User:John R. Brews/Coriolis effect

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In psychophysical perception, the Coriolis effect is a form of nausea induced by the Coriolis force (also referred to as the Coriolis illusion).[1][2][3][4] The Coriolis effect is a concern of pilots, where it can cause extreme discomfort and disorientation.[5][6][7][8]

Subjects in a rotating environment that reach to point at a target make errors consistent with the Coriolis force acting upon their arms.

A rotating subject that has reached equilibrium with their rotation finds that upon tilting the head the feeling is that a rotation is occurring about the new axis of the head, when in fact that is not occurring at all. http://books.google.com/books?id=_6hymYAgC6MC&pg=PA175&lpg=PA175&dq=VESTIBULAR+CORIOLIS+ILLUSION&source=bl&ots=Nv8fRQGIUr&sig=32jT7VepXv9mVOa0WmJDvYqpJuk&hl=en&ei=0j1eTZT5HoassAO4kdDSCA&sa=X&oi=book_result&ct=result&resnum=6&ved=0CDYQ6AEwBQ#v=onepage&q=VESTIBULAR%20CORIOLIS%20ILLUSION&f=false NASA

Vestibular system

(PD) Image: NASA
Vestibular system in the human ear.
(PD) Image: John R. Brews
When the semicircular canal stops rotating, inertia causes the cupula to register a false rotation in the opposite sense.

The vestibular system of the ear senses balance, motion, and body position. The three semicircular canals observe angular acceleration in the three planes of motion: pitch (nod yes), yaw (twist your head no), and roll (pivot head from left to right shoulder without twisting). The otolith organs, that is, the utricle and the saccule detect linear acceleration and the tilt of the head.

The semicircular canals contain the endolymph, a fluid that shifts with angular acceleration, pressing unequally upon the two sides of a membrane, the cupula, when acceleration occurs, causing deflection of the cupula. The endolymph action lags the motion of the canal itself, due to its inertia.

If angular motion is held constant, a steady state is reached where the endolymph and the canal are moving at the same rate, the cupula no longer deflects, and the motion is not sensed. This situation is shown in the upper panel of the figure. In a similar manner, if the rotation abruptly stops, the canal stops rotating but the endolymph takes time to adapt, leading to the false impression of rotation in the opposite direction to what previously prevailed, shown in the bottom panel. (Under clockwise acceleration of the canal, the endolymph lags the canal, leading to a relative counterclockwise motion that is interpreted correctly as a clockwise acceleration.)

Notes

  1. ↑ Jeffrey W. Vincoli (1999). Lewis' dictionary of occupational and environmental safety and health. CRC Press, p. 245. ISBN 1566703999. 
  2. ↑ Mark S Sanders & Ernest J McCormick (1993). Human Factors in Engineering and Design, 7th Edition. McGraw-Hill, p. 644. ISBN 0071128263. 
  3. ↑ Sheldon M. Ebenholtz (2001). Oculomotor Systems and Perception. Cambridge University Press. ISBN 0521804590. 
  4. ↑ George Mather (2006). Foundations of perception. Taylor & Francis. ISBN 0863778356. 
  5. ↑ Arnauld E. Nicogossian (1996). Space biology and medicine. Reston, VA: American Institute of Aeronautics and Astronautics, Inc, p. 337. ISBN 1563471809. 
  6. ↑ Thomas Brandt (2003). Vertigo: Its Multisensory Syndromes. Springer, p. 416. ISBN 0387405003. 
  7. ↑ Fred H. Previc, William R. Ercoline (2004). Spatial Disorientation in Aviation. Reston, VA: American Institute of Aeronautics and Astronautics, Inc, p. 249. ISBN 1563476541. 
  8. ↑ Gilles Clément (2003). Fundamentals of Space Medicine. Springer, p. 41. ISBN 1402015984. 
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