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Q:
i have heard of the moses effect where a really powerful electromagnet was placed in a tube with water. when the magnet was turned on, all the water moved away from the magnet. i have 2 questions about this
1: if the polarity was reversed, would the water move towards the magnet?
and 2: is it the hydrogen in the water, that makes it magnetic? and if so, does that mean everything containing hydrogen is potentially magnetic?
- joel (age 14)
st. catharines ontario canada
A:
Joel-
Things that move away from magnetic fields are called diamagnetic.
Many ordinary materials (including water, it sounds like) are weakly
diamagnetic. Superconductors are very strongly diamagnetic. To answer
your specific questions:
1. No, changing the polarity of the field won't matter. The weak
magnetism induced in the water by the magnetic field will also change
polarity, and thus will still repel the field.
2. No, it's not specifically the hydrogen that gives this effect.
Nearly all materials have some background diamagnetism (it's caused by
the way the quantum mechanical states of the electrons are changed by
magnetic fields ) but some materials also have stronger magnetic
effects which cause them to be pulled into fields (paramagnetism). The
paramagnetic effects come from little magnetic parts (often, electrons)
which line up in a field to lower their energies, and thus get sucked
into the field. In most materials, the electrons are in pairs whose
magnetism cancels, eliminating that source of paramagnetism. The
hydrogen nuclei (protons) are actually very weakly paramagnetic at room
temperature, so they slightly reduce the net diamagnetism.
Mike W.
(published on 10/22/2007)
Follow-up on this answer.
