### Balance Stacking Sculpture

Another wonderful desing by BinDesign- get one here in black or natural wood:

From Etsy: **BUY NOW: Bin Design Balancer Puzzle**

Balance Stacking Sculpture: a series of torques in unstable equilibrium complete this Calder-esque structure. As each component is added its weighted end balances all the others before it, with the initial small piece weighing about a gram or so. Remove the end piece and the whole structure comes down. Another wonderful design by artist Bin Xu.

### Aperiodic Monotile

Learn more about this recent math dicovery here: An aperiodic monotile (arXiv)

Althogh the math says they can tile the plane, getting them to do so is more challenging than one might think!

Get a set of laser cut hat tiles here:

From Etsy: **BUY NOW: "the Hat" monotile set**

See other aperoidic tilings in my collection.

Aperiodic Monotile: this newly discovered 13 sided shape, named “the hat”, will tessellate a plane to infinity, similar to how squares or hexagons can tile out with no gaps. However the hat tiles the plane aperiodically- if one tries to shift a part of a hat tiling, the shifted part will not align or match up with any other part of the same tiling- all the way out to infinity! The fact that aperiodic tessellations exist at all is pretty amazing, and Sir Roger Penrose (Nobel prize in physics 2020) is also famous for discovering a pair of regularly shaped polygons that tile in this aperiodic way. However it was not clear until a few weeks ago if a single shaped tile could tessellate aperiodically when the hat was described in a paper by Smith, Myers, Kaplan, and Goodman-Strauss uploaded to arXiv March 20.

### Penrose Aperiodic Rhombs

A nice version of Penrose Tilings is available here:

From Etsy:** BUY NOW Penrose Tiles **

Penrose Aperiodic Rhombs: a famous aperiodic tiling with just two shapes- a pair of rhombuses with equal sides, but with the ratio of their areas made to equal the golden ratio. Note that although the starting pattern of 10 tiles is symmetrical, adding any further tiles breaks the symmetry, as highlighted by the path of the double curves. Sir Roger Penrose- who just won the Nobel prize in physics for his contributions to General Relativity- also discovered tessellations (tilings) that are aperiodic even though the two tile types are regularly shaped polygons. If one tries to shift a part of a Penrose tiling, the shifted part will not align or match up with any other part of the same tiling- all the way out to infinity! In this construction, single and double line patterns must align such that the tiles can only connect in specific ways to ensure the non-repetitive nature of the Penrose tiling structure. Shown here is one way these two tile types will fill the plane.

Wikipedia has the details on Penrose Tilings and their inventor Sir Roger Penrose (Recently won Nobel Prize!)

### Penrose Tiling Puzzle

This puzzle was produced and sold in the 1990s.

The individual tiles can be found on eBay (and sometimes the whole puzzle):

From eBay: **Search NOW Penrose Pentaplex Puzzle **

Wikipedia has the details on Penrose Tilings and their inventor Sir Roger Penrose (Recently won Nobel Prize!)

A nice basic version of Penrose Tilings is available here:

From Etsy:** BUY NOW Penrose Tiles **

Penrose Tiling Puzzle: a challenging puzzle with pieces that come in only two shapes. Sir Roger Penrose- who just yesterday won the Nobel prize in physics for his contributions to General Relativity- also discovered tessellations (tilings) that are aperiodic even though the two tile types are regularly shaped polygons. If one tries to shift a part of a Penrose tiling, the shifted part will not align or match up with any other part of the same tiling- all the way out to infinity! This puzzle, entitled “Perplexing Poultry”, created and sold by Penrose himself, uses polygons modified into crazy looking birds such that the tiles can only connect in specific ways to ensure the non-repetitive nature of the Penrose tiling structure. Shown here is one way these two tile types will fill the plane.

### Kinetic Balance Ribbon Sculpture

This vintage art often found here:

From Etsy: **BUY NOW:** **John Anderson Kinetic Art**

Kinetic Balance Sculpture: two ribbons of aluminum balance on a third in equilibrium with gravity- but free to rotate about pivot points above each system’s center of mass. A vintage find from 1974 by artist John W. Anderson.

### Glow Trace Chaotic Pendulum Kit

This kit (usually part of a subscription) often available here:

From eBay: **BUY NOW: Glow Pendulum Kit**

Get amazing quatilty science kits delievered to your home- this glow pendulum is part of the Tinker Crate subscription.

From KiwiCo: LEARN MORE**: Tinker Crate Subscription**

Glow Trace Chaotic Pendulum: this fun and amazing DIY kit features a UV diode to trace the intricate path of this double pendulum system on to a phosphorescent screen, revealing the physics of chaotic motion. It’s amazing that such complex motion can arise from a simple assembly of two pendulums, one attached to the end of the other. Chaotic motion, such as that observed here, is characterized by extreme sensitivity to initial starting conditions, tiny differences in how the system is released leads to dramatically different outcomes each time.

### Air Stream Levitation

Similar device available here (comes with disks):

From eBay: **BUY NOW Air Stream Levitation **

Here are some Styrofoam balls that will levitate with this device:

From Amazon: **BUY NOW: Foam Spheres **

Zero Gravity / Air Stream Levitation: a physics toy employing the CoandÄƒ effect- the air stream attaches and wraps around the styrofoam ball trapping it in the center of the stream. As the air changes direction to flow around the ball, momentum is imparted to it pushing the ball against gravity. Gravitational force on the ball is not zero of course, but the sum of forces (gravity + push from air stream) is zero putting the ball in suspended equilibrium.