With his scruffy jeans, piercing blue eyes and long red beard, Aubrey de Grey looks every inch the eccentric scientist. But in the past year, this self-taught biogerontologist, based in Cambridge university's genetics department, has attracted serious attention for his theories about ageing.

Mr de Grey argues that radical increases in life expectancy will become possible within 30 years. "As medicine becomes more powerful," he says, "we will inevitably be able to address ageing just as effectively as we address many diseases today." He sees no reason why many people alive today should not live to 150 or beyond. The basis for such a confident prediction is a project he leads called "strategies for engineered negligible senescence" (Sens). This has identified seven types of molecular or cellular damage linked to ageing, each of which "is potentially fixable by technology that already exists or is in active development".