Wednesday, January 21, 2026
– Live Presentation with
Oskar van Deventer –
Session at 12 Noon Atlanta time
(check your time here)
Please join us starting 10 minutes before this session using the following button.
For published CoM presentations please visit the G4G YouTube channel
After this virtual CoM presentation on Zoom, we will meet for an informal social session in a different Zoom space where we can all see each other (see the blue button below). That Zoom meeting will start around 1pm ET.
Please join the social using the following button:
Puzzle Collaborations
Regular viewers of Oskar’s YouTube channel may have noticed that he often mentions collaborators. In his presentation, Oskar shall present a medley of puzzles that resulted from such collaborations. Some provided a puzzle idea that Oskar worked out into a working prototype. Some accepted a design challenge from Oskar. Some made a prototype for which Oskar needed help. And more collaborations. Here are some examples.
-A flat 2D mechanical puzzle, where the number of moves to solve increases exponentially with the number of parts.
-A 3D puzzle, where the number of moves to solve increases hyper-exponentially with the number of parts.
-A rock, from which you need to remove a golden nugget.
-A puzzle that no human has yet managed to solved without looking at the spoiler
-A box with seven Soma pieces, where it is hard to even remove all the pieces
-A flat geared twisty puzzle, where the gearing ratio varies while turning
-Puzzle based on the ancient Inka theme
-Puzzle-ring innovation, including an inverse puzzle ring
-Recursive Penrose-tiling-based puzzle
-Chanoeka-themed twisty puzzle
-An unexpected pattern-matching puzzle
-A symmetry puzzle
-A vanity maze
Etcetera, etcetera
Oskar van Deventer is a Dutch puzzle designer whose work lives at the intersection of mathematics, physics, and playful ingenuity. Best known for creating intricate combination puzzles—many brought to life through 3D printing—he has designed everything from elegant mechanical curiosities to record-breaking Rubik’s-Cube-style monsters, including the once-world-record-holding 17×17×17 Over the Top Cube.
Beyond the puzzle table, Oskar is also a research scientist with a Ph.D. in optics, and a prolific contributor to technology and standards research, holding dozens of patents and publications. Whether collaborating with academic institutions or designing puzzles for mass production, his work embodies the spirit of mathematical exploration: serious ideas, joyfully expressed.