Make A Motorized LSD Spiral - A Powerful Illusion on Your Wall!

The "LSD Spiral" is one of the most powerful illusions I have ever encountered.  It's simply a spiral that reverses its directionality a few times.  When a spiral spins, it gives the impression of expansion or contraction depending on which way it's going.  Because of the reversals in the LSD Spiral, when spun it creates neighboring areas of opposing motion.  If you stare at its center for a while as it spins, you will 'get used to' the motion - the parts of your brain that respond to it slow their firing rate.  The result of this is quite impressive - when you look away, your brain will be biased towards the opposite direction of motion.  It's somewhat similar to color-based after-images, but higher-level.  You get a very noticeable bubbling and bulging of your surroundings, which is said to be similar to the effects of hallucinogenic drugs.

Being a neuroscience major, I'm fascinated by these sorts of things.  I decided to make a real-life motorized LSD spiral that I could hang on my wall and enjoy whenever I wanted to.  Here's what you'll need to make your own!

Materials:

• Large sheet of cardboard/thin plywood (I was lucky enough to have a big tv box)
• Acrylic paints (black and white are probably best, but I'm sure other colors would work too)
• Photo-editing software (mspaint is fine!)
• A printer
• A good knife or box cutter
• Some k'nex, including a motor
• Clear plastic tubing (optional but recommended)
• A drill and some scrap wood

I actually can't find the original video I used on youtube anymore, so instead I've uploaded the images I used to make my stencils onto imgur here.  You can download them and print them yourself.

Here's a video of it in action!

Stare at the center of the spiral until I move away from it. At that point, you can either look at your hand, some type, or anything else that doesn't usually bubble and shift crazily. The effect will only affect the part of your vision the spiral was in - so lean in close or make the video bigger (if possible) for a bigger effect.

Step 1 Prepare your circle

I got a new big screen tv, and used part of the huge box it came in for my spiral.  A thin sheet of plywood would be fine, but you're probably best off just finding a big box (maybe even a large pizza box?  That might be a bit weak, but it could do).

Decide how big you want your spiral to be.  Keep in mind that the effect it gives is limited to the space it actually occupies in your visual field.  The bigger it is, the larger the effect will be from any distance.

Cut out a circle (I used a string tacked to the center of the cardboard with a pencil tied to the end to mark it out) and paint it entirely white.