27 December 2007

A mystery shadow

Turkish has one word, gölge, to mean both "shade" and "shadow". Because I was not used to distinguishing between those 2 meanings, when I was new in this country I would often use "shade" to mean "shadow" or vice versa. My wife (maybe we weren't yet married then), a native English speaker, would correct me: You mean "in the shade".

Earlier today while playing with Google Earth, I noticed an interesting shadow along the railroad tracks not too far from my house.

signalpostshadow1

At first, one sees what seems to be a series of shadows cast by some trees. But a closer look at the one above the green patch makes one wonder if it may have been cast by something else, although nothing unusual is visible in the picture.

But, I am not being entirely honest here. I cut out the top of the railroad tracks (and turned the picture). In the full picture below, you will find the answer.

signalpostshadow2

There is a signal post on each side of the tracks and those peculiar shadows belong to them. (I know those are signal posts, because I have been there.)

I suppose this is how military personnel whose job is to interpret aerial photographs learn how to recognize ground features in photographs: by first learning what known objects look like in aerial photographs.

1 comment:

xoggoth said...

I have been looking at aerial photos a lot recently in connnection with a boundary dispute. Useless as almost impossible to reliably distinguish the objects from their shadows. Not sure about their shades, perhaps I should get in a medium for that.