This week, the intriguing question of how visible light, but not microwaves, can escape through the grille of a microwave oven, how far Earth and Mars are apart, the speed of a falling meteor, why parking a car in reverse is easier, the reason that oil and water won't mix, and the prospects of alien life. Join Dr Chris Smith and Talk Radio 702's Azania Mosaka for the answers... Like this podcast? Please help us by supporting the Naked Scientists