Monday, 1 April 2019

Through The Galactic Center

Poul Anderson, Tau Zero, CHAPTER 15.

See: Tau Zero: The Successive Crises.

The stages summarized:

(i) plunge through the galactic center and out into inter-cluster space;

(ii) plunge through a cluster into inter-clan space;

(iii) accelerate between clans;

(iv) orbit around the monobloc.

On pp. 127-128 of 190, we are still at stage (i).

At the galactic center, there are crowded star clusters. The ship could hit a star hidden in a dust cloud. The star might go nova and the ship would be destroyed. (Later, at a higher acceleration, I think that they might be able to survive a collision with a star.) There is clear space, like the eye of a hurricane, at the exact center. Later theory places a massive black hole at each galactic center. The thronged stars include kinds unlike any in the outer galaxy.

Emerging from the nebulae at the far side of the galactic nucleus, the ship flies back through the home spiral arm with a fireball dwindling behind and darkness gathering ahead.

2 comments:

Sean M. Brooks said...

Kaor, Paul!

Now that's a telling point about TAU ZERO, no mention being made about black holes in the story. How might Poul Anderson have written TZ if he had incorporated the then very new theories about black holes in it? But the problem was the core of what became TAU ZERO, "To Outlive Eternity," was written before black holes became so widely known.

The earliest Anderson might have known about black holes might have been a year or so before the first publication of his black hole story "Kyrie" in THE FARTHEST REGIONS (1968). The complete text of what became TAU ZERO was pub. in 1970. Theoretically, Anderson should have included something about black holes in the book. However, TZ was based on "To Outlive Eternity," pub. by ASTOUNDING in 1967, and Anderson probably felt bound by what he had previously written, even if it would have been more scientifically accurate to incorporate black holes.

"Kyrie" interests me in how it shows Anderson striving to keep up with advances and speculations in scientific knowledge.

Sean

Anonymous said...

"The ship could hit a star hidden in a dust cloud."
mMybe, but probably not:
"Space is big. Really big. You just won’t believe how vastly hugely mindbogglingly big it is. I mean you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space."

-The Hitchhiker’s Guide To The Galaxy, The Hitchhiker’s Guide To The Galaxy

The galactic center stellar density is ~100/pc exp3 (https://physics.stackexchange.com/questions/25706/what-is-the-density-of-stars-near-the-center-of-the-milky-way), so each star is roughly 0.2 PC (or 40,000 AU) from each other ~1000x the distance from Sol to the dwarf planet Pluto.
Also, if there really WERE some danger of hitting stuff in the galactic plane or the galactic hub, just go "up" or "down" a few hundred (galactic plane) or thousand (galactic hub) ly.

-kh