Pepper’s Ghost, Part II

this hummingbird 1_edited 1This is not the first Pepper’s Ghost illusion to appear on Pop Goes the Page. Back in 2020, we posted a kid-friendly version featuring a spirited fox. The illusion is basically a reflection trick, but it’s very effective when done right!

seeing spirits   You’ll need:

  • A clear plastic drink container lid
  • Paper (heavier paper or thin cardboard works best)
  • A small section of clear plastic (like the lid of a food container)
  • Scissors and pencil for construction
  • Cell phone

The project was originally designed and posted by artist Joshua Ellingson on his Instagram. First, wash a clear plastic drink lid. Then cut a half circle template out of paper. When you have a half circle that correctly fits at a 45 degree angle inside your cup lid, trace the paper template onto a piece of clear plastic. We used an acrylic gift box, but plastic food containers work great too. Tape the plastic half circle inside the cup lid. The hardest part is getting that 45 degree angle just right. I made about 4 templates before I finally nailed it. Here’s my finished cup with the plastic half circle:

Head to YouTube for a Pepper’s Ghost illusion on a black background. We tried a couple different ones, but had the most success with this hummingbird. Cue up the video on your phone, maximize it to full screen, and lay the phone on a tabletop. Place the cup lid on top. Finally, roll the video and turn off the lights! Your object will appear to float inside the cup lid! It’s really quite remarkable.


The original designer, Joshua Ellingson, also made a GIANT version of this craft with a thrift store bubble chair and his flat screen television. It’s a must see! And Disney’s Haunted Mansion famously employs this illusion, including an entire ballroom of ghosts!

Cotsen Ghosties

book cover 3Last Halloween season we took a stroll through our special collections pumpkin patch. Today, we’re looking for ghosts! And we found them in this amazing optical illusion book titled Spectropia; or, Surprising Spectral Illusions. Showing ghosts everywhere, and of any color. Published by J.H. Brown in London in 1864, the book teaches the concept of “the persistency of impressions, and the production of complementary colours on, the retina.”

The illusion is very simple. In the image above, stare at the small black dot by the ghost’s neck for 20-30 seconds. Then look away at a white wall or ceiling. Her ghostly image will appear in your vision, except in different colors (in this case green wreath, blue ghost)!

Scientifically speaking, this is called an afterimage. The color receptors in your eyes work in pairs (red/green, blue/yellow, etc.). When you stare at the drawing and one color fatigues your receptors, the other receptor will step in and dominate for a bit.

The book has a very lengthy description of this concept, as well as viewing instructions that include having the “gaslight turned low.”

Spectropia also has a disclaimer at the beginning: “As an apology for the apparent disregard of taste and fine art in the plates, such figures are selected as best serve the purpose for which they are intended.”

I wish they might have reprinted the disclaimer before THIS image, which honestly is going to haunt me clear through December:

The book concludes with a grand finale image that is not a ghost, but a rainbow! Definitely try this one, because it is so cool to see the colors flip in the afterimage!

Looking more more optical spooky fun? Try making our tabletop Pepper’s Ghost illusion!


Images from Spectropia; or, Surprising Spectral Illusions. Showing ghosts everywhere, and of any color. J.H. Brown, London. Griffith and Farran.1864. Cotsen Children’s Library, Department of Special Collections, Princeton University Library.

The Discovery Museum: A Famous Scientist Virtual Escape Room

Scientist Museum cropped

Welcome to our latest virtual escape room, this time with a scientific twist…solve the puzzles, crack the code, and learn about five famous scientists and their contributions to the world!

Ready to explore? Click here

Interested in our other virtual escape rooms, all designed by our amazing Katie? Solve a case with Sherlock Holmes here, and search for pirate’s gold here. Want to try to design your own room? You’ll find Katie’s helpful tutorial here.