This page loaded quickly for the amount of stuff it has on it, but it scrolls slowly in some parts (and really slowly in one, the part after WORLD WIDE WEB, with the CERN Welcome screens). It also pegs my CPU the entire time. I assume this is due to some of the animations happening constantly throughout the page, even when things are not on screen, since this happens with constantly running CSS transitions on any website. Since this is done in Javascript, why can't they detect if the specific element is on screen and enable/disable the transitions happening for it? A page like this is uncommon since it's a showcase of the tech but I would imagine this would save a lot of headaches for future designers when designing multiple animations on a page (or at least give the option to "stop when not on screen" for an animation).