thermal referral

When warm thermal stimulators are placed on the ring and index fingers of one hand, and a neutral-temperature stimulator on the middle finger, all three fingers feel warm. This illusion is known as thermal referral (TR).

See http://www.nature.com/articles/srep35286

Cataldo, Antonio, et al. "Thermal referral: evidence for a thermoceptive uniformity illusion without touch." Scientific reports 6 (2016).

Closed Form Solution of Absolute Orientation using Unit Quaternions

Horn, Berthold KP. "Closed-form solution of absolute orientation using unit quaternions." JOSA A 4.4 (1987): 629-642.

http://people.csail.mit.edu/bkph/papers/Absolute_Orientation.pdf
See Sim3Solver of ORB-SLAM2 project.