Magnets were one of the first natural forces to be discovered by humans. Their history dates back to the 4th century BC when Chinese literature referred to the attraction between iron and lodestone. Lodestone is a natural permanent magnet, meaning it creates its own magnetic field; this is what attracts the iron, which is an “induced” magnet i.e. it becomes temporarily magnetized when it comes into contact with a permanent magnet. A ferrofluid is an induced magnet in liquid form; the liquid becomes magnetized in the presence of a magnetic field.
There have been many uses for magnets throughout history, most of which have been developed as modern technology has advanced. It is said that Cleopatra slept on a bed made from lodestone for years in the belief that its magnetic properties slowed down the ageing process. While science has not been able to prove a connection between magnets and a youthful appearance, magnets are still used today within alternative medicine as treatments for many common health complaints. Many sportsmen and women use tectonic magnets to relieve pain and inflammation from sporting injuries. Alternative health practitioners may place warm lodestones on a patient’s back, as they believe that they help realign the spirit and promote a greater sense of wellbeing. Medical science regularly uses magneto encephalography to monitor brain activity and magnetic shock therapy to kick-start a stopped heart.
Many NASA experiments into the altitude control system of a spacecraft have used magnets and ferrofluid. In modern medicine, ferrofluids are used within cancer detection processes and there is ongoing experimentation with different cancer treatments using magnets ad ferrofluids, such as magnetic hyperthermia, based on the heat that is released from a ferrofluid when it is placed in an alternating magnetic field. Further research is needed to establish the true potential of magnets in the world of medicine.
A remarkable recent invention based on the power of magnets is the MAGLEV (magnetically levitated train). This train levitates above the single rail train track, virtually cutting out all friction and wear and tear on both the train and the track. This makes extremely high speeds possible; a bill signed by the former President Bush in 2008 supported the creation of the first MAGLEV train, which is to travel between Las Vegas and California. The magnetic technology will allow passengers to complete their journey at a speed of close to 300 miles per hour and reach their destination in a little less than two hours, around half the time the trip would take if going by car.
As modern technology continues to advance at an incredible rate, it seems likely that we will continue to discover new uses for magnets, both in our daily lives and as part of exciting modern inventions.