@ 10 gee
14.5 days vs. 14.5 weeks
@ 100 gee
45.9 days vs. 45.9 weeks
@ 1/1000 gee
145 days vs. 145 weeks
distance from here to Uranus, nearly four times as far as from here to Jupiter. When Pluto is out there - l 865 or 2114 A.D. - it takes light 6 hours and 50 minutes to reach it. Pluto - the Winnuh and still Champeen! Sour grapes is just as common among astronomers as it is in school yards.)
- and the rabbit is out of the hat. You will have noticed that the elapsed - time figures are exactly the same in both columns, but in days for Mars, weeks for Pluto - i.e., with constant - boost ships of any sort Pluto is only 7 times as far away for these conditions as is Mars even though in miles Pluto is about 50 times as far away.
If you placed Pluto at its aphelion (stay alive another century and a quarter - quite possible), at one gee the Pluto round trip would take 5.72 weeks, at 1/to gee 18.1 weeks, at 1/too gee 57.2 weeks - and at 'Iiooo gee 181 weeks, or 3 yrs & 25 wks.
I have added on the two illustrations at 'Iwoo of one gravity boost because today (late 1979 as I write) we do not as yet know how to build constant - boost ships for long trips at 1 gee, 1/10 gee, or even 1/too gee; Newton's Third Law of Motion (from which may be derived all the laws of rocketry) has us (temporarily) stumped. But only temporarily. There is E = mc2, too, and there are several possible ways of "living off the country" like a foraging army for necessary reaction mass. Be patient; this is all very new. Most of you who read this will live to see constant - boost ships of 1/10 gee or better - and will be able to afford vacations in space - soon, soon! I probably won't live to see it, but you will. (No complaints, Sergeant - I was born in the horse & buggy age; I have lived to see men walk on the Moon and to see live pictures from the soil of Mars. I've had my share!)
But if you are willing to settle today for a constant boost on the close order of magnitude of 1/1000 gee, we can start the project later this afternoon, as there are several known ways of building constant - boost jobs with that tiny acceleration - even light - sail ships.
I prefer to talk about light - sail ships (or, rather, ships that sail in the "Solar wind") because those last illustrations I added (l/t000 gee) show that we have the entire Solar System available to us right now; it is not necessary to wait for the year 2000 and new breakthroughs.
Ten weeks to Mars ... a round trip to Pluto at 31.6 A.U. in 2 years and 9 months... or a round trip to Pluto's aphelion, the most remote spot we know of in the Solar System (other than the winter home of the comets).
Ten weeks - it took the Pilgrims in the Mayflower nine weeks and three days to cross the Atlantic.
Two years and nine months - that was a normal commercial voyage for a China clipper sailing out of Boston in the last century ... and the canny Yankee merchants got rich on it.
Three years and twenty - five weeks is excessive for the China trade in the 19th century.. . but no one will ever take that long trip to Pluto because Pluto does not reach aphelion until 2113 and by then we'll have ships that can get out there (constant boost with turnover near midpoint) in three weeks.
Please note that England, Holland, Spain, and Portugal all created worldwide empires with ships that took as long to get anywhere and back as would a Vtooo - gee spaceship. On the high seas or in space it is
not distance that counts but time. The magnificent accomplishments of our astronauts up to now were made in free fall and are therefore analogous to floating down the Mississippi on a raft. But even the tiniest constant boost turns sailing the Solar System into a money - making commercial venture.
Now return to page 338.
"Tomorrow we again embark
upon the boundless sea."
- Horace, Odes
FOREWORD
One of the very few advantages of growing old is that one can reach an age at which he can do as he damn well pleases within the limits of his purse.
A younger writer, still striving, has to put up with a lot of nonsense - interviews, radio appearances, TV dates, public speaking here and there, writing he does not want to do - and all of this almost invariably unpaid.
In 1952 I was not a young writer (45) but I was certainly still striving. Here is an unpaid job I did for a librarians' bulletin because librarians can make you or break you. But today, thank Allah, if I don't want to do it, I simply say, "No." If I get an argument, I change that to: ''Hell, No!''
"Being intelligent is not a felony.
But most societies evaluate
it as at least a misdemeanor."
- L. Long
RAY GUNS AND ROCKET SHIPS
"When I make a word do a lot of work like that," said Humpty Dumpty, "I always pay it extra."
"Science Fiction" is a portmanteau term, and many and varied are the things that have been stuffed into it. Just as the term "historical fiction" includes in its broad scope Quo Vadis, nickel thrillers about the James Boys or Buffalo Bill, and Forever Amber, so does the tag "science fiction" apply both to Alley Oop and to Aldous Huxley's After Many a Summer Dies the Swan. It would be more nearly correctly descriptive to call the whole field "speculative fiction" and to limit the name "science fiction" to a sub - class - in which case some of the other sub - classes would be: undisguised fantasy (Thorne Smith, the Oz books), pseudoscientific fantasy (C. S. Lewis's fine novel Out of the Silent Planet, Buck Rogers, Bradbury's delightful Martian stories), sociological speculation (More's Utopia, Michael Arlen's Man's Mortality, H. G. Wells' World Set Free, Plato's Republic), adventure stories with exotic and non - existent locales (Flash Gordon, Burroughs' Martian stories, the Odyssey, Tom Sawyer Abroad). Many other classes will occur to you, since the term
"speculative fiction" may be defined negatively as being fiction about things that have not happened.
One can see that the name "science fiction" is too Procrustean a bed, too tight a corset, to fit the whole field comfortably. Nevertheless, since language is how we talk, not how we might talk, it seems likely that the term "science fiction" will continue to be applied to the whole field; we are stuck with it, as the American aborigines are stuck with the preposterous name "Indian."
But what, under rational definition, is science fiction? There is an easy touchstone: science fiction is speculative fiction in which the author takes as his first postulate the real world as we know it, including all established facts and natural laws. The result can be extremely fantastic in content, but it is not fantasy; it is legitimate - and often very tightly reasoned - speculation about the possibilities of the real world. This category excludes rocket ships that make U-turns, serpent men of Neptune that lust after human maidens, and stories by authors who flunked their Boy Scout merit badge tests in descriptive astronomy.
But the category includes such mind stretchers as Olaf Stapledon's Last and First Men, William Sloane's To Walk the Night, Dr. Asimov's The Stars, Like Dust, even though these stories are stranger than most outright fantasies.
But how is one to distinguish between legitimate science fiction and ridiculous junk? Place of original publication is no guide; some of the best have appeared in half - cent - a - word pulp magazines, with bug-eyed monsters on their covers; some of the silliest have appeared in high - pay slicks or in the "prestige" quality group.
"The Pretzel Men of Pthark" - that one we can skip over; the contents are probably like the title. Almost as easy to spot is the Graustark school of space opera. This is the one in which the dashing Nordic hero comes to the aid of the rightful Martian princess and kicks out the villainous usurper through super science and sheer grit. It is not being written very often these days, although it still achieves book publication occasionally, sometimes with old and respectable trade book houses. But it does not take a Ph.D. in physics to recognize it for what it is.