On the subject of interesting magnetic effects, a lot of people don't know that pretty much all matter is magnetic, just that the strength of the interaction is a lot smaller than what we're used to with ferromagnets.
All materials exhibit a diamagnetic (pushes against the field) effect, but in many materials, that effect is overwhelmed by a competing paramagnetic (pushes in the direction of the field) effect. Most of the things we call "magnets" exhibit ferromagnetism, which typically produces much stronger forces than either of the previous two.
H2O is particularly interesting, because it's actually diamagnetic, and will push away from magnetic fields. Given a strong enough magnet, you can have a lot of fun with this effect by putting common water-filled objects in its field:
http://www.ru.nl/hfml/research/levitation/diamagnetic/
I don't think any of these examples actually imply anything about whether aluminum is "magnetic" (for any definition of magnetic).
All the demonstrations rely on a changing magnetic field, either because the magnet is moving, or because the aluminum is moving. This induces an electric field in the aluminum (as it would in any conductor) which moves the aluminum, induces a magnetic field which moves the magnet, etc., but is independent of whether aluminum is ferromagnetic, paramagnetic or diamagnetic.
The one thing I really took away from this (and unfortunately not entirely relevant) is that American English also has it's own SPELLING of Aluminium, not just pronunciation.
It makes the difference in pronunciation make a lot more sense to me. Are there (m)any other cases of this, where both the spelling and pronunciation are different? Leisure, herbs, etc.? (Lift/Elevator doesn't count)
[+] [-] dkhar|11 years ago|reply
All materials exhibit a diamagnetic (pushes against the field) effect, but in many materials, that effect is overwhelmed by a competing paramagnetic (pushes in the direction of the field) effect. Most of the things we call "magnets" exhibit ferromagnetism, which typically produces much stronger forces than either of the previous two.
H2O is particularly interesting, because it's actually diamagnetic, and will push away from magnetic fields. Given a strong enough magnet, you can have a lot of fun with this effect by putting common water-filled objects in its field: http://www.ru.nl/hfml/research/levitation/diamagnetic/
[+] [-] snarfy|11 years ago|reply
http://physics.weber.edu/schroeder/mrr/MRRtalk.html
This video also talks about it: https://www.youtube.com/watch?v=1TKSfAkWWN0
[+] [-] pranjalv123|11 years ago|reply
All the demonstrations rely on a changing magnetic field, either because the magnet is moving, or because the aluminum is moving. This induces an electric field in the aluminum (as it would in any conductor) which moves the aluminum, induces a magnetic field which moves the magnet, etc., but is independent of whether aluminum is ferromagnetic, paramagnetic or diamagnetic.
[+] [-] PaulHoule|11 years ago|reply
[+] [-] k_sze|11 years ago|reply
Electromagnetics is awesome, nonetheless. :)
[+] [-] delbel|11 years ago|reply
[+] [-] JonRB|11 years ago|reply
It makes the difference in pronunciation make a lot more sense to me. Are there (m)any other cases of this, where both the spelling and pronunciation are different? Leisure, herbs, etc.? (Lift/Elevator doesn't count)
[+] [-] Hoff|11 years ago|reply
[+] [-] jmount|11 years ago|reply