Design: list of "knowledge types" to implement

[zverok]

Potential list of data (like cities and countries) to take in account. Possible consideration:

• "common knowledge" (geography, biology, planets)
• "actual" (currency rates, weather, sunrises and sunsets)
• "interesting" (movies, music groups, space sattelites)
• easy to extract from open APIs
• looking cool in demos
• useful for teaching and showcasing Ruby
• not included in this list

Good list to start from is Wolfram's list of scopes: http://reference.wolfram.com/language/