# Engineering synaesthesia

A street in Sante Fe

One of the most memorable places we visited when we lived in the United States was Sante Fe, New Mexico.  We rented a house on a hillside that was walking distance from downtown.  The landscape is stark, vast and vivid all at the same time.  Georgia O’Keeffe captured it beautifully in her paintings.  In our house in Liverpool, we have a number of prints from her paintings that we bought during a visit to the Georgia O’Keeffe Museum in Sante Fe about ten years ago. So it was a nostalgic experience to visit the O’Keeffe exhibition at the Tate Modern in London a few weeks ago and reacquaint ourselves with familiar originals as well as enjoy paintings we had not seen before. ‘Red and Yellow Cliffs‘ (1940) was one of my favourites in the exhibition which was reminiscent of many of the landscapes in New Mexico.  I also enjoyed the room entitled ‘Abstraction and the Senses’ that contained a series of paintings in which O’Keeffe took inspiration from sensory stimulation and expressed in her paintings the feelings induced by ‘signals’ from senses other than sight, such as hearing music.  This is known as synaesthesia: ‘the production of a sense impression relating to one sense or part of the body by stimulation of another sense or part of the body’, according the Oxford Online Dictionary.  Some people suffer from synaesthesia and hearing particular sounds might trigger a sensation of taste, or letters might be associated with colours, for instance ‘A’ with red. It can be very useful, for instance I ‘see’ numbers laid out in patterns and so can perform mental arithmetic pictorially.

Engineers make use of similar phenomena to visualize patterns of variables that are invisible.  For instance, moiré interferometry uses the interference between regular arrays of lines to magnify tiny differences in the arrays and generate visible fringe patterns – this is useful in comparing the dimensions of two objects to which the arrays are attached.  In photoelasticity, polarised light is used to generate colour fringe patterns that are contours of stress in transparent components or models of components [see my post entitled ‘Art and Experimental Mechanics‘ on July 12th, 2012].  Unfortunately this elegant, but analogue, technique has been almost completely usurped by digital analysis using computers. Many of these computers have a touch screen that convert your thoughts, conveyed by the tap or swipe of your fingers, into text or commands for devices attached physically or wirelessly to the computer. And, virtual reality goggles, head sets and haptic devices allow the computer to reverse the process by transmitting signals to our senses, which often confuse us as they become intermingled in a new form of synaesthesia.  Georgia O’Keeffe died in 1986 at the age of 98 and so missed out on this aspect of the digital revolution but it might have generated a whole series of beautiful paintings.

Sources:

http://www.nhs.uk/conditions/synaesthesia/Pages/Introduction.aspx