Help me A spinning blue plastic object made me sleepless.

[ltd5241]

Help me!A spinning blue plastic object made me sleepless.

I've seen the mit online vedio course Physics I: Classical Mechanics Lecture 21 Torques, Oscillating Bodies,near the end 44:19.There is a spinning blue plastic object,the teacher spun it, it revolved then it stoped,then it revolved reversely without any other force!
link:http://ocw.mit.edu/OcwWeb/Physics/8-01Physics-IFall1999/VideoLectures/detail/embed21.htm
WHY?

 

[Vorbis]

That is weird.

 

[MATLABdude]

Haven't seen the video, but it sounds like a rattleback:
http://en.wikipedia.org/wiki/Rattleback

Nifty little toy. However, nothing really mysterious about it.

 

[ltd5241]

Haven't seen the video, but it sounds like a rattleback:
http://en.wikipedia.org/wiki/Rattleback

Nifty little toy. However, nothing really mysterious about it.

Thank you! That's it.Rattleback.

 

[pantaz]

Edmund Scientific sells them as "Space Pets"
http://scientificsonline.com/product.asp_Q_pn_E_3039089