This month we very much enjoyed the many Optics and Visual Perception Experiments we tried. Many of these we wrote up in Scientific Method, listing Materials, Procedure, Observations, Conclusions, Diagrams.
The Jumping Finger and Bouncing Ring – These experiments helped the students to experience their “Dominant Eye” in dramatic fashion.
Double Finger or Double Phone – By focusing on the phone with index finger extended in the line of sight, we seemed to have grown a new finger. When we focused on our finger we seemed to have grown a new phone.
Blind Spots – Staring at objects with alternate eyes and moving closer and further we were able to find that each eye has a blind spot.
Holy Hand Robin! – Rolling up paper into a 1 inch tube and staring at an object across the room, with the tube at one eye and your hand held perpendicular to the tube, there was a large hole in your palm through which you can clearly see the distant object!
Afterimage Rectangle – By staring for 30 seconds at a dark rectangle and then immediately looking at a dark wall, a whitish rectangle ” afterimage ” will appear as if by magic.
Three Arrows through Water – This startling, simple experiment taught us about image reversal in a lens. Looking at three arrows pointing two directions through a clear glass of water showed the arrows reversed from how we drew them!
The Broken Pencil – The pencil seemed completely normal and entire until we placed it in the glass of water – then it broke, bent and got bigger; the light rays in air acting quite differently in water.
The Vanishing Coin – A coin under a glass remains visible until you put water in the glass and place a dish over the glass. The refraction of the rays make render the coin utterly invisible.
Mind Through Matter – We constructed pinwheels out of stiff paper and pinned them to pencil erasers. We then looked at the distant painting on the wall and blew on the pinwheel. Though the distant image should have been obfuscated by the paper of the pinwheel, ( and was when it was motionless ) when the pinwheel was spinning the painting was perfectly clear! The afterimage in the brain carried over until the next image was recorded, letting the mind overcome matter.
Spinning Discs – We constructed discs out of mat-board with four 3/4 inch holes, then strung them with string for winding and spinning. When spinning the holes disappeared leaving a circular void and a floating outer ring.
Slit Picture – Cut a 1/4 by 2 inch slit in a piece of typing paper and place on a vivid illustration in a large format book. When still the children saw a small puzzle-like portion of a picture. By moving the paper rapidly side to side across the page the whole picture suddenly becomes quite visible.
Grey Dots – Staring at 16 black squares in a 4×4 white field brings 9 phantom grey dots pulsing in your vision.
Floaters – Looking through a tiny pinhole at a lamp brings floaters, cells falling slowly across your eyeballs.
Red Becomes Aqua – Staring for 30 seconds at a solid red square and then looking away at a sheet of white paper brought gasps and ” beautiful!”s, as they saw a mirage in a blue-green aqua. Staring at a solid green circle and then looking away brought another mirage, a pink circle!
Black and White Color – We made two different discs with black and white patterns developed by physicists. Motionless they were black and white, but fastened to a sanding disc on a battery drill they turned many patterns and colors, blue, yellow, gold, purple, red, etc. Where did the color come from?
Color Wheel – We made color wheels, with orange, yellow, green, blue, violet, white, 3 times around the wheel. When spinning the bright colors become a muted tan.
Exploding (Dancing) Dots – Making a 7inch mat-board disc with regular holes and irregular dots, we fastened them to a pencil eraser with a pin. When spun while looking at the dots in a mirror they seem to explode in and out. Adding arms and legs to the dots makes them dance wildly!
Lines Aren’t Circles – Spinning two angled straight lines they seem to bend, curve and become circular.
Spinners – With bubbles on one side and a fish carefully lined up on the reverse side these cardboard spinners combine both images. The kids made up their own combination spinners.
Toothpick Twisters – They seem to pass through metal instantly.
Outside In, Inside Out – Squares, cubes and circles that keep flipping in and out in your minds vision.
Merry Go Round Curve – We tried this one on the little merry go rounds at Stewart Park. While sitting on the seat , throwing a ball to someone on the grass it goes perfectly straight; but when the children were turning rapidly on the merry go round, throwing the ball seemed to take a wild curve.
Physics Discovered – While the kids were swinging for recess at the park, we discovered that throwing a ball to someone out in front of the swing was easy when swinging toward them, but almost impossible while swinging away from them. We were excited about the physics discovery!
These are some of the many experiments we’ve tried this month.
The Finnstitute 