The difference in densities of water and oil makes oil float on water concurrently making it immiscible. Exploiting this property of oil in water combined with the principle of diffraction of light gives beautiful patterns. Different patterns were created using different set of lighting conditions. You can see further such images here .

These mystic astronomical-looking surfaces are just air blown into soapy water in dark background. The longer the air bubble sustains, the cooler it forms the patterns. The colors and patterns it forms are a feast to the eyes. Have a look at more such images here