Northern Lights
On some dark nights in certain parts of the world, an amazing green glow appears on the ho...
Pinhole cameras are so simple that people sometimes don't believe they will work. But physically they are almost identical to the human eye. The eye is a ball-shaped chamber. Light enters through the hole of the pupil and shines on the retina on the back of the eyeball. Likewise, the pinhole camera is just a box with a tiny hole in the middle of one of its faces. When you secure a piece of photographic paper inside the box on the side opposite the hole, the camera is ready. Because the box must not let any light in, it is usually taped closed with black electrician's tape. When you open the pinhole light enters the box and projects onto the light-sensitive paper. You have taken a picture. Later, you develop the paper in a darkroom with special chemicals. A negative image appears on the paper which means that dark things look light and light things look dark.
On some dark nights in certain parts of the world, an amazing green glow appears on the ho...
You might think mummies are only for Halloween, but mummies actually do exist. A mummy is ...
Ecosystems are communities of living things that are made up of different shapes and sizes...