Hyperbola Clock
This amazing clock available here:
From Etsy: BUY NOW: Kinetic Hyperboloid Clock
From Etsy: BUY NOW: Hyperbolic Hole Kit
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Hyperbola Clock: a straight rod glides through a curved hole in this unconventional clock based on the hyperboloid, the 3D ruled surface traced by rotating diagonal line. In this creation by Robert Darwen of Fibonacci Clocks, the rod serves as the hour hand with a smaller minute hand above the center of the base disk. (The time adjustment dial of the clock mechanism was connected to a small motor to produce the sped up motion in this video so that 1 second = 1 hour)
Tenebrescence and Fluorescence of Hackmanite
Get a sample here:
From Etsy: BUY NOW: Hackmanite Samples
365 nm UV flashlights available here:
From Amazon: BUY NOW: Convoy UB Flashlight
Note: this site contains affiliate links for which I may be compensated
Tenebrescence: a property of the mineral hackmanite which temporarily changes color when exposed to UV light- from pink/white to violet. Photochromism from a naturally occurring mineral! Similar physics to phosphorescence (glow in the dark) the purple color fades back to normal over about half an hour, and the mineral can be put into this excited state over and over again by the UV rays of the sun, or this high intensity UV flashlight. Also- hackmanite has a bright orange fluorescent glow under UV.
Tenebrescence of Hackmanite
Get a sample here:
From Etsy: BUY NOW: Hackmanite Samples
You will also want a powerful UV flashlight:
From Amazon: BUY NOW: High Power UV Light
Note: this site contains affiliate links for which I may be compensated
Tenebrescence: a property of the mineral hackmanite which temporarily changes color when exposed to UV light to a deep shade of violet- photochromism from a naturally occurring mineral! Similar physics to phosphorescence (glow in the dark) the purple color fades back to normal over about half an hour, and the mineral can be put into this excited state over and over again by the UV rays of the sun, or this high intensity UV flashlight. Also- hackmanite has a bright orange fluorescent glow under UV.