See Airflow on Camera in This Awesome Harvard Demonstration of Schlieren Optics

Schlieren flow visualization and photography is one of those things that is just too cool. Using an optical trick, it allows a camera to capture, “small changes in the index of refraction in air.” In other words, it can see anything that affects airflow: heat, sound waves, or just plain old air currents themselves.

And the video above, uploaded at the beginning of this year by the Harvard Natural Sciences Lecture Demonstrations YouTube channel, is one of the most fascinating demonstrations of Schlieren optics we’ve ever seen.

Starting with a flame, moving on to a blow dryer, and then starting to mess with air and certain chemicals in a glass, the demo covers a plethora of things you can only see using Schlieren optics:

Check out the video at the top to see the magic for yourself, and then, if you’d like to learn more about this specific setup, click here to read up at the Harvard Natural Sciences Lecture Demonstrations website.