Dark matter and dinosaurs: meet Lisa Randall, America’s superstar scientist

Harvard professor's radical theory of dark matter wiping out the dinosaurs and enigmatic research on extra dimensions has made her a true trailblazer

It's a bright, chilly winter morning in Cambridge, Massachusetts, and in Peet's cafe, just around the corner from Harvard University, the coffee grinders are going hell for leather. Hunched over their laptops, students peer at seemingly never-ending dissertations while the edge is taken off their caffeine spikes by a soundtrack of soporific crooning.

I bag two chairs and wait for Lisa Randall to walk through the door. America's superstar scientist turns up a little late, negotiates the throng and perches her petite figure on a stool. But while the surroundings are humdrum, our discussion is anything but. Because Randall is here to talk about dark matter - and dinosaurs. Or, more precisely, how a putative disc of dark matter in our galaxy could potentially be responsible for dislodging lumps of rock from the distant Oort cloud which then hurtle towards Earth - possibly leading to events as catastrophic as the planet's fifth mass extinction - every 35 million years, or so.