Why are some Volcanic Eruptions stronger than others? Why can't aeroplanes fly around the ash in the sky? Is our ozone layer still a concern? Why will sea levels rise if the ice caps melt? We take on these explosive questions in this week's show as well as find out if dogs can communicate, how boats sail into the wind, how outdoor infra-red heaters work and why clingfilm expands over food in the microwave. We also investigate is silverfish are related to dinosaurs and where water goes when it evaporates!