Doubling Earth’s energy imbalance

Nasa scientists have observed that the Earth’s energy imbalance has doubled in just 15 years. As greenhouse gas atmospheric concentrations have risen, so too has the difference between the total amount of energy being absorbed from the sun, and the total amount being reradiated back into space. Meanwhile, as we all heat up, scientists at the LIGO Gravitational Wave Observatory have managed to do something very cool with their mirrors. Such is the precision with which the detectors have been engineered, they have managed to effectively reduce the temperature of one of the big 10kg reflectors to such an extent that it betrays its quantum state, as if it were simply one big subatomic particle. So what? Roland Pease finds out. Presenter: Roland Pease Producer: Alex Mansfield (Photo: Giant sun in the horizon. Credit: Getty Images)