One day in the early 17th century, Hans Lippershey, the owner of an optical shop in a small Dutch town, lined up a convex lens and a concave lens in order to check the quality of the ground lenses. , looking through the lens, I found that the church spire in the distance seemed to become larger and closer, so I accidentally discovered the secret of the telescope. In 1608, he applied for a patent for the telescope he made and complied with the authorities' request to build a pair of binoculars. It is said that dozens of opticians in the town claimed to have invented the telescope, but Liebersch is generally believed to be the inventor of the telescope.
In the 18th century, the West began to explore various phenomena of electricity. Franklin, an American scientist, believed that electricity was a weightless fluid that existed in all objects.
The quantitative aspect of electricity began to develop in the 18th century. In 1767, Priestley and Coulomb in 1785 discovered the law that the force between static charges is inversely proportional to the square of the distance, laying the foundation for Basic laws of static electricity.
In 1800, Italian Volta made the first battery by immersing copper and tin sheets in salt water and connecting them with wires. He provided the first continuous power supply and was called The ancestor of modern batteries. In 1831, Faraday in England used changes in magnetic field effects to demonstrate the generation of induced current. In 1851, he proposed the concept of physical power lines. This was the first time that the concept of transfer from charge to electric field was emphasized.
In 1865, Maxwell of Scotland proposed the mathematical formula of the electromagnetic field theory. This theory provided the concept of displacement current. Changes in the magnetic field can produce an electric field, and changes in the electric field can produce a magnetic field. Maxwell predicted the existence of propagation of electromagnetic radiation, and in 1887 Hertz in Germany demonstrated such electromagnetic waves. As a result, Maxwell unified electricity and magnetism into one theory and also proved that light is a type of electromagnetic wave.