The Beauty of the Public Domain

Ah, the Public Domain! It is the well refuge of our cultural heritage and the well spring from which works such as A Zen Master In Oz arise.
In the United States an author's copyright on his/her work expires 70 years following their death. The copyright held by the publisher on material published from 1978 to present ends either 95 years after publication or 120 years after creation, depending on which is shorter. All copyrights prior to 1923 have expired. Work created from 1923 - 1963 expire 95 years following publication. Work published 1963 - 1977 also have their copywrites expire after 95 years. Material that does not have its copywrites regularly renewed during the period that they can be kept under copywrite production have theirs expire after 28 years.
In the UK it is a bit simpler. Copywrites for an author expire 70 years after their death. A publisher's copywrite ends 50 years after a product is released.
Things are different when it comes to Trademarks, since they do not expire as long as they are being used by a specific organization.
So, what happens to a book when 70 years pass since its author's death and it's been 95 years since it's been published? The book and it's locations, characters etc. go into the public domain, where they are free for anybody to play with. This can also happen if the owner of a copywrite does not have it renewed after 28 years. This is how things like comicbooks and movies etc. from just a few decades ago can end up in the public domain.
L. Frank Baum saw The Wonderful Wizard of Oz in 1900 and died in 1919. This puts all of the characters and places he created for that story well into the public domain. He wrote 17 Oz novels before his death. All of those works have passed into the public domain. That means nobody owns them or, if looked at from a different angle, everybody owns them. Dorothy, Scarecrow, Tin Man, Patchwork Girl, Tik-Tok, Ozma, Glinda and all the rest of the inhabitants of Oz created by Baum belong to the world. They are now part of our collective culture no strings attached.
What has this made possible? Well, if these works were not in the public domain we would not have gotten Gregory Maquire's Wicked and its sequels, which in turn spawned the hugely popular and awfully entertaining (and I usually loathe musicals) Broadway/West End musical version of Wicked. This musical has been inspiring kids around the world to be like the misunderstood "Ephelba" and sing songs about being "Popular". Of the hundreds of thousands, if not millions, of children that are inspired by Wicked, a few of them are going to use that inspiration to create new works of art using Baum's characters in new and exciting ways. If the Oz universe was owned lock, stock and barrel by a big corporate conglomerate, the whole Wicked phenomenon would have never been. What also would have never been was my little book, A Zen Master In Oz.
The Public Domain is where are common dreams are allowed to grow and be picked up by new generations. The maintaining of laws that allow works to "lapse" into public domain are essential to guaranteeing are shared culture does not become another commodity owned by a faceless corporation.