# The Ringworld Is Unstable! **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [February 24, 2005, 8:43pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763 "2005-02-24T20:43:10Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [February 24, 2005, 8:43pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/1 "2005-02-24T20:43:10Z")
From [this](http://boards.straightdope.com/sdmb/showthread.php?t=303776&page=1&pp=50) thread on a vacuum cleaner apperantly designed by the multitalened and prophetic Freeman Dyson (who knew?): > [@pinkfreud](#): > > > [@FinnAgain](#): > > > > I am such a geek… I saw this title and thought “She got a Dyson Sphere???” > > I thought the same thing. And I grumbled to myself, “Phooey. She has a nice new Dyson Sphere, and here I am stuck with this lousy, obsolete Ringworld.” Well, I was all set to discuss the various problems and complexities of planetary-sized artificial habitats, and it turns out to be a bigger and better Hoover. Blah. Where’s my flying car? Anyway, _the Ringworld is unstable!_ (I’ve always wanted to say that.) The reason shall be left for the reader as an exercise in elementry dynamics. That is all. Stranger ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [February 24, 2005, 8:52pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/2 "2005-02-24T20:52:00Z")
Someone read Larry Niven’s **All the Myriad Ways** Or else happened to be at the Boskone where they were chanting that. ---
**Author:** ![Scott\_Plaid](https://avatars.discourse-cdn.com/v4/letter/s/258eb7/32.png) [@Scott\_Plaid](https://boards.straightdope.com/u/Scott_Plaid)\ **Post date:** [February 24, 2005, 8:53pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/3 "2005-02-24T20:53:30Z")
It’s so unstable, that it’s spliting in two! ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [February 24, 2005, 9:01pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/4 "2005-02-24T21:01:09Z")
Well, obviously anything with the mass of a Dyson Sphere, or even a Ringworld, will have the gravitational attraction to make an excellent vacuum cleaner! ---
**Author:** ![Regallag\_The\_Axe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/regallag_the_axe/32/445_2.png) [@Regallag\_The\_Axe](https://boards.straightdope.com/u/Regallag_The_Axe)\ **Post date:** [February 24, 2005, 9:02pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/5 "2005-02-24T21:02:53Z")
Wait, wait, I gotta clear something up first; what’s a dyson sphre? ---
**Author:** ![Ephemera](https://avatars.discourse-cdn.com/v4/letter/e/8baadc/32.png) [@Ephemera](https://boards.straightdope.com/u/Ephemera)\ **Post date:** [February 24, 2005, 9:07pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/6 "2005-02-24T21:07:38Z")
It’s a hypothetical construct suggested by Freeman Dyson wherein a shell would be built around a star at orbital distance so that all its energy could be harnessed. ---
**Author:** ![Regallag\_The\_Axe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/regallag_the_axe/32/445_2.png) [@Regallag\_The\_Axe](https://boards.straightdope.com/u/Regallag_The_Axe)\ **Post date:** [February 24, 2005, 9:11pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/7 "2005-02-24T21:11:45Z")
Ah. I have heard of this idea, I just never heard what it was called. ---
**Author:** ![Regallag\_The\_Axe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/regallag_the_axe/32/445_2.png) [@Regallag\_The\_Axe](https://boards.straightdope.com/u/Regallag_The_Axe)\ **Post date:** [February 24, 2005, 9:16pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/8 "2005-02-24T21:16:53Z")
Ah! Two threads with iden ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [February 24, 2005, 9:17pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/9 "2005-02-24T21:17:25Z")
> [@Regallag\_The\_Axe](#): > > Wait, wait, I gotta clear something up first; what’s a dyson sphre? A [Dyson Sphere](http://en.wikipedia.org/wiki/Dyson_sphere#Bubble) actually consists of several different configurations, but the most common is a shell that surrounds a sun, absorbing all energy coming from it. A shell is inherently stable because of its, well, spherical (regular) geometry. A toroid, however…not so stable. And obviously, neither are my threads, this one having split into two. Not quite certain how _that_ happened. 😕 Stranger ---
**Author:** ![Regallag\_The\_Axe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/regallag_the_axe/32/445_2.png) [@Regallag\_The\_Axe](https://boards.straightdope.com/u/Regallag_The_Axe)\ **Post date:** [February 24, 2005, 9:18pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/10 "2005-02-24T21:18:25Z")
ticle OP’s! Nooooooo! ([http://boards.straightdope.com/sdmb/showthread.php?t=304128](http://boards.straightdope.com/sdmb/showthread.php?t=304128)) ---
**Author:** ![Barbarian](https://avatars.discourse-cdn.com/v4/letter/b/e19adc/32.png) [@Barbarian](https://boards.straightdope.com/u/Barbarian)\ **Post date:** [February 24, 2005, 9:28pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/11 "2005-02-24T21:28:40Z")
That pak? It’s killing your offspring. ---
**Author:** ![Scott\_Plaid](https://avatars.discourse-cdn.com/v4/letter/s/258eb7/32.png) [@Scott\_Plaid](https://boards.straightdope.com/u/Scott_Plaid)\ **Post date:** [February 24, 2005, 9:59pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/12 "2005-02-24T21:59:30Z")
[How the hell did I get here?](http://boards.straightdope.com/sdmb/showpost.php?p=5880620&postcount=3)[What the hell was that? I blame the Old Ones.](http://boards.straightdope.com/sdmb/showthread.php?t=129288) ---
**Author:** ![Meurglys](https://avatars.discourse-cdn.com/v4/letter/m/258eb7/32.png) [@Meurglys](https://boards.straightdope.com/u/Meurglys)\ **Post date:** [February 24, 2005, 10:56pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/13 "2005-02-24T22:56:17Z")
It was actually James Dyson who invented it… [Dyson web site](http://www.dyson.co.uk/nav/inpageframe.asp?id=DYSON/HIST/MENU&sinavtype=menu) ---
**Author:** ![MEBuckner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mebuckner/32/2896_2.png) [@MEBuckner](https://boards.straightdope.com/u/MEBuckner)\ **Post date:** [February 24, 2005, 11:02pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/14 "2005-02-24T23:02:15Z")
**Moderator’s Note:** Duplicate threads merged. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [February 24, 2005, 11:09pm UTC](https://boards.straightdope.com/t/the-ringworld-is-unstable/291763/15 "2005-02-24T23:09:35Z")
> [@Meurglys](#): > > It was actually James Dyson who invented it… > [Dyson web site](http://www.dyson.co.uk/nav/inpageframe.asp?id=DYSON/HIST/MENU&sinavtype=menu) Nah, _Freeman_ Dyson definitely came up with the concept of the Dyson sphere. Oh, you’re talking about the vacuum cleaner. That thing; ffffttt. If Freeman had designed it, it would have been built by General Atomics and would have run for a hundred years off of a single charge of enriched uranium. It would also be capable of cleaning any carpet from here to Alpha Centuri in the lifespan of an average astronaut. Don’t worry about the fallout. That’s nothing. Think of the future! 😉 Stranger