Rubies and emeralds have the colors they do because, like many substances, they absorb some colors of light. Most visible light, like sunlight, is composed of all the colors of the rainbow: red, ...

navi allows you to browse through cheatsheets (that you may write yourself or download from maintainers) and execute commands. Suggested values for arguments are dynamically displayed in a list.

Where would carbon-based life be without carbon? There are 118 known chemical elements, but carbon is the fourth most ...