There is magnetism all around us, yet it remains invisible to the naked eye.
One of the most prominent examples of magnetism can be observed in the giant magnetic field that envelops our planet, Earth.
We will use iron filings to see the magnetic field in 3-dimension. By sprinkling these filings around a magnet, we can visualize the magnetic field in three dimensions.
(Here’s an example on 2-dimensional magnetic force field.)
Magnetic force can permeate through materials, such as paper, cellophane, plastic or glass.
As the iron filings align themselves with the force field of the magnet, they spread out and create a visual outline of the magnetic field in three dimensions.
Try this magnetic field experiments.
Warning: Magnets are very hazardous if swallowed. Please keep them away from children who still put everything into their mouths.
- a few strong magnets (neodymium magnets, a rare earth metal, are very strong magnets)
- iron filings
- adult supervision
- a clear bottle (can be glass or plastic)
- Tape the strong magnets on the opposite sides of the bottle. Make sure the opposite poles are facing each other (e.g. N with S, or S with N).
- Poor iron filings into the bottle and then close the cap.
- Rotate the bottle so that iron filings are stuck on both sides of the bottle where the magnets are.
- Observe how the filings move and distribute.
- Move the bottle to another position and see how the iron filings move with it.
- If you don't have a clear bottle, you can also use a piece of paper or in our case, we used a sheet of cellophane at the beginning. It's also spectacular since you can see it up close.
So what you see is the outline of the 3-dimensional magnetic field.
But there is another force at play in this experiment, which is gravity.
By rotating the bottle, we can observe the iron filings moving around, responding to the change in gravitational force.
This adds an extra layer of complexity to the experiment, making it a fascinating study in the interplay between different forces.
Magnetism is a crucial aspect of understanding the world around us. Even though it is invisible, it is constantly present and its effects can be observed in a multitude of ways.