Oldness is a library and shell command that places the age of a published work on a semi-arbitrary five-star scale.
gem install oldness require 'oldness'
$ oldness list animation comic film history literature novel philosophy rpg scifi videogame $ oldness rate comic 1987-10 **** $ oldness ranges movie *****: 1894-02-05..1972-09-14 **** : 1972-09-14..1998-11-27 *** : 1998-11-27..2007-08-22 ** : 2007-08-22..2010-07-21 * : 2010-07-21..2012-01-04 $ oldness first novel Tale of Genji (1010), by Murasaki Shikibu
Declaring the existence of a medium is easy; you don't need a national reputation as a culture critic or scholar.
class Rubies < Medium began Date.new(1979) end
Although of course it would be better if you could point to a particular work that you saw as kicking things off.
class RockNRoll < Medium began Date.new(1944), :with => "Strange Things Happen Every Day", :by => "Sister Rosetta Tharpe" end
Mediums know how to rate by date.
Rubies.rate(Date.new(2010, 8, 29)) # => 3 Rubies.rate("2012-1-4") # => 1
They also know what dates fall under what ratings.
Rubies.ranges #=> #<Date: 1979-01-01>..#<Date: 2001-01-02>
And, if you've told them, they remember their roots.
RockNRoll.first.title #=> "Strange Things Happen Every Day" Rubies.first.by #=> "Unknown"
Just a reminder: mediums are timeless, so they never need to be instantiated.