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 Before the Copyright Act of 1976 became effective on 1 Jan 1978, unpublished works were.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.
the exclusive right to make copies, license, and otherwise exploit a literary, musical, or artistic work, whether printed, audio, video, etc.: works granted such right by law on or after January 1, 1978, are protected for the lifetime of the author or creator and for a period of 70 years after his or her death.