Moving microsphere optics

[dsnyder]

What if I replace the sand in an hourglass with tiny glass spheres (microspheres), then shine light through the falling spheres and onto a screen? Or, if I modify an hourglass so the microspheres form a "curtain" then shine the light through that? At least in the latter case, if full spectrum light is used, I would expect a rainbow effect. I know that microspheres are commonly used in road marking paint as they reflect some incident light back toward the source, making markings more visible at night. But from my (very) limited understanding of optics I would expect light entering a sphere to go in all directions. Will the microspheres in the upper and lower chambers of the hourglass "light up"? The variety and sizes of microspheres available is simply bewildering to me. (coated, hollow, fine as dust, as big as sand, many materials, etc.)

I'm not really looking for answers here; I think I'll try this. But I might benefit from some "consultation". For example, I'm simply not competent to think about the result as sphere size and frequency of light vary. What difference would it make if the spheres have the same diameter as the frequency of the incident light?

 

Any suggestions? Thanks.

 

D. Snyder