CGI is everywhere, but there's something about practical effects that are just way cooler, especially when you dig into what it takes to make them happen. "Cloud Tanks" are tools that have been used in plenty of great films like Raiders of the Lost Ark, Star Trek II: The Wrath of Khan, and Poltergeist to make weird alien atmospheres. This is how they work.
It's really just a mix of water, salt, and various sorts of colorings, but the result is mesmerising, and the process behind it is at once both simple and intriguing. If you can do this with a fish tank, why would you ever use it for fish? [Shanks FX via PetaPixel]