The idea that Earth is a magnet is far from new. It was first proposed in 1600 by a British physician named William Gilbert. Knowing it acts like a magnet is one thing. Knowing why it acts like a magnet is more difficult. In fact, finding out why is a fairly recent discovery. To find out why required new technology. It was the seismograph that made it possible to learn why the Earth acted like a magnet. Seismograph are used to study earthquakes. By studying earthquake waves they were able to learn about Earths interior. They discovered that Earth has an inner and outer core. The outer core consists of liquid metals, mainly iron and nickel. Scientists think that Earths magnetic field is generated here. It is caused by the motion of this liquid metal. The liquid metal moves as Earth spins on its axis.

How did they learn why the Earth acts like a magnet?

Comanche Indians have trapped the evil of their land in a monster made up of a mixture of other animals . The Comanche have placed a protective spear in the ground to contain the evil . A young boy pulls the spear from the ground while pocketing a rabbit foot talisman . He starts to play with the spear . A Comanche catches the boy , and startled , he runs away with the rabbit's foot . The Native American places the spear back , realizing too late that the rabbits foot is now gone . After that , white men come and start drilling for oil . Skip to current time , a divorced father , Mance Cashen , moves to the area with his new wife , baby , and his son from his first marriage , Willy ( played by ( ( Chris Miller , who is visiting . Willy notices something peculiar in the house and tries to warn his father and step-mother . They do not believe him . Willy is attacked while on a tire swing over a small water hole . The creature grabs his foot and Willy struggles , eventually getting away . He eventually befriends the local drunk , T. C. van Houten . A nice old man with some bad memories who knows something about the evil near the oil well and was in a situation similar to Willy's . In the meantime a Comanche Indian , Chief Sam John , comes to warn Mance of the evil and the need to keep it contained . Sam John informs Mance the evil was originally intended to stop the white man , but it is indiscriminate in whom it kills instead . Mance will have none of it . Willy eventually takes a spear he finds on his property to Sam John and tries to find out what is going on .

Who befriends T. C. van Houten?

Sound waves are mechanical waves. They can travel only through matter. They cannot travel through empty space. This was demonstrated in the 1600s by a scientist named Robert Boyle. Boyle placed a ticking clock in a sealed glass jar. The clock could be heard ticking through the air and glass of the jar. Then Boyle pumped the air out of the jar. The clock was still running, but the ticking could not be heard. Thats because the sound couldnt travel without air particles to transfer the sound energy. Is there any other place where sound cannot be heard? Here is a hint: is there any other place that does not have air molecules? Thats right, in space sound cannot be transferred. So can astronauts hear each other? Yes, they can, because they are in enclosed space stations or pressurized suits.In both cases, they are surrounded by air molecules. If they left their space ship and did not use their electronics, they would not be able to hear each other. Next time you watch a science fiction movie, think about this factoid. When spaceships are destroyed by hostile alien beings, there would be no sound heard. Sound waves can travel through many kinds of matter.
Can sound waves travel through empty space?