http://www.perlmonks.org?node_id=1146634


in reply to Re: What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?
in thread What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?

A closely related issue "How is the cable attached?" What rotation is allowed without winding (or twisting) the cable?

UPDATE: Please consider an attachment via a "cargo net" which would allow any rotation (assuming it is slippery enough).

Bill
  • Comment on Re^2: What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?

Replies are listed 'Best First'.
Re^3: What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?
by LanX (Saint) on Nov 01, 2015 at 21:37 UTC
    Let's suppose we have a rope with more than 10% elasticity (relative delta of distance)

    The earth is always visible from the near side of the moon (that's the other half from what people erroneously call the "dark" side).

    If the moon was always visible from one of the poles (like the sun is for almost half a year) you'd only need to compensate approximately 360°/24h (the moons orbital rotation of 360°/month doesn't matter much) with something like a slowly rotating swivel.

    But that's never the case, I suppose the moon is at best only visible for 18 days in a row IIRC.

    So you'd end up constructing a large tower in Antarctica, such that from top the moon is always over the horizon.

    No idea how tall this tower must be, but if it crosses the atmosphere (I'm pretty sure it must¹) this would also solve the problem of a giant whip lashing thru air.

    All the construction problems aside, I wouldn't be surprised about electrostatic problems arising from connecting two giant bodies.

    Can't see the benefit of such a construction, that's at best a theoretical question for math class.

    Cheers Rolf
    (addicted to the Perl Programming Language and ☆☆☆☆ :)
    Je suis Charlie!

    PS: pollsters seem to be desperate. ;-)

    ¹) too lazy for calculations, but alone with an ecliptic angle of 23° something like 1-3 thousand km would be "reasonable".

    update

    Quick calculation say a tower on the pole needs roughly 1000km height (at least) to be able to see the moon all year from the tip. (6371/cos 30° = 7356 )

    Well that's already 3 times higher than the ISS orbit...

      the other half from what people erroneously call the "dark" side

      While there can be no doubt that some section of the populace erroneously call it the dark side we can only hope that their number is small. The rest of us call it the dark side metaphorically. Nobody (excepting perhaps that same section of the populace) is suggesting for a moment that the Dark Ages were literally dark or that the Dark Web is literally dark. We use "dark" as a metaphor for things which are or were unknown.

      That said, there's nothing wrong for non-astronauts referring to it as the far side of the moon instead.

        Then again, you can't really have a "side" of a spherical object can you!

        Well, maybe inside and outside; though, as Morin demonstrated, even that's not strictly true for a hollow sphere; but I digress.

        I guess we might call it the 'Dark Hemisphere'; but with 'dark' being so controversial, perhaps not.

        The 'Far Hemisphere' suffers from the same problem as 'Next City'; just a teansy weansy bit short-sighted relatively (NOTE: not relativistically) speaking.

        Of course, the 'Occulted Hemisphere' suffers the same problem, even if it wouldn't be condemn by great swaths of religious leaders.

        How about the 'Lunar Hemisphere We Don't Normally See'? (Will the use of 'Normal' be controversial in some circles I wonder?)

        Plus, good luck getting Pink Floyd to retroactively modify their lyrics to incorporate that.


        With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
        Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
        "Science is about questioning the status quo. Questioning authority". I knew I was on the right track :)
        In the absence of evidence, opinion is indistinguishable from prejudice.
        The rest of us call it the dark side metaphorically.

        Well.

        1. No enlightenment without perception. Light is what reveals all things to the eye. Unseen, unrevealed, they remain in darkness.
        2. From full moon towards new moon, the darkness from the dark side of the moon slowly creeps upon the bright side of the moon! The moon isn't turning around. But the new moon now has two dark sides.

        So, let us refer to them two sides as "front" and "back". Or else.

        perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'
        Would s/erroneously/misleadingly/ be OK?

        Btw in average its indeed darker, cause earth light (see earthshine) never gets there.

        But with the wire we can finally realize electrical street lights and illuminated craters.

        UPDATE

        > That said, there's nothing wrong for non-astronauts referring to it as the far side of the moon instead.

        They must be predominant on Wikipedia. See far side of the Moon

        Cheers Rolf
        (addicted to the Perl Programming Language and ☆☆☆☆ :)
        Je suis Charlie!