Uploaded May 2012 | Updated September 2026, 3 hours ago

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In a perfect world, the model would run forever... but, apart from the air friction, there is also the friction of the bottom sphere rotating over the table: watching at this video you'll discover is this last friction can be considered negligible or not!

Model inspired to this beautiful work youtube.com/watch?v=VjBlxtFojRk
by youtube.com/user/garridoasecas