Not the DNA unwinding enzyme.
A tall, narrow book case in the form of a helix (single or double). Suitably counterweighted, or balanced with a second similar book case, the helicase can be screwed down through a hole in the floor or, if you're in the room below, screwed out of the ceiling.-- MaxwellBuchanan, Oct 08 2012 Like this? http://s1.juniormag.../original/10151.jpg [Phrontistery, Oct 08 2012] Helical wine cellar http://s3files.core...ges/0spircell03.jpgHelical wine cellars, built around a helical staircase dropped into a cylindrical hole in your floor are pretty popular now, and there are several specialist building companies that do nothing else. One of these could be repurposed to be a bookcase. [hippo, Oct 08 2012] Sort of like that, [phrontistery], but rotatier and with more up and downability.-- MaxwellBuchanan, Oct 08 2012 Hate to say it, but a spiral staircase seems both necessary and good enough.-- 4and20, Oct 08 2012 It's a nifty idea, why not expand it to be a staircase with scaled-down helical bookcases rising on posts from the handrail at measured intervals? Not only pleasurable to select books from these mini-libraries as you ascend and descend the stairs but would also look rather wonderful.-- Phrontistery, Oct 08 2012 Yes, like Phronhistery's idea better. Call it a "Bookwell".-- blissmiss, Oct 08 2012 //but a spiral staircase seems both necessary and good enough.//
The key element that's missing in a spiral staircase is, as aforementioned, rotatiness and up and downability.
I want this bookcase to revolve smoothly on the lushest and most unctious of bearings, so that it screws itself upwards into, or down from, the ceiling.-- MaxwellBuchanan, Oct 08 2012 (....+....)-- 2 fries shy of a happy meal, Oct 08 2012 Now I keep thinking of seasickness.-- Phrontistery, Oct 08 2012 I suppose a copy of Dante's Inferno would reside on the very bottom shelf.-- RayfordSteele, Oct 08 2012 I was hoping for a suitcase with rotor blades. [+] anyway though.-- TomP, Oct 09 2012 Make it a double helix, with the two bookcases intertwined, contrarotating and counterweighting each other.-- mitxela, Oct 09 2012 When one removes a book from the shelf, will the bookcase start creeping upwards?-- TomP, Oct 10 2012 I realised I didn't know exactly what unctious meant, so I looked it up on dictionary.com. Apparently: Unc"tious\, a. Unctuous. [Obs.]
It took a few moments to figure that one out.
...
It seems to me that the obvious embodiment for a helical moving bookshelf is for a rigid double-helix with books on slats between the two helices[1]. This suggests a form of movement in which the helix rotates as it moves so that at any particular height the shelf position is fixed. The shelves then scroll past in a manner condusive to review, and holes in the ceiling & floor can then approximate the shape of the shelf so there is no vaguely annoying hole between storeys.
However, the potential elegance of the system is to me marred by the relative shortness of the shelfing (vertically) and the fact that one can reach the end of it - at which point it presumably bangs into the stops and some of the books may fall out. Furthermore, a naively implemented helicase with decent travel requires twice as much height as is available for storage[2], and shelving is also presumably either absent from some access storeys or some shelves are only acessible from some heights. In light of that, I'd like to suggest the possibility of an endless-loop shelf, which uses some form of paternoster-style arrangement to move chunks of helix-shelving from the ascending to descending path at the top and vice-versa at the bottom. Horrendously complicated to implement, but out of sight and yielding a very attractive, infinitely scrollable display.
[1] As aforenoted this necessitates either a counterweight or a second, equally loaded bookshelf. Unfortunately, the lower the friction against movement, the more equally one must balance one's books.
[2] Suppose one had a helicase with a total shelf height of 'h' to be accessible from within one vertical window 'w'. To access every book from that range of heights, one needs to be able to wind the helicase up to reach the bottom shelf, and down to reach the top shelf. Therefore one needs a total height of w+2*(h-w) = 2h-w. w is obviously smaller than h (because otherwise there's no need to move it). I suggest that w must be significantly smaller than h to gain much appreciation of the system; in the limit we can approximate this to 2h.-- Loris, Oct 10 2012 I love this idea [+]. For added coolness, make it a multiple helix. Say you have a central bar around which the thing rotates when screwing the case in and out of the floor. Just make it so that the bar can be decoupled from one helical ridge and attached to another, entwined. In that way you could have a double helix, one for your English books, the other for the French. Of course you can add more helices if you have the space (and language skills). As an extra bonus, the bar can be decoupled from all helices and be used for pole dancing.-- placid_turmoil, Oct 10 2012 random, halfbakery