According to the boffins at Technion, the Israel Institute of Technology, the theory could allow future generations to travel into the past.
“In order to travel back in time, the spacetime structure must be engineered appropriately,” said Professor Amos Ori of the Technion’s Faculty of Physics.
“This is what Einstein’s theory of general relativity deals with. It says that spacetime can be flat. That is – it has a trivial, simple structure. But it can also be curved with various configurations.
According to the theory of relativity, the essence of gravitational fields is in the curving of spacetime. The theory of relativity also defines how space is curved and how this curvature develops over time.”
Ori explained travelling back in time is actually closing time-like curves so researchers can go back to an event in the past. In flat space, it is not possible to close curves and go back in time. In order for closed time-like curves to exist, there has to be a curvature of a specific form on spacetime.
The question Ori is investigating is – do the laws of gravity permit the development of spacetime with the required curvature (closed time-like curves)? In the past, scientists raised a number of objections to this possibility.
However, the Technion team is proposing a theoretical model for spacetime that could develop into a time machine. The model overcomes some of the questions, which, until now, scientists have not succeeded in solving.
One of the difficult claims against a time machine was that, in order to create a time machine, it would be necessary for it to contain material with negative density.
And since we do not have such material – and it is also not clear if the laws of nature enable the existence of such material in the quantities required – it is not possible to build a time machine.
But Ori proposes a theoretical model that does not require material with negative density. The model that he proposes is, essentially, a vacuum space that contains a region field with standard positive density material.
“The machine is spacetime itself,” he explained. “Today, if we were to create a time machine – an area with a warp like this in space that would enable time lines to close on themselves – it might enable future generations to return to visit our time. We, apparently, cannot return to previous ages because our predecessors did not create this infrastructure for us.”
Boffins unveil time machine theory
By Robert Jaques on Aug 10, 2007 12:15PM