Photograph of (optical) caustics

[Andy Resnick]

Caustics are singularities in the optical field:

http://en.wikipedia.org/wiki/Caustic_(optics)

I took this photograph of caustics created by the sun reflecting off of moving water today-

The spatial pattern of spots is related to the (local) slope of the water: Each dimension in this image corresponds approximately to 1m at the water, to give you a sense of scale. Each individual spot is not an image of the sun, but a focused spot due to (I think) a cusp catastrophe:

http://en.wikipedia.org/wiki/Catastrophe_theory#Cusp_catastrophe

 

[Greg Bernhardt]

Very cool! How did you capture these?