“Immortality” in science fiction (sf) can mean just that someone is immune to disease and old age but not also to accident or violence. He is not indestructible. By contrast, in Neil Gaiman’s fantasy series, The Sandman, the source of Hob Gadling’s immortality is supernatural, not chemical or genetic. The anthropomorphic personification of Death has agreed not to come for Hob. Consequently, he enjoys, or endures, more than just perpetual good health and middle age: he can be immersed, burnt and deprived of food but cannot be drowned, burnt or starved to death.
Hob’s immortality differs from that of Bernie Capax who is older – he remembers the smell of mammoths – but who meets Death when a wall collapses. Bernie then learns that his soul has a different kind of immortality. The fantasy Sandman presents the full panorama of Heaven, Hell and states between. Although Hob, like a few other deathless men, welcomes his physical immortality, The Sandman presents two other characters who, having become physically indestructible, long for extinction, the mythical Orpheus and the super-heroine Element Girl. (All mythologies and many comic book characters co-exist in this series of “graphic novels.”)
Fictional vampires have the same problem of living indefinitely and needing to conceal their longevity but we know how they can be killed.
Although there are many other examples, I will mention briefly just twelve instances of sf immortality. Of the three Campbell future historians, Robert Heinlein, Isaac Asimov and James Blish, two addressed the idea. In Heinlein’s Future History, the Howard Families breed for longevity. After a few generations, they live well into their second century. The oldest member present chairs meetings. Like Hob and similar characters, they practice what they call the Masquerade: to conceal the fact of longevity, they periodically move elsewhere and change their identities. Later, public disclosure of the Howards’ longevity inspires a research project that finds a means of indefinitely extending anyone’s life span. Such artificial means of longevity exist in other works to be mentioned below but, first, there is another idea in the Future History.
An early Howard, Lazarus Long, lives indefinitely, for millennia, and becomes “the Senior”, the oldest member of the human race. Thus, he is a mutation who need not have been born to Howard Family parents. “Lazarus Long” is a Masquerade name. His birth name, Woodrow Wilson Smith, is a clue to his real age. In The Boat Of A Million Years by Poul Anderson, a small group of such mutations survives through recorded history and into an indefinite future. Crossing interstellar space, they split up but plan to meet again in another million years.
Of course, Anderson could not possibly have written what these characters would be like after a million years. By that time, either they would all have died in accidents or those who yet survived would have become different characters. How much would they even remember? Each of them had already preserved his or her sanity by somehow marshaling inner resources in order to resist being overwhelmed by accumulating memories. By living that long, they perform functions that are usually performed by successive organisms without a memory accumulation problem. Death is the natural mechanism for memory deletion.
In Asimov’s future history, extra-solar colonists, inhabiting a germ-free environment, extend their life spans well into a second century and usually record their age in decades, not in years. A year becomes more like a month on that time scale. The only immortal being in this future history is a humaniform robot, not a human being. Thus, Robot Daneel Olivaw, having been introduced in the Robot novels, appears again millennia later in the Foundation novels which had originally been an unrelated series.
In James Blish’s Cities In Flight future history, antigravity and antiagathics make interstellar travel possible. Star-traveling characters live for centuries although we only realize later in the main volume that so much time has elapsed since the beginning of the book. Logically, some of the characters happen to live until the end of the universe although, for story purposes, that ending is brought much closer to the present than we would have expected. In fact, the date given, 4004 AD, contradicts suggestions in the previous volume that several millennia have elapsed during the interstellar period. Despite antiagathics, everyone dies but new universes begin.
In Larry Niven’s Known Space future history, “boosterspice” performs the same function as antiagathics. Further, protector-stage humanoids are immortal, although at the expense of no longer being “breeders”. However, in his alternative future history, A World Out Of Time, Niven imagines an elegant alternative source of immortality. If teleportation is possible, then the chemicals associated with aging can be teleported out of the body. Thus, the instant elsewhere is a young forever. It is perhaps a more acceptable form of immortality than another in the same book which arrests physical development before puberty, producing immortal children who must preserve mortal adults for breeding.
In Anderson’s Psychotechnic History, modeled directly on Heinlein’s Future History, it is suggested that an organism can be made immortal only by shielding it from all radiation, thus by incarcerating it underground, consequently producing a human being with an extremely limited experience and mental range. Scientists care for an immortal hospital patient: a dead end. Appropriately, this story is called “What Shall It Profit?” In Anderson's Technic History, “antisenescence” explains why Dominic Flandry remains active and might yet have more children although he is nearly seventy. However, antisenescence delays aging but does not prevent death.
By contrast, in Anderson’s World Without Stars, every human being uses “the antithanatic.” A few immortals lead changeless lives on planetary surfaces or in orbiting space stations but many trade and explore endlessly between galaxies which are made accessible by a series of instantaneous jumps in a spaceship. Many memories are artificially deleted to prevent cerebral overloading but it is necessary to preserve the overall pattern of the past and the important details. Hugh Valland, three thousand years old, remembers Mary O’Meara who died young in 2037 just before she would have had access to antithanatic. He revisits her grave on Earth as if revisiting a living woman and recounts experiences on many planets but must also have deleted many intermediate memories. He has somehow made sense of his indefinite longevity by focusing on one set of memories.
At any given time, what exactly does Hugh Valland remember? First, he has normal memories of whatever he has experienced since his most recent memory deletion. Secondly, he preserves vivid memories of Mary O’Meara. Thirdly, he remembers the pattern of his life since leaving Mary. Fourthly, within this pattern, he has perhaps a natural life span’s worth of memories of experiences in space, on other planets and back on Earth. However, he must have had to delete far more details than he has been able to retain. He maintains his purpose and remains celibate by focusing on ever fresh memories of one person. Only at the end when we realize that that one person is long dead do we doubt Valland’s sanity.
It seems appropriate to begin a brief consideration of fictitious immortality with the fantasy character Hob Gadling and to end with the sf character Hugh Valland.