Don’t worry, nothing too personal here; just an interesting phenomenon. We have a soap dispenser in the shower, which usually has white liquid soap in it. For some reason we bought clear liquid soap recently. To refill the dispenser I poured about 500 ml of clear soap on top of about 50 ml of white soap. This was the result, 24 hours or so later:

Looks like the white soap is a little less dense so it’s slowly rising to the top, although I wonder if the action of the pump at the bottom may have also influenced the mixing. (Anyone with less rusty fluid dynamics want to comment?)

Amusingly, as an undergrad I had a co-op job at the Canadian Space Agency, where my project was to design an experiment to look at mixing of different-density fluids in microgravity! And the person I worked for was astronaut Bjarni Tryggvason, who is now at Western. Small world.

I’m off to buy some more opaque soap so I can do some more mixing experiments.