Necker Island (British Virgin Islands) would survive their castaway adventure for at least three weeks, but as McCullin later recounted, "because of our gathering weakness ... out of temper, and out of water, we hoisted the red flag and were taken off in the early hours of the fifteenth day". According to McCullin, there was nothing idyllic about the desert island: "The mosquitos and other insects were more venomous and persistent than any I had encountered in Vietnam or the Congo." Richard Branson's "Extreme Tech Challenge" has been hosted annually at Necker Island since 2015. Described as one of the largest technology competitions in the
Necker cube in the Psychology Department of City University, London, were provided with assignments to measure their Introversion-Extroversion orientations by the time it took for them to switch between the Front and Back perceptions of the Necker Cube. The orientation of the Necker cube can also be altered by shifting the observer's point of view. When seen from apparent above, one face tends to be seen closer; and in contrast, when seen from a subjective viewpoint that is below, a different face comes to the fore. The Necker cube is discussed to such extent in Robert J. Sawyer's 1998 science fiction novel