# Physicists have proposed, according to them, a working mathematical model of a time machine

Theoretical physicist Ben Tippett from the University of British Columbia, along with the University of Maryland astrophysicist Devidomom Zang created, according to them, a working mathematical model of the "time machine" that uses the principle of the curvature of space-time universe. Research and findings of scientists published in the journal Classical and Quantum Gravity.

The scientists on the basis of general relativity have deduced a mathematical model, which they called the TARDIS or Traversable Acausal Retrograde Domain in Space-time ( "walkable akazualnye retrograde area in space-time"). But do not rejoice in the opportunity to visit in the past your long-defunct grandmother, the researchers note. There is a problem that does not allow them to verify the correctness of the mathematical model, but more on that later.

"People think about time travel as science fiction. In fact, we believe it is impossible because we have not tried to do it in reality, "- says physicist and mathematician Ben Tippett.

"However, the time machine is possible, at least mathematically," - adds the scientist.

The model is based on the idea of scientists about the presence of the fourth dimension of the universe, which is time. In turn, this suggests the existence of a space-time continuum in which various directions of space and time are connected cloth universe.

Einstein's theory of relativity, gravitational effects binds the universe with the curvature of space-time phenomenon behind the elliptical orbits of the planets and stars. If there is a "flat" or curved space-time, the planets would move in a straight line. However, the theory of relativity says that the geometry of space-time becomes curved in the presence of very massive objects, causing them to spin around stars. Tippett and Tsang believed that curved in the universe can be not only a space. Under the action of the object with a large mass can be bent and time. As an example they cite the space around black holes.

"The passage of time movement in space-time can also be curved. As an example, black hole. The stronger we are approaching them, the slower for us begins to flow time ", - says Tippett.

"My time machine model uses the curved space-time to the time for the passengers was a circle, not a straight line. And the movement of this group can send us back in time. "

To test the hypothesis, the scientists propose creating a kind of bubble, which will be able to carry all those in it will be through time and space on a curved path. If this bubble will move at a speed greater than the speed of light (according to scientists, it is also mathematically possible), it will allow everyone who will be in a bubble, move back in time.

The idea becomes clearer if one looks at the scheme proposed by Tippett. It has two protagonists: one is inside the bubble / time machine (person A), the other - the external observer located outside the bubble (person B).

The arrow of time, which under normal circumstances (ie in our universe) is always moving forward, in the present scheme makes the past become the present (indicated by black arrows). According to the scientist, each of these people is a different feel the passage of time:

"Inside the bubble object and seeing that the event B vary periodically, and then reversed. Located outside the bubble observer B sees that the two versions of A out of the same location: the hour hand turns to the right, and another - to the left. "

In other words, the outside observer will see two versions of the objects inside the time machine, one version will evolve forward in time, and the other - back.

Sounds all, of course, very interesting, but Tippett and Zhang say we have not reached a level of technology that this hypothesis could be tested in practice. We simply do not have the right to build a time machine materials.

"Although from a mathematical point of view, it might work, to build such a car to move around the space-time, we can not, because they do not have the need for this material. And the materials are required exotic. They allow to bend space-time. Unfortunately, science has not yet invented anything like this ", - says Tippett.

The idea Tippett and Zang in common with another idea of a time machine, so-called bubble Alcubierre, the basis of which should also be used exotic materials to move in space and time. Only in this case it is not a circular motion in the field of space-time, and on the movement by squeezing the space in front of and behind its expansion.