Genuinely lovely double rainbow near my home today.
Lost an hour reading about the complex interplay of refraction and reflection involved in this phenomenon, and now know something new: that I should not attempt to understand optics on a Wednesday night after a whisky.
@RussInCheshire Did you know you can make a rainbow on your wall by shining your mobile flashlight (with a diy slit disc) through a red wine glass filled with water? 🌈🍷📱#scienceteacher
ALT: a 6 sec video scanning from bottom to top showing a mobile phone with light on shining up through a water filled wine glass to a small rainbow projected on a nearby wall.