Saturday, 23 August 2014

Atlantean Astronomy

Copied from Poul Anderson Appreciation, 29 Oct 2013.

I missed some salient data about Atlantean astronomy in a recent post. The information is scattered through the text(s). I am finding it informative to reread the novelization, Virgin Planet, immediately after rereading the original, shorter, "Virgin Planet". Information is repeated, amplified or nuanced in the longer version.

Atlantis is an Earth-like moon of the gas giant, Minos, which is permanently visible above the colonized hemisphere of Atlantis. When full, Minos is fourteen times the size of Luna as seen from Earth! Also, four other inner Minoan moons may be visible. On one occasion:

"...overhead...were two crescents, dim by daylight: one almost twice the apparent size of Luna seen from Earth, the other half again as big."
(Starship, New York, 1982, p. 97)

I wondered, "Half again as big as Luna or half again as big as the moon that is twice as big as Luna?"

The novel elaborates:

"Overhead...were two crescent moons, dim by daylight, one almost twice the apparent size of Earth's, the other half again as big as Luna seen from home..." (Virgin Planet, London, 1966, p. 31)

The Author's Note to the novel elaborates further:

in full phase, Minos is as bright as twelve hundred full moons on Earth;
the moons Ariadne and Theseus are each several times brighter than Luna;
Aegeus and Ariadne never set but instead move rapidly across Minos from west to east, then behind Minos from east to west;
Aegeus crosses the sky in 3.1 hours and completes its phases in about 30 hours;
occasionally, the full Ariadne changes color as it transits the full Minos at midnight.

What a sky! What might native Atlanteans have made of it? But there are no natives, only colonists. The colony is three hundred years old so its inhabitants are thoroughly familiar with their complicated celestial mechanics - and when a survey man arrives, he knows what to expect.

More could have been done with these ideas. The Author's Note includes information that did not make it into the texts, e. g.:

there are a few primitive mammals on the outer hemisphere but the colonists never see them;
the mountainous main content, on the inner hemisphere, was later named Labyrinth.

After the events of "Virgin Planet", men would arrive, bringing technology. Thus, the colonists would stop reproducing by parthenogenesis, society would modernize and many sequels could have been written about this one planet.

Friday, 22 August 2014

The Quiet Earth

Originally published on Poul Anderson Appreciation, Oct 2013.

This occasional sf idea has a modicum of plausibility: FTL will move human activity out of the Solar System so Earth will become a quiet place. Obviously, an entire planetary population would not emigrate immediately, even if given unlimited living space to colonize, contra Bob Shaw in Orbitsville. However, the home population might indeed decline over time.

In James Blish's Cities In Flight future history, antigravity-powered cities leave Earth for economic reasons:

"Earth itself became a garden planet, bearing only one city worth noticing, the sleepy capitol of a galaxy. Pittsburgh valley bloomed, and rich honeymooners went there to frolic.
"Old bureaucrats went to Earth die.
"Nobody else went there at all."
- James Blish, Earthman, Come Home (London, 1963), p. 13.

These reflections are occasioned by the fact that essentially the same future Earth exists both in Poul Anderson's Psychotechnic future history and in his stand alone novel, World Without Stars.

"Earth is a quiet world."  - World Without Stars (New York, 1966), p. 120.

The following passage describes:

great forests;
low population;
starport towns;
educational centers for galactic youth;
flourishing art;
living science and scholarship;
but no new buildings;
preservation of the old;
immortal space travelers' property unchanged after centuries of robotic supervision.

In "The Pirate," a Psychotechnic History story, Earth is commended for "...its quiet, its intellectuality..."
- Starship (New York, 1982), p. 212.

In The Peregrine, a Psychotechnic History novel, Earth is green with forests through which "...isolated houses and small village groupings..." are scattered.
- The Peregrine (New York, 1978), p. 24.

The following passage describes a planet with:

a small, mostly creative, population;
scientific research;
arts -

- so it definitely reads like World Without Stars revisited.