I thought I'd share this because it's a photo. Of. An. Atom. (!!) It's emitting light it absorbed from a laser that's illuminating it. Those two electrodes on either side, by the way, are only two millimeters apart. https://t.co/hJGzXA5s7w pic.twitter.com/YiDojkUspu

— Sophia Nasr (@Astropartigirl) February 25, 2018