Earth Science: Physics and Technology – Electromagnetism Gravity-the fact that all objects attract each other in proportion to their mass—is familiar to everyone. In fact, life without it can hardly be imagined. Electricity and magnetism are different; even through the early 19th-century phenomena such as naturally magnetic minerals were scarcely known and not understood. Earth … Read more
Earth Science: The Magnetic Field of The Earth What do a compass needle pointing north, the glowing veils of polar lights and the sense of direction of carrier pigeons have in common? All three are influenced by the invisible force of the Earth’s magnetic field. The Earth’s magnetic field is like a gigantic bar magnet … Read more
Facts At Your Fingertips: Energy and forces – Electromagnetism An electrical current always produces a magnetic field around it. Electromagnets are made by passing electricity through a wire that has been wrapped around a piece of iron. Unlike permanent magnets, an electromagnet loses its magnetism as soon as the electrical current is switched off. How … Read more
Facts At Your Fingertips: Energy and forces – Magnets in action We use magnets in many different ways. The motors inside many machines are driven by small magnets, while large magnets can power trains. Compasses use Earth’s magnetism to show us the way. Electric motors This toy car is powered by an electric motor, which … Read more
Facts At Your Fingertips: Energy and forces – Magnetism Magnetism is a force that can attract (pull toward) or repel (push away). Materials that are strongly attracted to magnets, such as iron or nickel, are called ferromagnetic materials. Some magnets are permanently charged with magnetism, while others are only magnetic when they are inside a … Read more
