Water displacement through diamagnetism – did Moses know about this?
Online since: 03/01/2008, Number of visits: 77331
In this video, I want to demonstrate the effect of diamagnetism. Diamagnetism refers to the behaviour of a material to create an inner magnetic field that is directionally opposite to the outer magnetic field. It is a property of all matter. But it can only be observed in materials where the diamagnetism is not masked by paramagnetism (strengthening of the outer field through inner processes) or by ferromagnetism. Diamagnetism is very weak compared to the other types of magnetism.
Particularly diamagnetic materials are copper, bismuth, gold and silver. (Source: Stöcker, Taschenbuch der Physik, 5. korrigierte Auflage 2004 [Stöcker, Pocketbook of Physics, revised 5th edition 2004])
Bismuth has the strongest diamagnetic properties (Source: Wikipedia).
My video shows four stacked magnets Q-20-20-10-N. So the entire stack is easier to hold, a small piece of metal (in this case an iron knife) was placed between the second and third magnet.
The magnets were positioned over a glass bowl filled to the rim with water. The distance between the water surface and the bottom of the magnets is about 1 to 2 mm. The camera was positioned in front of the glass bowl, with the view angled slightly upwards towards the surface of the water from beneath. At this shallow angle total reflection exists, thus excluding the possibility that the observed effect could simply be a reflection of the magnet's underside.
A white piece of paper was laying on the table behind the glass bowl (not directly visible, only in the reflections of the water). Behind the glass bowl and directly behind the paper stands a dark-green background (the lighting reflects in it).
When the magnetic field gets close to the water surface, a small indentation emerges. This indentation is only indirectly visible: Because the smooth surface of the water reflects the dark background and the small bulge reflects the white paper, it is clearly visible that the water surface has been distorted.
To prove that this effect is not caused by the magnets touching the water, the magnets were purposely brought into contact with the water surface. Immediately, the underside of the bottom magnet becomes visible.
The movement of the magnets above the water shows that the effect is only caused by the positioning of the magnets.
Further research showed that this water displacement effect is stronger in inhomogeneous magnetic fields than in homogeneous ones, such as used here. The effect could be increased through the use of stronger magnets. An inhomogeneous field would further increase the effect.
At this point, I would like to stress that Moses did not use this method to part the waters of the Red Sea. A strong-enough magnetic field would likely only be created in (neutron) stars.