Writer of science with the
mission of the magician:
to encourage people
to approach life in
a state of Wonder.




Precognitive shadow

Have you ever seen a shadow anticipating a future action? Look at the green disk and its shadow in this non-Photoshopped image:

How do you explain it?


The acquisition of this digital image is not recorded from a snapshot of a single point in time, but rather by scanning across the frame either vertically — starting from above. Not all parts of the image are recorded at exactly the same time, even though the whole frame is displayed at the same time during playback. This produces predictable distortions of fast-moving objects or when the sensor captures rapid flashes of light. This is in contrast with global shutter in which the entire frame is exposed for the same time window: the lower part is recorded a bit later, showing the disk already thrown.

Many thanks to Stefano Pascolutti for pointing it out.