Gregory Benford by Essays & Short Stories

Author:Essays & Short Stories [Essays & Stories, Short]
Language: eng
Format: epub
Published: 0101-01-01T00:00:00+00:00

GREGORY BENFORD

LIFE AT GALACTIC CENTER

We’re not in a lucky part of the galaxy, at least for views.

Our sun is tucked down in the disk’s plane, though this took centuries to realize. In retrospect, perhaps it is puzzling that astronomers did not guess until the nineteenth century that the Milky Way is a disk, seen edge on.

Ancients used water analogies to describe it, images of rivers and streams. How much easier matters might have been if we could have seen the truly gaudy attraction in all the galaxy, the brilliant center.

Perhaps, thought, our ignorance is good luck. Dark dust clouds block our view in the constellation Sagittarius, so we cannot see in the optical frequencies beyond the edge of our local spiral arm. Beyond that are immense dark lanes, blotting out the next arm and the hub beyond.

One way to see the center would be to live much nearer. But that could be fatal.

The galactic center is about 25,000 light years away. We orbit about two thirds of the way out into the spiral disk, a benign, even boring neighborhood. The nearest star, Alpha Centauri, is 4.2 light years away, an average stellar separation for our region, where there is a star in roughly every fifty cubic light years.

Were we to approach the galactic hub, well past the dust clouds, we would find a halo of stars glowing brightly, growing ever denser. In 1932 Carl Jansky discovered that, to his shock, the galactic center was the brightest radio location in the sky, outshining even our sun. Something was going on.

In the core, within a few light years of the exact center, there are a million stars within a single light year. On average, the nearer stars are only a hundredth of a light year away. This is only ten thousand times the distance from the Earth to the sun. Imagine having several stars so close they outshine the moon.

As one might expect, this is bad news for solar systems around such stars. Close collisions between all these stars occur in about a hundred thousand years, scrambling up planetary orbits, raining down comets upon them as well.

The galactic center is the conspicuous Times Square of the galaxy — and far more deadly than the comfortable suburbs like ours. Joel Davis’s Journey to the Center of Our Galaxy details how horrific it is, points out that the survival time for an unshielded human within even a hundred light years of the core is probably hours.

I began studying the galactic center in the mid-1970s, out of curiosity. I did not guess that this mysterious region would intertwine two of my passions, physics and science fiction, though in part I was interested because I had begun writing a series of novels which seemed pointed in that direction.

The first was In the Ocean of Night, exploring the discovery that computer-based life seemed dominant throughout the galaxy. The action followed a British astronaut, Nigel Walmsley, cranky and opinionated. It detailed a few incidents in our solar system,

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.