The Relativistic Hall Effect Describing Objects Rotating At Speeds Comparable With The Speed Of Light Has Now Been Reported

As any cameraman knows, recording a fast rotating object such as a fan using a “rolling shutter” camera, like those found on mobile phones, results in weird distortions. 

Credit: http://www.youtube.com/watch?v=17PSgsRlO9Q, http://www.youtube.com/watch?v=LVwmtwZLG88&feature=fvwrel.

Less widely understood — until now — is the link between these distortions and some of the landmark theories in physics, namely Einstein’s relativity and the Hall effect. 

(a) A relativistic rotating flywheel in the rest frame. (b) Deformations of the wheel shape in the frame moving with a velocity comparable to the speed of light.

Credit: Wikipedia 

Hall effects describe the interplay of rotation and linear motion in objects. There are already a number of manifestations of the Hall effect, including classical, quantum, and ‘spin-based’. 

That’s what happens when you record the plane’s blades with a Nokia N95.

Credit: RIKEN

Relativity describes effects that arise when an object approaches the speed of light. This study considered the Hall effect as arising naturally under special relativity conditions without any external fields. The researchers found that a relativistic treatment of rotating bodies and quantum wave systems with angular momentum results in deformations and a shift in the geometric centre. The distortions have parallels with those found when recording a rotating object with a rolling shutter camera.

“Our description makes relativistic and quantum aspects of angular momentum fully　consistent with each other,” conclude Bliokh and Nori.

This relativistic approach may find applications over a wide range of length scales including elementary spinning particles, classical light and, even rotating black holes.