There was once a group of scientists doing field work in the north-east of Greenland a couple of decades ago. One day they had split up into two groups, there was a smoker in one of the groups. The groups went up on both sides of a glacier on foot. In the middle of the day there was barely any wind, one group was taking a lunch break in the most magnificent weather when one of them suddenly said, “I smell cigarette smoke”. They noted the time and place. When they met up with the other group it was confirmed that the smoker had smoked a cigarette around the noted time. On the map they checked where they were – they had been 5 km. apart.