Deforming Ovals Materials Required: Proximity to a photocopying machine Some paper Myriad optical illusions are created when figures are drawn on a disk and rotated slowly. Here is how you can try it. Use a photocopying machine to copy the square shown in the illustration, with the three nested ovals. Cut the square out and crease it along both diagonals (dotted lines) to form two “valley” creases (that is creases that...

Converging Light Materials Required: A cardboard box of 60 cm to 90 cm high Two flashlights A clear evening, at dusk Galileo’s discovery of the telescope in 1609 was a huge development in the science of Astronomy. This allowed people to see hitherto unseen things in the sky at night. What we see at night with the naked eye, are not merely shining points of light, burning with different intensities, but...

Changing Colours  Materials Required: Crayons Five paper plates Five sticks A cloudless dark evening Adhesive tape It becomes hard to see, as the sun goes down. We will find out if it becomes more difficult to spot colours, as the sun goes down. Draw two crossed lines on a paper plate, thereby dividing the plate into 4 equal parts.  With a red crayon, colour two opposite sections, leaving the other two...

Distance and Size Materials Required: A full moon evening Some coins A Street with telephone poles A measuring stick With a diameter of 865,000 miles, it is very evident that the sun is very big. The moon on the other hand, with a diameter of only 2,160 miles is rather small. An eclipse is caused when the moon’s path, brings it between the sun and the earth. The sun is blocked...

Bending the Light Materials Required: A small steel ball bearing A strong magnet A flat table Something that causes a change in something else is known as a Force. Gravity is a force which stops us from moving upwards. Larger objects have greater gravity and this is why the Sun’s gravity forces the planets to remain stuck to it. Similarly, the moon too exerts its gravitational pull on the Earth and...

A Mask That Moves Materials Required: A Party mask Paints A lamp or any other source of light Scare the wits out of your friend. Use a Party Mask to create a scary optical illusion. Use crayons, water colours or other hues of paints to colour the lips red, cheeks pink and eyes blue. Darken the eyebrows. Hang the mask on the wall, painted side out. Direct light at it, from...

Effects of Friction Materials Required: Paper and Pencil Erosion is caused by moving water, glacier and winds. Apart from it, things can be worn out by friction force too. When you rub two materials against each other, the traction from it can wear them out. Look around you to find some proof of wear and tear. Make a chart of things in your neighbourhood or school and find the cause of...

Understanding Trajectories Materials Required: Some modelling clay A paper towel roll tube Marble Several sheets of typing paper Some adhesive tape A pencil A cardboard An uncarpeted floor under the table The path that an object takes as it travels through air is known as its Trajectory. Due to the earth’s gravity, objects that are thrown will never go straight, but will rather fall to the ground. If you throw it...