Giant Magnetoresistance Effect Responsible for iPod

Can you imagine a world with out iPod's? As the world becomes more and more technogically advanced and dependent, it would be hard to think of a world without iPod's and mp3 players.



The interesting thing is that without a relatively new finding by two physicists, this could have been a possibility. Albert Fert and Peter Grunberg received the Nobel Prize in Physics for their work in the discovery on how to influence thin layers of atoms magnetic and electrical properties so that they can store large amounts of data on miniature discs.


Albert Fret


Peter Grunberg

iPods and mp3 players record data such as music, videos, and games as magnetic combination of zeros and ones, which is scanned by a small head and converted to electrical signals. Together Fert and Grunberg discovered an effect that Fert termed as giant magnetoresistance. Giant magnetoresistance allows for large changes in electrical resistance with only miniscule changes in magnetic field. Because the data is converted to electrical signals, and giant magnetoresistance can increase electrical resistance, more data can be put onto the iPod or mp3 player.

The link below is from a website designed by IBM. It is a animated video that breaks down the basics of the hard drive used to copy data. It includes the analysis of the small head that converts the scanned data to electrical signals.


This link is completely designated for the giant magnetoresistance effect. Within the link, there are eight videos with descriptions explaining the effect. It is very helpful in understanding the effect.


The head, which scans the data to convert it to electrical signals, is made up of layers of magnetic iron and nonmagnetic chromium. Fret and Grunberg found that by minimizing the thickness of these layers, there can be an enhanced sensitivity to magnetic fields. This enhanced sensitivity to magnetic fields, is the giant magnetoresistance effect.

I am currently planning on becoming a physical therapist. I have observed many physical therapists who have said that the biggest problem in physical therapy is getting their injured patients to do the proper exercises and to stay active despite their injury. From my own experience, having music on in the weight room and listening to my iPod while running motivates me to keep working hard. I believe that with the discovery of the giant magnetoresistance effect, it is now easier for injured patients to workout and stay active because they can go on walks with their iPods and stay motivated to become healtier and prevent future injury.

This is a link to a website that explains how listening to music makes it easier to exercise longer.


Take care!
Ryan