At what point does a drop of fluid pinch off into two droplets? University of Chicago professor of physics Sidney Nagel snapped the photo of such an event:
How does one fluid body become two? At what point do the two separate, but still hold together? For Sidney Nagel, it was is not enough just to ask these questions, it was necessary to see exactly what this moment looks like. This image, titled “Two-Fluid Snap Off” was created by Nagel, a professor in the department of physics at the University of Chicago. It shows one drop of glycerol breaking apart inside the surrounding oil (Polydimethylsiloxane). Nagel writes that since the viscous fluids were both transparent, it was difficult to show the details of the shape at the breaking point. Using customized dark-field lighting, he was able to make even the narrowest point of contact clearly visible.
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