Colorful nebulae made with ink spreading in water

https://www.youtube.com/watch?v=BmBh0NNEm00

Macro Room made a simple and beautiful video of inksquirts: "This time we dived into the hypnotising beauty of colored ink in water and the interaction of this substance with different elements." I love how their videos are carefully devised to show both sides of the curtain. Here's another: