As build a compass at home and with few materials? The answer could surprise you (it's very simple!) And, above all, it could make your children happy, looking for a tool of adventure and creativity. But what do you need to build a compass? And how to proceed without making mistakes?
How to build a homemade compass: instructions for making a DIY compass with a needle, a cork and a magnet. Here's everything you need to build amagnetic field. What is a magnetic field? We will also explain this to you.
What it takes to build a compass
Let's start with what you need to be able to build a compass. The ingredients are simple: a cutter, a cork, a needle, a magnet it's a bowl. Considering that the first experiment may not be as exciting and effective as expected, try to stock up on corks and needles: in this way, after a first test, you can build your new compass in a better version!
The cork disc
Having clarified the above, the first step is to create the cork disc. With the cutter, cut a cork disk from the cork, trying to obtain a thin washer. If you don't have a cork stopper, another floating material, such as a piece of polystyrene, will do.
Once this is done, take a pen or a thin-tipped felt-tip pen, and draw four cardinal points on the cap.
Build the compass with a needle
Once you've made your base, all you have to do is magnetize the needle, which will be the pivot of yours compass. To do this you simply have to rub it on a magnet, going to rub its tip on the magnet at least fifty times, always in the same direction.
The operation must be carried out every time you need to use your compass. It is not really the best of comfort but ... it is a small sacrifice that you can certainly support in order to create a beautiful do-it-yourself compass with which to amaze your little ones, and more!
Having also overcome the above, proceed to insert the needle into the cork washer, in such a way that it enters at the south in order to be able to exit where you have indicated the north. It is also important to make sure that the part protruding to the south is identical to that of the north.
Put the DIY compass into operation
Once this is done, all you have to do is put your compass into operation. Take a bowl and fill it with water. Then, place the cork washer on top with the needle passing from side to side. The latter should align with the Earth's magnetic field, "magically" indicating the north!
What is the magnetic field?
But what is the magnetic field, towards which our compass points?
In summary, the magnetic field of our Earth is a sort of straight "magnet" that is ideally located at the center of the Planet, and is inclined by about 11 degrees with respect to the Earth's axis. On what "moves" the magnetic field, there are still important aspects of uncertainty: however, it is thought that different electric currents that run through the outer core are able to exert this force, resulting in a magnetic field of similar magnitude
Hence, the further consequence: where did the electric current which is supposed to be able to traverse the outer core? Also in this case, we can only rely on some hypotheses. In particular, the outer core should be rich in iron and, therefore, an element capable of playing the role of a good conductor for electric current. Being mixed by convective movements, the material from which it is composed makes continuous circular movements, going up and down.
It is therefore possible that the Earth went through a magnetic field, probably of solar origin, while the convective motions were taking place in the outer core: by interacting with the moving fluid iron, this scenario would have been able to generate the Earth's magnetic field, which in turn would be able to feed itself through currents electric, in a chain path that maintains itself.
Among the most curious effects of this magnetic field there is also the possibility of influencing a needle charged with magnetism after being rubbed on a magnet: you will therefore see the cork move in the bowl of water, with the "charged" tip that will be directed towards the north of the Earth!