motion for causality

Michotte experiments

two blobs of light
one approaches other, short stop, other moves

                         [http://www.carleton.ca/~warrent/210/lecture03/A Michotte/michotte.htm]

qualitatative thresholds
<70 ms: launch
70-160 ms: delayed launch
>160 ms: uncorrellated

[Fig 6.37, Ware, p. 237]