Just how did that pesky little Sars-CoV-2 virus jump from bat to humans, bringing Covid-19 with it? Steven Soderbergh’s 2011 film Contagion provides as plausible a scenario as any – from bat to half-eaten banana to pig to pork to chef to, as it were, Gwyneth Paltrow and then you’re away.
Yet, in that chain of events, had anything been ever so slightly different then the virus would not have spread, the infection would not have taken hold, the whole world would have been different. Ditto – most likely – the real life Covid-19. At work here is chaos theory, which, more formally, is known as ‘non-linear dynamics’. It is the notion that very small differences in the initial conditions of otherwise similar patterns can eventually produce enormously different outcomes essentially because there is feedback between cause and effect.
It is widely caricatured as ‘the butterfly effect’ because something as innocuous as a Blue Morpho butterfly flapping its wings at a critical juncture of four-dimensional space-time in the Amazon jungle sparks a hurricane that wrecks the east coast of the US before smashing New York.