This is an amazing thing-a-ma-jig.

 

Reader Susan Schwartz sent it to me a long time ago. I decided to save it and share it with you as a Christmas present.

 

When you open the link, you will see a vast crowd. You can click on it and enlarge the image, click on it again and again, and pick out any face in the crowd, and in a few seconds, the face is completely recognizable, down to small details. It is an astonishing technological feat.