# Spinning tops. **URL:** \ **Category:** Factual Questions\ **Created:** [August 14, 2001, 6:47pm UTC](https://boards.straightdope.com/t/spinning-tops/76240 "2001-08-14T18:47:42Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![ProfFrink](https://avatars.discourse-cdn.com/v4/letter/p/8baadc/32.png) [@ProfFrink](https://boards.straightdope.com/u/ProfFrink)\ **Post date:** [August 14, 2001, 6:47pm UTC](https://boards.straightdope.com/t/spinning-tops/76240/1 "2001-08-14T18:47:42Z")
Has anyone thrashed around the deal with those fancy spinning tops - you know, the ones that spin, and after a while, FLIP UPSIDE DOWN and keep spinning? Love to know if this dead horse has taken a whack on this site. 🙂 ---
**Author:** ![mohnkern](https://avatars.discourse-cdn.com/v4/letter/m/ebca7d/32.png) [@mohnkern](https://boards.straightdope.com/u/mohnkern)\ **Post date:** [August 14, 2001, 8:05pm UTC](https://boards.straightdope.com/t/spinning-tops/76240/2 "2001-08-14T20:05:27Z")
There wasn’t actually a question in this post, but I assume the question is “How is it that these spinning tops flip?” (As opposed to something more mundane, like, where can I buy one?) Tops that flip over are often referred to as “Tippee Tops.” Personally, I think “Flippy tops” would have been a better name. The Quasar Club, in the Physics Department of the University of Queensland, reports that these tops flip over due to gyroscopic forces. See [http://www.physics.uq.edu.au/quasar/past/gyro.html](http://www.physics.uq.edu.au/quasar/past/gyro.html) The MIT Media Lab, in its infinite wisdom, held a course, in 1995, that did nothing but explore tops, and what they are about. [http://www.mit.edu:8001/people/lmtancre/le95/le95.html](http://www.mit.edu:8001/people/lmtancre/le95/le95.html) Unlike MIT, who didn’t do any mathematical analysis of why tippee tops flip (they just confirmed that they do), Dartmouth has in fact, asked students to explain the mathematics behind it. [http://www.dartmouth.edu/~phys15/labs/rotation.pdf](http://www.dartmouth.edu/~phys15/labs/rotation.pdf) So in short, Tippee tops should really be named flippy tops, and, they flip, because of gyroscopic forces. ---
**Author:** ![mohnkern](https://avatars.discourse-cdn.com/v4/letter/m/ebca7d/32.png) [@mohnkern](https://boards.straightdope.com/u/mohnkern)\ **Post date:** [August 14, 2001, 8:10pm UTC](https://boards.straightdope.com/t/spinning-tops/76240/3 "2001-08-14T20:10:51Z")
There wasn’t actually a question in this post, but I assume the question is “How is it that these spinning tops flip?” (As opposed to something more mundane, like, where can I buy one?) Tops that flip over are often referred to as “Tippee Tops.” Personally, I think “Flippy tops” would have been a better name. The Quasar Club, in the Physics Department of the University of Queensland, reports that these tops flip over due to gyroscopic forces. See [http://www.physics.uq.edu.au/quasar/past/gyro.html](http://www.physics.uq.edu.au/quasar/past/gyro.html) The MIT Media Lab, in its infinite wisdom, held a course, in 1995, that did nothing but explore tops, and what they are about. [http://www.mit.edu:8001/people/lmtancre/le95/le95.html](http://www.mit.edu:8001/people/lmtancre/le95/le95.html) Unlike MIT, who didn’t do any mathematical analysis of why tippee tops flip (they just confirmed that they do), Dartmouth has in fact, asked students to explain the mathematics behind it. [http://www.dartmouth.edu/~phys15/labs/rotation.pdf](http://www.dartmouth.edu/~phys15/labs/rotation.pdf) So in short, Tippee tops should really be named flippy tops, and, they flip, because of gyroscopic forces. ---
**Author:** ![ProfFrink](https://avatars.discourse-cdn.com/v4/letter/p/8baadc/32.png) [@ProfFrink](https://boards.straightdope.com/u/ProfFrink)\ **Post date:** [August 15, 2001, 5:29am UTC](https://boards.straightdope.com/t/spinning-tops/76240/4 "2001-08-15T05:29:11Z")
> [@](#): > > \*Originally posted by mohnkern \* > There wasn’t actually a question in this post, but I assume the question is “How is it that these spinning tops flip?” (As opposed to something more mundane, like, where can I buy one?) I apologize for lack of clarity in my post. My question should read: [list=1] [li]Is there general interest in tippee tops and their curious method of suddenly flipping over?[/li][li]Would an explanation of their behavior be of interest to the general public?[/li][/list=1] > [@](#): > > The Quasar Club, in the Physics Department of the University of Queensland, reports that these tops flip over due to gyroscopic forces. > > See [http://www.physics.uq.edu.au/quasar/past/gyro.html](http://www.physics.uq.edu.au/quasar/past/gyro.html) Unfortunately, a site directed toward observation of the phenomenon. > [@](#): > > The MIT Media Lab, in its infinite wisdom, held a course, in 1995, that did nothing but explore tops, and what they are about. > > [http://www.mit.edu:8001/people/lmtancre/le95/le95.html](http://www.mit.edu:8001/people/lmtancre/le95/le95.html) Unfortunately, again a site directed toward observation of the phenomenon. > [@](#): > > Unlike MIT, who didn’t do any mathematical analysis of why tippee tops flip (they just confirmed that they do), Dartmouth has in fact, asked students to explain the mathematics behind it. > > [http://www.dartmouth.edu/~phys15/labs/rotation.pdf](http://www.dartmouth.edu/~phys15/labs/rotation.pdf) Unfortunately, the Dartmouth students do not share their discoveries here. > [@](#): > > So in short, Tippee tops should really be named flippy tops, and, they flip, because of gyroscopic forces. \*\* Unfortunately, I cannot find a relevant reference to the mechanism of this. I believe that, more specifically, the tippee tops have two strongly stable equilibria, stem-up and stem-down, when spun at a rate at which the nutation frequency is above a certain threshhold. Upon reaching the critical nutation frequency, the trace of the Hamiltonian for the stem-up mode declines to |TrA|\<2, but the stem-down remains at |TrA|\>2, thus resulting in only one real extremal of the Hamiltonian, that is stem-down. _Proposed but not proven._ And I’ll find a place to buy one and play.