A transition between a subway train arriving to Kamppi station in Helsinki and a plane passing overhead while in the woods in Ottawa.

May 10th, late afternoon. Mud Lake conservation area, Ottawa. Outdoors. Zero peopliness. In the woods (birds etc); a plane passes overhead, close enough to be quite loud. Does this constitute a transition? I have not moved; my space has not changed. But the shift from natural sound to the sound of the plane is a dramatic shift in cultural space... (Plus the plane has a nice symbolic link with our themes of transitions, different local and geographical spaces, etc...)