Why do we draw stars with spikes when actual stars are round? #optics
The Mary Sue has a great post on optics and the reason why we draw stars with spikes.
Draw a star. It probably looks something like the ones in the picture above. Stars have points when we draw them, but why? Real stars, the ones in space, are round. So how did we get to the pointed star shape from balls of fire incandescent plasma?
One explanation might be diffraction spikes, optical artifacts created when light passes through a reflecting telescope. It results in what looks like rays shooting out from the center. The spikes are due to light bending around the support rod structure that holds the reflecting element of a telescope in place. Therefor, the pattern of the diffraction spikes mimics that of the support rods in a telescope.
Here’s a photo of the support structure of a reflecting telescope:
And this is an example of diffraction spikes in a photograph of stars:
Makes sense, right? Except, humans have drawn stars with points well before the invention of the reflecting telescope in the 17th century. The paint L’Adoration des Mages was done in the 15th century by Jean Fouquet. Check out those sweet diffraction spikes!
Since Jean Fouquet clearly didn’t have access to a reflecting telescope, what with dying more than 100 years before its invention and all, what’s happening here? Simpler telescopes that relied on lenses only predate the reflecting telescope. They began appearing in 1608, but they don’t predate this painting.
Any time light passes through a lens, it becomes somewhat distorted. If you wear glasses or have ever looked through the windshield while driving at night, you know this already. Glasses date back to the late 13th century, so maybe Fouquet used them? This certainly isn’t the only example of a spiky star in art, and some date back even further.
Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here: adafruit.com/editorialstandards
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.
Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7:30pm ET! To join, head over to YouTube and check out the show’s live chat and our Discord!
