# Time travel: loophole discovered in Einstein's theory of relativity



## s12345 (Jul 11, 2011)

At 15 years of age, back in high school, a good friend of mine discovered a loophole in Einstein's theory of relativity, allowing for time travel to be possible.

His calculations were correct; he eagerly awaited the physics professor the next morning to ask him if his calculations were correct. The professor confirmed they were correct. Time travel is possible in theory. However, in order to actually make a time machine, one would need (depending on the application) an enormous amount of energy and money (and we're talking about as much energy as our solar system) to get it working.

I don't have his calculations, but I could always ask him of course. It's possible he might not want to give them to me, but that would be understandable.

In any case, at least this is good news I think.


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## Sacrieur (Jan 14, 2013)

Backwards or forwards? A time machine to the future is very possible.

A time machine to the past is less very possible. We have a theoretical approach to bending light to do it, but so far no dice. The best we have is evidence of retrocausality.


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## LudwigVanBetelgeuse (Apr 3, 2014)

Uhm, this is not a loophole by any means. It's a well known and easy to predict consequence of accepting the postulates of special relativity that time travel to the future is possible. We were taught that in high school.

No offense, but did you really think your high school friend outsmarted Einstein (and the tens of thousands of other scientists since then) and discovered something that somehow everybody overlooked? Please tell me this is a joke...


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## s12345 (Jul 11, 2011)

LudwigVanBetelgeuse said:


> Uhm, this is not a loophole by any means. It's a well known and easy to predict consequence of accepting the postulates of special relativity that time travel to the future is possible. We were taught that in high school.
> 
> No offense, but did you really think your high school friend outsmarted Einstein (and the tens of thousands of other scientists since then) and discovered something that somehow everybody overlooked? Please tell me this is a joke...


I did not mention what the precise loophole was and you're saying 'this' (=what?) is not a loophole. I'm sorry you misunderstood this. I did not mention the loophope as is.

If you think intelligence is something static and if you think we can't be as intelligent or more intelligent than Einstein, then I believe you have a lot to learn about life.


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## s12345 (Jul 11, 2011)

Sacrieur said:


> Backwards or forwards? A time machine to the future is very possible.
> 
> A time machine to the past is less very possible. We have a theoretical approach to bending light to do it, but so far no dice. The best we have is evidence of retrocausality.


Forwards, to the future.


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## LudwigVanBetelgeuse (Apr 3, 2014)

s12345 said:


> I did not mention what the precise loophole was and you're saying 'this' (=what?) is not a loophole. I'm sorry you misunderstood this. I did not mention the loophope as is.





s12345 said:


> His calculations were correct; he eagerly awaited the physics professor the next morning to ask him if his calculations were correct. The professor confirmed they were correct. *Time travel is possible in theory. However, in order to actually make a time machine, one would need (depending on the application) an enormous amount of energy and money (and we're talking about as much energy as our solar system) to get it working.*


This "loophole". As I said before, the allowance of time travel is nothing new. You phrased it like that was something unknown. If you're talking about a true and undiscovered loophole, why has nobody every heard of it since then? Why did you, your friend and the professor keep it a secret until now?



s12345 said:


> If you think intelligence is something static and if you think we can't be as intelligent or more intelligent than Einstein, then I believe you have a lot to learn about life.


When did I make any remarks about intelligence and what has this to do with any of this? You're assumptions are wrong, I don't believe in any of that. Of course there are people on Einsteins level and even beyond. I just find it extremely unlikely that your friend from high school was one of them, unless he happened to be something like a professor in physics. Even then the probabiltiy is very low that he discovered something as revolutionairy as a "loophole" in one of the most widely studied and experimentally verified branches of physics.


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## Sacrieur (Jan 14, 2013)

s12345 said:


> Forwards, to the future.


This is known as time dilation, we have experimental evidence of it. Known for quite some time. If you've watched the original Planet of the Apes, this is exactly what happens in the beginning of the movie.


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## arnie (Jan 24, 2012)

This is hardly something new:

*http://en.wikipedia.org/wiki/Time_travel#Time_travel_to_the_past_in_physics*

Actually doing it, is something else entirely.


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## ToeSnails (Jul 23, 2013)

arnie said:


> This is hardly something new:
> 
> *http://en.wikipedia.org/wiki/Time_travel#Time_travel_to_the_past_in_physics*
> 
> Actually doing it, is something else entirely.


Good read!


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## s12345 (Jul 11, 2011)

Jungle boogie.


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## s12345 (Jul 11, 2011)

Sacrieur said:


> This is known as time dilation, we have experimental evidence of it. Known for quite some time. If you've watched the original Planet of the Apes, this is exactly what happens in the beginning of the movie.


I already knew that. I believe my friend has discovered something different.


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## s12345 (Jul 11, 2011)

ToeSnails said:


> Good read!


Yeah and wikipedia is the world's most reliable source. I've got to say: the most reliable thing is my ignore list.


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## ToeSnails (Jul 23, 2013)

s12345 said:


> Yeah and wikipedia is the world's most reliable source. I've got to say: the most reliable thing is my ignore list.


Hahaha
Looks like someone's a tough guy


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## hoddesdon (Jul 28, 2011)

s12345 said:


> Forwards, to the future.


I think Sacrieur's point is that time travel to the future is already a fully recognized possibility. That is what happened in the first movie in the "Planet of the Apes" series. In theory if you were able to construct a space-craft that could travel fast enough and sent it on a five-year mission then on its return to Earth more than five years would have passed on Earth. Apparently taking a long-haul air flight results in travelling to the future by an extremely small period of time. So if I had never gone on flights like that then I would only now be commencing this post.


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## s12345 (Jul 11, 2011)

ToeSnails said:


> Hahaha
> Looks like someone's a tough guy


I'm Rocky Balboa.


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## MrKappa (Mar 18, 2013)

I can use my math to build a super nova blowing out of your rectum. Doesn't mean it's going to happen.


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## LudwigVanBetelgeuse (Apr 3, 2014)

Lester87 said:


> If time travel is possible it just means the human race goes extinct before we discover how to do it or we survive and never discover how to do it. The latter is highly unlikely as in billions of years we should know everything that is and isn't possible and should also have the technology to make it happen.
> 
> so the only question is assuming future humans do learn how, why did nobody ever use it to travel back in time, because we would have seen them if they had.


Time travel goes in both directions (past and future), this topic is pretty much about future time travel, which is definitely possible (time dilation has been experimentally verified on numerous occasions). Assuming time travel to the past is possible as well, the resulting paradoxes could be avoided if the multiverse hypothesis is correct.

Incidentally, you made some pretty...daring assumptions regarding the life span of the human race and our cognitive abilities. Do you really think we're still gonna exist in _billions_ of years from now? Considering all the mass extinctions that this planet's history had to face? Considering that Earth will no longer support organic life in a couple of billion years because of the increasing luminosity of the Sun?

And why do you think that human intelligence has no limits? It is a fairly realistic possibility that the human race as a whole is simply not intelligent enough to unravel the universe's greatest mysteries. Who knows, maybe there are even species out there who are that much more intelligent that they won't even recognize our species as intelligent at all.


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## Persephone The Dread (Aug 28, 2010)

In theory time slows down near black holes, so if you could manage to orbit one close enough to not get sucked in (and then leave later) you would slow time down for yourself there.

^ if that concept has been proven wrong recently or something, I wouldn't know so don't take it too seriously.


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## MrKappa (Mar 18, 2013)

Persephone The Dread said:


> In theory time slows down near black holes, so if you could manage to orbit one close enough to not get sucked in (and then leave later) you would slow time down for yourself there.


Does that mean if you got on a plane and flew from London to New York, as you traveled across time zones, time would slow down for you, relative to everyone else on the ground?

lol... lol...


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## MrKappa (Mar 18, 2013)

^So theoretically, if he could travel around the earth fast enough, he could see the dinosaurs walk the earth!


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## s12345 (Jul 11, 2011)

I always loved this Superman version of time travel:






It's so majestic.


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## LudwigVanBetelgeuse (Apr 3, 2014)

Lester87 said:


> I understand time dilation and relativity but that isn't really time travel in the sense of jumping from one point in time to another.
> 
> I think it was a fair assumption, i did start by saying we might go extinct first , if that doesn't happen its self evident that our technology and intelligence will improve over time. Humans are still evolving and at the current rate of technology we will be able to control it ourselves in the near future, we already can with serious consequences so we don't experiment, but once we know more about DNA and genetics we will be able to create gene therapies. We can already safely alter sex, hair color , eye color and various other things and it's only been 50 years, whats possible after 500-5000 years?
> 
> ...


Time travel usually does not mean "jumping" in time, but travelling in time, which can be achieved through the effects of time dilation (just a simple misunderstanding then).

Also, you really sound like a futurist (not that there's anything wrong with that). I'm just a little bit more sceptical. With our current computer technology we will certainly reach a limit since we can't make components infinitely small (or computers infinitely large), so we need to develop a whole new generation of computers. While concepts like quantum computing or the technological singularity are certainly a possibility of the future, I do not take them for granted. This is actually a huge scientific debate and there are a lot of scientists on either side of the spectrum.

You say it is self evident that we will simply continue to become more intelligent as time progresses, but how can you know that? What if our technological growth slows down and eventually converges as we get closer to physical limits? Our current rate of technological progress is insane, and most of it happened in an extremely short time span (approx. 200 years). If you just assume that this progress will continue forever, then yeah, in 500 years we might overcome aging and disease and achieve immorality. In 5000 years we will be able to create magical unicorns through telekinesis and in a billion years we will all be gods of our own universes.


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## s12345 (Jul 11, 2011)

Indeed. One important thing to consider is that technology does not always evolve exponentially or linearly. There have been many examples of this in the past.

Some political structures to consider when looking at technology evolution:
- social acceptance of the technology (social constructivism)
- instrumentalism (does the government want to invest money in the technology? See LHC problem)
- how does the technology affect our society (value-laden, value-free) (substantivism)

There are many factors that determine how technology evolves. Social and cultural factors have been the biggest determinants in the past: e.g. Western Society developed artillery, while the idea came from China.


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## LudwigVanBetelgeuse (Apr 3, 2014)

^Very good points. I was only considering cognitive and physical limits in my post, but of course political and social factors also play a huge role in this discussion.



MrKappa said:


> ^So theoretically, if he could travel around the earth fast enough, he could see the dinosaurs walk the earth!


No, only if he travelled at velocities greater than the speed of light, which we all know contradicts our current understanding of physics. Moving at high velocities (or being close to a strong gravitational field) slows down your own time relative to someone moving at slower velocities (or standing in a weaker field), but time always progresses in the same direction.


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## Milco (Dec 12, 2009)

His name escapes me, but it was a German mathematician who first showed that mathematics allow for time travel within Einstein's theory of relativity, though from what I remember (and it's many years I heard about it now), it would take something like half of all the energy in the observable universe to go back just one second.
That mathematical solution has been around for many decades though.


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## Tensor (Mar 9, 2013)

Milco said:


> His name escapes me, but it was a German mathematician who first showed that mathematics allow for time travel within Einstein's theory of relativity


Kurt Gödel, an Austrian.


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## MrKappa (Mar 18, 2013)

LudwigVanBetelgeuse said:


> No, only if he travelled at velocities greater than the speed of light, which we all know contradicts our current understanding of physics. Moving at high velocities (or being close to a strong gravitational field) slows down your own time relative to someone moving at slower velocities (or standing in a weaker field), but time always progresses in the same direction.


So basically if I walked next to this machine I would start to become younger?

http://www.news.harvard.edu/gazette/1999/02.18/light.html

Aw screw it... I'm just going to save up and get me one of these...


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## s12345 (Jul 11, 2011)

Lester87 said:


> because the universe has laws that put limits on everything


I do not agree with this. It's not that the universe has laws, it's that the universe appears to have laws. We defined those laws by observation.. also known as science. Do you think we already discovered most there is to know about our current reality, about the universe? Come on.. we merely know a spickle of the observable universe.. what about the universe that is not observed yet? So many more things to learn. You could as well be an entity in an endless sea of randomness and the laws you see are just an overlap between the randomness. Here it is explained better:




Let us not forget that the shape of the universe is merely an observed one. For more explanation see this series:





Please look outside of your box.. there is more to what you see and know.


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## Milco (Dec 12, 2009)

Tensor said:


> Kurt Gödel, an Austrian.


Funny how nobody seems to remember who's German and who's Austrian :um
I did think if maybe it was him, but couldn't quite narrow it down. Thanks though.


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## LudwigVanBetelgeuse (Apr 3, 2014)

Lester87 said:


> We would only need infinitely small/large computers if there was an infinite amount of knowledge or information and that is not the case because the universe has laws that put limits on everything, what i meant when i said no limit to our intelligence was more to do with knowledge and understanding.


You didn't get my point. When I say we can't make infintiely small computers I mean that we will reach a limit once we get down to making transistors on atomic (or maybe subatomic) levels (which shouldn't be too far away). When I say we can't make infintiely large computers, I obviously don't mean we actually need infinitely large computers, but that simply building bigger computers doesn't seem like an appropriate solution because of practical and financial reasons. Or would you buy a computer as big as your living room? Size limits will eventually require us to develop a new type of computing if we want to keep up our current rate of technological progress.



Lester87 said:


> *For instance, assuming we knew every single thing about chemistry or gravity, that information could easily be stored on a computer. Do you at least agree that it is possible for a sentient being to understand everything about the universe? we have already discovered most the universes laws and understand them.*
> 
> If the human race continues to live and has experience we will also continue to learn. For us to not become more intelligent we would have to never learn or experience anything. I don't think technology will increase forever because that would require infinite new technologies and because of the laws there is a limit so advancement has to slow down over time.


No, no, no. You seem to underestimate the complexity of the universe to an extreme degree. First of all, how can you simply assume that we know "most" of the universes laws or how much knowledge the field of chemistry contains? That would require you to know the amount of laws/facts there are in the first place (if you'll ever figure that out, congrats, you just won the Nobel prize and any other scientific prize ever).

That said, if you ask any serious scientist how many 100% true facts we know about the universe, many will say we know next to nothing (and not only because scientists are often quite modest people). Just look at Dark Matter and Dark Energy for example, they make up about 95% of the unvierse and we have no clue what they are.

Also, it's funny that Gödel came up in this thread. Have you ever heard of his incompleteness theorems? I've only studied the very basics of mathematical logic, but essentially the theorems live up to their name. _The first incompleteness theorem states that in any consistent formal system F within which a certain amount of arithmetic can be carried out, there are statements of the language of F which can neither be proved nor disproved in F_. The second theorem states that _for any consistent system F within which a certain amount of elementary arithmetic can be carried out, the consistency of F cannot be proved in F itself._ (link). Even in mathematics, the most reliable branch of science because it doesn't rely on a posteriori knowledge, it has been proven that not everything can be proven (within the same system). Not long before that a lot of mathematicians believed in the completeness of mathematics, and that one day we will find a 100% true and reliable axiomatic system to describe all of mathematics. Now consider the fact that physics is based on mathematics, and chemistry is based on physics (and so on) and you might also gain a little bit skepticism towards your claim that "we can know everything".



> In 1931, the Czech-born mathematician Kurt Gödel demonstrated that within any given branch of mathematics, there would always be some propositions that couldn't be proven either true or false using the rules and axioms &#8230; of that mathematical branch itself. You might be able to prove every conceivable statement about numbers within a system by going outside the system in order to come up with new rules and axioms, but by doing so you'll only create a larger system with its own unprovable statements. The implication is that all logical system of any complexity are, by definition, incomplete; each of them contains, at any given time, more true statements than it can possibly prove according to its own defining set of rules.
> 
> *Gödel's Theorem has been used to argue that a computer can never be as smart as a human being because the extent of its knowledge is limited by a fixed set of axioms, whereas people can discover unexpected truths* &#8230; It plays a part in modern linguistic theories, which emphasize the power of language to come up with new ways to express ideas. And it has been taken to imply that you'll never entirely understand yourself, since your mind, like any other closed system, can only be sure of what it knows about itself by relying on what it knows about itself.





> Gödel showed that within a rigidly logical system such as Russell and Whitehead had developed for arithmetic, propositions can be formulated that are undecidable or undemonstrable within the axioms of the system. That is, within the system, there exist certain clear-cut statements that can neither be proved or disproved. Hence one cannot, using the usual methods, be certain that the axioms of arithmetic will not lead to contradictions &#8230; It appears to foredoom hope of mathematical certitude through use of the obvious methods.*Perhaps doomed also, as a result, is the ideal of science - to devise a set of axioms from which all phenomena of the external world can be deduced.*


Source


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## s12345 (Jul 11, 2011)

Lester87 said:


> It's not that the earth is round, it only appears to be round and we only defined it as round because of observation.
> 
> Let us not also forget that the shape of the Earth is merely an observed one.
> 
> question, are you 100% certain Earth is round?


I cannot state or affirm with 100% certainty that the Earth is round. You can never be 100% certain about anything. Yes, that is correct. Our mind observes the Earth to be a geometric shape called 'round', within our laws of our current physics model.


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## MrKappa (Mar 18, 2013)

LudwigVanBetelgeuse said:


> Even in mathematics, the most reliable branch of science because it doesn't rely on a posteriori knowledge


Ah, but that is all that mathematics is. There is no such thing as a straight line in nature. We agree as to what a straight line is, and we further reduce the concept of a geometric straight line to vectors. However, a straight line does not exist. We simply agree that straight lines may be used to represent the physical real and natural world. Much in the same we agree that a perfect sphere is much more easy to represent than a naturally flawed one. I am fairly sure science has yet to produce a perfect sphere, or if they have, it is only very recently and most certainly nowhere near as perfect as a mathematical notation.

This is all that mathematics is.

http://en.wikipedia.org/wiki/Axiomatic_system

Posteriori knowledge which is most certainly not a perfectly accurate representation of the real natural world.


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## LudwigVanBetelgeuse (Apr 3, 2014)

s12345 said:


> I cannot state or affirm with 100% certainty that the Earth is round. You can never be 100% certain about anything. Yes, that is correct. Our mind observes the Earth to be a geometric shape called 'round', within our laws of our current physics model.


On a theoretical level I agree (although on a practical level, the shape of the earth is definitely one of the more certain facts of science, as opposed to the Big Bang theory for example).

Lester, consider the following thought experiment in which we live in a universe with a 4th spatial dimension. We would never be able to recognize the true shape of anything, since we are 3-dimensional beings with perceptions limited to three dimensions. Likewise, a 2-dimensional being living on the surface of a sphere would assume to live in a 2-dimensional world. Only by "transcending" into a higher dimension it would realize that the world in which it lived is in fact a 3-dimensional object.

@MrKappa: Well yeah, I know that straight lines don't exist in nature. I'm not sure what you're trying to say. You're basically rephrasing a part of my post. My point was that the natural sciences rely on mathematics, and thus we can never get a complete and true description of nature.

edit: But then again, if we dive into the realms of the philosophy of mathematics and metaphysics, it is possible to argue that math actually does exist in nature, or that nature even is mathematics. It's an interesting debate whether math only exists in our minds or actually does have some objective existence to it (be it in a platonic world or in the real world).


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## coldsorehighlighter (Jun 2, 2010)

So, wait, your friend discovered a currently unknown "loophole" that permits time travel, he showed his evidence to his professor who agreed it was correct and then...they shared the evidence with the rest of the science world who could independently confirm it and bestow honours and awards onto them?


:?


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## MrKappa (Mar 18, 2013)

the cheat said:


> So, wait, your friend discovered a currently unknown "loophole" that permits time travel, he showed his evidence to his professor who agreed it was correct and then...they shared the evidence with the rest of the science world who could independently confirm it and bestow honours and awards onto them?
> 
> :?


Yes, but all this happened way back 15,000 BC after their first experiment and since then we've lost all the historical records of the event.


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## thecalisthenicsdude (Apr 12, 2014)

Lester87 said:


> @Ludwig
> 
> Well you don't really need to make computers bigger, It could be possible for computers to work together like a hive mind of sorts, that may already be possible i haven't really looked into it.
> 
> ...


That is what a supercomputer is. A cluster of computers working together.


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## LudwigVanBetelgeuse (Apr 3, 2014)

@Lester:

Don't get me wrong, I certainly do believe that concepts like strong AI, quantum computing, even a physical TOE (not to be confused with a true knowledge of everything) have a realistic chance of being possible. I'm the first one to defend the possibility of strong AI when some mysticist claims it to be impossible due to a computer's lack of a "soul".

On the other hand, arguments like "Strong AI is real because one day we will develop quantum computers" or "One day we will know everything because we will develop strong AI/we will continue to become smarter infinitely" have no value to me because they rely on highly uncertain assumptions.

I for myself don't think that Gödel's theorems necessarily forbid strong AI or even a TOE, but I'm aware that they might (especially since a lot of scientists from Roger Penrose to Stephen Hawking support this view, even though they form a minority). It is dangerous to simply ignore information that might contradict your own theories, you become trapped in one viewpoint and get tunnel vision.

In the words of Richard P. Feynman:


> Details that could throw doubt on your interpretation must be given, if you know them. You must do the best you can--if you know anything at all wrong, or possibly wrong--to explain it. If you make a theory, for example, and advertise it, or put it out, then you must also put down all the facts that disagree with it, as well as those that agree with it. There is also a more subtle problem. When you have put a lot of ideas together to make an elaborate theory, you want to make sure, when explaining what it fits, that those things it fits are not just the things that gave you the idea for the theory; but that the finished theory makes something else come out right, in addition. In summary, the idea is to try to give all of the information to help others to judge the value of your contribution; not just the information that leads to judgment in one particular direction or another.


I've pointed it out before: I'm a skeptic, you seem to be a very optimistic futurist, and we probably have reached a dead end here. I wish you a wonderful day nonetheless.


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## arnie (Jan 24, 2012)

thecalisthenicsdude said:


> That is what a supercomputer is. A cluster of computers working together.


That's what a beowulf cluster is. A supercomputer is more complicated. Latency and overhead become more of a concern.


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## HabitableExoplanet (May 11, 2014)

Didn't read through the entire thread, but there are solutions to the equations of general relativity that allow for the existence of backwards time travel. In fact, the first person to probably discover such solutions was Kurt Godel in 1949. This is nothing new.


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## HelpfulHero (Aug 14, 2013)

http://arxiv.org/abs/1306.1795


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