Pick out almost any frame in the original ALIEN and I’ll bet it’s something that has gone on to become iconic. The film is scene after scene of intense, disturbing, and innovative imagery. But a few stand out. The chestbursting, the facehugging, Ripley’s desperate sprint to the escape ship…For me, what stands out the most is the acid blood scene, where we discover that these xenomorphs have blood that can burn right through a spaceship. If you love that scene as much as I do, you’re in luck — we can recreate (in a safe way) that exact effect, with science!
While it looks like acid eating into metal, the special effects artists actually used run of the mill Styrofoam and the main component of nail polish remover, acetone. Styrofoam is the foam version of the long-chain molecule polystyrene, and those molecule stay stuck to each other using so-called non-polar bonds. In chemistry, like dissolves like, which is why water — an electrically polar molecule — has no effect on Styrofoam cups or plates.
Unlike water, acetone is a non-polar liquid and so it is very good at breaking the non-polar bonds that keep the Styrofoam foamy. Combine the two, and the air inside the foam is quickly liberated, returning the polystyrene to its once goopy state. The effect is exactly what we saw in ALIEN!
[You can try it yourself if you use plain old Styrofoam cups or plates, wear eye and hand protection, keep the extremely flammable acetone away from fire sources, and experiment in a location that has good ventilation.]
But knowing the science, I had to ramp it up. If you want to see not just surfaces but faces melt as if xenomorph blood showered them, check out the video above!
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Image: 20th Century Fox
