The subreddit interestingasfuck (sorry Mom) is, for my money, one of the best. The content is a curated mix of interesting photos, charts, and video clips featuring cool stuff you either regularly take for granted (like brick paths and the moon) or didn't know existed (like oxidation on the surface of Bismuth). This photo gallery includes pictures of natural phenomena, manmade things, the goings-on inside our own bodies, and tons of other cool sh*t that might even teach you a thing or two. The universe is pretty amazing. Let's look at it together!
http://www.ranker.com/list/interesting-pictures/robert-wabash,
Fireworks, When the Camera Refocuses During the Explosion
Wounded Lion Sculpture in Honor of Swiss Guards Who Died in the French Revolution - Luzern, Switzerland
Coins Stacked in Such a Way That They Extend Past the Edge of the Table
A Turtle Riding a Jellyfish
Grass After a Lightning Strike
Sunset and Eclipse Happening at the Same Time
This 3D-Printed Cast Uses Ultrasound to Heal Bones 40% Faster
This Eggshell Has More Than 20,000 Holes Drilled in It
Path-Laying Machine
A Child's Skull Before Losing Baby Teeth.