Just short demonstration of gyroscopic effects in high speed hard disks. I had some useless hard disks. It is old SCSI server disk ST39102LW. It is only 9Gb, but 10000 rpm (10K). This increase effect to noticible level. To feel effect you need just try to move working disk. I am not going to explain forces in this disk, lets give some words to wiki:
A gyroscope (from Greek γῦρος gûros, “circle” and σκοπέω skopéō, “to look”) is a spinning wheel or disc in which the axis of rotation is free to assume any orientation. When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, according to the conservation of angular momentum.
And look to this short movie in youtube:
Do not do this trick with good disk. And not effects with SSD ones
Original article in Lithuanian language. Dated 2008.