https://kirjabloggaus.blogspot.com/ Kimmo Huosionmaa The illusion can be caused by the line of two objects. In this picture, the cloud, what is behind houses seems like smoke, what is rising from burning things. That picture is picture one (Picture I) on the homepage. This kind of illusions causes many kinds of problems in the fire- and other departments of the cities. Optical illusions are fascinating, and they are claimed to cause even death of the travelers. There is a link to the page, where those pictures have been uploaded. http://kirjabloggaus.blogspot.com/p/two-optical-illusions.html The classical thing is the phenomenon, called fata morgana, what means the illusion, where the rising air causes the effect of the water in very dry places. And this phenomenon can make a traveler drink too much water, and then the filling of those bottles is not available, but this kind of stories might sometimes from the people illusion. The fata morgana can see even over the dry an...