Some magnets are natural (lodestone and magnetite are naturally occurring), and some magnets are man-made. The magnets made in the laboratory are usually made of a mixture of iron, cobalt, nickel and other elements. The substances are magnetized by a couple of different methods. You could move a permanent magnet in one direction across the [...]
The short answer is because of the nature of the ionosphere of the Earth. The ionosphere consists of several different layers of gases that have become conductive from the bombardment of the atoms by: solar radiation, by electrons and protons emitted by the sun, and by cosmic rays. These layers, sometimes called the Kennelly-Heaviside layer, [...]
What does Doppler radar mean and how is it different from other radar? RADAR, an acronym for Radio Detection and Ranging, operates by transmitting a wave and recording the time it takes that wave to bounce off of an object and return to the source. Since we know the speed the transmitted wave is traveling, [...]
Mathematical theory suggests that most comets may come to the solar system from very far away, as far away as 100,000 Astronomical Units. In this picture, the solar system is buried deep within the cloud. An Astronomical Unit (or AU) is the distance from the earth to the sun and is equivalent to about 93,000,000 [...]
Echolocation is the ability to locate objects by bouncing sound waves off of them, and then measuring the time taken for an echo to return, and calculating the direction the echo came from. Bats use echolocation to find their way around in the dark, and to locate their food. They send out sound waves which [...]
The principle factor affecting a moving (and spinning) baseball is air drag. Imagine a standard fastball thrown with a straight overhead motion. The ball will be spinning naturally on a horizontal axis (with the top of the ball rotating back toward the pitcher). This spin causes the magnitude of the drag vectors to be different [...]
First, the simplest definition of density: it is how heavy something is relative to its size. A pound of rocks weighs the same as a pound of ping pong balls. But the ping pong balls take up a lot more space. Hence, the rocks are much more dense. Another way to look at density is [...]