The eye is something like a camera, but there is a whole lot more to vision than that. One profound difference is that our vision, like the rest of our senses, is malleable and modifiable by experience.
Glass is anything that's rigid like a crystal, yet made of disordered molecules like a liquid. To understand why it exists, researchers are attempting to create the perfect, still-hypothetical "ideal glass."
An interactive map of mathematics as it stands today, mathematics as it is practiced by mathematicians. From simple starting points — Numbers, Shapes, Change — the map branches out into interwoven tendrils of thought.