Saturday, April 14, 2012

Wall Mounted Double Pendulum for Experimental Photography

(or how we went to outer space shot some galaxies and came back)
Through the lens of Abir Ghattas

My first interest in chaotic behavior can be traced back to this post. This time however, instead of simply developing a simulator I decided to build a real double pendulum. Watching a double pendulum dance erratically was worth a million simulation. If you are follower of this blog you will realize instantly that I could never let this opportunity pass without transforming it into some sort of a crazy experiment (-mostly photographic-).
The first step in the process was the design of the pendulum. The dimensions were chosen such as to maximize the chaotic behavior. Click here to download the AutoCAD .dwg file.

All dimensions are in cm
The material was chosen to be transparent 2mm thick plexiglass (4mm would have been ideal-but it was not available). The reason I chose to use a transparent material was so that the light can pass through in photography. I would definitely choose another material if I was using the pendulum for decorative purposes.

As for the components needed:
- 6mm ball bearings x4
- 6mm Hex Screw with nuts and washers  x2
- 3mm wall mounting screws and screw anchors x2

The following slideshow displays the assembly process

Here's a video of the double pendulum in action

After the assembly, Abir Ghattas and Patrick Abi Salloum came over for the photoshoot. We used LEDs of different colors connected to 3V coin batteries and we took long exposure pictures in the dark.
Left to Right: (1) Abir painting the pictures with LEDs (2)focusing (3) Patrick vs. Abu Ali
Courtesy of Patrick Abi Salloum

"Angel of Death" courtesy of Patrick Abi Salloum
For the result check Abir's website:
and Patrick's flickr: