Ghosts In The Future

Ghosts are fantasy, not sf - as a rule. Robert Heinlein's Martians have direct contact with their "Old Ones." CS Lewis surprised me when, reading his Ransom Trilogy out of order, I came across, early in Volume II, the startling statement that, on Mars, Ransom had encountered beings that were both extraterrestrial and supernatural - both alien and uncanny! Characters in hard sf can think that they see ghosts. See a relevant quotation from Poul Anderson's The Day Of Their Return here.

When Wells' Time Traveller first glimpses Morlocks as white figures at night, he remembers Grant Allen's notion that, if each generation dies and leaves ghosts, then the world should eventually become overcrowded with such ghosts. In The Goblin Reservation by Clifford Simak, because a future University has both a Time Travel Department and a Supernatural Department, William Shakespeare is able to meet his own ghost. See here.

This idea of ghosts in the future has enabled us to assemble references to:

Robert Heinlein
CS Lewis
Poul Anderson
HG Wells
Grant Allen
Clifford Simak

Names to conjure with. I had never heard of Grant Allen before but he is yet another period reference in The Time Machine. It is late, approaching the hour at which people see ghosts, and I am out of here.