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The Giant Atom-Smasher Being Built at CERN might be Possible to Travel Backwards or Forwards in Time as Time Machine
:: 11 February, 2008
Two Russian mathematicians have suggested that the giant atom-smasher being built at the European centre for nuclear research, Cern, near Geneva, could create the conditions where it might be possible to travel backwards or forwards in time. In essence, Irina Aref'eva and Igor Volovich believe that the Large Hadron Collider at Cern, which is due to be switched on this year for the first time, might create tiny "wormholes" in space which could allow some form of limited time travel.
If true, this would mark the first time in human history that a time machine has been created. If travelling back in time is possible at all, it should in theory be only possible to travel back to the point when the first time machine was created and so this would mean that time travellers from the future would be able to visit us. As an article in this week's New Scientist suggests, this year – 2008 – could become "year zero" for time travel.
Is this really a serious proposition?
The article points out that there are many practical problems and theoretical paradoxes to time travel. "Nevertheless, the slim possibility remains that we will see visitors from the future in the next year,".
It has to be said that few scientists accept the idea that the Large Hadron Collider (LHC) will create the conditions thought to be necessary for time travel. The LHC is designed to probe the mysterious forces that exist at the level of sub-atomic particles, and as such will answer many important questions, such as the true nature of gravity. It is not designed as a time machine.
In any case, if the LHC became a time machine by accident, the device would exist only at the sub-atomic level so we are not talking about a machine like Dr Who's Tardis, which is able to carry people forwards and backwards from the future.
What do the experts say about the idea of time travel?
The theoretical possibility is widely debated, but everyone agrees that the practical problems are so immense that it is, in all likelihood, never going to happen. Brian Cox, a Cern researcher at the University of Manchester, points out that even if the laws of physics do not prohibit time travel, that doesn't mean to say it's going to happen, certainly in terms of travelling back in time.
"Saying that the laws of physics as we know them permit travel into the past is the same as saying that, to paraphrase Bertrand Russell, they permit a teapot to be in orbit around Venus," Dr Cox says. It's possible, but not likely.
"Time travel into the future is absolutely possible, in fact time passes at a different rate in orbit than it does on the ground, and this has to be taken into consideration in order for satellite navigation systems to work. But time travel into the past, although technically allowed in Einstein's theory, will in the opinion of most physicists be ruled out when, and if, we develop a better understanding of the fundamental laws of physics – and that's what the LHC is all about."
Why is the possibility of time travel even considered?
It comes down to the general theory of relativity devised by Albert Einstein in 1905. It is the best theory we have so far on the nature of space and time and it was Einstein who first formulated the mathematical equations that related both time and space in the form of an entity called "space-time". Those equations and the theory itself do not prohibit the idea of time travel, although there have been many attempts since Einstein to prove that travelling back in time is impossible.
Is there anything to support the theory?
Lots of science fiction writers have had fun with time travel, going back to H.G. Wells, whose book The Time Machine was published in 1895 – 10 years before Einstein's general theory of relativity. Interestingly, it was another attempt at science fiction that revived the modern interest in time travel.
When Carl Sagan, the American astronomer, was writing his 1986 novel Contact, he wanted a semi-plausible way of getting round the problem of not being able to travel faster than the speed of light – which would break a fundamental rule of physics. He needed his characters to travel through vast distances in space, so he asked his cosmologist friend Kip Thorne to come up with a possible way of doing it without travelling faster than light.
Thorne suggested that by manipulating black holes it might be possible to create a "wormhole" through space-time that would allow someone to travel from one part of the Universe to another in an instant. He later realised that this could also in theory be used to travel back in time. It was just a theory of course, and no one has come close to solving the practical problem of manipulating black holes and creating wormholes, but the idea seemed to be sound. It spawned a lot of subsequent interest in wormholes and time travel, hence the latest idea by the two Russian mathematicians.
Apart from the practicalities, what's to stop time travel?
The biggest theoretical problem is known as the time-travel paradox. If someone travels back in time and does something to prevent their own existence, then how can time travel be possible? The classic example is the time traveller who kills his grandfather before his own father is conceived.
Cosmologists, renowned for their imaginative ingenuity, have come up with a way round this paradox. They have suggested that there is not one universe but many – so many that every possible outcome of any event actually takes place. In this multiple universe, or "multiverse" model, a woman who goes back in time to murder her own granny can get way with it because in the universe next door the granny lives to have the daughter who becomes the murderer's mother.
Where does this leave the time machine in Geneva?
The science writer and physicist John Gribbin, who explains these things better than most, points to a saying in physics: anything that is not forbidden is compulsory. "So they expect time machines to exist. The snag is that the kind of accidental 'time tunnel' that could be produced by the LHC in Geneva would be a tiny wormhole far smaller than an atom, so nothing would be able to go through it. So there won't be any visitors from the future turning up in Geneva just yet. I'd take it all with a pinch of salt, but it certainly isn't completely crazy."
So, not completely crazy, just a bit crazy.
So will we one day be able to travel into the future?
Yes...
* There is nothing in the laws of physics to prohibit it, and events in Geneva are pointing the way and could be a first step
* In physics, so the saying goes, if nothing is prohibited, it must happen at some point
* All we need to do is to work out how to manipulate black holes and wormholes, and away we go
No...
* The practical problems with time travel are too immense to solve, and even if you could, who would want to?
* You might travel back in time and kill one of your grandparents by accident. Then where would you be?
* If time travel is possible, why are we still waiting to welcome our first visitors from the future?
Note for Large Hadron Collider
The Large Hadron Collider (LHC) is a particle accelerator and hadron collider located at CERN, near Geneva, Switzerland (46°14′N, 6°03′E). Currently under construction, the LHC is scheduled to begin operation in May 2008. The LHC is expected to become the world's largest and highest-energy particle accelerator. The LHC is being funded and built in collaboration with over two thousand physicists from thirty-four countries as well as hundreds of universities and laboratories. When activated, it is theorized that the collider will produce the elusive Higgs boson, the observation of which could confirm the predictions and 'missing links' in the Standard Model of physics and could explain how other elementary particles acquire properties such as mass. The verification of the existence of the Higgs boson would be a significant step in the search for a Grand Unified Theory, which seeks to unify three of the four fundamental forces: electromagnetism, the strong force, and the weak force. The Higgs boson may also help to explain why the remaining force, gravitation, is so weak compared to the other three forces. In addition to the Higgs boson, other theorized novel particles that might be produced, and for which searches are planned, include strangelets, micro black holes, magnetic monopoles and supersymmetric particles.
The collider is contained in a circular tunnel with a circumference of 26.659 kilometres (16.5 miles), at a depth ranging from 50 to 175 metres underground. The tunnel was formerly used to house the LEP, an electron-positron collider.
The 3.8 metre diameter, concrete-lined tunnel actually crosses the border between Switzerland and France at four points, although the majority of its length is inside France. The collider itself is located underground, with many surface buildings holding ancillary equipment such as compressors, ventilation equipment, control electronics and refrigeration plants.
The collider tunnel contains two pipes enclosed within superconducting magnets cooled by liquid helium, each pipe containing a proton beam. The two beams travel in opposite directions around the ring. Additional magnets are used to direct the beams to four intersection points where interactions between them will take place.
Note for General Theory of Relativity
General relativity is a theory of gravitation developed by Einstein in the years 1907–1915. The development of general relativity began with the equivalence principle, under which the states of accelerated motion and being at rest in a gravitational field (for example when standing on the surface of the Earth) are physically identical. The upshot of this is that free fall is inertial motion: In other words an object in free fall is falling because that is how objects move when there is no force being exerted on them, instead of this being due to the force of gravity as is the case in classical mechanics. This is incompatible with classical mechanics and special relativity because in those theories inertially moving objects cannot accelerate with respect to each other, but objects in free fall do so. To resolve this difficulty Einstein first proposed that spacetime is curved. In 1915, he devised the Einstein field equations which relate the curvature of spacetime with the mass, energy, and momentum within it.
Some of the consequences of general relativity are:
Time goes slower at lower gravitational potentials. This is called gravitational time dilation.
Orbits precess in a way unexpected in Newton's theory of gravity. (This has been observed in the orbit of Mercury and in binary pulsars).
Even rays of light (which are weightless) bend in the presence of a gravitational field.
The Universe is expanding, and the far parts of it are moving away from us faster than the speed of light. This does not contradict the theory of special relativity, since it is space itself that is expanding.
Frame-dragging, in which a rotating mass "drags along" the space time around it.
Technically, general relativity is a metric theory of gravitation whose defining feature is its use of the Einstein field equations. The solutions of the field equations are metric tensors which define the topology of the spacetime and how objects move inertially.
About TARDIS
The TARDIS (Time and Relative Dimension(s) in Space). is a time machine and spacecraft in the British science fiction television programme Doctor Who.
A product of Time Lord technology, a properly maintained and piloted TARDIS can transport its occupants to any point in time and space. The interior of a TARDIS is much larger than its exterior, which can blend in with its surroundings through the ship's chameleon circuit. In the series, the Doctor pilots an unreliable, stolen, obsolete Type 40 TARDIS, once referred to as a TT Capsule, whose chameleon circuit is faulty, leaving it locked in the shape of a 1950s-style London police box. It was stolen from Gallifrey where it was undergoing maintenance, and the unpredictability of the TARDIS's short range guidance — that is, relative to the size of the entire Universe — has often been a plot point in the Doctor's travels.
Although "TARDIS" is a type of craft, rather than a specific one, the Doctor's TARDIS is usually referred to as "the" TARDIS or, in some of the earlier serials, just as "the ship". (In the two 1960s Dalek films, the craft was referred to as Tardis, without the definite article.)
Doctor Who has become so much a part of British popular culture that not only has the shape of the police box become more immediately associated with the TARDIS than with its real-world inspiration, the word "TARDIS" has been used to describe anything that seems bigger on the inside than on the outside. The name TARDIS is a registered trademark of the British Broadcasting Corporation.
About European Organization for Nuclear Research
The European Organization for Nuclear Research is the world's largest particle physics laboratory, situated in the northwest suburbs of Geneva on the border between France and Switzerland. The convention establishing CERN was signed on 29 September 1954. From the original 12 signatories of the CERN convention, membership has grown to the present 20 member states. Its main function is to provide the particle accelerators and other infrastructure needed for high-energy physics research. Numerous experiments have been constructed at CERN by international collaborations to make use of them.
The main site at Meyrin also has a large computer centre containing very powerful data processing facilities primarily for experimental data analysis, and because of the need to make them available to researchers elsewhere, has historically been (and continues to be) a major wide area networking hub.
CERN currently has approximately 2600 full-time employees. Some 7931 scientists and engineers (representing 500 universities and 80 nationalities), about half of the world's particle physics community, work on experiments conducted at CERN.
As an international facility, the CERN sites are not officially under Swiss or French jurisdiction, and some company vehicles have diplomatic number plates. This includes the organization's fleet of fire trucks.
Tags: mathematicians , atom-smasher , Cern , Irina Aref'eva , Igor Volovich , Large Hadron Collider , time machine , Dr Who's Tardis , Einstein's theory , fundamental laws of physics , theory of relativity , John Gribbin ,
