The rings left behind by coffee cups are distinctly uniform in their distribution–the stain is always around the edge. This video from the University of Pennsylvania’s Physics Department demonstrates why.
Check out the above video to see the physics behind the ring-shaped stains and how altering the shape of the particulate in the liquid completely changes the shape of the stain.
Jason Fitzpatrick is warranty-voiding DIYer and all around geek. When he's not documenting mods and hacks he's doing his best to make sure a generation of college students graduate knowing they should put their pants on one leg at a time and go on to greatness, just like Bruce Dickinson. You can follow him on Google+ if you'd like.
- Published 11/12/12