I bet you’re so used to a smartphone in your hand that you’ve never even asked yourself a question: why in the world is it rectangular? Why not square or round, for example?

Or why, for that matter, you can’t use it when in gloves? Why is it not recommended to use your smartphone while it’s charging? Can that blue light from screens of smartphones and computers mess with your sleep? Learn more about your ad choices. Visit megaphone.fm/adchoices