Fastest Spinning Object

Researchers from the University of St Andrews claim to have created the world’s fastest spinning man-made object.

The team of scientists were able to levitate and spin a microscopic sphere in a vacuum using only laser light. The sphere rotated at speeds of 600 million revolutions per minute (RPM) before it broke apart and disappeared.

In comparison this speed of rotation is half a million times faster than the spin speed of a washing machine and more than a thousand times faster than a dentist’s drill.

"This is an exciting, thought-provoking experiment that pushes the boundary of our understanding of rotating bodies,” said Dr Yoshihiki  Arita, one of the scientists involved in the project.  "I am intrigued with the prospect of extending this to multiple trapped particles and rotating systems.

“We may even be able to shed light on the area of quantum friction – that is – does quantum mechanics put the brakes on the motion or spinning particle even though we are in a near perfect vacuum with no other apparent sources of friction?"

As well as Dr Arita, the work was undertaken by Dr Michael Mazilu and Professor Kishan Dholakia of the School of Physics and Astronomy and published in the international journal Nature Communications.

The sphere itself was only 4 millionths of a metre in diameter and was constructed from calcium carbonate. It was held in place by the “miniscule forces” of radiation produced by the laser – a phenomenon similar to balancing a beach ball on a jet of water.

The team then span the sphere by using the laser's polarisation to exert a small twist or torque.

The vacuum conditions that the microscopic sphere was suspended in largely removed the drag (friction) that would have been present in a gas environment, allowing the team to achieve such a high rate of rotation.

“The rotation rate is so fast that the angular acceleration at the sphere surface is 1 billion times that of gravity on the Earth surface– it's amazing that the centrifugal forces do not cause the sphere to disintegrate!” said Dr Mazilu.

Professor Kishan Dholakia said: "The team has performed a real breakthrough piece of work that we believe will resonate with the international community. In addition to the exciting fundamental physics aspects, this experiment will allow us to probe the nature of friction in very small systems, which has relevance to the next generation of microscopic devices. And it's always good to hold a "world record" - even if for only a while!"