Sidewise in Time

Murray Leinster · 1934 · Short Story

Explore this on the mapTrace its ancestors and descendants live in the tree.

This short story is widely credited as one of the earliest and most influential explicit explorations of parallel universes and alternate histories in science fiction.

What it is

A geological cataclysm causes different historical eras and alternate realities to briefly overlap and swap positions across the Earth, leading to chaotic encounters between disparate societies. A group of academics tries to understand and survive the phenomenon.

↑Inherited from(1)

Flatland· 1884↑ open

While not directly stated, the concept of other 'dimensions' or realities co-existing, even if temporally or spatially shifted, aligns with Flatland's exploration of different planes of existence, inspiring early conceptualizations of alternate worlds.

↓Passed on to(3)

Ring Around the Sun· 1953↓ open

Leinster's story established the concept of parallel Earths, directly influencing Simak's narrative of multiple Earths existing side-by-side, accessible via specific mechanisms.

The Cosmic Puppets· 1957↓ open

While Dick's focus is on a single reality being manipulated, the underlying concept of reality being fluid and potentially different from what one remembers, echoes the 'sidewise' shifts of Leinster's story, inspiring Dick's early explorations of alternate realities.

The Man in the High Castle· 1962↓ open

The idea of different historical outcomes existing as distinct 'realities' or timelines, even if not physically overlapping, was foundational for later alternate history narratives like Dick's.