Imagine for a minute that everything you see around you is not actually there. It is just for lack of a better phrase, a figment of your imagination. Could it be? The world's top scientists now think that it could. In the Sunday Times from Britain, Prof. Sir Martin Rees suggested that life in the universe and everything in it may be nothing more than a giant computer simulation. The Royal Society professor at Cambridge University says humans may simply be bits of software. In other words, we program our world the way we want it. We create our own world, just like computers create a virtual world. Prof. Rees says that over the past few decades, computers have created a virtual world with extensive detail. "If that trend were to continue, then we can imagine computers, which will be able to simulate worlds perhaps even as complicated as the one we think we're living in." He adds that this fact raised the question: "could we ourselves be in such a simulation and could what we think is the universe be some sort of vault of heaven rather than the real thing. In a sense, we could be ourselves, the creations within this simulation." Though this idea has already been snatched up by Hollywood in such films as The Matrix, Vanilla Sky and The Hitchhiker's Guide to the Galaxy, back in ancient Greece the philosophers of the day did not find the notion so far fetched. Even as far back as 2,000 years, the Chinese philosopher, Chuang Tzu wondered if his whole life had been nothing more than a dream. And in the 1600s, Rene Descartes wondered the same thing as noted by his famous words, "I think, therefore I am." Then in the last century, Bertrand Russell propounded that humans might be just "brains in a jar" that were being activated by chemicals or electrical currents. Next month, Prof. Rees will present his ideas in a television documentary called "What We Still Don't Know." He is expected to emphasize that today's top physicists and cosmologists are seriously considering this theory. One of them, mathematical science Prof. John Barrow also of Cambridge University, will discuss the fine-tuned nature of our world and how event the slightest alteration in such things as gravity would have devastating affects. This, he believes, proves that intelligent design is at work. There are, however, those who do not believe in intelligent design and say the universe is far too complex to be a simulation. Quantum mechanical engineering Prof. Seth Lloyd of the Massachusetts Institute of Technology says he could begin to imagine a computer large enough to simulate a whole universe. What are your thoughts on Prof. Rees' theory?