Design

Physics Concepts

Reflection occurs when the light strikes a surface and bounces back off that surface.

Three Fundamental Laws of Light Reflection

1) The incident ray, normal, and the reflected ray are all in the same plane.

2) The incident ray and reflected ray are on the different sides of the normal.

3) The angle between the incident ray and the normal is equal to the angle between refthe lected ray and the normal.

Light generated from the screen hits the plastic pieces and gets reflected into your eyes.

This project aims to construct a handy Pepper's Ghost projector with simple materials that can be put on the top of cell phones or tablets.

Get a piece of transparent plastic sheet (Can be found in dollar store/art craft store/online, etc.).
Cut four equal trapezoid-shaped pieces with the dimension of

2.5 cm x 7.5 cm x 12 cm (upper length x height x lower length).

This is the ratio I used is for the projector that can be put on the top of a cell phone.

Tape the four pieces together to form a pyramid shape. I use coloured tape to tape the sides since the side view cannot perfectly reflected the image.
Put this pyramid projector upside down on the center of your device.
Turn off the light in the room. Play the video on your device (some video links are listed below).
View the projector horizontally and you will see the image appears in the center of the projector.

Video links:

A video of the Pepper's Ghost butterfly image produced by the plastic reflector.

demo.mp4