About the gas field or magnetic field of the human body?

Magnetic field is a special substance. There is a magnetic field around the magnets, and the interaction between magnets is mediated by the magnetic field. )

A special substance existing in the space around current, moving charge, magnet or changing electric field. Because the magnetism of a magnet comes from current, which is the movement of charge. Simply put, it is to generate a magnetic field by moving the charge or changing the electric field.

The basic characteristic of magnetic field is that it can exert force on the moving charge, and the force or torque of magnetic field on current and magnet comes from this. Modern theory shows that magnetic force is the relativistic effect of electric field force.

Similar to the electric field, the magnetic field is a vector field distributed continuously in a certain spatial area. The basic physical quantity describing the magnetic field is the magnetic induction intensity vector b, which can also be expressed by the magnetic induction line graph. However, as a vector field, the nature of magnetic field is very different from that of electric field. The total magnetic field generated by moving charge or changing electric field, or the sum of the two, is a passive and rotating vector field, and the magnetic lines of force are a closed family of curves, which are uninterrupted and do not cross. In other words, there is no source of magnetic field lines, and there is no tail that converges magnetic field lines. The closure of the magnetic field lines shows that the loop integral along the magnetic field lines is not zero, that is, the magnetic field has a spin field instead of a potential field (conservative field), and there is no scalar function similar to the potential.

Magnetic induction intensity: the number of magnetic lines passing through unit area perpendicular to the direction of magnetic lines, also called magnetic line density, also called magnetic flux density, expressed by B, and the unit is Tesla T.

Magnetic flux: Magnetic flux is the total number of magnetic lines passing through a certain cross-sectional area, expressed by φ, with Weber as the unit and Wb as the symbol. The expression of magnetic flux passing through the coil is φ = b s (where b is the magnetic induction intensity and s is the area of the coil. ) 1Wb= 1T m2

Magnetic field direction: specifies the direction of magnetic field force at a certain point in the magnetic field of the north pole of the small magnetic needle as the direction of electromagnetic field.

Magnetic induction line: draw some curves in the magnetic field so that the tangent direction of any point on the curve is the same as the magnetic field direction of that point. These curves are called magnetic field lines. The magnetic field lines are closed curves. The direction in which the north pole of the small magnetic needle points is defined as the direction of the magnetic field lines. The magnetic field lines around the magnet all come out from the N pole and enter the S pole. Inside the magnet, the magnetic field lines go from the S pole to the N pole.

Electromagnetic field is the medium of electromagnetic action and a unified whole. Electric field and magnetic field are closely related and interdependent. Changing electric field produces magnetic field, changing magnetic field produces electric field, and changing electromagnetic field propagates in space in the form of fluctuation. Electromagnetic wave propagation speed is limited, and energy and momentum are interchangeable. Interaction between electromagnetic waves and objects, mutual transformation between electromagnetic waves and particles, etc. It is proved that electromagnetic field is an objective substance, and its "special" is that it has no static mass.

Magnetic phenomenon is one of the earliest physical phenomena recognized by human beings, and compass is a great invention in ancient China. Magnetic fields exist widely in the earth, stars (such as the sun), galaxies (such as the Milky Way), planets, satellites and interstellar and intergalactic spaces. In order to understand and explain many physical phenomena and processes, we must consider the important factor of magnetic field. In modern science and technology and human life, magnetic fields can be seen everywhere. Generators, motors, transformers, telegrams, telephones, radios, accelerators, thermonuclear fusion devices and electromagnetic measuring instruments are all related to magnetic phenomena. Even in the human body, with the activities of life, some tissues and organs will produce weak magnetic fields. The magnetic level of the earth is opposite to the poles of geography.