Airplane mode is not just for when you want to secretly read your WhatsApp messages - it's actually supposed to be used on, you know, airplanes. You might not have realized it, but your phone's radio signals could be causing all sorts of havoc as you zoom through the sky, with knock-on effects that could even block our view of the stars. Take a look at the truth about airplane mode, and remember to slide that switch next time you fly.

Credit: TED-Ed