Turbulent Flow

Shot in our second macro photography class, this is actually a close-up without significant digital manipulation, but due to its appearance, I thought it might fit best here.

We were to bring in our own items this time. I brought a plastic "cell flask" with parallel sides of excellent clarity. I filled it about 2/3 with Karo corn syrup, viscosity ~ 4000 cps, and then added about 1/3 DI water, viscosity 1 cps. I then mixed these by tilting the flask, and then added a drop of blue food coloring and re-mixed (the teacher's idea).

The speed of light in a vacuum is constant, but it slows down when passing through transparent media and then speeds up again when leaving them. Unless the light beam enters the medium exactly perpendicular to its plane, this will result in a displacement of the beam's path. The degree of shift is associated with the "refractive index" of the medium.

Corn syrum and water slow the speed of light to significantly different degrees and the flow lines are thus highly visible looking through the liquid (as are several small bubbles).

I first tried shooting this against a black velet background (speedlite) with a Tamron 90mm 1:1 macro at about 1:2 without much success. Then the teacher suggested using a piece of aluminum foil as a reflective background. So in micro-domains, I think this image illustrates some principles fluids, namely laminar flow, and how that manifests in turbulence. And the bubbles show another property of hydraulic pressure.

In addition, I thought it had some aesthetic appeal as an abstract.