10 Myths about Space Travel that make SF better

Discussion in 'Science Fiction' started by Hobbit, Aug 22, 2012.

  1. Rosie Oliver

    Rosie Oliver Registered User

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    Okay... it's the battle of the dictionaries.... OED (Oxford English Dictionary) has

    centrifugal = moving or tending to move away from the centre

    centripetal = moving or tending to move towards a centre

    So the artificial gravity induced by spinning a spacecraft is centrifugal force as the people are being pushed outward from the centre.
     
  2. Steven L Jordan

    Steven L Jordan I like SF. SF is cool.

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    "Firmly in the realm of hard SF"? Not quite. No one's even proven that they can create a "warp bubble," much less sustain one, enlarge it, wrap it around a spaceship using "exotic matter" and shape it in order to squeeze the spacecraft through spacetime. I'd say #1 still qualifies as a myth.
     
  3. ian_sales

    ian_sales Registered User

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    See http://en.wikipedia.org/wiki/Centrifugal_force and http://en.wikipedia.org/wiki/Centrifugal_force_(rotating_reference_frame)

    (I should have put "reaction to centripetal force" earlier, which is reactive centrifugal force. But in the context of rotating something to generate gravity, centrifugal force is considered a fictitious force - see http://en.wikipedia.org/wiki/Artificial_gravity#Rotation)
     
    Last edited: Sep 19, 2012
  4. ian_sales

    ian_sales Registered User

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    Perhaps, but it seems silly to be scientifically inaccurate in a discussion on, er, scientific inaccuracies... :)
     
  5. Steven L Jordan

    Steven L Jordan I like SF. SF is cool.

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    The article seems to call centripetal force a "pseudo-force," because it is in reality an effect of the very real force of inertia upon rotational objects.

    Regardless, we know centripetal force can provide the effect of artificial gravity where there is none.
     
  6. Rosie Oliver

    Rosie Oliver Registered User

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    It also depends which object on which the force is being applied - spacecraft or human... however I can't resist adding....

    May the force be with you! :cool:
     
  7. Steven L Jordan

    Steven L Jordan I like SF. SF is cool.

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    From the list:

    This makes me think of a corollary myth:

    Ships traveling at faster than light can use sensors to examine the space around them.

    If a ship was traveling FTL, no light or other particles should be able to interact with it, outside of those directly in front of it, without becoming severely dopplered... and the light or particles couldn't catch up from behind. Therefore, an FTL ship should be totally blind to anything happening behind it, and tunnel-blind to anything happening ahead of it. And, of course, by the time they detect anything ahead of it, it would be behind them before the signal even made it through the ship's electronics, much less through the human passenger's optic nerves.
     
  8. SR_Seldon

    SR_Seldon SF Author

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    That's why I prefer to use hyperspace in my stories. A different dimension and a different set of rules. Unfortunately, from a science point of view, hyperspace is in pretty sketchy territory, even in theoretical physics. It just presents fewer complications when writing.
     
  9. Steven L Jordan

    Steven L Jordan I like SF. SF is cool.

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    "Hyperspace" should have been given a prominent spot on the original list, given that we don't know whether it exists, whether we can access it, what rules apply to it, and how it will make FTL travel workable. Hyperspace is the ultimate Handwavium.
     
  10. SR_Seldon

    SR_Seldon SF Author

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    One of the confusions about hyperspace is how Asimov used the term. Herbert later had a more mystical process but a better label - folding space. That describes Asimov's concept better. Hyperspace has come to mean more of a different dimension such as in Star Wars or Babylon 5. I found the book Hyperspace, my Michio Kaku, to be enlightening about how highly theoretical it might be.

    In my fiction, I consider it a different but parallel dimensional space where all the high gravity objects in real space are echoed, but in a smaller scale. As I prefer the more theoretical end of physics, I have no problem pulling different theories into something that works, sometimes in dramatic ways, for my stories. But then, I consider what I have written, and most of what I plan to write in the future, to be space opera, so it fits what I write.
     
  11. Steven L Jordan

    Steven L Jordan I like SF. SF is cool.

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    Never liked the "folding space" concept myself: Tearing open portals that magically bridged the distances between two points always seemed too convenient for words. (Much like hyperspace! :p)
     
  12. SR_Seldon

    SR_Seldon SF Author

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    Um... the information I have on how Herbert and Asimov both described the process is almost identical to the more detailed and modern version you mentioned you came up with on another thread. I believe Herbert specified that the mechanism for folding space was quantum mechanics. Asimov never got so detailed with what he labeled hyperspace, but both involve suddenly being someplace else, no holes, no movement, no portals, just lots of intense calculations.

    Now, that differs greatly from what the 1984 movie and the SFC mini-series offered up for how folding space works in the Dune universe. Those were both glammed up and dumbed down.
     
  13. psikeyhackr

    psikeyhackr Live Long & Suffer

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    All methods are just so much hand waving. It is just a matter of how detailed and complicated the writer wants to make the hand waving. Until we can do it or figure out with a high degree of certainty that it cannot be done, it is just a device to move the story forward.

    The galaxy is big and other stars are far away. The author must either come up with some "fantasy physics" and technology to get there or not write stories about it. I haven't heard to many people complaining about David Weber's "Washauski(sp) sails" and his method is about the most bizarre that I know of.

    psik
     
  14. JunkMonkey

    JunkMonkey Registered User

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    So this is why in well organised and regulated universe the major interstellar space lanes have bloody big mirrors posted along them facing back the way. Any FTL ship approaching would then be able to see events that happened a long time ago in the 'space' they crossed seconds before. This, of course, will be of no use to anyone at all but, I imagine, would be rather pretty and would give the passengers something to talk about.
     
  15. Steven L Jordan

    Steven L Jordan I like SF. SF is cool.

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    ...

    ...I like it.
     
  16. Rosie Oliver

    Rosie Oliver Registered User

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    The laws of physics are written in what I call a minimalist mode i.e. they describe exactly what happens and no more - so they can't describe what we can't yet perceive. It doesn't stop these minimalist laws being correct. Nor does it stop laws that behave exactly like the minimalist laws in our known universe with extensions of the laws in as yet unknown ares of the universe. If you are up to it, examine gauge theory in electromagnets... this is where I tiptoe away...
     
  17. Steven L Jordan

    Steven L Jordan I like SF. SF is cool.

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    In terms of SF, this sounds a lot like saying: "The universe is not all understood, and our corner of it isn't the same as all the others; therefore, the laws we want to exist must exist out there somewhere." IOW, somewhere in the universe, anything is possible.

    Dammit, Spock, I'm a writer, not a quantum physicist! What does all that gaugey-mathy-wathy stuff have to do with space travel myths?
     
  18. SR_Seldon

    SR_Seldon SF Author

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    Yeah, I have a problem with this. If you are going to hypothesize some alteration to physics (such as a far fetched theoretical theory turning out to be true), you need to make it consistent across the board. All the corners of the universe should be the same. I mean, even black holes behave themselves.
     
  19. Rosie Oliver

    Rosie Oliver Registered User

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    Sorry to be even more Spockish... Gauge theory is not quantum mechanics, but derivations of laws of electromagnetism.

    Now I don't expect 'normal' science fiction writers to have this depth of knowledge... just to explain their universe in simple terms to the ordinary man in the street. In many cases this is done by noting cause and effect of the laws of physics... you don't have to explain the theory.

    However, your prod does lead me to note one thing... hard science relies on the science in the story being correct (as far as the science is known at the time of writing) and woe betide any such science fiction writer who gets it wrong. Could this be one reason why there is a lack of hard science writers these days?
     
  20. Steven L Jordan

    Steven L Jordan I like SF. SF is cool.

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    Well, insofar as quantum physics has become more familiar (as a concept, if not in fact) to the public and to SF readers, it clearly raises a pretty daunting bar for any hard SF writer who wants to attempt it.

    On the other hand, not all science is quantum mechanics; other areas can be explored that are just as hard, but more down-to-Earth than quantum theory. But maybe hard SF writers don't want to write in those other areas.

    Hard to say.