For now, time travel is confined to the mind. Imagine how much more exciting it would be, though, to travel through time in both mind and body. One moment, you are in the realm of the dinosaurs, hearing the screams of a pterodactyl overhead. The next, you are in the year 3033, exploring a 'holodeck', your personal virtual-reality playground. The idea of a time-travelling device was popularised by science-fiction author H.G. Wells in his novella The Time Machine, published in 1895. Few inventors have dared try to transform the central tenet of a sci-fi story into reality; the rigidity of time is so much part of our everyday assumptions about how things hang together. Treating time like just another force to be manipulated seems outrageous, like devising designer babies or doing away with death. But Ronald Mallett, a professor of physics at the University of Connecticut in the United States, is taking a stab at the ultimate breakthrough. In 1955, Mallett's chain-smoking father died, aged 33, of a heart attack. Inspired by a comic-book adaptation of Wells' story, a 10-year-old Mallett resolved to travel back in time to save his father. That desire blossomed into a lifelong obsession. Now, Mallett has concocted a plan to test his time-warping theory. Deploying equations based on Albert Einstein's relativity theories, he is proposing to use circulating laser beams to warp space; imagine coffee (representing space) in a cup being stirred up and twisted by a spoon. According to Einstein, whenever you exert an influence on space, you also change time. Twisting space distorts time. So, with a little luck, you might take a stroll through time just as you walk through space. A non-profit foundation under the University of Connecticut has opened an account to manage funding for Mallett's research, called 'The Space-Time Twisting by Light' project. In 2006, Mallett's memoir, Time Traveller, was published. Ricardo Rademacher, founder of online game publisher Futur-E-Scape, whose flagship game is The Physics Adventures in Space and Time, is pessimistic about Mallett's proposed time-travel machine, however. 'The problem with Professor Mallet's attempt, indeed with any attempt, is the sheer scope of the ignorance of that which we are attempting to manipulate, circumnavigate or otherwise just plain understand,' he says. Given advances in several cutting-edge fields of science, Rademacher says, relying on relativity 'would be futile at best and dangerous, potentially universe-shattering, at worst'. Any realistic stab at time travel is apparently thwarted by an increasingly incomplete set of equations: relativity and quantum mechanics. 'Current physics is full of problems where relativity, the standard model, or conventional wisdom just don't have the answer,' says Rademacher. Science may still be light years away from performing successful time-travel experiments.