Fourmilab is chock-full of interesting things. Be sure to check out the gravity detector, too. And the SlideScreen screen saver for Windows is still the best s

Fourmilab is chock-full of interesting things. Be sure to check out the gravity detector, too. And the SlideScreen screen saver for Windows is still the best slide-show screen saver on that platform, after 15 years or more. Not to mention how interesting John Waters, the creator of the site and Autodesk founder is.