SNO-Ball

George W. Hart



SNO-Ball celebrates the Nobel-prize-winning research at the Sudbury Neutrino Observatory, which showed that neutrinos have mass.  The design is evocative of a swirling ball of fluid, meant to symbolize both the sun, where neutrinos originate, and the sphere of heavy water central to the detector.  The 1.5 meter diameter sculpture is composed of thirty planar wooden components (arranged with icosahedral symmetry and twelve 5-fold swirls) plus six brass rods that pass through radially (arranged with the symmetry of a cube's right angles).  The interplay of these two symmetries take some time to understand.
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We assembled the sculpture on May 13 as a group project at Science Rendezvous Kingston 2017.  This is a public outreach event that exposes thousands of people to ideas from science and mathematics.  It was commissioned by the Queen's Science Rendezvous Coordinators to celebrate Art McDonald's Nobel prize, Queens University's 175th anniversary, and Science Rendezvous' 10th anniversary across Canada.




If you study the sculpture for a while, you will see that each piece is a flat shape that looks like this (but only six of the parts have the small central hole shown above).  This derives from an earlier sculpture I made while exploring ideas for this commission, but there are sixty additional connection points here around the 3-fold axes, which I added to ensure rigidity at this larger scale.  The laser-cut Baltic birch plywood parts are yellow on the outside and orange on the inside.




During the assembly, we had to keep track of three subtly different part types.  Six have the central circular hole mentioned above, twelve have no hole, and twelve have a semi-elliptical half-hole on one edge, as can be seen near the bottom of the image above.




The parts join together with cable ties.  White ones are used on the exterior connections and black ones around the 3-fold axes.




After the wooden components were all tightly connected, I clipped the tails of the cable ties and inserted the brass rods.  Currently, the space where the sculpture will be displayed is being refurbished, so it is not yet installed.  I will add another photo once it is in its permanent place.




Before building anything, I made a variety of virtual models, exploring a range of design ideas.  This rendering is how I envisioned it at one stage.  Note that the orange and yellow colors are reversed from the final version.  (It is also of the mirror-image handedness.)  You can get a better sense of it's structure from this animation.




This is a one-third scale model I made to test out everything and be sure I would like it, before laser-cutting the larger pieces for the full-scale version. (It still has the earlier color scheme and reversed handedness)




Here is a test-fit of the full-size parts at my studio in NY, after staining and finishing the wood and beveling all the mating edges to the proper dihedral angles. At this point, I was still in the process of adding the remaining cable ties.  After some experimenting, I eventually decided on black ties (which last longer) for some of the connections.  Note that plastic cable ties should be replaced every decade or so, which can provide an activity for future anniversary parties.

Thank you to everyone who helped assemble it and everyone who collaborated on this project, especially Lynda Colgan at Queens University, who somehow made it all happen.  And thank you to the MSTE group at Queen's Faculty of Education, which partially funded it.

This design document gives some background about my thinking and how the sculpture relates to the SNO project.


Copyright 2017, George W. Hart