Geometrically, a spiral is a smooth curve that winds about a central point or axis while also receding from it. Spirals form some of the most graceful and powerful forms in nature, and you see them in places big and small: from the double helix of DNA and the butterfly’s tongue to the swooping dive of a peregrine falcon.  Spirals can be found in the curl of a fern tendril, the shape of an octopus’ retracted arm, a mountain goat’s horns, the curving shell of the nautilus (one of Inq’s cephalopod relatives!), fossilized ammonites, the horns of the kudu antelope, the arrangement of seeds in a sunflower, the scale of a pinecone, the curl of a chameleon’s tail, and the pattern of buds on a pussy willow stem. Martin Gardner pointed out that the Eperia spider spins a web that is a logarithmic spiral.

And of course, about a third of the known galaxies in our universe are spiral shaped, including our own Milky Way. The question of why the spiral shape is so common in duodecillion-ton masses of stars is still a subject of research and debate. The basic cause is that galaxies rotate; the problem is they often rotate faster at the core than the edges, and eventually that would destroy the spiral pattern. What seems to keep the spiral arms intact – somehow – are “density waves,” which are pileups of stars that happen when a lot of them are in motion: think of it like how cars sometimes bunch up on a freeway. The movement of stars in these waves keep the arms from bunching up, and boom – you get a cool-looking galaxy. 

What’s this about radar? In the electromagnetic spectrum, every frequency has a wavelength – the distance between the top of one wave and the next. The lower the frequency, the larger the wave: radio waves can be the size of buildings, x-rays the size of a water molecule. The size of the wavelength of your spiral is about 2.5 cm (1 inch), which turns out to be roughly 11 gigahertz (GHz). 11 GHz is the wavelength of radar, specifically the “X-band” used for military and space-borne radar systems. Circular polarized EM waves propagate in a spiral, so when you hold your Mephisto spiral, you’re looking at a model of a circularly-polarized 11 GHz wave. 

And finally: who is Mephisto? The name might sound familiar; there’s a Marvel comics supervillain with that name, and if you’re into classical music, Franz Liszt wrote his the “Mephisto Waltzes” between 1859 and 1885 (as well as one Mephisto Polka, no joke). Etymologically, Mephisto is another name used for Mephistopheles, the devil of the famous Faust legend, the classic folktale where a Renaissance scientist sells his soul to the devil in exchange for knowledge. In this case, it may refer to the devilishly puzzling way the spiral seems to unwind forever. But we promise there are no real devils involved – just a fun and interesting optical illusion. So enjoy!