Hi Everyone :) Welcome back! I get asked often: "Where did you get all this stuff?" My goal is to share the real magic of science and physics- and to this end I will update here (and in my store) suggestions on where to get some of these toys, kinetic art pieces, and scientific curiosities for yourself. Purchasing items from the links on these pages will help support my IG page of science and wonder. Buy physicsfun toys on : https://bit.ly/2MOjFET (Official website 🇺🇸) physicsfun toys on amazon : https://amzn.to/36RRxt0 Follow on Instagram : @physicsfun This video contains : 👉🏻 Squaring Circles: from one particular point of view these wireframe sculptures looks like a circles/squares, from another it’s a square/circle! 👉🏻 Undial Sundial: modern design of an ancient timekeeping device where a slanted stick (the gnomon) casts a shadow to indicate the time (this one designed for 30-40 degrees latitude). This novel design has no dial underneath, instead the hours are laser etched into clear acrylic such that the time appears projected within the cast shadow. 10 AM to 3:00 PM of a sunny day in Fresno are shown here in time-lapse. Note the movement of the shadow cast by the sun as the Earth turns underneath during this five hour period. Perfect for a windowsill that gets noonday sun! 👉🏻 Franklin's Bells 👉🏻 Electrostatic Levitation: hand held Van de Graaf generator charges and repels a cylinder of thin aluminized Mylar. 👉🏻 Electrostatic Motor: induced charge supplied by a hand held Van de Graaf generator powers this simple motor. 👉🏻 Equatorial Bulge Demo: two springy circular rings flatten along their axis of rotation in proportion to the rate of spin in this classic teaching demonstration. This device demonstrates that centripetal accelerations applied to an elastic sphere will cause it to bulge at the equator- becoming an oblate spheroid. Isaac Newton predicted that given the Earth’s rotation, the radius to the equator would be larger than the radius to the North Pole by 1 part in 230. He was correct! (although overestimated slightly- swipe for description) Modern measurements indicate 1 part in 294.7. Question: At what location on Earth could you stand on land and be furtherest from its center? Mt Everest is a good guess, but the correct answer is the top of Mt Chimborazo in Ecuador. Although Everest is higher above sea level, the equatorial bulge puts the top of Chimborazo a 2.2 km further into space from the center of the Earth. 👉🏻 Mini Acoustic Levitator: small pieces of styrofoam become trapped between areas of higher pressure induced by high frequency sound waves. Ultrasonic transducers placed at the top and bottom are basically speakers that emit sound waves at a frequency of 43,000 Hz, which corresponds to a wavelength of 8mm for dry air. 👉🏻 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. 👉🏻 Balance Stacking Sculpture: a series of torques in unstable equilibrium complete this Calder-esque structure. 👉🏻 Dither Image Encryption: three images hidden in random dither patterns are revealed by precisely overlaying and aligning any two patterns in the generated set. Amazingly each pattern holds two encrypted images where b+c=♣, a+b=♦, and c+a=♥. 👉🏻 Tumble Rings: the links in this chain are connected in a special way such that the top ring appears to tumble to the bottom- a compelling illusion! 👉🏻 Van de Graaff Generator: this miniature electrostatic generator can create potentials of more than 50,000 volts allowing sparks to jump a few centimeters through dry air. Similar physics to the sparks created when shoes scuff on carpet, a moving rubber dielectric belt carries electrons away from the top sphere leaving it positive charged- as can be seen by the electrostatic repulsion of some Mylar strands. A small battery powered 3V motor drives the belt via the bottom pulley in this unit that costs less than $10 US. 👉🏻 Handheld Van de Graaf Generator 👉🏻 Pendumonium: stick man chaotic pendulum with 4 degrees of freedom. 👉🏻 Digital Sundial 👉🏻 PHYSICS BRAIN TEASER Background music by : YouTube Audio Library 1) New Day - Patrick Patrikios 2) Tempos Vari - Freedom Trail Studio 3) Icelandic Arpeggios - DivKid 4) Bay Street Billionaires - Squadda B 5) Interstellar Mood - Nico Staf 6) Can't Sleep - Eveningland 7) Vital Whales - Unicorn Heads