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How to Build a Time Machine
frank249 writes "The September issue of Scientific American has an article discussing the possibility of time travel. They say that it wouldn't be easy, but it might be possible. It could be a while until we can expand worm holes and tow them to a neutron star but didn't someone say that if it is possible it will happen. If it is impossible it will just take a little longer."
Go back in time and whack RMS. This way the whole GPL software would never be around to infect legitimate companies. You know you agree with me, too!
C - A language that combines the speed of assembly with the ease of use of assembly.
first one?
To all my dead homies. fp too.
Oh, btw, your link is broken, learn to fucking code Taco.
Yeah, I wish they had a time machine so I could go back and get first post!
It won't happen in our lifetime.
Oh wait...
I move we call for a slashback in a few hundred years when this might be possible. ;-)
#1? Maybe...Likely not
Wouldn't the best way to speed up things for this be to leave a post-it note stuck in the files saying "when this is finally invented, please travel back to August 24, 2002AD and provide the HOW-TO."
--
Todd
It ain't easy, but not impossible. Heck, there are gazillion things that are not easy but not impossible, doesn't mean it'll happen anytime soon.
After watching the mid-season finale on Sci-Fi last night, with all the time travel, paradoxes, unrealized realities, and wormholes... it gave me a bit of a headache :-(
Are you local? There's nothing for you here!
Go back in time and stop CmdrTaco from starting Slashdot. This way the trolls would never be around to make asinine comments like the parent. You know you agree with me, too!
It's nice that serious scientists are willing to spend time researching things that have very little chance of actually working. Who knows what new insights will come out of this..
;-)
Of course, the science fiction possibilities are really nice, too...anybody have a favorite time travel story to share?
Twenties Retirement
As long as you pay the toll...
"Somebody's gotta go back and get a shitload of dimes!"
This post made to eliminate an accidental bad moderation on the parent. please ignore.
This only works for going forward, not backward in time. Going forward is easy (as the article says when you're on a jet) going backward is the hard part (and in all likelihood impossible for us).
I thought the reason that clocks ran faster in the attic than the basement was because of gravity's affect on the MECHANISM rather than gravity's affect on time. Likewise could be said about the atomic clocks. The clock is travelling thru quite a bit more space than it would if it were sitting, could subatomic particles affect it's function and accuracy?
The previous has been a secret message to my comrades.
This article was posted years ago.... Oh umm. Wait a minute. Never mind. I never saw this article before. Yea thats it. I never this article before. Realy I have never saw this article. Why are you looking at my third eye funny?
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
If there's a chance time travel might become a reality, how come nobody from the future has visited us yet?
Quick lesson in physics for those that don't want to read the article...
Time travel. Possible? Yes. It happens relativly speaking every day.
When you get onto an airplane you slow down in time. To say this simply. The faster you go, the slower time moves around you. This was confirmed back in the 1970's using atomic clocks. Although this isn't exactly time travel it's called time dilation which is a product of the general theory of relativity.
A quick little reference for those not familar with Relativity is a set of lecture notes from a basic astronomy class in U of Oregon.
For a little more in depth reading I'd look into buying The Large Scale Structure of Space-Time by Stephen W. Hawking. Or for those that are sadistic you can read Quantum Field Theory in Curved Spacetime and Black Hole Thermodynamics. That is a collection of lectures from the University of Chicago. Although good in a sense of understanding relativity it kinda takes a tagent into the debate about light being a particle or a wave argument.
Can a mod please explain to me why this pseudo-scientific crap gets it's own story,
and I can't even get this post modded above 0??!?
Time travel into the past, if achieved, will have a destructive impact on our notion of causality. Either that, or our romantic ideas about free will will fly out the window. Possibly both will be lost.
:)
Either way, our entire understanding of self, universe, and the relationship therebetween will be radically changed.
it was nice knowing me.
Also paraphrased in John Brunner's Stand On Zanzibar as "The difficult we did yesterday; the impossible we're doing right now."
Christ, what an imagination I've got.
You really need to real Einstein's General theory of relativity.
Suppose that time travel was possible, but only on a microscopic scale, such that it was impossible to send humans, or even small robots through time, but just enough so as to send information.
:-)
Hook up a computer to a time machine and let it do all its processing in the past. The information need not be detectable in the past (so it doesn't change anything, and doesn't give us a paradox) but it effectively allows the computer to solve almost any solvable problem instantly, as it can use billions of years for processing...and then use them again if it needs more time.
NP-completeness might not be meaningless (if it would take a trillion trillion years of processing time to solve a problem by brute force, it would still take a while doing it in billion year chunks) but if you could use 2 billion billion years every second, a lot of problems would become tractable
Of course, how the processing during those billions of years will happen, since the computer stays where it is, is another question..
Twenties Retirement
Time travel is fundamentally impossible. One does not travel through time. One travels through space and time is how we measure this travel.
Remember, nothing moves in spacetime.
A simple way to think of it is this: Movement through space is represented as distance/time. How would one represent movement through time? It should be time/, but there is nothing to put in the denominator.
Of course, this induces the potential for paradox, causing great cosmological and philosophical consternation. I don't know what will happen if/when someone goes backwards through time, but here's some ideas:
- The universe forks in two when a paradox is induced.
- The universe forks in two at the instant the traveller enters history (because at a micro-level, paradox is induced as soon as they appear).
- Paradox induces a cascading feedback loop of self-modifying universes (each inducing a time-traveller who goes back and causes another chage) until the sequence halts with a universe in which time travel is not developed. My bet is that if time-travel is possible, then this is what has happened, because there is no evidence of time travel.
Forward time travel is of course possible right now, requiring only some patienceCrispin
----
Crispin Cowan, Ph.D.
Chief Scientist, WireX Communications, Inc.
Immunix: Security Hardened Linux Distribution
Available for purchase
If it was possible to travel back in time, wouldn't we have encountered something from the future? I mean, eternety lies ahead, and *somebody* would've come to this exact place at this exact time sometime during eternity.
I mean, the possibility of it happening is endless and therefore a fact.
Smoke me a kipper, I'll be back for breakfast.
...go back and tell your mother that the sperm seepage from her ass after a serious ass banging can indeed make her pregnant if she's not careful during "cleanup", and the feces/ecoli infected sperm would likely lead to an offspring like you.
assuming that time slows down (relative to the observer) more and more as you approach the speed of light, and assuming that sometime in the future, we'll have the technology to go, say, 80% of that speed; what is the maximum realistic ratio of 'your time to their time?' any physics gurus care to share?
*Humans* will never time travel. If it were to ever happen, so idiot would abuse it and we would have already seen the effects.
sorry
Maybe this is dorky, but isn't the following evidence that time travel is impossible:
Since no person from the future has ever come back to say hello to us, wouldn't that imply that time travel will never be invented. Or else it will be invented, but our era in history was just too damn boring for people to come back to visit...
Artificial inteligence is no match for natural stupidity. --unknown
is first outlined by physicist Kip Thorn and widely accepted by the scientific community as a real possibility. It is a method which utilise the ability of keeping worm holes open and high speed travel IIRC.
:)
Black Holes and Time Warps: Einstein's Outragous Legacy by Kip Thorn is perhaps one of the best science books I read, though I didn't really read that many of them.
geek page at KY speaks
Nowhere does it say to disregard forces other than time that may change the measuring device. It's like saying that an arc welder speeds up time, because if I wear a wristwatch while welding, it'll run fast.
(For those who don't know, the magnetic field created by a welding lead in use will seriously mess with a quartz watch)
The previous has been a secret message to my comrades.
At least according to this book. There is also an interesting interview with the author here.
Can someone explain to me how do you tell which twin ages more quickly if you can't tell which is actually moving closer to the speed of light? Isn't it possible that the Earth is moving through the universe at a high speed so the spaceship is really at rest, in which case woudn't the spaceship twin age more quickly?
I've given this some real thought and if it's possible to time travel at all, it would not be as how we see it in the movies. I'm a philosopher at heart and I think these points have been heard in many different forms:
I just don't see it as a reality. I think what will actually happen is something altogether different-- but not a physical human being traveling into the past to hang out with Babe Ruth. Know whut I mean, vern?
"Politicians find new names for institutions which under old names have become odious to the people."
Anyone else see this in the middle of page 3?
Censored!
Wear weird clothes (not weird in the everyday weird people sense, but truly out of place). Walk up to someone (inventing an accent is fun) and ask them what year it is. When they say, puzzled, "2002", get a huge smile and dance a future dance away yelling "it worked, it worked!"
Fun to confuse people with.
Just as fun: Dress up like a hippie or something else interesting from the past and change everything accordingly to the past.
I would go to 1894 and stop the conception of a certain somebody named Gavrilo Princip. The man whos actions set off chain reactions to WW1 and beyond.
The man indirectly responsible for 80,000,000 deaths in 20th century alone. 80M. That's not a joke.
bio
Sorry this is nothing scientific, but thought I would share that small fact which is overlooked in history books.
Wouldn't this mean that it's possible to send matter from a certain 'time-frame' to another time-frame, thereby increasing the total amount of matter in the latter time-frame's universe (or parallel universe, if you wish), and reducing the total amount of energy in the former time-frame's universe?
Consequently we've created ourselves another paradox: if you travel back in time to a period where you already existed, there'll be two copies of you, of a different age (most likely, at least). Which one of these travels back into time, and won't there be already two copies waiting? And then three copies will be there in the same period, no?
So if one were to travel back into time, wouldn't that automatically cause this traveling back in time to be repeated ad nauseam?
The first thing we've to do is to completely dismiss the idea that time is merely linear.
Whatever we think time is or might be is precisely what it is not or can't be.
Site & blog: http://www.mayaposch.com
I think it was Douglas Adams who said that once invented, time travel will simultaneously exist at all points in time.
This is what turned me off on time travel as a whole... It may be kept a secret for some period of time after it's invention, but one leak into the past and whamo, its everywhere.
I would go back in time a register slashdot.org
Maybe then, that site could be used for something useful...
I am trapped in a prison of the mind.
If science can't measure or rationalise it, it cannot possibly exist.
If it is from the west it has to be true.
If it is from the east it has to be false.
If they told me that I only had to train my mind to see that time and space were an illusion, I would tell them that there must be a microscope that could prove it, or a machine that could replicate it.
I am trapped in a prison of the mind.
http://www.sivanandadlshq.org/messages/mind.htm
There's another possibility that was not mentioned in the article, namely, the possibility of different quantum realities. Imagine for an instant, that whatever could happen, does in fact actually happen. Through what what called an Einstein-Rosen bridge (remember the TV show Sliders, the concept does have some scientific merit after all), different quantum realities can be bridged. So, if you go back in time and kill one of your parents, you would still exist because you entered a different reality, one amongst an infinite number of them. Paradox solved. QED.
Now every script kiddie will know how to go back in time and mess around with history. Why don't we just put the bomb secrets out there too?
I mean, the possibility of it happening is endless and therefore a fact.
You took way too many math classes...
You can't take the sky from me...
The article says that altering the past is "obviously impossible". But isn't travelling back into the past a way of altering the past? Or was my arrival in the past something that happened back then, before I even made the trip back in time...? Or are such paradoxes impossible, maybe because every possible event in any given time in history exists in its own universe, waiting to happen when the right preceding event occurs? If someone changed what we call the past, would we notice it?
Will work for bandwidth
This article creates some interesting questions. I believe that time is relative to the observer. For instance, if there was an object in space that consisted of two platforms with a laser beam projected from the bottom platform and reflected off of the top one back to the bottom, it would appear to make a straight line to an observer in the shuttle, while on earth it would form an upside-down V shape. Now, according to Einstein,light cannot slow down so time must slow down. Therefore, on earth it will appear that time slows down for the being in the ship, while the being in the ship will experience no change in time. So in the example with Sally and Sam, from Earth's point of view, it would seem that Sally took ten years, but what about from Sally's point of view? Time on earth would seem to slow down. So, wouldn't that mean that the two time shifts would cancel each other out when Sally was to return to earth? (the two points of view would then merge into the same) Perhaps Sally would be in the future while she remained off of earth, but I believe that she would return to earth and experience the same time as Sam and would have physically aged the same amount. I'm not a physicist or anything like that, these are simply my observations after a few lessons on this subject. Hopefully if I am mistaken, somebody with more knowledge on the subject can help me become clear on the subject :)
SIGFAULT
And tomorrow will be like today, only more so. -- Isaiah 56:12, New Standard Version
Freaky. What future bastard is playing with my head??
"They do not preach that their god will rouse them, a little before the Nuts work loose." Kipling, 'The Sons of Martha'
This is tricky. The key is that when the spaceship gets to its destination, it has to turn around somehow, which implies that it has to do some acceleration, which is why its frame of reference isn't valid. (I think this is the case...)
Because it would already have been done, and we would have met our descendents already.
Nowhere does it say to disregard forces other than time that may change the measuring device.
If these forces weren't readily detectable, that would mean that they were present everywhere, affected all our clocks, mechanical or electronic, in exactly the same way, which would mean that their effect could not be readily separated from the actual forces that directly affect time, and such a separation would also be pointless according to Occam's razor.
An arc welder on the other hand creates a visible distortion making one clock run very different from others, and is therefore an easily identified source of error easily to be taken into account when performing an experiment.
"Everyone who believes in telekinesis, raise my hand..." - James Randi
Hasn't the stock market already proven time travel. My holdings look like circa 1998.
I've just seen Terminator a few minutes ago. Why does this seem like a bad idea ?
My understanding was that the time dilation effect was from a change in the rate of entropy related in some way to the change in mass. If that's so then you could speed up or slow down entropy, and hence the perceived passage of time, but you can't reverse it. I would think travel to the past would need to reverse entropy in some way. Or I could be wrong, physics class was a LONG time ago.
1. Build a time machine.
2. ?????
3. Profit.
1 tequila 2 tequila 3 tequila floor
That should tide you over. The rest, you'll have to learn on your own.
I'm applying for a construction permit for the Restaurant at the end of the Universe. Gnab Gib anyone?
They can't travel back before the wormhole was created, according to the article. And that's GOTTA be true because everything on the Internet is 100% true.
-=Lothsahn=-
With one of these gizmos, I'll be first posting every time!
If Slashdot were chemistry it would look like this:Cadaverine
Time travel. Possible? Yes. It happens relativly speaking every day.
Nonsense. Time dilation is not time travel. For whatever it's worth, nothing can move in time, forward or backward. The entire spacetime of relativity is frozen from the infinite past to the infinite future. I'll let the smart ones (i.e., the ones who were not irreparably brainwashed) figure that one out. In the meantime, those of you who are really interested in the truth can take a look at this following link for a complete debunking of time travel and other crackpottery from the physics community. Wild eyed Star-Trek fanatics need not bother.
Voodoo Physics
..and here's the living proof. I originally wrote a lengthy article about how the reality or, er, reality could not support such a thing as time travel, but I was later proven wrong, and hence came back here to pre-emptively edit my original post into this form. Now do you believe?
E
Marxist evolution is just N generations away!
Forward time travel is of course possible right now
This is sad. Why does the physics community insist on putting out such unmitigated crackpottery? The truth is that nothing can move in time, forward or backward. The entire spacetime of relativity is changeless, from the infinite past to the infinite future. Karl Popper had a name for it: Einstein's block universe. More details can be found at this site:
Voodoo Physics
What would happen, If I travelled back in time, and did a thing, that would change something that had already happened? Would the "new" thing happen in the current time, or what? I just dont get that.
If the everett/wheeler interpretation is true (ie, quantum states never "collapse", the universe branches into as many variants as are necessary to express every outcome) then time travel (into the past) is just a special case of ordinary time travel (into the future, at 1 second per second). By travelling into the past you'd be hopping over into a new universe (one where you showed up), not the universe you left (where you clearly never did show up). An excellent description of this notion can be found in David Deutsch's book, "the fabric of reality"
The correct URL is: Voodoo Physics
Voodoo Physics
"This little affair," said the Time Traveller, resting his elbows upon the table and pressing his hands together above the apparatus, "is only a model. It is my plan for a machine to travel through time. You will notice that it looks singularly askew, and that there is an odd twinkling appearance about this bar, as though it was in some way unreal.' He pointed to the part with his finger. "Also, here is one little white lever, and here is another."
The Medical Man got up out of his chair and peered into the thing. "It's beautifully made," he said.
"It took two years to make," retorted the Time Traveller. Then, when we had all imitated the action of the Medical Man, he said: "Now I want you clearly to understand that this lever, being pressed over, sends the machine gliding into the future, and this other reverses the motion. This saddle represents the seat of a time traveller. Presently I am going to press the lever, and off the machine will go. It will vanish, pass into future Time, and disappear. Have a good look at the thing. Look at the table too, and satisfy yourselves there is no trickery. I don't want to waste this model, and then be told I'm a quack."
Oh, wait...
"All art is quite useless." -- Oscar Wilde
modern physics won't be able to make any large advances until we realize that time isn't a dimension.
I predict the wormhole concept will be achievable. But there will be one hitch: you will only be able to travel through a wormhole in one direction, and the physical distance you emerge from the wormhole entrance will be equal to or greater than the time it takes to travel at the speed of light to that location.
Thus, you will be able to go back in time, but even if you then raced at the speed of light back home, you wouldn't be able to arrive before you departed.
So you'd travel back in time sure enough, but never able to affect your own past. Another way to phrase it would be: you can go back in time, but only someone else's history.
Of course, you could, say, still go back in time and kill someone in another part of the Galaxy. Maybe terrorist possibilities, etc. Gives a whole new meaning to a leader staying close to his people.
OK, one more speculation. Wormholes will turn out to repel each other, or maybe wormhole exits and entrances that are close to one another create catastrophic feedback loops, making them impossible.
Otherwise, you could take the W-80 (Milky Way --> Andromeda) from near Sol, then catch the W-95 (Andromeda--> Millky Way) near Kl'Kithus, which , it turns out, dumps you right out at Sol again.
And that would make your own past accessible and that's Bad (tm). I guess it could also allow you to go farther and farther into the past by traversing the loop multiple times.
Of course, it's not clear why someone would want to travel to a time before indoor plumbing or computer games.
Time Travel Ad
didn't Zeno bother mathematicians and physicists with the same sort of argument for hundreds of years? You know how they solved his paradox right? They forgot about it.
The best education consists in immunizing people against systematic attempts at education. - Paul Feyerabend
It's called a bed. Every night I close my eyes and in a moment it is six hours later.
"God fights on the side with the best artillery." - Napoleon, Marshal of France - speaking truth to power
Matter can neither be created nor destroyed. So, in the sense of time travel, either to the future or to the past, would we not be introducing new matter into a time by bringing it from another time? If matter can't be created, do the laws of physics allow for matter to be transposed across time?
Skiers and Riders -- http://www.snowjournal.com
I find it interesting that the article suggests towing a wormhole using a "spaceship, presumably of highly advanced technology" to place a created or expanded wormhole in a powerful gravitational field. Maybe I'm just envisioning this wrong, but I don't know if a wormhole is really what I'd consider to be an "object." Rather, as a rift in spacetime, I'd think would be a thing (for lack of a better word) that is defined by both lack of object, and by objects around it, like the hole in a doughnut, and thus the only way to "move" it would be to alter the objects that surround it, like stretching or shrinking areas of the dough to change the location of the hole with respect to locations on the dough . You can't just grab a hole in a doughnut with a pair of pliers and move it around. In the case of wormholes through spacetime, I'd imagine the way to move a wormhole is to warp the space around it with immensely powerful gravitational fields, folding the space around it and causing it to "fall" to its neutron star target. However, this would certainly require a mastery of gravity far beyond what we have presently attained. When the two ends of the wormhole are created/expanded to macroscopic size, they will need to be separated, with one end taken to a neutron star. Building a tow-ship that can warp the space around a wormhole would require far more knowledge about gravity than we presently possess and far more mastery. Despite being perhaps the most obvious of the fundamental forces of physics, it is probably the least well-understood. Gravitions have never been found in particle accelerators, nor Higgs bosons. Gravitational waves have not been conclusively detected. No coherent theory of quantum gravity exists. We will have to be able to manipulate gravity with the ease that we manipulate electromagnetism if an "interstellar tow truck" is to be built. "Highly advanced technology," indeed!
Using the neutron star itself to attract one but not the other would be very difficult, but possibly workable- especially if Podkletnov's spinning superconductor gravitational shield works (which it doesn't, that I am sure of). However, you certainly can't use a natural source to reunite the ends once you've "twin clocked" the exit end- the exit is sitting near the surface of a neutron star- so you really won't be able to pull it away with anything less than another neutron star or a black hole, perfectly positioned to make use of the three body problem to slingshot the wormhole out of the star system. Conceivable, but highly unlikely.
You can't just leave the exit there, either. It would continue to accumulate time difference, so each trip would take you farther from your present time, but actually further and further along in time, since you can never actually travel backwards to before the creation of the exit hole, and since it is in fact still moving forward, albeit slowly, in time. Also, you would leave the exit and find yourself right around the surface of a neutron star, which is a somewhat dangerous location. Worse, you would have to travel at a relativistic velocity to escape the neutron star's monstrous gravity, which means your fast clock would run very slow, so the rest of the universe would be aging faster than you. Also, the nearest neutron star is several light-years away, adding to your return-trip travel time. I'm sure it would be a fantastic adventure, but sort of a waste to fly into a wormhole, travel centuries back in time, and rocket away from a neutron star at nearly the speed of light- only to get back home and find that due to relativistic effects and travel time, you are right back where you started, or even farther along!
I haven't done the math, but I suspect that sort of scenario could be one of several ways the universe is protected from time travel paradoxes- you can go back in time, but due to relativistic time dilation and the effects of gravitational fields, you can never make it back in time to affect events in the past of your light-cone, preventiing you from creating an inconsistent causal loop.
"FDA staff reviewers expressed concern about the number of patients who were left out of the study because they died."
I love it.
Someone could become very, very rich if this were possible. Let's see, travel back to 1997 and tell your past self to invest in Pets.com, Enron, and Worldcom, but tell your past self to get out by 2000.
I think Larry and Bill must be time travelers
I hope that someday we will be able to put away our fears and prejudices and just laugh at people. - Jack Handey
Don't people think?? going back in time will never happen! because then people would have come back from some point in the future (a time when they've created the machine) and tell us about it!... and it hasn't happened therefore you will never be able to go back in time!
A couple of weeks ago I was in a used bookstore, and happened across a copy of Robert Monroe's Far Journeys, which spends a few words on the subject of time travel. Mr. Monroe was one of the first people to write about Out of Body Experiences in western society. To make what could be a very long post much shorter - time travel is real, it can be experienced - you just need to learn how to leave your physical body behind. OOBE's are just another way to hack your wetware. To quote the K5 story, "... anything is possible, when you have root access to your mind's /dev/."
Learn the rules so you know how to break them properly.
www.teslabox.com
The theory seems pretty good (by my layman's understanding, anyways.)
;P
But it's like saying that you can only melt metals to make a ring near a volcano, because that's the way we figured out how to do it originally. Obviously, we don't have to, because we have things called forges!
Once they figure out how to fiddle with wormholes and know what they are trying to do (big, big if) they'll just change the wormhole parameters so that the other end appears where and whenever they want.
Bing, there's the time machine. It'll probably recquire a traveling(space)craft/machine to pass through the aperature.
Arthur Hansen
No! It's a *SIG*. Keep the Special Interest Groups away! (Con joke!)
I'm not sure why sadists would want to read that second really long-titled book, unless it explains how to use physics to hurt people. Masochists, on the other hand, might read it in an effor to cause themselves pain.
Mod me down, and I will become more powerful than you can possibly imagine!
Time travel isn't possible, except for the everyday kind that your wristwatch measures.
If time travel were possible, somebody (human, alien, whatever) from the future (perhaps billions of years into the future, or maybe just next week) would have traveled into the past already.
So, let's consider what can happen. Somebody will travel back in time to before the initial discovery in order to beat the ``original'' researcher to the punch. Now, we've got a cascade of ``inventions'' of the time machine racing backwards through time. Life and time-travel technology reach the earliest time after the Big Bang that the two are sustainable and both are prolifically spread throughout the infant universe. Clearly, that hasn't happened.
Don't think that some sort of morality would prevent this from happening, either. Time travel is an incredibly powerful weapon; consider what a knife to the throat of the infant Hitler would have done to history, and how many people would leap at the chance, consequences be damned. All it would take is one person to do so...at any time in the next many billion years.
The instant time travel becomes possible, the only possible method for self-preservation is to race to the beginning. After all, how do you know that some far-distant alien race with souls of pure evil won't do the same just out of spite?
There's a wonderful quote, and I wish I could remember who said it. ``Time is Nature's way of keeping everything from happening all at once.'' The obvious corollary is that, if you can break time, then everything will happen all at once.
Some people try to get around this in a few different ways. For one, there's the many-universes ilk: each act of time travel creates a whole new universe. In such a case, all of those universes would be on the same headlong rush to take time travel as early as possible. Besides, think of the incredible amount of energy and information needed to duplicate the universe--but I digress.
Others try to justify it by saying that it requires huge energy sources or otherwise make it hard. To this I say, ``so''? All you're talking about is a hard engineering project that'll take a lot of time. And--guess what? Even if it takes ten thousand years to build and the energy output of several stars, the payoff is worth it. Again, the alternative is to let somebody else do it...and invite certain disaster.
I take the mere fact that I'm typing this note as all the proof that I need that time travel is pure fantasy.
Cheers,
b&
All but God can prove this sentence true.
BTW the movie Timeline Movie trailer is out and looks pretty good if you like 13th century adventures mixed in with time travel.
Today's vices may be tomorrow's virtues.
This is just a repeat story. From the future.
homer [as he is being sucked into a blackhole]: there's so much i don't know about astrophysics. i really wish i read that book by that wheelchair guy...
Satanists get good grades too...suspiciously good grades
entitled "How to build a time machine"
Quite an interesting read for those of you interested in this topic. It's a little lighter than Brian Greene or Stephen Hawking, but thorough none-the-less.
Satanists get good grades too...suspiciously good grades
A simple way to think of it is this: Movement through space is represented as distance/time. How would one represent movement through time? It should be time/, but there is nothing to put in the denominator.
This is the first original thing I've read all day here!
Hire a Linux system administrator, systems engineer,
I think you have just highlighted the difference between experimental physicists, and theoretical physicists. To dismiss one "school" of physics because you don't have experimental evidence is obviously not good science. There is a similar debate going on when it comes to measuring the cosmological constant. Briefly, the theoretical physicists have a number larger that the experimentally determined value. So who's right? Obviously, more work needs to be done on that end, so we can't simply dismiss one or the other. Sure we need experiments in science, but the pillars of science (and dialectical materialism for that matter) are laws that have to exist independent of experience - namely, the harmony between cause and effect, and the law of non-contradiction.
Leela: Don't you want to go see the 20th century theme park?
Fry: ah, if I wanted to go back to the year 2000, I could just have myself frozen again.
Today's vices may be tomorrow's virtues.
Check out time travel here.
But seriously. The idea's I've seen on time travel aren't really based on going "back" or "forward" in time, but actually inventing a device which would need a 100% identical device to travel too.
For example (because sometimes I can't be clear enough): A equal pair of machines would be built. One would be sent into space and likely be sent at speeds approaching light speed. Then we could travel to that device (and back) and use that shortcut to save time in travel, and depending on the speed it flys maybe into the past or whatever.
Please correct me... I never understood this approach.
But Feynman Diagrams show that theoretically matter travels back and forth through time all the time.
But also since we are made of "star dust" we've already sort of time traveled. We are made up of particles (or waves for the cry babies) which existed forever, we can look at ourselves and see the big bang.
Get your Unix fortune now!
According to the article general relativity allows time travel. But it doesn't says that time travel is ok with quantum dynamics.
I'm not a physicist, but I think time travel of things larger than a sub-atomic particle is not possible.
The laws of quantum mechanics provide information of the state that a system will have in the future given the state of the system in the present. But they also can be used to calculate the state of the system in the past. So, if I'm alive now, the laws of quantum mechanics say that my parents were alive when I was conceived. So the laws wouldn't permit that I traveled to the past and killed one of them.
In fact, they wouldn't permit that I change nothing of the past, because breathing there wold cause a perturbation that wouldn't be allowed by quantum mechanics.
Do we know that a wormhole blocks gravity? If it doesn't, then time won't vary significantly on the two ends.
Did you check the couch cushions? Those carbon molecule gnomes can be a tricky bunch.
I have a few conjectures.
1 - If time travel is possible it would be difficult for larger massses. If possible what would be first done is send a few photons back in time.
2 - If these are accurately targeted to a particular fiber optic cable, and sent in proper sequential order, information could be sent - perhaps even as TCP packets onto the internet - directed to a particular bulletin board -at any particular time
3 - Only governments or immensely wealthy individuals will have the resources to do this.
4 - Since history might be changed by this action the only ones who might attempt this might be particularily powerful evil individuals - attempting to change the course of history that did not go their way.
I am working out the ramifications of this these conjectures.
You are my hero.
let it do all its processing in the past.
Uh, and where is this computer that existed a billion years in the past to which you are going to send information to going to come from? You said yourself we couldn't send it back there ourselves. *sarcasm* Perhaps space aliens will build it for us.*/sarcasm*
as it can use billions of years for processing...and then use them again if it needs more time
Except that the computer would still be bussy with the first computation, so you'd need another computer. You'd need a compter for every computation you ever wanted to do (or do the problems sequentialy)
Of course we have problems making computers last months/years, how are you going to make a computer run for billions of years without breaking? And where are you going to put it?
Mabe that what the pyramids realy are for!
"You saved 1968." - Ms. Valerie Pringle to the crew of Apollo 8
If time travel is ever invented, it already has been.
think about it.
if i'm a grammar nazi, you're an illiteracy nazi.
The problem with traveling back in time would be that out clothes would probably not have existed....unless we brought them with us, or somehow nothing happened to torch em during the trop, we would be naked when we arrived. Maybe those so called "streakers" are really explorers from the future
Karma: Bad. Mostly because the only moderators that notice me are conservatives.
What, does he think that the universe revolves around his theories?
There's no place I can be, since I found Serenity.
I couldn't agree with you more. The Comman Man (aided by the clueless media) seems to have a fascination with what I like to call "voodoo Science." The more outlandish, the better. While real physics has always been about rigorous (and vigorous) lab work, the popular image of physics, and Science as a whole, has strayed from this considerably.
Witness, for example, the popular celebration of Einstein's thought experiments. The average layman is under the impression that Einstein reached his great intellectual climaxes by just sitting and thinking about things, maybe over a cup of hot chocolate. What people don't see is the hours of experimentation (real experimentation) as he tried to verify and correct the results of his thought experiments.
So why is it like that? Are people just stupid? I don't think so. My best explanation is that people are looking for something to but their faith into, to believe in. Since the collapse of the Catholic Church in the times of Galileo Galilei, there has been a vacuum where religious fervor once stood. Science (or this fantastical mockery of Science) has filled that void, uncomfortably. We will not see great physics (and hence time machines) capture the imaginations of the world's peoples again until organized religion can once more comfort their spirits.
Best wishes in your efforts.
Karma: Good (despite my invention of the Karma: sig)
Has he done anything independently creative within the last twenty years? He either rehashes well-known things, that have been kicking around in the scientific community for quite some time (the article referred to here being a case in point,) or he just rewrites the same book over and over again, every iteration with a more irritating title - The Mind of God taking top prize.
The best thing about having a working time machine would be pushing all who find this fascinating into it and sending them elsewhen.
If time proves to be a complex number, while I would find that fascinating I wouldn't tempted in the slightest to project the terms "backward" or "forward" into a polar coordinate system.
If there's any virtue at all to a discussion about time travel, it's that you can't determine whether mathematics or linguistics is taking the worst beating.
has anyone considered that maybe the atomic clock measures time based upon it's velocity? The same goes for quartz.
Just because a clock measures time by how often an electron moves around a neucleus, how fast a crystal spins, or even how fast c12 decays doesn't mean that I experience time in the same fasion. Be sure you aren't trying to measure time with a ruler and call it evidence that they are related:)
Also someone asked how do we know what absolute zero velocity is. According to relativity, we can measure this with three rays of light from three non-coplaner axis, we can measure the difference of the phase shifts to determine which way we are moving absolutly. That is unless someone here says that light shining out of a front of a car going at 65mph travels at the c+65mph. (I'm not arguing that it does or doesn't, it's not a fact until it's proven.)
Karma Clown
For a little more in depth reading I'd look into buying The Large Scale Structure of Space-Time [amazon.com] by Stephen W. Hawking.
I'm sorry but I was just reminded of that episode of the Simpons where Homer is transported into the third dimension. Scared of the strange things he sees in this new universe he mutters to himself:
"I wish I read that book by that wheelchair guy!"
GMD
watch this
This is about the 30th article in my lifetime that Scientific American had an article about time travel and how it might be possible to do it. This isnt news, it's tradition.
Often wrong but never in doubt.
I am Jack9.
Everyone knows me.
I have this strange urge to go save whales.
Table-ized A.I.
ever seen BTTF?
I don't think timetravel for people isn't the brightest thing to do!
While real physics has always been about rigorous (and vigorous) lab work, the popular image of physics, and Science as a whole, has strayed from this considerably.
Gees. Not only do you insult theoretical physicists here but every other science that does not involve experimentation such as computer science and mathematics. Who are you to define what "real physics" and "real Science" is?
Witness, for example, the popular celebration of Einstein's thought experiments. The average layman is under the impression that Einstein reached his great intellectual climaxes by just sitting and thinking about things, maybe over a cup of hot chocolate. What people don't see is the hours of experimentation (real experimentation) as he tried to verify and correct the results of his thought experiments.
Einstein did some of his best work while employeed as a patent clerk [1] [2] [3]. As a patent clerk, he most likely did not have access to the laboratory equipment needed to perform experiments involving speeds close to that of light. In fact the first experimental verification of general relativity was done some years after his papers and by someone else.
So why is it like that? Are people just stupid?
Okay, you've called us all stupid. Now here's your chance to back up that claim by showing us proof of these supposed "hours of experimentation (real experimentation)" that Einstein needed to work out relativity.
Since the collapse of the Catholic Church in the times of Galileo Galilei, there has been a vacuum where religious fervor once stood. Science (or this fantastical mockery of Science) has filled that void, uncomfortably.
I don't know what country you live in, but here in the US, the Cathloic Church is a formidable force in people's lives and in public policies. It certainly has not collapsed.
Show the theorists some respect.
GMD
watch this
Slashdot is going to post this same story on 2/17/2003.
Damned editors!
Table-ized A.I.
That's strange. I always thought we were continually moving forward through time.
That's what you and I have been taught to believe but it is wrong nonetheless. What strange about it is that supposedly intelligent people in the physics community believe and teach the same crap to young people.
The impossibility of motion in time is easy to grasp if one is willing to put a little bit of thought into it. The truth is, there is only the present and time does not pass. Most physicists, including (and especially) the most famous and admired ones (we all know who they are), are completely out to lunch on this issue. That Scientific American can treat time travel as a serious scientific subject is a sad commentary of the sorry state of theoretical physics.
My advice is, think for yourself. Don't let charlatans and crackpots do your thinking for you, especially if they are famous. Don't believe what I write either. Figure it out on your own.
Voodoo Physics
If time travel were possible, why wouldn't someone have gone back in time and kicked Jesus in the nuts? I mean, what else would you use a time machine for?
Ok, everyone knew it but I claim that backward time travel is possible (in a sense) but cannot be observed. It is really simple to prove.
:-]
First, we have to understand time itself. My hypothesis is that time is an observation of irreversible processes. If a process is not irreversible, then going through that process will not get you forward in time [nor backward for that matter].
Obviously, it is possible to create a loop using just reversible processes [any two 'instances' of the same part of a reversible process are indistinguishable]. This means that any such loop would be confined in the same time. [Physicists actually observe such loops, a pair creation followed by annihilation is one such loop]. Note that this implies that time travel is really possible. What you do is you use pair creation to build two exactly similar objects, one from matter, another from antimatter. The antimatter version travels backwards in time [as observed by external observers made of ordinary matter], and the matter version travels forward. As long as you do not use irreversible processes, you can at some point annihilate those two versions, and have provided such a loop. However, to ensure that, you cannot observe that object (observation is irreversible!). You can however observe *parts* of such object, and all such observations will influence both 'copies' of the object [since it's actually the same object just observed from different locations!].
Now consider photons. How would you *ever* observe the 'same' photon at two different times? I would say you cannot have done that, because time doesn't pass for a photon! So if you consider a single photon, its creation (some atom emits the photon) and its destruction (absorption) occur at two adjacent units of time [from the point of view of the photon!]. The reason that the external world observes light to travel at high speed is because there are many irreversible processes in the observers, and those processes bring those observers away from (or towards) the stationary photon!
In contrast, consider the reversible process of a photon creating a electron-positron pair. A photon and the electron-positron pair are obviously interchangeable [since the process is reversible].
If you now observe the created electron, the electron has transformed into something that you cannot any more transform back to the original photon. Therefore, the positron that was left must also have changed 'at the same moment' [otherwise the process would be reversible]. So the 'next unit of time' for the positron must have been when the positron is destroyed (or observed), and this must occur at the same time as when the electron was destroyed. From this, you can determine that the directions and speed that the electron-positron pair start to travel on pair creation must be such that the destruction of the components of the pair occur 'simultaneously' [at next unit of time from the points of views of both the electron and the positron!].
This model also explains why time can pass in different speeds in different parts of the universe [some parts of universe just happen to be more suspectible for initiating irreversible processes]. So measuring time is a way of measuring the rate of change of entropy. In particular, any processes that only use reversible processes are observed to move at the speed of light. In effect, "moving at the speed of light" is the (only) way to not change at all. [Here, 'change' means that there is a state reachable from the initial state through a series of irreversible processes; obviously, you cannot refer to time when defining 'change'].
Then, according to this model, what is gravity? Acceleration of the gravity would be an artifact from the way that objects interact. In particular, it would be caused by (causal) interaction of objects whose time passes in different rate and the structure of those interactions. The difference in elapsed time between two interactions of the same pair of objects would be directly translated to corresponding observed acceleration between those objects [the conversion ratio is obviously the speed of light]. This explains why there is an approximate correlation between decay rate of particles and their mass.
Now, consider backward time travel in a way that you would actually be able to observe it. That would mean that your irreversible processes used to observe the information would start to reverse themselves! That is a contradiction.
[I hope nobody actually believes this
-- Esa Pulkkinen
The theory of Schrödingers Cat suggests that for each possible outcome since time began, dimensions are split to include all outcomes. This means that the future is already set! All potensial outcomes of the future I might add. The dimension you follow is somewhat random and pherhaps subjective to you. If timetravel makes a "paradox", f.ex where you stop yourself from beeing able to do the actual time-travel in the past, you will enter a new split dimenasion where that so is the case. There will be two copies of you from that point in time. When travelling "Back to the future" there will also be two copies of you when you arrive, the one you meet will never have done the actual time-travle though (you follow?). This means that when you travel back in time, you "jump dimensions" as well, possibly creating a new one. The problem of course is to jump back to the dimension you originated from. Open for discussion! Mindflow
A time when much like today we can 'roll your own' kernel, we will be able to fork our own alternate reality through time travel.
?-|||-----x<*))))><
Ok, from what I understand of relativity, and I did read a book specifically about this subject, the twin paradox is this.
One of the twins gets on a rocket going at a fraction speed of light. And each twin has a telescope to see the other. From each of the twin's point of view, the other twin is aging slower than he is. This aging factor is related to the speed of the rocket.
Now, from article, they say that one twin will have aged more than the other twin even when they are at the same time frame, which is totally wrong. What will happen if the twin returns to earth is that each of the twin will see the other aging more rapidly, and finally when they arrive at the same space-time frame, they will be at the same age.
Can any physicist confirm that this is the correct interpretation?
According to the article, when a person goes in a rocket at speeds comparable to the speed of light, time slows for him, and when he returns he finds himself in the future of the earth.
I have never understood why doesnt the reverse happen?
According to general relativity, there is no absolute frame of reference, so why cant we consider that the earth is actually moving at a very high speed while the rocket is stationary, and that the earth time slows as a result. How can you form asymmetry in the frames of references of the rocket and the earth?
I have found a solution to Riemann's Hypothesis, but have run out of spac
Imagine a point in the future where a time machine has been invented where you could travel back in time. What would you do with it?
One of the things you would do would be to go back to historical events and watch them. Which events would you watch? Ones about which there is considerable uncertainty about what REALLY happened.
Which events come to mind? How about, for example, the Kennedy assassination? Look at the evidence. Oswald was either a far right wing fanatic or a far left one, depending upon which evidence you read. Groups all over the map have ties to both Oswald and Ruby. Wouldn't this be of interest to you?
OK, here's where it gets weird. You go back to watch what REALLY happened, but your going back disturbs the fabric of the universe. Thus, paradoxes abound. The accused assassin becomes both a right wing and a left wing nut. Everyone becomes a suspect. Thus, the fact that someone traveled to watch the assassination is the very reason it cannot be solved!!
Time travel has happened.
Here is a thought experiment. Suppose I have such a worm home set up in my computer lab, one end a year in the future. It is a microscopic one, cause I am a computer guy with no use for planet sized machines. I want stuff that is small and uses minimal power. So my wormhole is just big enough for me to connect to the wireless LAN in my lab 1 year in the future. I change the IP address of my WLAN every 6 months so that there is no conflict.
Now, I start a prime number factorization on my beowulf cluster that will take a year to crack an RSA key. I start the computation, and ssh through the microscopic wormhole to see the result immediately. Cool!
Ok, now I want to crack another key, and I don't want to wait a year, so I interrupt the program. I've already copied the result of the previous computation, and verified that it is correct, so I don't need to actually finish it. Now I can crack another key! In fact, this 1 year microscopic wormhole makes a great way to accelerate any long running computation - provided your computer can stay up for at least a year. (So it won't work for Windows.) Think of being able to render computer animated movies in fantastic detail in seconds!
This smells of a paradox to me, unless I'm missing something.
Wow. (sarcasm) So now that I've read that I'm thoroughly convinced time travel is NOT possible. (/sarcasm).
For the love of God, give me a break!
You're telling me that you come up with some potential scenarios based on human tendencies that is proof why time travel isn't possible? Sure..let's not base it on any real scientific proof. I could draw a simple couple scenarios that would disprove your weak arguments.
1) In reference to the article, time travel IS possible but limited. As stated in the article, a wormhole is a potential way to go into the passed. But, according the nature of how it works, one could only go back in the past to the point where the wormhole was created, but NOT before. That would easily stop you from going to the "beginning of time".
2) Let's not confuse time-travel with space-travel. And let's not assume you could necessarily start and end at arbitrary points. These limitations knock most of your arguments down. Even if you assumed the above, you'd have to assume that these "alien beings" of yours could survive indefinite amounts of time aboard some sort of space ship.
All in all, your arguments are weak. There are too many holes.
"Injustice anywhere is a threat to justice everywhere." - Martin Luther King, Jr.
Your theory, and millions of other ones, are based on the theory that one cannot travel faster than light(e).
You consede the fact that one can travel at half the speed of light(e/2). Assume that two object(a&b) both have a y and a z coordinate of 0 and that they each have a y and z velocity of 0. If object a is heading with an x velocity of e/2 and object b is heading with an x velocity of -e/2. Object a and object b then have a velocity of e relative to eachother.
Origin (0,0,0) only exists for the purposes of describing mathematical situations and velocity cannot be measured relative to a nonexistant point. When all speed is relative, it cannot be capped. Why the hell does everyone insist that nothing can go faster than light when no one can give me a reason WHY.
I've heard that it is "infinit speed". That's complete BS. Does infinity==299,792,458!? If it is not infinite speed, then a craft wouldn't need to carry infinite fuel. Hell, a craft doesn't even need to carry its own fuel!
I do not have a phd. I do not have a college degree. Hell, I don't even have my high school diploma yet. If you can explain this, please email me.
That said, time travel would be a great way to make seemingly instantanious trips. I think that "facsimily transmissions", such as that episode of the Outer Limits would be the fastest way, without time travel. That said, it would take a LOT of money to make it legally permissable.
You can't judge a book by the way it wears its hair.
How to Build a Time Machine by Paul Davies. A very fascinating look at this subject, and also addresses the issues of paradoxes and all the other "hang-ups" to time travel. Check it out.
"We shall show mercy, but we shall not ask for it" -- Winston Churchill
http://www.pbs.org/wgbh/nova/transcripts/2612time
Here's my favorite part:
KIP THORNE: I believe we will know in ten to 15 years when we have the
full laws of quantum gravity in our hands. My best guess, and I would
be willing to lay a fairly heavy odds on this on a bet with Hawking
but he won't take the other side, my best guess is that when we have
those full laws in our hands they will say no, you cannot make a time
machine and go backward in time ever. But until we have those full
laws we just have to leave it as a possibility that remains a
possibility.
STEPHEN HAWKING: I wouldn't take a bet against the existence of time
machines. My opponent might have seen the future and knows the answer.
I think this sums things up quite nicely.
When Grady Booch and Dick Bolz were developing the first Ada programming class, somebody heard how much time they had to do and told them, "That's impossible." Dick Bolz says Grady Booch's reply was, "If it happens, it's possible."
Perhaps time travel just needs a little more, well, time.
Sometimes I worry that I'll develop Alzheimer's disease, but no one will notice.
If it was actually possible too make a time machine, how come we haven't seen any time-travelers from the future coming back?
Jonahweb.com has stuff.
I can't even begin to explain the reason (unfortunately) however Igor Novikov in his lecture at Kip Thorne's 60th birthday party explains the reasoning behind why we know that paradoxes cannot occur. His lecture is reprinted in a book called The Future of Spacetime. The relevant section is on pages 81 and 82. Basically all events concerning a paradox are resolved correctly such that no paradox could ever occur in the first place.
I guess I'll attempt a quick explanation.
You have a very sensitive bomb drifting toward a wormhole (that allows time travel). It enters the wormhole at just the right angle and speed such that once it enters the wormhole and reappears coming out of a nearby wormhole it is able to collide with itself (the bomb in the past before it went into the wormhole) and thus explode. Well this is a paradox. If it explodes before it enters the first wormhole how is it able to exit the 2nd wormhole and hit itself to even detonate?
Novikov says that the proper sequence of events occurs such that the bomb enters the first wormhole but only a fragment exits the 2nd wormhole. The reason being the "bomb" actually did hit the past form of itself but only a fragment ended up entering the wormhole because of the explosion thus causing the fragment to reappear from the 2nd wormhole and causing the original explosion.
The book explains a couple other examples of paradoxes resolving themselves.
I hope this resolves any questions.
this nation, under God, shall have a new birth of freedom. -- Lincoln, Gettysburg Address
... despite all the math that seems consistent, don't both the future and the past not exist? I mean, the futures isn't yet, and the past isn't anymore. I wonder how I could express that in a formula?
Don't tell me I've got to read this crap posted at Slashdot again and again. It was bad enough the next 100 times.
Don't tell me that I'm going to have to read this crap posted at Slashdot over and over again! It was bad enough the next 100 times.
Incidentally, that's what he mentions in his article as 'redshift .2'
Now think of it this way: the magnitude of the various forces is being multiplied by this factor. The object continues to "move through time" at a constant rate, but the laws of physics affecting it are slowed down. If the time dilation was reduced to zero, rather than disappearing from the next "time frame", the object would continue to exist in the present, but would be in a frozen state.
Well, yes, and no... The laws are not slowed down, merely their effects. See below.
What if time dilation became a negative value? The object would remain in the present, the past would stay unaffected, and all forces on the object would reverse. Gravity would push. Magnetic opposites would repulse
Well, no... First, this doesn't follow from your earlier logic - if time dilation were negative, the object would be moving backwards in time but the forces would not be moving backwards... simply its direction along the time-axis of spacetime.
However, I think you're not fully understanding time dilation. Think of spacetime in a condensed format, with one axis representing time, and one axis (at a right angle) representing the three dimensions of space.
We normally move at almost the speed of light along the time axis and _very_ slowly in the space axis... Light, on the other hand, moves at the speed of light on the space axis and not at all in the time axis (there's a theory that photons don't experience time). Now, the faster you go along the space axis, the correspondingly less you go along the time axis, because your total motion (space motion + time motion) has to be equal to c.
That's time dilation. The faster you move in space, the slower you move in time.
-T
Just another thought:
If you travel through time, wouldn't it require that you become the energy/matter pattern you were at that point in time?
Let's say you travel back to 1 minute after your parents conceived you. At that moment, you did exist, only in another form, which was a few million molecules and the small amount of potential energy that would eventually be required to slowly duplicate the cells into a foetus.
Now, if you travel to just 1 year after your death, then you're a decomposed body at that moment. You still exist (nothing is created, nothing is lost, said Lavoisier) but as a bunch of molecules and some energy that serve other purposes than being assembled into a living being. Visiting a point in time occuring after your death would mean you could not experience it, because you're past your death.
Just because you find a way to twist the time/space continuum does not mean you can magically make a snapshot or a copy of yourself, let alone send that copy and let it experience other time periods.
I'd travel back in time to 1994 with all my stock charts and ...
1) Buy a NYSE index fund in 1994 and sell it in 1999.
2) Short Nortel at $120.
3) Short Worldcom at $65
4) Buy Yahoo! in 1994 and sell it in 1999.
I could go on...
This space left intentionally blank.
"The bizarre consequences of time travel have led some scientists to reject the notion outright." -excerpt from How to Build a Time Machine, 8/12/02, ScientificAmerican.com
I'd like to speak Sci with the rest of you but all I speak is OrdinaryJoe.
Dang! That article is one of the best pieces of scifi I've read in a long time!
Experiencing the effects of time more slowly or more quickly relative to something else isn't really time travel. Well, I guess if you interpret "time travel" semantically to mean that, that's what it is. For example, during an orgasm, I experience time as stopped. Pretty cool, huh?
The article is fun for a "what if?" treatise. And since it uses lots of scientific terminology, I guess Scientific American is as good a place as any to print the article.
BOTTOM LINE: One to many vital "if's" and "suppose's" are missing for me to buy; but if you're buying, I've got some "God" to sell you.
Do you need a science degree to offer conjecture? Or does it just make one's conjecture more plausible?
Is there an english major in the house--or at least someone with some time on their hands? I'd appreciate any grammar and spelling tips.
But seriously, what if I could somehow do some serious backward time travel? What would I do?... I'd go back in time to find out if Natalie really does eat hot grits or I'd beat the crap out of the guy who started that load of bull. Why? Because I worship Natalie and so I eat hot grits daily. But the stuff is nasty as hell.
The truth is out there...
p.mon
OW MY SIDES
Physics was never my strong point. Someone explain to me how, if it takes forever for something to fall into a black hole, anything ever falls into a black hole? I would think that once you reach the point of singularity, your black hole would never gain any more mass and would eventually evaporate.
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
Don't you think they'd be here by now?
Seriously. But then again, maybe they are? Maybe the alien visitors from other planets are part of our future and they are just mere history students studying their past? Or is time really linear.
A good book to check out in regards to time travel from a non-scientific and more along hte lines of philosophical standpoint: Mercia Eliade's _The Myth of the Eternal Return_. At least.. its a fun read for those who are interested.
uh, does anyone else agree that such a statement reflects complete ignorance of time travel and its implications? If time travel is possible, it doesn't take "a little longer". Time travel either is possible or it is not (I mean travel into the past. We are all traveling into the future, yes?).
Actually, that was all very convincing. Not 100%, but something more to chew on than 80% of the comments posted. IF time travel were possible, the man is right, their'd be a temporal race of epic porportions and we probably wouldn't just enounter just ourselves, but multiple other factions and species warring over the same fulcrums in time. Maybe there would be police that would "put things right", but if you use any form of law enforcement as an example, it's nowhere near 100% effective. Time would be majorly screwed up. Surely we'd be finding pulse rifles and tacheon cannons fossilized in the ground or something.
But...
Just because we haven't see anything doesn't mean it can't or hasn't happened. I'm assuming a war like this would be highly destructive and create multiple paradoxes during the length of the war (assuming there was one). Obviously, time continues to trek regardless. I would think that when a paradox is created, enough random chance exists in the universe to where the events that cause the paradox are eventially (after a couple billion timeline recycles) circumvented. Maybe through a change in the species evolution, or maybe they didn't carry the two when building their time machine. Don't know, but perhapse the timeline would naturally heal through random chance.
In the end, I'm inclined to agree with the parent. Either it's never going to happen, or it already has and we'll never know about it.
You need a FREE iPod Nano
Because the guy in the rocket isn't in an inertial frame when he slows down & turns around. When he opens the door to the old rocket refrigerator, his carton of eggs will jump out & hit the wall as the turnaround occurs. It won't happen on Earth.
I wonder what programming languages would look like if time was not assumed to flow just forward. Instead of Brainfuck, somebody please invent Timefuck. Instead of "goto", will it have "camefrom" statements, or something yet weirder?
(Cicso can perhaps sell it to the wormhole aliens.)
Table-ized A.I.
one of the theories about anti matter that I have come across was that we live in a 3 dimensional world and anti matter exists in 4 th or 5th dimension. when a particle moves at the speed of light it enters other dimensions where it collides with antimatter, thats how an atomic bomb actually functions. when you talk about travelling at the speed of light you would surely be breaking the 3 dimensional barrier and would thus land up in some 4th or 5th dimension, now that anti matter exists in this 4 or 5 dimensional world, you would be immediately annihilated. Who knows if wormholes does exist in the backyard of your house, maybe they just exist in some other dimension. We have had a very narrow attitude when it comes to looking at the universe, just because we live in a 3 dimensional world doesn't mean that the universe also exists in 3 dimensions
Of course, you have to realize the proof you have here is based on a faulty assumption.
There is one thing of which you can be certain in any form of argument: It is absolutely impossible to disprove the existence of anything.
Quantum mechanics alone indicates there is a possibility, however unlikely, that you are going to spontaneously appear in my room right now right after I type this.
You have to learn that what you believe is not the same as what actually is. Someone may very well have gone back and time and you just did not realize it yet.
this is a common logical fallacy. Remember, the key to wisdom is knowing what you do not know. It will serve you well in the future if you remember that simple truth.
I don't read or respond to AC posts
Things Slashdot has taught me #34:
Just because someone has a Ph.D. does not mean they have any idea what they're talking about.
Especially well demonstrated by Zeinfeld, self-important tosser extraordinaire.
The closest quote I could find on the net to "if it is possible it will happen. If it is impossible it will just take a little longer." was "Things are only impossible until they're not" by the distinguished captain, Jean-Luc Picard.
Anyone else come up with a better match?
When will people lean to stop biting the carbon molecule trolls..
I quote king of the hill
"Boy, I do believe you are retarded"
- It is (theoretically) impossible to accelerate to the speed of light, because it would require an infinite amount of energy to do so, so the best we can do is approach the speed of light.
- The closer you get to the speed of light, the harder it is to accelerate, because of said energy requirement.
Wouldn't time distortion then simply occur because things simply could not happen as fast? Your aging, your blood flow, the chemicals flowing between your synapses (this altering preception), the rate at which something burns, the rate electricity moves at, etc. all happen slower than they would if the object where traveling at a lesser speed, because the whole process takes more energy, correct?If this is true, what happens when an object comes to a complete halt in space, the absolute zero of velocity, if you will. Could that make a black hole or something?
IADNAP.
CAn'T CompreHend SARcaSm?
if you could travel back in time, you could kill your mother before she gave birth to you, but then your birth would be an impossibility, which contradicts the fact that you are alive.
Therefore it can't be possible. Wow, this hurts my head to think about.
There is one serious logical flaw with the H.G Wells Time Machine concept.
Supposedly, the story describes someone who gets into the machine and travels in time, actually, while the machine is working - it is the whole universe that travels in time!
The time traveler is the only one who does not change.
If I travel in time 5 years backwards - I'm supposed to be 5 years younger. If I traveled to before I was born - I would not exist at all and therefor would no be able to go back. What people refer to by time travel is therefor much harder to achieve than just moving a specific person through time - they would like a machine that moves "life, the universe and everything" through time.
Something that has always perplexed me about the possibility of time travel is apparent contradictions with the law of conservations of mass/energy. If an object (say a person) were to travel into the past, wouldn't his/her matter be lost? Correspondingly we would have to surmise that there are three possibilites:
1: Something of equal mass would have to come from the past or be created in the universe simultaneously.
2: Massive amounts of energy would be released when the mass "went back" in time, to compensate for the matter lost. This would make time travel an interesting source or energy, sending useless objects back in time and harnessing the energy released.
3: Law of conservation of mass/energy would have to be adapted in some way to apply to some form of mass/energy integrated over time so that there is a constant amount throughout the life-span of the universe. This would have interesting ramifications if theories of time forking were to prove true, ie which alternate time lines would this time:mass/energy integration be applied?
These are just some idle thoughts I've had... Anyone with some more ideas let me know what you think!
-- Mr. E Gecko
Snarfle.
build a time machine. Make a small wooden box, place yourself in it a week, and when you come out of it, boom, you've traveled a week in time (!).
We always call time the 4th dimension, so this may be the reason for many of us to believe, that we can simply move something around on the "time line" - just like moving your mouse around on your desk, changing it's x/y/z coordinates.
But time is somehow different, it's more like a result of everything that happens.
Traveling through time on one specific place (not everywhere) would just be like one object in 3-dimensional space which has got 2 x-coordinates, but only 1 y- and 1 z-coordinate.
Doesn't look like we will ever be able to travel through time. We are just constructing too complex solutions around very simple facts, and everything looks right, when it actually isn't, because we do not have enough knowledge to prove our theories. It's always just one theory built on (or proven by) another theory...
There's a reason the site's called "Voodoo Physics":
voodoo:
4. Deceptive or delusive nonsense.
People will pass up steak once a week, for crap every day.
Here, since no one seems to be putting theories forward, here goes.
I think of time like a flashlight shining on a wall.
There is only one point shining at any one time. It may be possible to 'see' into the future, or travel there, but not backwards, namely because the Langoliers have eaten it.
It certainly is possible to travel faster than light, and will not result in time-travel. As time has shown again and again, there are no limits. Sound, Light, Warp 10, etc. So, this should tell you all one thing...
NEVER speak in infinitives. You will ALWAYS be proven wrong.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
All of these arguments that the lack of time travelers is evidence that there is no backwards time travel got me thinking: Maybe there are time travelers, but we've given them no reason to show themselves publicly. So...
We need to prepare if we want to find out if backwards time travel is possible.
Here what we to do. We set up a well publicized botique for time travelers, a place that sells tee shirts that says "My parents went backwards in time and all I got was this lousy tee shirt!" If anyone buys the tee shirt then we know that time travel is happening.
Rocky J. Squirrel
I haven't seen anyone mention this, but has anyone considered the effects of a wormhole in a computer ? Let's say we have an iterative function, for example x1= 0.5 * (x0 + 2 / x0) (which will find the square root of 2). Given a wormhole computer, we can send the result of x1 back in time to be used as x0. Thus we could compute values for any iterative function in the time it takes to compute a single iteration. This would work even with very small (subatomic) wormholes. A usable wormhole need only be large enough to send a few electrons through. Perhaps even electrons are larger than we need ? I can't believe I'm the only one whose thought of the implications of this, so does anyone know of any work in this area ?
Ok, one cannot reach the speed of light but suppose one can. Now if someone were shot to earth at the speed of light from 1 light year away, that person will reach earth 1 year later and everyone will witness the death of the universe in a fiery fireball of energy.
Now the speed of light is constant for both the observers and the person travelling at light speed. So although time has stopped for our unlikely hero, he would still perceive 1 year passing in his time frame before he arrives. At which point he discovers eternity has passed and there is nothing left of the universe.
How can both these realities be reconciled???!!! huh? huh?
--
# I have no brain
Of course, you have to realize the proof you have here is based on faulty assumption.
Of course, you have to realize I never meant it as a proof. That is one reason that I titled my comment "evidence...", not "proof...."
As several people have pointed out, my logic may have indeed been faulty. Of course, that's what evidence is there for.
I wouldn't have been so arrogant as to label what I said a "proof."
Artificial inteligence is no match for natural stupidity. --unknown
Fortunately we are responsible scientists and won't breathe a word of this until we've rigorously tested it. And maybe not even then, because imagine the weapons possibilities of time travel.
Uh. You're on slashdot. You know this right?
And there's another snag: to be able to go back to the time of construction you have to keep on dragging one of the end points at the speed of light. Anything slower and you will not be able to go that far back in time anymore. And it's a bit difficult to catch up with that, and even if you do, travelling at the speed of light yourself, your travelling in the future with respect to the other end point. So the end result is zip, no change.
Then again, it is not sure yet if this is even possible in theory. Let alone in practice. Plenty of physicists have been working on it, and it is very possible that only energy would be able to pass through a worm hole and that all information would be lost.
At the entrance all of your matter gets converted to energy. That energy get's to the other side. But along the way all info of the original matter that it's coming from is lost. So at the other end, if the energy forms particles again, it's not even going to be the same particles. Let alone that they would be ordered the same way, with the same impuls (speed and direction) to form the same person again.
That's all it is about. Just feed the plebs with tales of time travel and "wormholes" to keep them away from knowledge.
Meanwhile, we couldn't stay alive without a supeluminal causal interaction which the gravity is. And a local "absolute" ref sys can be constructed as proved by GPS; and there's no reason to believe it cannot be done for a system of arbitrary complexity, e.g. universally.
One of the most horrible examples of outright lies about the speed of interactions is whatever we're taught of the Coulomb electric field, which actually is exactly as instantaneous as gravity and not "propagating at c" off the source. Just imagine the energy of virtual photon flux to carry the momentum exchanged in Coulomb interaction!
So we've spent about a century believing fast space travel is impossible or is only by unengineerable "wormholes", that's instead of trying to engineer sane approaches to the task. Somebody might've needed exactly that.
BTW, the same thing happened to the "free energy" concept. For ages we had a source of free energy lying around unattended. Every permanent magnet delivers a flux of first-order (force) field; connecting the poles with a magnetic conductor creates energy in that magnetic conductor (ferromagnetic core) proportionate to the flux squared and the length of the core; hence the longer the core - the more energy created for free!
But just imagine both the superluminal travel and free energy in the hands of everybody around! It doesn't take a terrorist to blow the world away, an idiot is quite sufficient for the task...
That's X-L-N-tay!
Thanks, epine. If I had mod points to award, and could award them to just a portion of a post, I'd rate that sentence a "5".
But I don't and I can't.
The article says
'Paradoxes of this kind arise when the time traveler tries to change the past, which is obviously impossible'
why? Is there a theory that proves this? I remember Michael Crichton's timeline where he argues why one can not change the past with the example of changing the outcome of a baseball game - one person can't go to the stadium and change the outcome. I didn't buy that.
Just change. But perhaps the simplest explanation is not always the right one...
Time flies like an arrow...
fruit flies like a banana
--Groucho Marx
If we ever was to be able to build a time machine, shouldnt we then at some point have had visitors from the future? As far as I know, we still havent so I believe it's very unlikely that a time machine ever will be built...
umm...
TIME TRAVEL IS NOT POSSIBLE!
THEORETICAL PHYSISISTS ARE MUPPETS
worm holes are non proven hypothesis based on divide by zero errors.
time can be thought of as an asymetric z transform. We can calculate previous states but cannot reverse to them due to factors such as entropy and inertia. The only way to approximate time travel would be by localised spacetime simulation.
Also einstein was wrong for a number of reasons that I wont go into here.
for further reading please try: "alice in wonderland", "the muppets bedtime stories", and "cloud cuckooland".
Just think, it would be one heck of a plus to send the solution back in time with a quick hint to post it on "/.". Perhaps it is because it didn't happen and the usual trolls got there, that we can say that time-travel doesn't exist.
Yes, someone *did* say that. It was me. I also am known for saying "you couldn't tell the difference between bear poop and apple butter".
Good way of making money quickly. Of coursem your time machine probably breaks SEC insider-trading rules.
i was fucking his mother just the other day and she's quite the crack whore
I tried to read up on inertial and non-inertial frames reference. But the definition they give is vague in itself. The inertial frames of reference are those which dont accelerate. But Sir, respect to what?? Since Einstein proved that there is no ether, and there is no absolute frame of reference, how can you prove that a frame is not accelerating?
For example, how can you take the earth as an inertial frame of reference, since the earth is also moving wrt Sun, and Sun is also moving wrt Galaxy, which in turn is also moving. Everything is moving!
I agree that objects on earth are not going hither-thither but that does not prove earth is a perfect inertial frame of reference. This will happen on every body with some gravity.
Earth may be "more inertial" than the rocket, but that again does not prove anything.
Also, the rocket will be non-inertial for a short period of time when it is accelerating and decelerating, otherwise it will have constant velocity.
I am totally confused.
I have found a solution to Riemann's Hypothesis, but have run out of spac
You humans and your wormholes. When will you learn?
We all know that subspace exists, but why are we using it? We don't know what "space" is. We can define the basic physics of the environment as "no air, near-weightless (since gravity is everywhere and exerts some sort of pull on objects), and filled with almost every source of noise known to man". What if space is a sphere and subspace is like the chicken and gravy under the crispy, flaky crust of the pot pie?
Another factor to consider, what if we live in a closed space? An open space would have the same adverse affects of time travel. Time pockets where time may run slower or faster or not at all, then there are problems with rate of growth/collapse of the universe. Where would we come out? We wouldn't know since we have no way of calculating the physics of subspace since no one has been there.
The idea is all fine and dandy, but how are we going to produce the power necessary to break the subspace barrier? We're a wimpy level 3 civilization. Until we become a true level 2, we have no hope. And HOW are we going to break the subspace barrier?
Is it me or am I just nuts...
-- Game Developers: Stop porting badly-textured games from crappy console systems!
The way I look at timetravel is that it spawns a sort of alternate reality that is different from the one that it came from. For instance, because we make choices, different dimensions of reality spin off from those choices. ie. I had cereal instead of toast this morning. Well maybe if I had toast it would have been so dry that I would have choked on it and died. That's an extreme example but you understand what I mean. There are an infinite number of realities out there that are spawning an infinite number of other realities from the infinite number of events that someone or something else creates.
Now, if you look at our history, Time Travel is only mentioned in theory and in Science Fiction. I think it's safe to assume that even though we think we would be able to control ourselves, that there would be someone that would take a time travelling machine and travel into the past to cause some sort of trouble that would eventually lead to the world discovering about time travel. I have limited knowledge of world history, but I don't think that has happened yet. On a side note, one could also argue that we are being visited by time travellers already in the form of "aliens". Not only would the alien theory support a one timeline theory, but you could also assume that someone with a time travelling machine would also have the technology to protect this knowledge from our primitive selves. I'm going to assume that all this is tripe and that time travel does not exist in present day. No aliens, no time travellers from the future, and no secret time travelling (ie. Abe Lincoln was not a time traveller).
Now, the way that I look at it is that our reality is the one from which time travel is eventually created, and that if we were to travel back into time, our reality would remain unchanged, but other realities would be spawned from that event. Now here's the thing that I think is what makes my theory kind of unique- I think that our reality is the one that is the "backbone" of all other realities in terms of Time Travel, we invent time travel, and we travel back into the past and create a new reality that has time travel actively affecting that specific history (at least, I think this is unique.. anyone else ever heard of it?). This means that you wouldn't be able to just travel back in time and find out what happened with the pyramids, and freeze yourself in cryonics to tell everyone about it in the future, because you would affect the future just by being there. An infinite number of realities spawned from your time travelling experience. You would also not be able to come back to our time unless you had some sort of Dimension Hopper, in which case you would have to freeze yourself anyway and jump back at the exact moment you left your timeline.
Also, you would have to deal with the fact that the earth is moving around the sun , our solar system is moving relative to a point, and other such physics, which means you would have to have a spaceship that could travel at great speeds to travel the distance towards earth where it will be however many years that you decide to go back. Presumably we would be smaller and have larger brains in the future... ?? Wait a minute.. Maybe the alien thing was right on??
in girum imus nocte et consumimur igni
I still have my old Neo Geo somewhere in the basment :)
Hey time travel happens all the time, I was sent to kill President Kennedy to prevent some horrible things, but you didn't notice any change do you? No. To you it's been this way always...
Of course I never go back, but someone had to do it you know...
Anyone out there know enough about Relativity to explain what would happen if you had two spacecraft orbiting at high speed around the sun in different directions.
Both are subject to the same (but opposing) accelerations.
Both are moving at high speed wrt each other at all times.
Given atomic clocks in each, that start when they pass at 0 degrees, it would appear that both must show the same time at 180 degrees and at 360 degrees ?
Any thoughts ?
If local time slows down the fast you get, does that mean that if you found a way of being completely still, would time go very fast?
I realise that being perfectly still may be impossible, since the earth, the sun, and the galaxy are all moving, so to know excatlly what would happen is impossible, but does anyone have any theroys?
Uh, no. You are precisely, exactly wrong. Clocks in the attic run faster than the basement because of gravity's effect on spacetime.
I think it is that the speed of light is always constant from a given point of reference (even if that point is moving), or something.
Time still "moves" in only one direction and that is into the future.
Once an event has happened neither the people flying nor the ones Earth bound can revisit it.
If time travel was possible somebody would have visited us already making plain obvious it is achievable.
IANAL but write like a drunk one.