Reading Dan Dare, between the ages of seven and eleven, I was vaguely aware of the distinction between interplanetary space and interstellar space but thought that they were called "space" and "outer space." (I was seven in 1956 when Poul Anderson's first Nicholas van Rijn story was published.)
No one taught me this but, by reading books on astronomy, I learned for myself that:
planets are millions of miles apart whereas stars are millions of millions of miles apart;
no extra-solar planets are or can be visible at such distances so they might not even exist (big surprise and disappointment!).
In Poul Anderson's Tau Zero, as the Leonora Christine leaves the Solar System, the first officer is bothered by idiotic beamcasts from Luna asking how things are going. She will be glad when they "'...get out into the Big Deep.'" (p. 29)
Does she mean when they are far enough away that the time lag will make such radio inquiries impracticable? Or does radio become difficult/impossible to detect and respond to when the ship has accelerated to Bussard ramjet speeds? Calling interstellar space "the Big Deep" makes it sound like the Atlantic or Pacific explored in a submarine, thus not quite as far away from home and our habitable environment as it really is.
9 comments:
Kaor, Paul!
The thought I had was to be VERY puzzled over why past astronomers should have been so skeptical about other planets existing and orbiting other stars. Even if all they KNEW for sure, circa AD 1960, the planets in our Solar System, shouldn't that have been poof enough that other planets were very likely to exist? Would it really make sense to think our Sun was the only star to have planets?
Note, I said PLANETS, not necessarily other planets with oxy/nitrogen atmospheres.
Sean
"...the first officer is bothered by idiotic beamcasts from Luna asking how things are going."
This seems a little perplexing- if these broadcasts were part of the launch routine, why would she find them idiotic, as they would be carefully designed for specific purposes? These sound more like tweets, and who/would be sending this sort of message to a departing starship, and how would these messages be sent/received? If routine, these are the sorts of things an AI should be handling, so as to not bother the crew.
-Keith
Sean,
We must not generalize from a single instance, e.g., a single star with planets.
There was a theory of planetary formation which would make planets very rare, i.e., two stars pass so close to each other that gravity draws out stellar matter which goes into orbit and cools down. See the Lensman series.
Paul.
Kaor, Paul!
A single example is not enough to safely generalize from? Granted!
I have heard of the old theory of planetary formation you mentioned. But, it seems to have been falling out of favor by the 1950's, as we see in WE CLAIM THESE STARS, where gravitational attraction by a slowly coalescing proto-star was how planets formed. I think that is still generally favored even now.
Sean
One surprise from the discovery of extrasolar planets has been the large numbers of large planets very close to their Sol-like suns- "Hot Jupiters" (https://en.wikipedia.org/wiki/Hot_Jupiter) and "Hot Neptunes" (https://en.wikipedia.org/wiki/Hot_Neptune). It looks like it's not easy to significantly deplete a gas giant's atmosphere unless it's REALLY close in (<0.015 AU)...
I can only imagine what wonderful stories PA would come up with knowing what we do today!
-Keith
A whole new series would start.
Yes, it's a tragedy Poul died so (relatively) young, if only for the pleasure some of the new scientific discoveries would have given him. And the revival of space travel and the prospect of large-scale interplanetary travel and colonization in the immediate future.
About that immediate future space travel: I will be skeptical until it happens and pleased if it does.
Kaor, Keith!
I have read about these hot Jupiters at the CENTAURI DREAMS website. Many BIZARRE things are out there!
Kaor, Mr. Stirling!
I too wish Poul Anderson could have lived another ten years--if only for the pleasure and interest the new discoveries in space would have given him. Ditto, what you said about a REAL space program!
Kaor, Paul!
Which is why I hope so much that Elon Musk actually succeeds in sending a manned colonizing expedition to Mars. And that we even get BACK to the Moon as President Trump has declared should be done.
Sean
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