What effects can underground nuclear explosions have on our land? How do antibacterial cleaners work? Could bacteria be used to clean up our environment from pollutants? We take on these question in this week's show as well as find out why the colour blue is so hard to see at night, why grass can survive when covered with snow, whether tanks could be made with armoured glass and how data can be saved on non-magnetic disks. Plus, we find out how scientists are developing flexible touch screens!