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BABBLE DABBLE is a fabulous website with some great ideas.

It has some amazing Art, Science, Engineering and Creative Projects.

One of the project ideas is the DECOTROPE

I love illusions as you know, I have dedicated a whole page on my website to illusions and this one will be added to list. LOVE ITThe DECOTROPE produces the same a visual trick that 'MOVING PICTURES produce. But it is science, not trickery. It is like a 2 frame mini-movie. WATCH the Video


The Science Behind The DECOTROPE

DECOTROPE and Thaumatropes are an example of persistence of vision. This is a phrase used to describe how our brain combines multiple images together when they are rapidly flashed in front of the eyes. This is the basis for film in fact. All movies are simply long strings of still images flashed in quick succession in front of the eyes.


Most movies are played at 24 frames per second, meaning there are 24 still images per second flashing in front of you. It is thought that the brain perceives anything from upwards of about 10 frames per second as motion. This is about as fast as you

can thumb through a flipbook.

And the Name: Trope is the part of the word that means turning around and Deco stands for decorative.






CONSTRUCT a generic DECOTROPE using the template supplied by Dabble Babble.


DESCRIBE what you observe - what is happening when you spin the DECOTROPE, what do you see.


RESEARCH the scientific explanation for this phenomena.


EXPLANATION write an explanation of the phenomena




PREDICT what you will see when you spin it.


FEEDBACK send in your kids constructions, and I will publish them here.


CHALLENGE Prove the concept. Use Stop Motion app to photograph each side of your DECOTROPE make sure it is in exactly the same place each time - use a tripod and position accurately. Photograph each side of your DECOTROPE at least 10 times. Then you can multiple select the slides and copy and paste them.  Increase the frame speed to 24 frames. Check it out - what happens? Describe what you see..


Another DECOTROPE Optical Illusion Experiment Fish in a bowls


Beau Lotto: Optical illusions show how we see



Optical Illusion Dance - An amazing demonstration of dancing - your mind struggles to make sense of it.


After Experiencing This Mind Blowing T-Rex Illusion, I Will Never Trust My Eyes Again...


Top 10 - Optical Illusions that are not known by everybody


Rotation mask illusion


Stephen Fry Optical Illusions - rotating mask


Amazing illusions


Bifaloo Illusions Like the one below. Great static illusions.

Say the colours don't read the names as fast as you can. Is this difficult?


106 Visual Phenomena & Optical Illusions

by Michael Bach

The emphasis here is on the beauty of perceptual phenomena, on interactive experiments, and explanation of the visual mechanisms involved – to the degree that they are understood

Check out Silencing by Motion and the many other interactive illusions on this page. Change the colour, ratios, sizes and intensities and see what happens. Fabulous




Watch these amazing YouTube videos

Honda - making impossible, possible

Amazing candles

Rolling uphill

Crazy cube wallpainting

The last 3 are optical illusions by brusspup


Optics for Kids - Ideas for making optical illusions

Try the Muller-Lyer Illusion


All about Eyes


Can You Trust Your Eyes? Great Video from ASAPScience

Pupil Dilation is increased in the dark, more light smaller pupils


Cow's Eye Dissection


Interactive Human Eye



© Cathy Brown 1998 - 2019