Time Travel - Fact or Fiction?

Tom

An Old Friend
Large Hadron Collider Could Be World's First Time Machine, Researchers' Theory Suggests

ScienceDaily (Mar. 15, 2011) — If the latest theory of Tom Weiler and Chui Man Ho is right, the Large Hadron Collider -- the world's largest atom smasher that started regular operation last year -- could be the first machine capable of causing matter to travel backwards in time.


"Our theory is a long shot," admitted Weiler, who is a physics professor at Vanderbilt University, "but it doesn't violate any laws of physics or experimental constraints."
One of the major goals of the collider is to find the elusive Higgs boson: the particle that physicists invoke to explain why particles like protons, neutrons and electrons have mass. If the collider succeeds in producing the Higgs boson, some scientists predict that it will create a second particle, called the Higgs singlet, at the same time.
According to Weiler and Ho's theory, these singlets should have the ability to jump into an extra, fifth dimension where they can move either forward or backward in time and reappear in the future or past.
"One of the attractive things about this approach to time travel is that it avoids all the big paradoxes," Weiler said. "Because time travel is limited to these special particles, it is not possible for a man to travel back in time and murder one of his parents before he himself is born, for example. However, if scientists could control the production of Higgs singlets, they might be able to send messages to the past or future."
Unsticking the "brane"
The test of the researchers' theory will be whether the physicists monitoring the collider begin seeing Higgs singlet particles and their decay products spontaneously appearing. If they do, Weiler and Ho believe that they will have been produced by particles that travel back in time to appear before the collisions that produced them.
Weiler and Ho's theory is based on M-theory, a "theory of everything." A small cadre of theoretical physicists have developed M-theory to the point that it can accommodate the properties of all the known subatomic particles and forces, including gravity, but it requires 10 or 11 dimensions instead of our familiar four. This has led to the suggestion that our universe may be like a four-dimensional membrane or "brane" floating in a multi-dimensional space-time called the "bulk."
According to this view, the basic building blocks of our universe are permanently stuck to the brane and so cannot travel in other dimensions. There are some exceptions, however. Some argue that gravity, for example, is weaker than other fundamental forces because it diffuses into other dimensions. Another possible exception is the proposed Higgs singlet, which responds to gravity but not to any of the other basic forces.
Answers in neutrinos?
Weiler began looking at time travel six years ago to explain anomalies that had been observed in several experiments with neutrinos. Neutrinos are nicknamed ghost particles because they react so rarely with ordinary matter: Trillions of neutrinos hit our bodies every second, yet we don't notice them because they zip through without affecting us.
Weiler and colleagues Heinrich Päs and Sandip Pakvasa at the University of Hawaii came up with an explanation of the anomalies based on the existence of a hypothetical particle called the sterile neutrino. In theory, sterile neutrinos are even less detectable than regular neutrinos because they interact only with gravitational force. As a result, sterile neutrinos are another particle that is not attached to the brane and so should be capable of traveling through extra dimensions.
Weiler, Päs and Pakvasa proposed that sterile neutrinos travel faster than light by taking shortcuts through extra dimensions. According to Einstein's general theory of relativity, there are certain conditions where traveling faster than the speed of light is equivalent to traveling backward in time. This led the physicists into the speculative realm of time travel.
Ideas impact science fiction
In 2007, the researchers, along with Vanderbilt graduate fellow James Dent, posted a paper titled "Neutrino time travel" that generated a considerable amount of buzz.
Their ideas found their way into two science fiction novels. Final Theory by Mark Alpert, which was described in the New York Times as a "physics-based version of The Da Vinci Code," is based on the researchers' idea of neutrinos taking shortcuts in extra dimensions. Joe Haldeman's novel The Accidental Time Machine is about a time-traveling MIT graduate student and includes an author's note that describes the novel's relationship to the type of time travel described by Dent, Päs, Pakvasa and Weiler.
Ho is a graduate fellow working with Weiler. Their theory is described in a paper posted March 7 on the research website arXiv.org.


Large Hadron Collider could be world's first time machine, researchers' theory suggests
 
Survey shows belief in time travel


http://www.hucknalldispatch.co.uk/news/survey_shows_belief_in_time_travel_1_3168543

Published on Tuesday 15 March 2011 06:35
Nearly a third of Britons believe their lives could soon be made much easier thanks to the gift of time travel, research commissioned by Birmingham Science City has found.
A survey of 3,000 people has revealed that 30% of adults across the UK mistakenly believe that time travel is actually possible and not confined to the realms of fictional films or television.
The research suggests that programmes such as Doctor Who and Ashes to Ashes may have had a hand in the blurring of lines between science fiction and science fact.
Results also showed that nearly half of adults (44%) wrongly believe that memory-erasing technology similar to that used in the film Men in Black and hover boards, such as those showcased in Back to the Future, exist in reality.
The possibility of being teleported was also an option for nearly a quarter of those surveyed (24%) who wrongly think it is a real mode of transport, while 22% of people think light sabres exist not just in Star Wars, but also in real life.
The team of researchers, who carried out the study to celebrate National Science and Technology Week, said it was "not surprising" that people sometimes get science fact and science fiction confused because of the major scientific advances being made across the world.
For example, over three quarters (78%) of Britons believe that invisibility cloaks exist only in the fictional world, and yet a team at the University of Birmingham, led by Prof Shuang Zhang, has developed a method for making objects appear invisible.
Nearly nine out of 10 people (89%) think it would be impossible to grow an extra pair of eyes, even though scientists at the University of Warwick have found this is possible in frogs. The team members believe they will be able to use the technology to explore eye development in humans and grow an "eye in a dish".
Dr Pam Waddell, director of Birmingham Science City, said: "While films and TV can be acknowledged as creating confusion, it is also worth highlighting how advanced science has now become and many things deemed only possible in fiction have now become reality or are nearing creation due to the advancements of science."
"What's clear from this research is that science captures everyone's imagination, so we must continue to invest in it and strive to develop the latest 'stranger than fiction' creations."
 
David Darling's Internet Encyclopedia of Science writes this on Time Travel

time travel

[FONT=Arial, Helvetica, sans-serif]Can we travel through time? Of course, we do it all the time! But can we do it at a different rate than normal? Again, the answer is "yes" because of the phenomenon known as time dilation in Einstein's relativity theory. However, time dilation enables, even in principle, only a limited kind of leap into the future – one from which we cannot return to the present. By genuine time travel is meant the ability to jump forward or backward through time at a rate other than that of the ordinary progression of events or that enabled by the relativistic time dilation effect.

The possibility of traveling through time poses such a threat to causality and opens the door to so many disturbing paradoxes that many scientists feel inclined to dismiss it out of hand. However, it has been a favorite theme of science fiction since the 1880s. In The Time Machine (1895), H. G. Wells gives a pleasant preamble about the nature of the fourth dimension before whisking his hero 802,000 years into the future. Says the Time Traveller (we never learn his real name), "[A]ny real body must have extension in four directions: it must have Length, Breadth, Thickness, and-Duration. There are really four dimensions, three of which we call the three planes of Space, and a fourth, Time. There is, however, a tendency to draw an unreal distinction between the former three dimensions and the latter, because it happens that our consciousness moves intermittently in one direction along the latter from the beginning to the end of our lives."

Unfortunately for would-be chrononauts (an early version of The Time Machine was called "The Chronic Astronauts"), Wells is not specific about how his time traveling device works, though we know that "Parts were of nickel, parts of ivory, parts had certainly been filed or sawn out of rock crystal." In more recent times, physicists, speculating on some of the more esoteric byways of relativity and quantum mechanics, have been a little more forthcoming about how time travel might be achieved in practice. These speculations have variously involved wormholes (shortcuts outside of normal space and time), faster-than-light particles known as tachyons, and unusual cosmological models, such as the Gödel universe, which allow movement to any point in the future or the past (see time machine.) Let us leave aside the practical aspects, however, and focus on the logic of breaking the time barrier.

The various time travel possibilities dealt with in science fiction fall into two broad categories. In the first the time-line, from deepest past to darkest future, is frozen and immutable, like a film-strip. Any time-traveling that takes place is constrained by this preordained structure – effectively, already written into the narrative of the world (the "block universe" of Einsteinian physics) – and is thus prevented from leading to paradoxes. In one variant of this scenario, the so-called Novikov self-consistency principle applies. Named after Igor Novikov, an astrophysicist at Copenhagen University, this asserts that any attempt at time travel that would lead to a paradox, such as the Grandfather Paradox, is bound to fail even if the cause of failure is an extremely improbable event. In other words, try as you might to introduce a contradiction into the time-line, like killing yourself or one of your ancestors in the past, circumstances will always conspire to prevent you. An excellent example of this type of universe is found in Robert L. Forward's novel Timemaster. Another variant on the fixed time-line concept is that any event that appears to have caused a paradox has, in fact, created a new time-line. The old time-line remains unaltered, and the time traveler becomes part of a new temporal branch line. One difficulty with this arrangement is that it might violate the principle of conservation of mass-energy, unless the mechanics of time travel demand that mass-energy be exchanged in precise balance between past and future at the moment of travel. However, the concept of branching universes and alternative histories is not outrageous in physics where the many worlds hypothesis and of Feynmann's sum-over-histories are routinely debated.

The second main type of time travel entertained in science fiction assumes that the time-line is flexible and changeable. This can lead to all sorts of mind-boggling difficulties and contradictions. A way to offset some of these problems is to stipulate that the time-line is very resistant to change. In the extreme case, as writer Larry Niven has argued, it may be a fundamental rule that in any universe where time travel is allowed, no actual time machine is ever invented. The English physicist and mathematician Stephen Hawking put this idea on a more formal footing with his chronology protection conjecture. On the other hand if the time-line is presumed to be easily changed, paradoxes threaten to spring up at every turn. One of the most remarkable of these is the closed causal curve paradox in which, it seems, something can be got for nothing. Samuel Mines summarized the plot of his 1946 short story as follows: "A scientist builds a time machine, goes 500 years into the future. He finds a statue of himself commemorating the first time traveler. He brings it back to his own time and it is subsequently set up in his honor. You see the catch here? It had to be set up in his own time so that it would be there waiting for him when he went into the future to find it. He had to go into the future to bring it back so it could be set up in his own time. Somewhere a piece of the cycle is missing. When was the statue made?"

Closed loops in time can also conjure knowledge out of thin air. A man builds a time machine and travels into the past to give the plans for the device to his younger self who then builds the machine, travels into the past, and so on. Where did the plans originate? A curious thing about time loops is that they have no easily discernible future and past because all the events taking place in them affect one another in a circular way. Time loops also put a question mark over free will. What happens if the younger man, given the time machine plans by his older self, decides not to build the device? Can he make that choice given that, in some sense, he has already built it? Perhaps the apparent absence of time travelers and time machines in the real world is a sign that we do not have to worry about such issues – at least, for the present.
[/FONT]
 
A few notes from a Skwirlinator:

Everything in the Universe is moving. Not only would a time traveler need to traverse time he would also need spacial transport to keep from materializing in interstellar space. The Earth is NOT at the same spacial coordinates it was 1 year ago. The Earth moves, the moon moves, the sun moves, the galaxy moves and the galactic superclusters move in relation to the universe as a whole.
The Earth is moving towards Leo at a speed of 390 kilometers per second.
Starryskies.com

Could the LHC cause a balance issue with the time continuum? Might it rip our universe with time holes? Infinitesimal at first, might they grow as time progresses?
 
thxs for the messages Skwirlinator. i particularly like this bit,


quote -:
"The various time travel possibilities dealt with in science fiction fall into two broad categories. In the first the time-line, from deepest past to darkest future, is frozen and immutable, like a film-strip. Any time-traveling that takes place is constrained by this preordained structure – effectively, already written into the narrative of the world (the "block universe" of Einsteinian physics) – and is thus prevented from leading to paradoxes. In one variant of this scenario, the so-called Novikov self-consistency principle applies. Named after Igor Novikov, an astrophysicist at Copenhagen University, this asserts that any attempt at time travel that would lead to a paradox, such as the Grandfather Paradox, is bound to fail even if the cause of failure is an extremely improbable event. In other words, try as you might to introduce a contradiction into the time-line, like killing yourself or one of your ancestors in the past, circumstances will always conspire to prevent you. An excellent example of this type of universe is found in Robert L. Forward's novel Timemaster. Another variant on the fixed time-line concept is that any event that appears to have caused a paradox has, in fact, created a new time-line. The old time-line remains unaltered, and the time traveler becomes part of a new temporal branch line. One difficulty with this arrangement is that it might violate the principle of conservation of mass-energy, unless the mechanics of time travel demand that mass-energy be exchanged in precise balance between past and future at the moment of travel. However, the concept of branching universes and alternative histories is not outrageous in physics where the many worlds hypothesis and of Feynmann's sum-over-histories are routinely debated. " -: unquote





my mind is going "round and round !" the universe is definitely a strange place. so many "varying parts" to it ! thxs _
 
The idea of time travelling is indeed exciting to me but I think it will be at lest another thousand years before man is able to go backward in time at will.

I think we as a species will master the craft and science of going forward in time but not backward as that is more reserved to Providence. I think some of mankind might abuse the backward time travel abilty the way some of the villains in Doctor Who and JJ Abrams Star Trek have diabolically done.
 
The idea of time travelling is indeed exciting to me but I think it will be at lest another thousand years before man is able to go backward in time at will.

I think we as a species will master the craft and science of going forward in time but not backward as that is more reserved to Providence. I think some of mankind might abuse the backward time travel abilty the way some of the villains in Doctor Who and JJ Abrams Star Trek have diabolically done.
With reverse time travel I would be less concerned about villains as much as those who tend to cause carnage in the name of good. I'm quite sure that it wouldn't be long before somebody came up with the idea to go back & kill Hitler before he rose to power or to interfere with other major events in history.
 
the question is whether there are mulitple universes or just one, that can be altered. and: would you remember the 'oder version' if it was altered? if not you wouldn't notice it anyway and there would be the possibility of alterations all the time!
 
time travel is indeed possible I came back from the future to let you all know that us nerds are still going strong in the future lol

seriously nasa did an experiment they used two special clocks set to the same time one on earth one on the shuttle when they checked them after the mission the one on the shuttle had sped up so it proved that the faster you go the faster time goes it was very interesting
 
yeah - that's realitivity of time: the faster you move the slower time ticks. that has been proven multiple times (they adjust time on gps satalites for that reason!)
 
you can :
make the time faster
make the time Slower
make the time Stop (or near zero)
but can't go back in time

i thing few time that you can se the past
after all we do it evry day by looking into the stars
lots of these starts may die years ago

so why we can't make same thing that can watch spot on earth before 2 years ago
 
Back
Top