Smartphone Hologram Pyramid
Source: Stemoto Original
Bring the future to your living room! By cutting clear plastic into a pyramid shape and placing it on a smartphone screen, kids can project 3D 'holograms' floating in thin air using the Pepper's Ghost illusion.
Categorisation
Props & Materials Required
- •A smartphone
- •Clear, stiff plastic (like a CD case or clear plastic packaging)
- •A printed template for the pyramid sides
- •Scissors or a craft knife
- •Clear tape
- •A dark room!
Step-by-Step Instructions
Trace the Shapes
Print or draw a template of an isosceles trapezoid (a pyramid side with a flat top). Trace this shape four times onto your stiff clear plastic.
Cut the Plastic
Carefully cut out the four clear plastic trapezoids. Be very careful to keep the plastic clean and free of fingerprints!
Build the Pyramid
Use small pieces of clear tape to connect the slanted edges of the four pieces together. You will end up with an upside-down pyramid with a small square hole at the bottom.
Load the Video
Open YouTube on your smartphone and search for '3D hologram video'. These videos have four identical animations playing on the edges of a black screen.
Cast the Illusion
Turn your phone brightness all the way up and lay it flat on the table. Place your plastic pyramid upside-down exactly in the center of the playing video. Turn off the room lights and look at the pyramid from the side!
Why It Works & Notes
This project uses a 19th-century theater trick called 'Pepper's Ghost.' The clear plastic acts as both a window and a mirror. When placed at a 45-degree angle on a bright phone screen, it reflects the screen's light into your eyes while still letting you see through to the dark background, creating the illusion of a floating 3D object.
Parents should handle the cutting if using a hard CD case, as the plastic can be sharp. Clear plastic food packaging works just as well and is easier to cut! AI Optional: You can find hundreds of specific 'hologram videos' on YouTube, but older kids can use AI video generators to try creating their own 4-sided animations!