While driving home after a hard day's work,
I came upon the following problem.
An entire town had been painted black;
the roads, pavements, buildings, hedges,
and everything that did not move had been painted black.
In addition, my vehicle's headlights were not working,
no moon was visible, and power was off in the area,
so there were no street or house lights around. At that moment,
I entered a curve where a solid black dog (deaf,
and thus unaware of the approaching car) was sitting in the road.
He had his back to me, so there was not even a glint in his eye,
yet I was able to swerve round him quite easily and without danger.
but How was this achieved?