Radon is a dangerous gas. It is colorless and odorless and is always being emitted from our planet-don't worry, it's not enough to harm you.
Copyright for published works in the USA has been according to a federal copyright statute, since the first U.S. copyright statute in the year 1790. Before the Copyright Act of 1976 became effective on 1 Jan 1978, unpublished works were. protected by state law, known as common-law copyright.
A copyright is the set of exclusive rights you receive from the federal government to publish, copy, adapt, display or perform your original work, which is good from the time you create it until 70 years after your death.