Persistence of Vision Double Fan

This two-headed fan does more than cool you off - it delivers a dazzling lesson in persistence of vision! Each fan blade contains five colorful LEDs that flicker at different speeds, giving the illusion of streams of light instead of individual dots. (This is the same principle that turns a sequence of still images into a motion picture.) Turn it on and enjoy a double light show in red, green, yellow, and blue. Better still, give the blades an extra spin to increase the speed of the rotating arm so that the two individual fan patterns merge into a larger, ever-changing geometric design: triangles, loops, spirals, and more! We guarantee you haven't seen a persistence of vision device like this before! Requires 3 AA batteries (included).

Used these in my science class. Had three of them. By the end of 3rd hour, one propeller had lost its lights. A second had stopped spinning and the third's main motor stopped working. Kids loved them, but my 7th graders destroyed them pretty fast.

Very cool toy; glad I ordered 2, because the fan blade flew off during the second time I used it. Could not get the fan blade back in to fix it. 5 stars for the awesome concept; 1 star for the craftsmanship.

Michelle

Owner Response: We apologize for the faulty fan blade. Customer service will be in touch to make your order right for you!

NGSS

This product will support your students' understanding of the Next Generation Science Standards (NGSS)*, as shown in the table below.

Elementary

Middle School

High School

1-PS4-2

Students can use the Persistence of Vision Double Fan to make observations to construct an evidence-based account that objects can be seen only when illuminated.

2-PS1-1

Students can use the Persistence of Vision Double Fan to plan and conduct an investigation to describe and classify different kinds of materials by their observable properties.

K-2-ETS1-2

Students can use the Persistence of Vision Double Fan to develop a simple sketch, drawing, or physical model to illustrate how the shape of an object helps it function as needed to solve a given problem.

4-PS4-2

Students can use the Persistence of Vision Double Fan to develop a model to describe that light reflecting from objects and entering the eye allows objects to be seen.

4-LS1-2

Students can use the Persistence of Vision Double Fan to use a model to describe that animals receive different types of information through their senses, process the information in their brain, and respond to the information in different ways.

MS-PS4-2

Students can use the Persistence of Vision Double Fan to develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.

MS-LS1-8

Students can use the Persistence of Vision Double Fan to gather and synthesize information that sensory receptors respond to stimuli by sending messages to the brain for immediate storage as memories.

MS-ETS1-4

Students can use the Persistence of Vision Double Fan to develop a model to generate data for iterative testing.

HS-PS4-3

Students can use the Persistence of Vision Double Fan to evaluate the claims, evidence, and reasoning behind the idea that electromagnetic radiation can be described either by a wave model or a particle model, and that for some situations, one model is more useful than the other.

Suggested Science Idea(s)

The loopy and colorful patterns of this fan are dependent on the 'persistence of vision' phenomenon: when the eye and the brain work together to create an illusion of a whole image. Hold the illuminated fan stationary so students can see the structure.

By tapping the fan with the edge of your hand, the LED lights will change patterns. The wave patterns formed by this action are a foundation for a vast array of investigations.

* NGSS is a registered trademark of Achieve. Neither Achieve nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of, and do not endorse, this product.