Use a touchscreen to search for any number hidden in the first 3 million digits of pi. Use a touchscreen to search for any number hidden in the first 3 million digits of pi.
Use aluminum foil, salt water, and activated charcoal to construct a simple battery strong enough to power a small motor or light. Cut a piece of aluminum foil that is approximately 6 x 6 inches (15 × ...
Measure the height of an object indirectly using your hand and a ratio. Many of the numbers we use in science have never been measured directly; we only know them from indirect measurements. How far ...
Compare the brightness of two light sources using an oil spot on a white card. When an oil spot on a card is illuminated equally from both sides, it mysteriously disappears. This allows you to compare ...