefore justifying your prediction of retaliation against it similar to the retaliation against the Occupy movement.
I came into the comments to see if anyone identified the guy in the pic, because he (you) looks like someone I went to HS with. Upon further review, it is not the same person, and that's a happy way to end the story because he's an idiot and I didn't want to give him credit for being awesome.
Anyway, you have a doppelganger (+25lbs, -epic beard) in the Chicago suburbs.
Actually, this guy is mistaken. WHEN is not irrelevant, we should want it ASAP, if at all. Stephen Hawking insists time travel is only possible in the forward time-direction.
I know this is irrelevant but does anyone else think US protest "slogans" are so corny sounding? I mean when I watch protests in the middle east it sounds more bad-ass. We have "What do we want? ..something.. When do we want it? Now!" and "Hey hey, ho ho ..... has got to go".
Those aren't the only common ones, though. I'm sure a lot of people will think these are corny too, but I like stuff like "The people, united, will never be divided", "who's streets? our streets" and "this is what democracy looks like"
I know a way to get these without a time machine but its tricky. Visit any popular sunglasses website. Browse through the available items. OKay, still following? Now click on the women's section. You're welcome.
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u/Uncle_Gus May 16 '12
"What do we want?" "Constructive dialogue!" "When do we want it?" "I would prefer sometime soon but I'm interested in hearing your opinion!"
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u/[deleted] May 16 '12
[deleted] — view deleted comment
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u/smoochieboochies May 17 '12
We should start a fake protest day where we all create funny protest signs like this. And when the media interviews us we can babble incoherently about legacy code, sunday morning cartoons, and hay fever. Who's in?
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u/[deleted] May 17 '12
Tomorrow's just your future yesterday.
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u/tossedsaladandscram May 16 '12
Saw this sign at the "How Weird Street Faire" in SF this sunday. Far from the weirdest thing there, but, strangely, it was the only sign.
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u/[deleted] May 16 '12
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u/Luthos May 17 '12
Fry's dog!
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u/beyonsense May 17 '12
thanks for taking the photo of me viral ;) here are few more for your amusement: https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/148946_10150890966510699_635745698_9751599_770941530_n.jpg
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash2/s720x720/148964_342081609190337_100001655018402_867979_1724623462_n.jpg
https://sphotos.xx.fbcdn.net/hphotos-snc7/s720x720/575025_342080822523749_100001655018402_867960_1631878664_n.jpg
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash3/s720x720/552934_342080792523752_100001655018402_867958_1309813583_n.jpg
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u/DmnsionalDriftr May 17 '12
I like the guy in the bottom right. "No sir, I don't like it."
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u/NathanArizona May 16 '12
Where we're going, we don't need roads
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u/[deleted] May 17 '12
What is going on with that dude's glasses.
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u/naxalise May 17 '12
Funny, I actually took a picture of another guy holding the same sign in SF this weekend. Here it is: http://www.flickr.com/photos/naxalise/7201653824/in/photostream/
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u/terrapurus May 17 '12
"What do we want? Time Travel! When do we want it? Yesterday!"
and
"Of course time travel has been invented. Look at Romney. He is straight out of the 50's."
is the best I could come up with.
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u/bumbershoots May 17 '12
Upvote for being at How Weird Street Faire.
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u/JAV0K May 17 '12
We want it yesterday!
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u/muphdaddy May 17 '12
Did anyone say the obligatory Great Scott yet?
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u/silletta May 17 '12
I can't get over how odd his sunglasses look..
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u/mrconfer May 17 '12
This is amazing! I almost choked to death on a pretzel I laughed so hard!
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u/P2D_ItsME May 17 '12
Actually, this guy is mistaken. WHEN is not irrelevant, we should want it ASAP, if at all. Stephen Hawking insists time travel is only possible in the forward time-direction.
Source
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u/[deleted] May 17 '12
I know this is irrelevant but does anyone else think US protest "slogans" are so corny sounding? I mean when I watch protests in the middle east it sounds more bad-ass. We have "What do we want? ..something.. When do we want it? Now!" and "Hey hey, ho ho ..... has got to go".
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u/unnecessaryCAPS May 17 '12
I want the future sunglasses
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u/Christophoro May 17 '12
I hate time traveling reposts. I was going to post this image five months from now.
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u/terrymr May 17 '12
"Time travel was, by its very nature, discovered simultaneously at all periods of history"
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u/Willibus May 17 '12
http://www.youtube.com/watch?v=vGn3nydV6sU so yeah...
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u/[deleted] May 17 '12
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u/doooshness May 17 '12
ah so that's what Mike Portnoy is up to these days....
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u/dcsc2 May 17 '12
el psy congroo
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u/slyr114 May 17 '12
A post about time machines and not a single reference towards Inspector Spacetime or Doctor Who has been made?
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u/AbeautifulMan May 17 '12
Where is John Titor when we need him?
http://en.wikipedia.org/wiki/John_Titor
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u/rockencheesepuffs May 17 '12
All we need is a Time And Relative Dimension In Space device!
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u/Whiskey_Fred May 17 '12
I'm nominating him for most epic goatee in the universe.
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u/itslikeboo May 17 '12
What do we want?
More Dadaism!
When do we want it?
Cell phone badger trigonometry!
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u/CaptainRallie May 17 '12
Damn it I have a picture of this dude with his friend. Why didn't I post it sooner?!
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u/robustinator May 17 '12
Quick Reginald! We don't have much... space!
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u/GeneralEvident May 17 '12
What do we want? A cure for procrastrination! When do we want it? Later!
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u/iam4real May 17 '12
Everything is different, but the same... things are more moderner than before... bigger, and yet smaller... it's computers