This glass device is available from this shop in Germany:
From experimentis-shop.de: BUY NOW Vanishing Glass Demonstration
Refraction Vanishing Act: the liquid (immersion oil) in this glass tube has the same index of refraction as the glass. When the oil covers the glass rod inside the tube, the rod becomes invisible! Immersion oil is used with high resolution microscopes and designed to have the same index of refraction as the glass slide and objective lens. This physics puzzle demonstration was handcrafted by a glass maker in Germany and is sold by experimentis, the online shop for physics.
These Light Blox are available in this nice kit from Laser Classroom, a science education supplier:
From Laser Classroom: Light, Color and Shadow Kit
Wikipedia has a fantastic introduction on the topic of RGB Color Theory
RGB Color Addition: three LED light boxes demonstrate the additive nature of colored light. Mixing Red, Green, and Blue to create Yellow, Magenta, and Cyan. An object casts shadows showing the following mixings: R+G=Y, G+B=C, and R+B=M. Adding all three R+G+B produces White (a little pinkish here as the Red is a little bit bright for complete white balance). RGB color addition is the basis for all computer and TV displays- all the colors you are looking at right now on your screen are made from adding pixels of R G and B in different proportions and intensities!
This unique toy came to me from Germany:
From Kreiselparadies.de: Orbit Spin Disk
Orbit: spinning disk toy with off-center sphere. Spinning things obey different rules!- its center of mass goes to the top when spun. Very similar physics to that of the tippy-top (a few posts back on this stream).
From Amazon: BUY NOW Andrus Tri-Zonal Space Warper
From eBay: BUY NOW Tri-Zonal Space Warper
Magician and professor of psychology Richard Wiseman describes the genius of Jerry Andrus and the psychophysics of the Space Warper.
Andris Tri-Zonal Space Warper: Stare at the center of the spirals for at least 15 seconds- the next thing you look at will appear to be in motion. This spinning disk top features the famous illusion by magician Jerry Andrus that demonstrates aspects of the physics and psychophysics of our visual perception- specifically the part of our brain that detects motion. The effect is even stronger in person than in the video.
Wikipedia has this introduction to the phenomena of the Aircraft Glory
For a detailed discussion with math, see this entry from the Physics Stack Exchange
Airplane Glory: optical phenomenon that forms rings of color in the clouds- in this case around the shadow of my 737 flight, and is not the same physical process as that of a rainbow. Airplane glories are produce only by very tiny droplets (tens of visible light wavelengths across) in the cloud, and arise due to complex process called wave tunneling, where the electromagnetic waves that make the colors are induced in the drop by a photon only passing close by its surface. Interestingly, the exact details of this phenomenon is still an active area of research! Caught this out the window returning yesterday from a national science teachers convention in Atlanta.
This image by István Orosz is available as a poster and as a puzzle:
From Amazon: BUY NOW Mysterious Island Puzzle
From MathArtFun.com: BUY NOW Mysterious Island Poster
For those who want to see the math behind this art, here is an initial paper on the topic published in 2000 in the American Journal of Physics: Anamorphic Images by Hunt et al.
Many books are available (with mirror cylinders) from Amazon: Anamorphic Art in Books
Mirror Anamorphosis: this famous print by artist István Orosz has a hidden anamorphic image revealed by placing a mirrored cylinder over the depiction of the moon in the image. The work visualizes a scene from the book “The Mysterious Island” by the science-fiction author Jules Verne- whose portrait emerges in the reflection on the cylinder. The math describing this mapping is quite complex and was given in detail in a physics journal in 2000, but before that Martin Gardner described the math in 1975. Repost for this week’s theme as I head to G4G!
Get a set here:
From Amazon: BUY NOW Balance Cups
Balance Drinking Vessel: physics meets design in this stainless steel cup- when empty the cup tilts to one side, but when full it stands straight. The walls of this spherical vessel are hollow, asymmetric, and weighted, designed with the center of mass displaced from the symmetry axis such that the empty cup rests in stable equilibrium at a 23 degree tilt. The addition of mass (pouring a drink) within the offset interior of the cup places the center of mass (cup + contents) onto the symmetry axis allowing an upright stable equilibrium. Designed by Katja Hoeltermann for Carl Mertens design of Solingen Germany.
Available here- four versions of 360° Books to choose from:
Amazon: BUY NOW 360° Books
360° Book: Earth and Moon by Yosuke Oono- whimsical art for the science and sci-fi enthusiast. Love the UFO abducting the cow!
I made this set of tumble rings from reading Martin Gardner's description in his famous mathematical recreations books- highly recommended:
From Amazon: BUY NOW Knots and Borromean Rings by Martin GardnerDescribes the Tumble Rings
From Amazon: BUY NOW Books on recreational math and puzzles by Martin Gardner Lots of physics and math toys in these pages!
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!
From MovaGlobes.com: BUY NOW Pluto MOVA Globe
Wikipedia has a wonderful summary of the 2015 Pluto flyby and the complete mission of the New Horizons space probe.
Pluto Globe by MOVA: simulate the historic 2015 Pluto flyby of NASA’s New Horizons space probe with this self rotating detailed image of the dwarf planet’s surface. Each MOVA rotating globe is sealed within a clear liquid filled acrylic sphere. The rotation is powered by light that shines through the semi-transparent Pluto globe on to solar cells inside the globe which drive a motor. But what does the motor push against to maintain the rotation? Believe it or not it uses magnets to push against the Earth's magnetic field like a compass needle. Love this clever device. With thanks to @movaglobes for sending me this amazing globe.
This vintage item is out of production. Here are some similar times based on whirlpool vorteces:
From Amazon: BUY NOW Vortex Lamps
"Pet Tornado": whirlpool powered by a magnetic stirrer (like those in a chemistry lab). The knob on the side has settings F1 through F5 ? One of my sillier toys- but vortices are just so cool.
If you are ever in Florence be sure to visit the Galileo Museum and see the original- as well as a collection of Galileo's telescopes and experiments.
Visit: Museo Galileo
Optical Trick Portraits: Hold a flat mirror up to this painting of Charles III, Duke of Lorraine, to reveal his daughter Christina in this 1593 work by Ludovico Buti. A very early example of lenticular images, Gioco Ottico hangs in the Galileo Museum in Florence as part of the Medici Collections. I got this toy version from the museum gift shop a couple months ago.
This sculpture and others available here:
From eBay: BUY NOW Steinbach Reflection Scupltures
Reflection Symmetry Sculpture: precision etched into one side of a triangular prism, multiple reflections within the optical grade glass create the 3D castle and grounds. Fun use of symmetry and geometry in this optical crystal sculpture series by Steinbach.
See more illusion art from Victoria Skye here:
From victoriaskye.com: Illusion and Impossible Objects
Skye Blue Café Wall Illusion: the horizontal blue lines appear to be sloped but they are actually parallel, as verified by sighting a straight line from the edge of the image. This visual illusion is related to the level of contrast between sharp boundaries, and if the boundaries are blurred (here with a plate of frosted glass) the illusion is broken and the lines appear parallel. Note that even after we verify the lines are parallel, our perception still misleads- a reminder that we need science to transcend the limits of our senses and cognition. This award winning illusion was created by artist Victoria Skye and is featured here with permission. @vicskye
The best effect (highest fountain) is obtained by using #10 size chain with a bead diameter of 3/16" (4.8mm). This spool has 100 feet of chain, the same length as used in the video.
From Amazon: BUY NOW #10 ball chain
Wikipedia has the details on the discovery of the chain fountain, and for those that want the physics here is the paper: Understanding the Chain Fountain from Proceedings of the Royal Society A, 2014
Chain Fountain: as the chain flows out of the glass under the pull of gravity the beads don't simply roll over the edge but instead arc up upward like a fountain. As each link is pulled and tilted upward the adjacent link is tilted downward and pressed into the pile- by Newton's 3rd law the pile presses back pushing each bead upward into the air. A segment of the video is shown in slow motion where the fountain is at maximum height. This phenomena was recently discovered by Steve Mould (more to be seen at his YouTube channel) and the details of the physics is described in the Proceedings of the Royal Society by Biggins & Warner (2014).
Another science toy from Taiwan! Produced by the Mr. Sci Science Toy Factory
From Mr. Sci Science Toy Factory: Buy Now Civilized Glass
Learn more about the Pythagorean Cup on Wikipedia
The Civilized Glass: a most elegant version of the famous Pythagorean cup. Functions as a normal glass, but if the glass is filled above the top of the central column a siphoning effect is triggered and all the contents in the glass drains out the bottom through the hollow stem. With this glass moderation is key! This well made glass design by @mrscisciencefactory allows one to see the mechanism of the siphon tube usually hidden in ceramics