Celebrating the story of manned flight, from the first fearless pioneers to the crowded skies of today, Reaching for the Sky makes four stopovers at the most important stages in the history of air travel. The series takes off in the shape of The Dream of Flight, which illustrates how the fantasy of flight eventually became reality.

Artificial Intelligence looks to a future that is both fascinating and unforeseeable. The coin’s reverse features the outline of a head that symbolises our ignorance about the future functioning of humanoid ‘super intelligence’. The fact is that we do not know what will happen when artificial intelligence has worked out how to improve itself and no longer relies on us. Will it imprison us or will it set us free? Only time will tell, but in the meantime the thought-provoking 2019 addition to our bestselling Silver Niobium series uses its electric-blue niobium core and silver outer ring to beautifully visualise our uncertainty.