@physicsfun STEMcell Science

Computational Caustic Projection

Exclusive offer: get this limited edition sample of this new artform here:

From STEMcell Science: BUY NOW:  Caustic Projection Lion

Computational Caustic Projection: an image is formed by refraction through a free form lens in a new process that utilizes the physics behind how light is concentrated into caustics. This piece of molded acrylic has a surface of slight but precisely constructed curves, that when lighted by a broadband light source (Maglite flashlight bulb), projects an image of a lion onto a plane. This is not a hologram, but instead a new proprietary light redirection technology by the company RAYFORM. Special thanks to @rayform technologies for sending me this sample.

More from Rayform: The RAYY Ring

Glass Hydro-Top

Available in four colors and designs: 
From the @physicsfun collection: BUY NOW: Glass Water Tops

Glass Hydro-Top: under centripetal acceleration a liquid will flow to create a cylindrical surface parallel to the axis of rotation. This blown glass dreidel contains a small amount of colored water that when spun resembles a blue gemstone banded around the rim. A unique design with fun physics!

Thermochromic Safety Sticker

These stickers transition back and forth and can be used on many surfaces. Get some here:

physicsfunshop: BUY NOW: Thermochromic Saftey Sticker

Thermochromic Safety Sticker: the liquid crystal ester dye in this reusable sticker is calibrated to change color when the surface temperature exceeds 50°C (122°F)- that at which prolonged contact (more than 0.5s) will burn skin. Here the safety sticker is attached to a slab of aluminum and heated with a simple candle- it took about 3.5 minutes for the heat to distribute and bring the aluminum to the threshold temperature. When the surface cools the sticker again appears blank and can transition over and over again


Uranium Glass Marbles

Available here: 
From STEMCell Science: BUY NOW: Uranium Marbles 

And get the 405nm Laser here: 
From eBay: BUY NOW: 405nm Laser 

Uranium Glass Marbles: the very small quantities of uranium oxide in this glass give it its green color and produces brilliant fluorescence under a 405nm violet laser pointer. Uranium is of course radioactive but the tiny amount in this kind of glass poses no risk. The florescence has nothing to do with the radioactivity- in fact it is myth that radioactive items glow!

JSC-MARS-1 Martian Soil Simulant

Currently avaiable simulated martian regolith:
MMS-2 Mars Regolith Simulant developed by the Exolith Lab at University of Central Florida

From STEMcell Science: BUY NOW:  Martian Soil Simulant Sample

JSC MARS-1 Martian Soil Simulent: what the rust colored dirt of the Red Planet would look like up close! Produced by NASA for engineering studies of future human activities on Mars, this simulated regolith closely approximates the chemical, mineral, and grain size distribution based on data from the Viking and Pathfinder landers. 

 

JSC 1 Lunar Soil Simulant

Currently avaiable simulated lunar regolith:
LMS-1 Lunar Mare Simulant developed by the Exolith Lab at University of Central Florida

ORDER HERE:  Lunar Soil Simulant Sample

In the video: JSC-1 Lunar Soil Simulant- if you could scoop up a handful of the surface of the Moon, this is how it would look. Produced by NASA for engineering studies of future human activities on the Moon, the simulated regolith closely approximates the chemical, mineral, and grain size distribution found in actual lunar samples from the Apollo missions. Sourced from slightly porphyritic basalt ash sampled from craters near Flagstaff AZ and then processed. The LMS-1 Lunar Mare Simulant developed by the Exolith Lab is the latetest and most up to date version. 


Acrylic Rattleback

These acrylic versions work great and are inexpensive: 

From STEMCell Science: BUY NOW: Rattlebacks 

Acrylic Rattleback: a favorite from my collection- prefers to spin counter clockwise. If spun clockwise, a complicated combination of friction, precession, and instability induced vibrations transforms the rotational energy into into rattling (energy of oscillations) and then into rotational energy in the opposite direction! This behavior is related to the asymmetric shape of the bottom of this kind of rattleback, it's somewhat propeller shaped with an "S" curve along the bottom ridge

Precision Tippe Top

Get a flip over tippe-top here:   

STEMcell Science Shop: BUY NOW Tippe-Tops 

Precision Tippe-Top: spinning things often have surprising physics! This aluminum version of the famous flip-over top works better than any I’ve seen. Friction with the desk surface provides a torque that acts on the existing angular momentum of the top to flip it over. The top will stay flipped until the spin rate slows down enough to where its center of mass pulls it back to the resting position.

Woodwork Rattleback

The amazing work of Emmanuel Péluchon can be purchased here:
From Boisselier.ca: BUY NOW: Fine Woodworked Rattleback

Inexpensive rattlebacks can be found here:
From STEMCell Science: BUY NOW: Rattlebacks 

Woodwork Rattleback: prefers to spin counter clockwise- If spun clockwise, a complicated combination of friction, precession, and instability induced vibrations transforms the rotational energy into into rattling (energy of oscillations) and then into rotational energy in the opposite direction. This behavior is related to an asymmetry in weight along the left/right symmetry axis- the dark wood is Apple which has twice the density of the light colored Basswood(Linden). This asymmetry in weight induces an instability, quite like the vibrations that arise from an unbalanced tire, that transfers the rotational energy to the intermediate rocking vibrations. This beautiful physics toy was produced by Emmanuel Péluchon.