Wednesday, January 16, 2013

Easy Kaleidoscope


This kaleidoscope is easy to make and kid friendly since it doesn't involved any sharp (or expensive) materials like mirror pieces.  Chances are you will already have the following materials:
  • sheet of transparency paper
  • paper towel tube
  • foil
  • transparent and colorful beads
  • a sheet of colorful construction paper
  • glue or tape
  • scissors
  • a ruler
  • a pen or marker



Use the pen to mark three dots 1 3/8" apart from each other.


Use the dots as a guideline to fold a triangular prism (lengthwise).


Trim off the extra of the transparency sheeting, leaving a small overhang.  Tape along the overhang to secure the prism into place.  Make sure that the folds in the transparency sheet are nice and crisp so an equilateral triangle is formed.


Wrap foil around the prism, shiny side facing inward.  This piece will function as a mirror.


Insert the prism into the tube. 


It should fit slightly loose.  If it's too snug, the triangle shape will become distorted.  Secure with a little tape or glue if needed.  At this point, you could look through the tube and see reflections of the world around you.


Use one end of the tube to trace two circles onto the leftover bit of transparency paper.


Tape these two circles together 2/3 of the way to create a little envelope.


Fill with transparent beads.  Ideally, the beads will be able to move around.  Don't overcrowd the beads, and try placing one or two large beads in the middle so smaller beads will fall around them.


You could glue the bead packet into one end of the tube, but it should fit snugly inside.  By not gluing it, you could create different packets with different colored beads, allowing you to change up your kaleidoscope at will.


If you don't have beads, drawing designs and patterns in a circle of transparency paper with colorful, permanent markers creates a similar affect.


Hold the kaleidoscope up to a light source and rotate it to see colorful, changing designs.

Here's a little science and geometry behind this kaleidoscope:  Light bounces off things in many direction, but it behaves differently when it encounters a mirror.  Light rays bounce, or reflect, off mirrors in only one direction and at the same angle in which the light hit the mirror.  This angle that light hits the mirror is called the angle of incidence, and the angle that the light reflects from the mirror is called the angle of reflection. 

Together, the transparency paper and foil reflect enough of the light it receives to form an image much like the original, thus functioning as a mirror.  Since the transparency paper and foil are folded into a triangle with equal angles and equal side lengths, they form a prism of an equilateral triangle.  Since the three corners, or vertices, of a triangle form three angles that equal 180°, an equilateral triangle has three 60° vertices.  Each panel of the mirror is 60° from the others.  The light that enters the kaleidoscope reflects off each of the three panels at 60°, forming eight images. 


Magnetic Marble Run


If you have an old chalk board or white board that is  magnetic, creating a marble run from recycled materials is really simple.


 

Cut plastic, or even cardboard, tubing in half lengthwise to create the basic "ramp" for the marbles.


Hot glue magnets on the back so each ramp will stick to the chalk board.


To create a "pinwheel" within a tube, use a small nail to poke two holes opposite each other in a short length of tube.


Cut a piece of straw slightly smaller than the diameter of the tube and use short pieces of masking tape to create "spokes."


Two strips of tape make two spokes.


Secure the straw inside the tube by stringing it on to a short piece of skewer affixed into the two nail holes.



As the marble falls vertically, the pinwheel will spin.


Attaching several magnets to the a piece of flexible, foam tube will allow you to create different curves.


A magnet attached to a plastic cup can create an end point to catch the marble.


PVC pipes make great tubes as well.


A fun thing to experiment with is creating a V shape with two straws.  Even when parallel, the marble will move along with the widening V.


The upside down tops of soda bottles will make the marble swirl around before it drops.


Adding thumbtacks, or even strips of hot glue or sandpaper will add some friction to the course.


Since everything is magnetic, this marble run can be rearranged over and over again.



The marble is moved down the ramp by gravity.  An attraction, or gravitational force exists between the marble and the earth.  Since the earth is much more massive than the marble, the marble wants to get as close as possible to the earth.  If you drop a marble out of your hand, it falls straight down to the earth.  In the magnetic marble run, the marble has to go through the different obstacles to get as close as it can to the earth.

The marble will speed up or slow down depending on the obstacle.  Pipes and tubes that are nearly flat and ones with higher friction will slow down the marble, while steep obstacles will low friction will speed up the marble.  When an object is sitting on a flat surface, the only force acting on it is gravity, which is always downward.  The object cannot move any farther down on a flat surface since gravity is not strong enough to push it through the surface. When an object is sitting on an incline, or ramp, the downward force of gravity