It is said that Albert Einstein, as a child, was amazed to observe how the needle of a compass moved. He immediately wondered what that magical force was like that moved the little needle without being detected by his senses. This experience led him to become interested in the study of nature, particularly in physics.
Who has not been amazed as a child by this phenomenon? Many times adults tell us "this movement is due to magnetism" and with that our curiosity is satisfied, but not the minds of many men who have begun to deeply investigate the nature of the magnetic force.

2.1 What is magnetism

The term magnetism comes from the city of Magnesia on the Meander, in ancient Anatolia where this phenomenon was first noticed by Thales of Miletus. Certain types of stones have the property of generating a magnetic field in a natural way, as is the case with magnetite, this intrigued the ancient sages who soon discovered the healing properties of magnets.
Modern science¹ has discovered that electricity and magnetism are closely related, in fact they form a single phenomenon: electromagnetism. Each electrically charged particle, no matter how small, when moving generates a magnetic field around it.

An electron, which is a subatomic particle with a small negative charge, by rotating on its own axis (spin) is already generating a tiny magnetic field. Thus we can understand that each atom, of the billions that make up all the matter that surrounds us, has its own magnetic field.
So why aren't all elements magnetic?
This is because in most elements and compounds each atom rotates independently. In other words, we have disordered magnetic fields, or to put it another way: each atom has its magnetic field randomly oriented. Which causes the magnetic fields to cancel each other out resulting in an imperceptible magnetic field. In the case of magnetized materials, a large part of their atoms are aligned in a single direction and this causes a resultant force, the effect of which is a magnetic field that we can perceive in the macroscopic world.

2.2 Universal law of charges

So a magnetic object, no matter how small it is (an electron) or no matter how large it may be (a black hole), generates a magnetic field around it where a series of magnetic lines are generated that go from one pole to the other. The number of magnetic lines increase in direct relation to the intensity of the magnetic field, so when we talk about magnetic intensity, which is measured in Gauss, we are really talking about magnetic lines.
Magnetism is based on a simple universal principle that says: like charges repel, unlike charges attract. This is the basis for understanding chemical reactions and many other phenomena where electrical charges are involved.

2.3 Types of magnets

• Natural magnets. They are materials such as the stone called magnetite in a natural way, probably as a result of the electric discharge of a lightning, it was magnetized and has been able to conserve that magnetism, so they can also be considered permanent magnets.
• Permanent magnets. They are materials (metals) capable of maintaining their magnetic field permanently. This is because its atoms can stay aligned in only one direction, generating a magnetic field. They can usually maintain their magnetic field indefinitely, as long as they are not altered by high temperatures.
• Permanent magnets with inductor. This is a type within the group of permanent magnets. We can find them in electronic devices such as old televisions or speakers. They are composed of a donut-shaped ferrite magnet and have an inductor made of another metal in the center. The particularity that these magnets have is that they present both polarities on their two faces. The characteristic of the magnetic field along the surface of the magnet varies depending on the shape of the magnet.
• Paramagnetic material. They are materials that are attracted by a magnetic field and only retain their magnetic property while they are within a magnetic field, this is the case of some metals such as aluminum, magnesium, titanium, tungsten, and so on; but once they are no longer under the influence of a magnetic field they lose their magnetism.
• Diamagnetic materials. They are those capable of repelling magnetic fields, some examples are: water, metallic bismuth, hydrogen, helium and other noble gases, sodium chloride, copper, gold, silicon, germanium, graphite , bronze and sulfur.
• Electromagnets. It is about materials (metals) that generate a magnetic field only while there is an electric current flowing in them, this is the case of electric coils found in all electric motors and generators. Once the electric current stops, the magnetic field disappears.

2.4 What type of magnets are used in the Biomagnetic Pair

At present there are devices that allow the creation of magnetic fields of very precise frequencies and intensities. Or, they generate pulsating magnetic fields that can have beneficial effects on health. They are frequently used in the so-called magnetotherapies, helping the regeneration of muscles, ligaments and bones.
Expensive and sophisticated devices are not required for medical biomagnetism. The biomagnetic pair uses permanent magnets of medium intensity, greater than 1500 Gauss. The metals most frequently used in biomagnetism are ferrite and neodymium. These types of magnets are inexpensive, practically within the reach of any pocket. Also, if lined and treated with care, they can last indefinitely.

Ferrite magnets are the cheapest. It is recommended to line them to prevent them from breaking; and also because it is more comfortable and safe to use.
Neodymium magnets can pack more power into a smaller size, leading some therapists to prefer them.
Actually, for practical purposes there is no difference between the two materials - ferrite and neodymium -. Any of them can serve in the same way, as long as the power of the magnet is greater than 1500 Gauss and less than 5000. A power greater than 5000 Gauss is unnecessary and, on the contrary, can cause undesirable effects. First, given their greater power, the magnets have to be handled with greater care to avoid bruising or pinching the therapist's fingers or any part of the patient's body. They can also alter organs and tissues if they are left in the body for too long - more than 15 minutes. Special care should always be taken when placing magnets on the face and near the eyes. Since they do not provide greater benefit in terms of the practice of biomagnetism, it is recommended not to use magnets of higher power than 5000 Gauss.

2.5 How to identify the polarity of a magnet

As we saw previously, every object with an electric field produces a magnetic field, from an electron to planet Earth or a star. They all have a positive pole (+) and a negative pole (-) and the magnetic field flows continuously between one pole and the other. The same goes for a permanent magnet. To be useful in biomagnetism, the magnet is required to have a positive and a negative side. You can identify the polarity of a magnet in several ways:

1. By using another magnet already identified, following the rule of: like poles repel, unlike poles attract.
2. Using the Earth's magnetic field. You can suspend the magnet from a string or float it on water (with a cork) to see where their faces line up.



3. By intelligent muscle response^*: First extend the arm of a person and measure their strength, trying to lower his arm pressing two fingers on her wrist. Place the magnet on her shoulder (deltoid muscle). The arm will lose strength when the negative pole of the magnet is placed in contact with the person's shoulder. If the strenght remains the same it means you are placeing the positive pole in contact with the body.



4. Using a smartphone. This is one of the easiest way to identify the poles of a magnet. Almost all smartphones can detect magnetic field, this is used in application such as Waze or Google maps. First you must download some digital compass application. Once installed enter the application and place the magnet close to the smartphone, inmediatly you will see how the compass moves in the screen. If the red side of the arrows point to the magnet it indicates that is the the north pole. If you rotate the magnet 180° you will see that the arrows rotates to the other arm.

Once the polarity of the magnet has been identified, it is marked or lined. We will always use red to designate the face or side of the magnet with the positive pole (+), and black to designate the negative pole (-). Lining the magnets is the most convenient, so they will be protected (especially ferrite ones) and will be safer and more comfortable to use.

2.6 Care of magnets

The biomagnetic pair can be practiced with just one pair of magnets. In fact, it is advisable to have a pair of magnets on hand, especially when one goes on a trip they can be very useful in case of an emergency, headache, fatigue or even in case of contracting an infection. But to give a biomagnetism session you can use up to 6 pairs of magnets, that is a total of 12. They can all be the same size or you can buy 2 or 4 smaller magnets and reserve them for the face and eyes .

It is important to line the magnets to use them more comfortably and to avoid accidents (bruises). Also to protect ferrite magnets that can chip or break with a blow. Of course, they can also be obtained already lined through the internet (we do not sell them). So if you already have them lined you can skip to the next lesson.
Leather or synthetic vinyl imitation leather can be used to cover the magnets, other materials such as fabric can be less durable and difficult to wash, so they are not recommended.
The colors that are conventionally used are red for the positive pole and black for the negative pole. You must already have identified the polarity of the magnet following one of the methods that we explained in the previous section. You can line the magnets by sewing the covers, for which you will need a thick needle and thread, as the material is quite thick.
The most common is to glue them using contact adhesive. First clean the magnets well with water and detergent or some soap to remove dust and grease. Next, glue the positive side of the magnet and the red lining. Wait a few minutes, as indicated by the glue instructions, and then glue and press the lining with the magnet. Next, glue the rest of the magnet and the black side of the lining. Again, after waiting another few minutes, glue the black lining, trying to eliminate all the air so that the linings have the greatest contact with the magnet. Finally, with scissors refine the contour of the linings to give it a better finish. With this procedure you can simultaneously line several magnets or go one at a time.
The small investment of time in lining the magnets will pay off in an extraordinary work tool that can last for years.

 

 

---

1 Faraday discovered through various experiments that both electricity and magnetism were a single phenomenon; and a few years later, in 1865, the physicist and mathematician Clerk Maxwell developed the equations that mathematically express the electromagnetic phenomenon.
Watch the video: Chapter 3: Magnetism and biomagnetism.

* Later on, we will see in more detail what intelligent muscle response consists of.

 

Next Lesson