The issue of travelling in time is not new because it has interested people for centuries and continues interesting us today. However, in spite of people’s high concern and eagerness to uncover time’s mysteries, it still keeps its secrets as it did centuries ago. Even in our time, when a huge progress in science and technology has been achieved, it seems that we have managed only to touch the surface of this issue and something “floating just above the surface” (Hawking, 2002, p. 17).
Time travel can be referred to as a voyage across time in a way that is parallel to movement across space, like sending something back in time or peeking into the future, without the experience of the intervening duration. In such a case, a time machine can be considered as a mechanism used to travel in time, regardless of hypothetical or fictitious issues.
Presently, it is revealed that if the laws that watch over physics assent to travel back in time, even though this notion has been widely used in fiction, one-way travel is likely via the discernible fact of time dilation which is velocity based in the common relativity theory (Hawking, 2002).
The question that arises concerning this issue is whether traveling through time is possible either practically or hypothetically. That is why, if proven to be achievable regardless circumventing paradoxes, this possibility should be taken into account. Also factored, the possibilities of imbalances are caused by the time traveler.
Through calculations and stated principles, the overall picture is that the paradoxes cannot be created by uncomplicated masses moving through wormholes of time. When time travel is introduced, preliminary conditions leading to paradoxes are left behind. If the calculation results are taken generally, none of the imaginary paradoxes created by myths on time travel can start physically at an exact stage.
Certain incidences seem to generate machinery to facilitate communication or travel. The speed of time travel is much quicker than the velocity of light. Some explanations deduce that there is an instant exchange of information among elements to sustain association among particles. This process was described as a “spooky action at a distance” by Einstein and examined in his researches as it is mentioned in Gott’s Time travel in Einstein’s Universe: The physical possibilities of travel through time (2002).
Regardless of this, modern theories do not manage the idea of time travel or communication across time that is quicker than light, even though causality that is conserved in quantum mechanics is a painstaking consequent of new theories related to quantum (Nielsens & Chuang, 2000).
Displays showcase that today some people were visited by so called “future humans” who may have highly advanced technology that facilitates travel in time. But there has been lack of positive response and very poor turn-outs for such events as people have little patience for these affairs. Hypothetically, without a time machine, travel back in time is impossible that is why to get to the moment before the machine was invented would be unattainable. Therefore, a machine that would allow them time travel with less limiting factors has to be invented.
There have been a number of experiments performed to contribute to the idea of inverted outcomes that are interpreted differently by scientists.
The first experiment to be looked at is the delayed choice quantum eraser carried out by Marlan Scully. In this trial, intertwined photons are alienated into ‘idler’ and ‘signal’ photons whereby signal photons show up from any of the two points, thus their locations are calculated. The experimenter is able to either determine the source of the signal photons between the two locations or erase the information. Assuming that the signal photons are preferred to the idler photons, they are measured first. There is still an alternative that “may seem to retro-actively ensure whether or not an intrusive model is well thought-out in the duration of correlating magnitude of idler photons to the ones of signal photons” (Nielsens & Chuang, 2000). Due to this, experimenters are not able to establish what choice would be made in advance by just considering signal photons.
Another experiment was carried out by Guntz Nimtz and Alfons. They claim to have transferred photons at a faster speed than that of light, therefore, violating Einstein’s theory of relativity. These physicists assert to have used quantum tunneling; a phenomenon when microwave photons are relocated amid a pair of prisms positioned three feet apart. Other physicists have disputed this phenomenon saying that it cannot transfer information at a speed faster than that of light.
In any specified case where Faster-than-Light situations were alleged, a lot of details on analysis proved that to acquire signals, a certain type of conventional communication should have been employed. An example is that the no-communication theory has a generalized verification that quantum entanglement cannot be employed in transmitting data quicker than conventional signaling.
A number of presumptions, most of them concerning unique and common relativity, propose that appropriate geometries of space-time or precise kinds of space movements may permit time travel to the past or into the future if the geometries or movements are achievable. In technological manuscripts, physicians normally use the common language of motion. Here, motion usually refers only to a change in spatial position as the time coordinate is varied, and instead discuss the possibility of closed time like curves, which are world lines that form closed loops in space-time, allowing objects to return to their own past (Hawking, 2002). Again, there exists an explanation to equations of space and time in the common relativity theory. It says that space has time-like curves i.e. the Godel space-time, while the physical plausibility of the clarifications remains doubtful.
On the other hand, relativity states that if one were to move away from Earth at relativistic velocities and return, more time would have passed on Earth than for the traveler, so in this sense it is accepted that relativity allows future travel (Thorne, 1994). In the relativistic sense, no purposeful solution exists showing the amount of time that really passes between departures and returns, but there seems to be an objective explanation for the proper time experienced by the earth and the person traveling. For example, the ages of both the traveler and earth can make this issue clear. In contrast, a lot of scientists believe that backward time travel is very much unlikely. Every assumption that would permit time travel requires the difficulties of causality to be dealt with. A typical instance of a setback relating to causality is the “grandfather-paradox”. As described in Black holes and time warps: Einstein’s outrageous legacy by Thorne, the author considers what would happen in case if one goes back in time and kills his/her own mother before he was conceived (1994, p. 56). But some scientists believe paradoxes can be avoided, either by appealing to the Novikov self-consistency-principle or the notion of branching parallel-universes.
With the present revelations on time travel brought forth, one can safely conclude that time travel is rendered impossible and not real except theoretical approaches. Theories on time travel have been floated since time immemorial by philosophers and scientists as well, but no conclusive or practical evidence has been produced. Therefore, time still remains a mystery and is vaguely understood by human beings. Moreover, it will remain a pipe dream to uncover its secrets until reliable proofs are presented.
References
Gott, J. (2002). Time travel in Einstein’s Universe: The physical possibilities of travel through time. Boston: Mariner Books.
Hawking, S.W. et al. (2002). The future of spacetime. New York: W. W. Norton & Company.
Nielsens, M. & Chuang, I. (2000). Quantum computation and quantum information. Cambridge: Cambridge University Press.
Thorne, K. S. (1994). Black holes and time warps: Einstein’s outrageous legacy. New York: W. W. Norton & Company.