Scientist Ray Kurzweil believes immortality may become reality within just twenty years thanks to rapid advances in medical technology:
Mr Kurzweil adds that although his claims may seem far-fetched, artificial pancreases and neural implants are already available.
Mr Kurzweil calls his theory the Law of Accelerating Returns. Writing in The Sun, Mr Kurzweil said: "I and many other scientists now believe that in around 20 years we will have the means to reprogramme our bodies' stone-age software so we can halt, then reverse, ageing. Then nanotechnology will let us live for ever.