The Long Earth is the first novel in a collaborative science fiction series by British authors Terry Pratchett and Stephen Baxter.
== Plot summary ==
The "Long Earth" is a (possibly infinite) series of parallel worlds that are similar to Earth, which can be reached by using an inexpensive device called a "Stepper". The "close" worlds are almost identical to "our" Earth (referred to as "Datum Earth"), others differ in greater and greater details, but all share one similarity: on none are there, or have there ever been, Homo sapiens - although the same cannot be said of earlier hominid spec...