Science: Ludwig's hair lead, what makes the aurora colours?

Science correspondent Allan Blackman joins Kathryn to talk about the new research conducted on samples of composer Ludwig van Beethoven's hair, clipped from his head from fans as he lay dying. It's found a staggering amount of lead and other toxins in his body - could wine be to blame? And amid aurora-fever, what causes the different colours that feed into the incredible light display? Allan Blackman is a Professor of Chemistry, School of Science, Auckland University of Technology.