Aberrant Light And Colour (After The Rainbow) by Maureen De Jager

Rainbow Over Grahamstown, 7 February 2010

The term ‘rainbow nation’ was coined by Archbishop Desmond Tutu to describe post-apartheid South Africa after the 1994 elections. It was re-iterated by President Nelson Mandela in his first month of office, when he spoke of ‘a rainbow nation at peace with itself and with the world’ (Manzo 1996:711). Thereafter the term ‘rainbow nation’ quickly gained credence as a signifier of multi-culturalism and diversity, contra Apartheid’s discriminatory division of South Africans into ‘black’ and ‘white’. However, detractors of the term have also been quick to offer critique, arguing that it glosses over the legacy of racism by evoking a false semblance of peace, stability and reconciliation.

My paper considers an alternative angle on the problem of ‘smug rainbowism’ (Jeremy Cronin quoted in Manzo 1996:71), by detouring back to an ‘original’ rainbow and hence to a pivotal moment in our understanding of light and colour: Sir Isaac Newton’s 1665 experiment wherein he split light into the spectrum by passing a sunbeam through a prism. Taking Newton’s prism as both starting point and metaphor, my argument aims to unsettle the rainbow’s status as a stable, dependable and unambiguous signifier. Instead, I suggest that the rainbow – as optical phenomenon – is aberrant and unstable, a spectral spectrum, summoning the vicissitudes of indeterminacy and doubt rather than some steady reality.

 Rainbow Over Grahamstown, 7 February 2010

Optically and philosophically, Newton’s dispersion of light into the spectrum undermined the ostensible stability of vision and replaced this with mutability and flux. It did this by insisting that colour is both relative and non-intrinsic: colour is the result of the different rates of vibration of the waves comprising the spectrum. Entering the prism as a unitary beam, these waves are deflected proportionate to their speed of vibration. Red pulsates slowest and is thus least refrangible, whereas violet vibrates fastest and is thus deflected more from its course. Colour waves, in this sense, ‘model a universe whose constituents move at different rates, reaching locations at different times’ (Armstrong 2008:267-82).

Newton’s splitting of light into the spectrum thus initiated some surprisingly ‘postmodern’ ideas. It emphasised ‘the ungroundedness existing at the core of perception’ (Armstrong 2008:271) by asserting that the velocity of light rays, and the distances they travel, are differential factors in how and what we see. Because light takes time to reach the observer, and because we occupy different time-space relationships to the things that we observe, the relationship between observer and observed is constantly changing and variable. What we ‘see’, in effect, is the always-belated arrival of light rays and colour waves – an after-image displaced in time and space from the ‘real’.

Like light rays emitted then and visible now, I argue that Newton’s prism experiments still have implications for us today – especially in a South African context, where colour has so often been used as a stable, delimiting marker of race and identity. For, against the logic of classification and certitude, Newton’s colour spectrum prompts us to remember the variable, ungrounded and aberrant nature of light and colour, and hence of all perception.
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1Manzo, K. 1996. Creating boundaries: the politics of race. Colorado: L Rienner Publishers.
2Armstrong, I. 2008. The lens, light, and the virtual world. In Victorian glass worlds, 253-271. Oxford: Oxford University Press.