Â鶹ԼÅÄ

Light from distant quasars challenges Einstein's theory of relativity in some circumstances. Will disease once again reach British seal colonies? The life and achievements of Nobel-laureate Paul Dirac, the physicist who founded quantum mechanics, in the centenary year of his birth. How mental aerobics maintain the brain and memory working at full power in old age. Clever Caladonian crows – a bird brain displaying high levels of ingenuity.