Archives: Summa Amare

Magnetism and the Lunar Eclipse

Magnetism is an entirely separate force despite similarities and it depends more on particular properties rather than simply mass, such as electrons and can both push and pull. Magnetism is present throughout the universe and we can experience it in many ways; when I am out hiking, my compass explains the pressure of magnetism and direction with the movement of the needle as it is attracted by the force.

There are a number of properties and varieties of magnetic forces that explain invisible fields that applies a force that influence objects or material from the magnetism. There are rules that confirm magnetic fields are dipolar and just like earth has both a north and south magnetic pole and the ‘magnetic flux’ explains how the force and attraction between the poles – usually represented by lines as visible in the image below – that can be averaged by the magnetic field and the perpendicular area the field infiltrates. Measurements of the force is determined by the mathematical formula F= qvB (Lorentz Force Law), which is the magnetic force, the charge, the velocity and the magnetic field and the unit of these field are measured in terms of Standard International (SI) units known as tesla.

Earth’s magnetic field is known as a geomagnetic field and magnetosphere the predominate reason for the magnetic field is the liquid iron core surrounding the solid inner core is the source of this phenomenon, the very ‘magnet’ where the electric currents produced by the flow of iron and other metals including nickel cause convection currents from the inertial force of the Coriolis Effect that ultimately splits the field into a surrounding force that envelops Earth and aligns back into the same direction. The changes in temperature and composition of the liquid core creating the currents that rise or sink matter all play a part in Earths magnetic field, that can be captured visually when solar winds collide with it (usually where the magnetic force is much stronger near the north and south poles) and the charged particles trapped by the magnetic field produce the aurora borealis or the aurora australis.


The picture explains the rotational poles but that their alignment geographically differs from our north and south poles on earth, whereby the magnetic south poles resides further north of Antarctic’ South Pole and quite close to the south of Australia while the north magnetic pole is closer to northern Canada and thus south of the North Pole. The magnetic lines explain the streamlined flow of the magnetic field that makes it easier to ascertain the process mathematically. Jupiter has a number of powerful toroidal magnetic fields where the intensity is said to have formed from the dynamic movements of the metallic hydrogen within; the field on the surface of the clouds is almost ten times stronger than earth’s. The Milky Way also has magnetic fields as do galaxies and the universe contains some colossal magnetic fields, where observations of galaxy clusters have found magnetic fields extending millions of light years!

The magnetic force is the attraction or the repulsion (as you experience when attempting to connect two magnets with equal poles) occurs from the magnetic field. The properties of electrical fields (pole) with a positive and negative charge differ with that of magnetic fields (dipole) despite a close correlation, because electromagnetism involves a magnetic dipole producing an electric field as it moves and conversely an electric field can produce a magnetic field meaning the difference is an elementary change in the field. A magnet does not have an electric charge as two separate poles, while a dipole interacts as a charge as visualised in the following image. What this means is that the electrical force itself behaves on a charged particle in the direction of the field and does not need motion while a magnetic force requires this motion and acts perpendicular to the magnetic field.

Gravitational fields also acts as force fields for mass and the gravitational force itself depends on the mass and the mass experiences the gravitational force. The gravitational field has a place in every direction and point in space and known by the formula g = F/m where F is the force of gravity.

Further Reading:

Maurizio Gasperini, Theory of Gravitational Interactions, Springer (2016) 115
Stephen Blundell, Magnetism: A Very Short Introduction, Oxford (2012) 106
Anupam Garg, Classical Electromagnetism in a Nutshell, Princeton University Press (2012) 83

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