Magnets have been in use since the time of Aristotle in 600 BC. Magnets were also being used at that time fos some type of medical treatment in India. The property that iron is attracted by a lodestone has been observed by the Chinese in 400 BC. (Lodestone is a naturally occurring oxide of iron that is magnetized) The notion of making a fine needle of iron and using it to navigate by the Earth’s magnetic field became popular in China around the year 1000. In 1187 Alexander Neckham was the first European to write about the compass and its use in navigation.
William Gilbert in 1600 wrote the first scientific work on magnetism and is credited with the discovery of the Earth’s magnetic field, and that the magnetic field and the difference between the center of the Earth’s rotation from the magnetic center. Gilbert’s work was so meticulous that Galileo credited him with the creation of the scientific method. Gilbert also differentiated magnetic attraction from electrostatic attraction and did a great deal of the first scientific treatment of these forces. The next major work on magnetism and observation of electromagnetism did not take place until the 1820’s when Faraday created the first electric motor.
Magnetism, like electricity, has been one of the most important elements of modern technology, and yet for all out technological sophistication, both phenomena are not very well understood. Magnetism and electricity both have observable rules and we are able to manipulate them to perform useful tasks, but they are still quite mysterious, their “inner workings” tied to atomic forces that today’s most advanced physics have not been able to fully explain.
The technologies made possible by understanding magnetism are everywhere around us. Hard disk drive motors are among the most sophisticated electromagnetic machines in the world today. Digital memory with incredible density is another application of the same. Magnetic resonance imaging the is able to look inside the human body would not be possible with the ability to manipulate magnetism.
We circle the globe, and peer into the details of the human body, yet barely understand what magnetism is. We can postulate and use the magnetic monopole to quantify it, and we can see the effects on permeable materials as they are magnetized and the molecules come into alignment. At the end of the day, it is a technology that still has come mysteries that we need to uncover.
Filed Under: Mechatronic Tips