Heinlein, Robert A – Friday

I don’t know. This ship has the biggest Shipstones I’ve ever seen but Tim Flaherty (he’s second assistant engineer) tells me that

they are charged down only at the middle of each jump, then they finish the voyage having used only “parasitic” power (ship’s heat, cooking, ship’s auxiliary services, etc.).

That sounds to me like a violation of the Law of Conservation of Energy. I was brought up to bathe regularly and to believe that There Ain’t No Such Thing as a Free Lunch; I told him so. He grew just a touch impatient and assured me that it was indeed the Law of Conservation of Energy that caused it to work out that wayÄ it worked just like a funicular; you got back what you put in.

I don’t know. There aren’t any cables out there; it can’t be a funicular. But it does work.

The navigation of this ship is even more confusii~g. Only they don’t call it navigation; they don’t even call it astrogation; they call it “cosmonautics.” Now somebody is pulling Friday’s leg because the engineer officers told me that the officers on the bridge (it’s not a bridge) who practice cosmonautics are cosmetic officers because they are there just for appearances; the computer does all the workÄand Mr. Lopez the second officer says that the ship has to have engineering officers because the union requires it but the computer does it all.

Not knowing the math for either one is like going to a lecture and not knowing the language.

I have learned one thing: Back in Las Vegas I thought that every Grand Tour was Earth, Proxima, Outpost, Fiddler’s Green, Forest, Botany Bay, Halcyon, Midway, The Realm, and back to Earth because that’s how the recruiting posters read. Wrong. Each voyage is tailored. Usually all nine planets are touched but the only fixed feature in the sequence is that Earth is at one end and The Realm, almost a hundred light-years away (98.7 +), is at the other. The seven way stations can be picked up either going out or coming back. However, there is a rule that controls how they are fitted in: Going out the distance from Earth must be greater at each stop, coming back the distance must decrease. This is not nearly as complex as it sounds; it simply means the ship does not double backÄjust the way you would plan a shopping trip of many stops.

But this leaves lots of flexibility. The nine stars, the suns of these planets, are lined up fairly close to a straight line. See the sketch with the Centaur and the Wolf. Looking from Earth, all those stars, as you can see, are either at the front end of the Centaur or close by in the Wolf. (I know the Wolf doesn’t look too well but the Centaur has been clobbering him for thousands of years. Besides, I’ve never seen a wolfÄa four-legged wolf, that isÄand it’s the best I can do. Come to think of it, I’ve never seen a Centaur, either.)

That’s the way those stars cluster in Earth’s night sky. You have to be about as far south as Florida or Hong Kong to see them at all, and even then, with bare eyes you will see only Alpha Centauri.

But Alpha Centauri (Rigil Kentaurus) really shines out, third brightest star in Earth’s sky. Three stars it is, actually, a brilliant one that is the twin brother of Sol, one not as bright that it is paired with, and a distant, dim, small companion that swings around both of them about a fifteenth of a light-year away. Years ago Alpha Centauri was known as Proxima. Then somebody bothered to measure the distance to this inconsequential third cousin and found that it was a hair closer, so the title of Proxima or “Nearest” was moved to this useless chunk of real estate. Then, when we set up a colony on the third planet of Alpha Centauri A (the twin of Sol), the colonists called their planet Proxima.

Eventually the astronomers who tried to shift the title to the dim companion were all dead and the colonists got their way. Just as well, because that dim star, while a hair closer today, will soon be farther awayÄjust hold your breath a few millennia. Being “ballistically linked” it averages the same distance from Earth as the other two in the triplet.