Sunday, 27 January 2013

FTL?

OK. Poul Anderson's explanation of hyperspace in his Technic Civilisation future history makes sense and is easy to understand:

if a spaceship jumps from one set of spatiotemporal coordinates to a nearby set without traversing the space between them, then the jump can be instantaneous because only the traversal of space is limited by the light speed barrier so if the ship makes billions of such jumps per microsecond then it can move at a psuedo-velocity far greater than light speed.

But I am still trying to make sense of the alternative method of FTL (faster than light) travel offered in the same author's The Star Fox. Anderson's knowledge of the science of physics enabled him to devise several different verbal formulae as rationalisations of FTL but this one reached its conclusion very quickly.

The rationale:

inertia exists only in the inertial frame of reference of the entire universe;
inertial and gravitational mass are the same (Einstein);
equations of warped space describe gravity;
therefore, inertia is an inductive effect of the cosmic gravitational field on mass;
if gravitrons can bend space through a closed curve, then the ship has no resistance to acceleration;
so it has no top speed.

Does that make sense?

15 comments:

  1. Hi, Paul!

    A physicist might understand either version of these two hypothetical FTL drives, but I don't pretend to claim I do! Needless to say, I hope someday we do have scientists who discover a real world FTL drive. I want to know what is out there in the universe. I want other planets to be colonized by mankind.

    Sean

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  2. The Technic History version is comprehensible. Moving from A to B by traversing the line AB is limited to light speed whereas disappearing at A and reappearing at B without traversing AB can be instantaneous. But PA needed to spell out the STAR FOX version a bit more.

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  3. I agree at least about getting some people off Earth for longer term survival.

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    1. Hi, Paul!

      I was unclear. I do get the bit about disappearing at point A to reappear "intantaneously" at B. And various rumors I hear about tachyons somehow going FTL, as in the experiments at CERN, are very interesting (to say the least). But, even if a hypothetically workable THEORY is developed, the ENGINEERING necessary for moving untold tons of matter (including people) remains a formidable barrier to building FTL ships.

      While we both agree in disliking most of Heinlein's later work, I think we can also agree with his comment that it's foolish for humanity to perist in keeping all it's eggs in the one basket called Earth. The danger of comets like Apophis hiting Earth should be enough, if we lived in rational times, to getting people off their duffs working for that!

      Sean

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  4. Yes, I am very worried about comets. It is only a matter of time.

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    1. Hi, Paul!

      Absoluutely! In fact, we are probably long overdue to getting smacked with a big comet. And we still FOOLISHLY persist in not doing what it takes to get off this rock!

      I have wondered if the Tunguska incident occurring around 1905 was a comet hitting Earth. If so, the next is either going to be bigger or even if "small" hit a populous area. Either would be a disaster of the kind described in Jerry Pournelle/Larry Niven's novel LUCIFER'S HAMMER.

      Sean

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  5. The comets that periodically fall into the inner system are getting progressively smaller (and disappointing in the night sky) because they lose matter every trip but something big and unexpected could be on its way.

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    1. Hi, Paul!

      Agree, but it only takes one even "moderately" large comet hitting Earth to spoil everyone's day! And sooner or later, it will happen. UNLESS we have the means for fending them off. And that first necessitates getting off this rock.

      But I know you agree!

      Sean

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  6. Even if just getting off Earth to the extent of mounting an adequate laser defence system? But there are other good reasons for having populations in self-sustaining space habitats if not down on other planetary surfaces. All sorts of things could happen to Earth. As long as nuclear weapons exist, they could be used.

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    1. Hi, Paul!

      I agree! For a really adequate big rock detecting and fending off system, we need to do it in SPACE. And founding settlements off Earth would act as insurance against us losing every thing due to a really big nuclear exchange.

      If an English socialist agnostic like you and a Catholic conservative like me can see that, why can't OTHERS????? Sometimes, I do feel discouraged.

      Sean

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  7. Signing off for about a week. This morning, driving to Leicester to visit my mother, 94, nearly bedridden, immediate future uncertain, but very resilient. I will have to go down there again soon. After that, don't know.

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  8. By the way, 2 days ago, 96 page views in the day, the most yet.

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  9. Hi, Paul!

    Hope you have a happy visit with your mother despite the uncertain future. Good to know she is still so resilient.

    And I hope some of those visitors to this blog will offer their own comments about both Poul Anderson and your notes!

    Sean

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  10. Thank you. I am back home and trying to update this and other blogs. Page viewing has dropped off in my absence but that can't be helped. Rereading THE STAR FOX has been rewarding and now I have its sequel, FIRE TIME, to reread as well.

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    1. Hi, Paul!

      I've also been thinking about THE STAR FOX, esp. the Aleriona leader Heim fought and why Alerion consides humanity a threat to her, even if humans don't WANT to be a threat to her.

      I reread THE STAR FOX last year. Thinking I should reread FIRE TIME soon.

      Sean

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