The document discusses how the iPod is able to store a large amount of data in a small space. It explains that giant magnetoresistance (GMR) allows for data to be read from tightly packed disks through the use of sensors. By controlling electron resistance through magnetic fields, more information can be stored in smaller areas. The discovery of GMR by Albert Fert and Peter Grunberg made portable devices like the iPod possible by allowing large storage capacities in small devices.

1. THE IPod

2. How does it work ?!?!

3. HOW IS IT SO SMALL?

4. WHERE DID ALL THE INFO GO? IT’S NOT BACK HERE!

5. 160GB =160 X 10^9 bytes

6. THAT’S MORE THAN THE NUMBER OF HUMANS WHO HAVE EVER BEEN ON THE FACE OF THE EARTH… EVER! IN HERE http://www.prb.org/Articles/2002/HowManyPeopleHaveEverLivedonEarth.aspx

7. IF EACH BIT WAS A RULER AND YOU TOUCHED THEM END TO END. http://neo.jpl.nasa.gov/glossary/au.html

8. YOU COULD TOUCH A STAR IN THE CONSTELLATION CENTAUR! http://www.astro.wisc.edu/~dolan/constellations/constellations/Centaurus.html

9. AND STILL HAVE ENOUGH TO BUILD A BRIDGE OF RULERS TO PLUTO THAT WOULD BE 1,642 RULERS WIDE. http://www.physlink.com/education/askexperts/ae498.cfm

10. AND THEN SOME, ALL IN THE BOTTOM HALF OF THE IPOD

11. ? ? HOW DO THEY DO IT? ? ? ?

12. GMR ACRONYM= BIG CONFUSING WORD GIANT MAGNETORESISTANCE SCREAMING IS APPROPRIATE

13. SIMPLY Let’s think about a sandwich

14. THE BREAD IS MAGNETIZED IN THE SAME DIRECTION, THE PB&J IS NOT

15. NOW, THINK ABOUT SHOOTING ELECTRONS THROUGH THE SANDWICH! e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- ----- ----- BUT WHAT HAPPENS IN THE SANDWICH?

16. ABSTRACT IDEA WARNING!!! OK, SO ELECTRONS HAVE THIS THING CALLED SPIN. http://www.ahajokes.com/cartoon/sharp_edges.jpg

17. KIND OF SIMILAR TO A TOP, THEY SPIN, BUT NOT ALL IN THE SAME WAY. OB

18. SOME WILL SPIN IN ONE DIRECTION TO THE MAGNETIC FIELD OTHERS WILL SPIN IN ANOTHER DIRECTION TO THE MAGNETIC FIELD www.pepperspollywogs.com/blog/wp-content/uplo

19. THE ANTI- PARALLEL THE PARALLEL

20. THE TWO PIECES OF BREAD ARE MAGNETIZED IN THE SAME DIRECTION NORTH TO NORTH SOUTH TO SOUTH

21. THE ELECTRONS THAT ARE PARALLEL WILL PASS THROUGH WITH LITTLE RESISTANCE SOME OF THE ANTI-PARALLEL ELECTRONS WILL WILL BE DEFLECTED, BUT OVERALL LOW RESISTANCE N N S S

22. BUT WHAT IF YOU FLIP ONE SIDE OF THE SANDWICH UPSIDE DOWN? N S S N

23. THE TOTAL RESISTANCE WILL BE HIGH WHY? http://mylifecomics.files.wordpress.com/2010/02/confused-face2.jpg

24. THE MAGNETIC FIELD DEFLECTS BOTH TYPES OF SPIN FEWERGO THROUGH THE SANDWICH

25. It is very similar to a goalie on his game Except the pucks are electrons http://2.bp.blogspot.com/_VrRxdJj53Js/SYXgP_C7p3I/AAAAAAAABKs/m8Eow4obCrQ/s1600/S0131no_call_w.jpg

26. But in a parallel field the goalie might be having an off night http://www.boston.com/community/photos/raw/davis_goalie.jpg

27. YOU CAN CHANGE THERESISTANCE OF ELECTRONS COMING OUT OF THE SANDWICH IN ENGLISH!!?!?

28. If you can change it You can control it http://sciencegeekgirl.com/files/2008/07/641px-mad_scientist_transparent_backgroundsvg.png

29. HOW DOES THE I POD FIT INTO THIS ? A BETTER QUESTION IS, HOW DOES THIS FIT INTO THE IPOD? http://irononstation.com/Merchant2/graphics/thumbs/ironon/spiritual/spiritual4.jpg

30. With special sensors, and using GMR effect, a computer is able to read tightly packed information on hard disks. THAT MEANS MORE INFORMATION IN A SMALLER SPACE!

31. 1981 vs 2010

32. 2010 1981 ; http://www.techrivet.com/resources/images/GigabyteComparison_20yago.jpg

33. Without GMR the IPod would be about the size of a truck Plus that giant rock. http://farm4.static.flickr.com/3478/3458191128_bbc3b9745f.jpg

34. You can thank : Albert Fert http://www2.pictures.gi.zimbio.com/Nobel+Prize+Winners+Honoured+Elysee+Palace+0iwkxqDKptAl.jpg

35. & Peter Grunberg http://nobelprize.org/nobel_prizes/physics/laureates/2007/grunberg_museum_photo.jpg

36. The 2 who discovered the GMR effect With out them life sure would be different. Cave man IPod IPod http://jelinek-art.cz/images/vedecke/vr020.jpg