So what is the site about?

FYFD is a blog that celebrates “the physics of all that flows”. The site was launched in July 2010 and after two years, it has become a real visual feast, with more than 500 eye-catching entries about vortices, turbulence, circulation and other fluid-dynamics phenomena. Most posts contain brief comments on the physics principles at work in a particular image or video, often with links to more detailed explanations elsewhere. However, a few are presented more or less “as is”, allowing viewers simply to marvel at the beauty of fluid dynamics.

Right, so what does “FYFD” stand for?

The site’s full name is Fuck Yeah Fluid Dynamics, and no, we are not going to repeat that. Many other sites on the Tumblr blogging platform, however, have similar names. For example, there is also a FYCS celebrating computer science and a FYMB that is profanely enthusiastic about molecular biology.

Can you describe a few of the posts?

One early post contains video footage from the launch of NASA’s Solar Dynamics Observatory in February 2010. The observatory zoomed into space on the back of an Atlas V rocket, and as the rocket approached the speed of sound, it happened to pass near a rainbow-like atmospheric phenomenon called a sun dog. The video shows shock waves from the rocket blowing the sun dog apart, leaving behind a ripple effect like the one you get from casting a stone into a still pool of water. It is truly amazing, and must be seen to be believed. More recently, FYFD paid a visit to the Olympics, with posts about the hydrodynamics of “fast” swimming pools and a nifty high-speed archery video showing how the fletches on arrows help straighten their path after they leave the bow.

Who is behind it?

FYFD‘s author spoke to Physics World on the condition that we do not reveal her name, because she wants people to focus on the blog’s science, not on her. However, she is an aerospace-engineering PhD student working on (surprise, surprise) fluid dynamics, and her speciality is “boundary-wave stability in hypersonic fields” – in other words, the transition between laminar and turbulent flow near the surfaces of objects travelling faster than the speed of sound. The physics behind this transition is still poorly understood, she says, because “fluid dynamics is the physics that physicists give up on”. Even Werner Heisenberg, she adds, stopped studying fluids after he realized that quantum mechanics was easier.

Why should I visit?

Although FYFD‘s full name is decidedly NSFFM (not suitable for a family magazine), we love the way it communicates the marvels of fluid dynamics to people who lack the expertise to understand the complex mathematics behind it. The messy technicalities of flowing matter often get short shrift in popular-science writing, but the glorious videos and images on FYFD suggest that the problem was mostly with the medium, not the message. It is impossible to capture the beauty and variety of fluid phenomena with words alone; in fact, why are you still reading? Go adjust the profanity filter on your web browser and check out FYFD for yourself.