If I have understood correctly, stars form in big clouds of gas and dust that are pulled together by their gravity. And the stars are often ignited when something disturbs the cloud, such as a passing massive body, or a wave like the once which create spirals in galaxies.
Are there any phenomena on earth that behave like these clouds, which could be used to illustrate and explain star formation? Something people might be familiar with and which you could show a video clip of?
I'm thinking about some gas that is disturbed then takes solid form? Or something completely different which looks similar?