Immortality: Physically, Scientifically, Now

Immortality: Physically, Scientifically, Now is a 1962 book by an early cryonics-advocate Evan Cooper, written under the pseudonym Nathan Duhring (i.e. N. Duhring, enduring). In the book, Cooper suggests the idea of cryonics, advocating what he calls a "freezing program". The copyright of the book expired in 1990.

In 1962, shortly after Cooper's book was published, Robert Ettinger privately published his book The Prospect of Immortality that independently also suggested the idea of cryonics.