Monthly Archives: February 2017

‘Rain bringing out the contours in everything’

16blindness9-custom1Last October I cited John Hull’s audio diary in which he said ‘Cognition is beautiful.  It is beautiful to know.’ [See my post entitled ‘Cognition is beautiful‘ on October 19th, 2016]  Last week, I watched the film ‘Notes on Blindness‘ based on his book ‘Touching the Rock‘.  We found it a moving and life-enriching experience. At one point, John Hull, after he has lost all of his sight, opens his front door during a rain storm and describes the beauty of the rain.  “Rain has a way of bringing out the contours of everything; it throws a coloured blanket over previously invisible things; instead of an intermittent and thus fragmented world, the steadily falling rain creates continuity of acoustic experience.”  You can read more of this extract at the Rock.html in which John wishes that rain could fall inside a room to give him a sense of the things in the room.  This seemed particularly poignant to me, a sighted person, who benefits from photons raining down on everything around us during daylight or when the light is switched on.  The photons cause light waves to radiate from every surface in a similar way that the rain drops cause sound waves to radiate from everything as John experienced. Our eyes are amazing with 137 million separate ‘seeing’ elements on the retina, or in digital camera terms, that’s 137 megapixels.  But to quote the Roman poet, Lucretius who in his poem ‘De Rerum Natura’ wrote “Nothing in the body is made that we may use it.  What happens to exist is the cause of its use.”  In other words, we do not have eyes so that we can see but we see because we have eyes.  John Hull discovered new ways to experience the world using what was available to him although he struggled with what he had lost.  It is difficult to imagine losing one’s sight but his diary and the film bring us considerably closer to an appreciation of the loss.

Yes, I know I switched from a particle to wave description of light but I wanted to emphasize that the photons don’t just bounce off surfaces, otherwise all surfaces would look the colour of the illuminating light.



John M. Hull, Touching the Rock: an experience of blindness, London: SPCK, 2016

Lucretius (author), Alicia Stallings (translator), The Nature of Things, London: Penguin Classics, 2007.

Charles Sherrington, Making of the eye, in The Faber Book of Science, John Carey (ed), London: Faber & Faber, 1995.

Picture: A production still from the film, Notes on Blindness, from NY Times on January 16th, 2016.



Digital limits analogue future

Feet on Holiday I 1979 Henry Moore OM, CH 1898-1986 Presented by the Henry Moore Foundation 1982

Feet on Holiday I 1979 Henry Moore OM, CH 1898-1986 Presented by the Henry Moore Foundation 1982

Digital everything is trendy at the moment.  I am as guilty as everyone else: my research group is using digital cameras to monitor the displacement and deformation of structural components using a technique called digital image correlation (see my post on 256 Shades of grey on January 22nd, 2014) .  Some years ago, in a similar vein, I pioneered a technique known as ‘digital photoelasticity’ (se my post on ‘Cow bladders lead to strain measurement‘ on January 7th, 2015..  But, what do we mean by ‘digital’?  Originally it meant related to, resembling or operated by a digit or finger.  However, electronic engineers will refer us to A-to-D and D-to-A converters that transform analogue signals into digital signals and vice versa.  In this sense, digital means ‘expressed in discrete numerical form’ as opposed to analogue which means something that can vary continuously .  Digital signals are ubiquitous because computers can handle digital information easily.  Computers could be described as very, very large series of switches that can be either on or off, which allows numbers to be represented in binary.  The world’s second largest computer, Tianhe-2, which I visited in Guangzhou a couple of years ago, has about 12.4 petabytes (about 1016 bytes) of memory which compares to 100 billion (1012) neurons an average human brain.  There’s lots of tasks at which the world’s largest computers are excellent but none of them can drive a car, ride a bicycle, tutor a group of engineering students and write a blog post on the limits of digital technology all in a few hours.  Ok, we could connect specialized computers together wirelessly under the command of one supercomputer but that’s incomparable to the 1.4 kilograms of brain cells in an engineering professor’s skull doing all of this without being reprogrammed or requiring significant cooling.

So, what’s our brain got that the world latest computer hasn’t?  Well, it appears to be analogue and not digital.  Our consciousness appears to arise from assemblies of millions of neurons firing in synchrony and because each neuron can fire at an infinite number of levels, then our conscious thoughts can take on a multiplicity of forms that a digital computer can never hope to emulate because its finite number of switches have only two positions each: on and off.

I suspect that the future is not digital but analogue; we just don’t know how to get there, yet.  We need to stop counting with our digits and start thinking with our brains.