space tunnel n.

Kubrick never even gives a hint that the monolith is a ‘space tunnel’ of some sort, a short-cut through the universe.

It appeared to be an Einstein-Rosen bridge, a space-tunnel leading into another universe.

A skyborne ram was scooping and bulldozing interstellar hydrogen before it until the accumulation was enough to trigger the black hole that would be the entry end of the space tunnel through which our flotilla would emerge at last at the white hole that was the other end of the Einstein-Rosen postulation.

And it, too, had at first looked like a small moon. But it had been a space tunnel, a wormhole transport point to a vast mappable net of usable tunnels. When a spaceship got itself laboriously out to Neptune and maneuvered inside Space Tunnel #1, it emerged elsewhere in the galaxy, directly outside a planetary system…and very near yet another space tunnel.

An isolated planet with a minimal level of technology, World would be of interest only to a few xenobiological specialists if not for its relics of the vanished ancient civilization which created the space tunnels between star systems.

There’s another room filled with strange stuff and there’s an arch that opens the space tunnel.