I dont think its accurate to equate floating trash and something dissolved in solution. Their behavior is likely to be very different.

This is presumably being downvoted for the unnecessary “gotcha” phrasing, but it is an interesting point of distinction. I have an intuitive guess as to the principles at work, but I don’t really know the actual physics.

> but I don’t really know the actual physics

Vastly oversimplifying: two versus three dimensions.

I don’t think that explains it at all. So garbage floats (more or less), so can be modeled as a 2D plane. But why do patches form? Why isn’t the garbage distributed uniformly across the plane? And why doesn’t that same mechanism apply in 3D?

Explain the lack of sodium islands.

E: "Cesium dissolves easily in water."[1]

[1] https://www.epa.gov/radiation/radionuclide-basics-cesium-137