Professor Ron Mallett of the University of Connecticut has been dreaming of time travel since he was knee high to a grasshopper. As per Mallett, his fathers sudden death when he was a young boy traumatized him to the point that he fantasized about traveling back in time and preventing it. Haven't we all done that, wish we could go back and fix something or prevent something that has already occurred from happening in our new version of reality ?
As he aged and traveled through time in the real world Mallett studied general relativity, gravitation, black holes, relativistic astrophysics, and quantum cosmology. He now believes that his childhood fantasy is within his grasp.
"I think of myself as being an ordinary person with a passion, and my passion is the possibility of time travel," Ronald Mallett
The Professor has devised plans for an actual time machine. A miniaturized table top gizmo was built to illustrate the principles he believes could be used to build a practical and working time machine.
Explaining his prototype Mallett states ". . . lasers are used to generate a circulating beam of light. The space inside this 'ring laser' should become twisted, 'like stirring a cup of coffee' [creating a vortex], . . . If space is being twisted strongly enough, this linear timeline is going to be twisted into a loop. If time all of a sudden is twisted into a loop that allows us the possibility of travelling into the past"
He also wrote a caveat...
'Although my work is based on Einstein’s general theory of relativity, it does not directly take into account quantum mechanics. Nevertheless, quantum mechanics could definitely play a role in understanding the consequences of time travel, namely, the so-called Grandfather Paradox. This paradox addresses the question of what could happen if, for example, you went back in time and prevented your grandfather for meeting your grandmother. In that case, your grandparents would not have your parents and your parents would not have you. So how could you go back in time to prevent your grandparents from meeting – that is the Grandfather Paradox. Quantum mechanics offers a way out via the concept of parallel universes. According to this concept, when you travel back in time you will arrive in a different universe. In that universe you can do whatever you wanted to and it would not affect the original universe you came from'.
In order to work, Malletts device would need boundless and almost unlimited amounts of energy and a mode of reducing everything to a microscopic, near quantum scale. Using the hypothetical time machine successfully would also require a detailed understanding of time physics.
The most popular theory among scientists is that the Universe is an unchanging block of space-time, a concept that arises directly from Einstein's equations. Without delvig into specifics The block universe theory, states that time travel is possible but time passing is an illusion. The universe, as per this theory is a giant block of all the things that ever happened, ever will happen and ever can happen at any time and at any place. On this view, the past, present and future all coexist and are equally real.
Dr Kristie Miller of the University of Sydney stated the following
'One way to visualise the block model is to think of other places in time as being like other places in space . . . We are here in Sydney, but there are other people located in Singapore and London. Those places are perfectly real, it's just that we aren't at them'
This theory should have medeival theologians who believed in predestination a sense of redemption as it implies that the past, present and the future are already written. Or maybe not, someone wanna go back and let them know ? So far as the aspiring time travelers it suggest that the grandfather paradox is a mute point as there is nothing to stop us from trading our current locale on the space time continuum with another equally viable reference point.
The block theory treats our everyday working concept of time as an illusion, a way that humans rationalize reality. ..."us physicists believe the separation between past, present, and future is only an illusion, although a convincing one." -Albert Einstein