The short answer is that there is no set limit that is rigid for a magnetic field strength. But some interesting things will start to happen when magnetic fields reach a high strength.
How does a magnetic field work?
A magnetic field will act in a way that exerts its force sideways onto a moving electric charge. This will cause it to turn sideways. This turning will continue for as long as the magnetic force is on and will in turn cause the electric charge to move in spirals.
An electric charge will then act like a permanent, oriented magnet, meaning that it will be repelled from the region that has a high magnetic field gradient.
This means that electric charges will mostly tend to spiral around lines of a magnetic field and are therefore pushed away from areas of collective and bunched together magnetic field lines.
The combination of these two effects will cause electric charges to become trapped along the magnetic field lines if they are strong enough.
This effect can be seen in earth’s ionosphere, where ions become trapped. As well as radiation becoming trapped in the belts of radiation of earth. And an example that is not on earth is the plasma that will loop over the surface of the sun in solar prominences.
What happens when the magnetic field gets stronger?
When a magnetic field gets stronger it simply means that the electrical charge will be more violently pushed to the side. This means it will spiral tighter and even faster.
It also means it will be pushed further from the areas of high magnetic field gradient. What happens to objects when this occurs can be very interesting.
A strong enough magnetic field could actually pull apart an object since call objects are made up of atoms. Atoms are made up of electric charges thanks to protons and electrons.
How strong can magnetic fields get?
Objects will get ripped apart when a magnetic field reaches around 500,000 Gauss (a unit of measurement). The objects are getting ripped apart due to the intense forces that are present in the atoms of the objects themselves.
This means that a machine designed to create a magnetic field can never be allowed to create one greater than 500,000 Gauss, since it will be pulled apart by its own creation.
If a machine was created that made a magnetic field greater than 500,000 Gauss, it would only survive around a fraction of a second before breaking apart.
So, there is a limit?
Although there is a limit of 500,000 Gauss, this is only a limit set by practicalities of working in the field of magnetic fields. This is a limit that has to be adhered to in order to stay safe around the heavy machinery and anything else that it near the machine that creates the magnetic fields.
But there is still a fundamental limit. The 500,000 Gauss limit does not apply when it comes to actual limits. There is a level of around a billion Gauss where an atom will be compressed to a tiny needle.
This destroys existing chemical bonds that will usually bind atoms together into molecules. This bonding makes chemistry possible.
Compressed to a needle?
This refers to the shape that the atoms become. They are compressed into tiny needles because the electrons are pushed into spinning in circles by the magnetic field.
But do not worry, this is only really possible in highly magnetized stars. These stars are called magnetars and are a type of neutron star that is the left-over product of a supernova.
Predicted theoretical effects of magnetic fields that could be stronger
This section will list some of the theories of the effects of very strong magnetic fields that some scientists have predicted. These are obviously predictions, but predictions based on informed research and experiments in the field.
- ‘Magnetic lensing’ – in which a very strong magnetic field would cause images to become magnified and even distorted. This prediction suggests that the way the eye or a lens would interpret light would be affected by a magnetic field.
- A strong magnetic field could, theoretically, cause photons to split in a rapid fashion and even merge with each other. Another prediction that involves light and the way that it could be affected by a strong magnetic field.
- Could distort atoms into a long and tubular shape. This prediction is based on the idea that a weaker magnetic field will cause atoms to compress into a needle-like shape.
- The final prediction is that an extremely strong magnetic field could cause the vacuum itself to become unstable. Since space is not a complete vacuum, but we tend to call it one, this prediction is the most interesting.
What is the most extreme thing that could happen?
Theoretically, a strong enough magnetic field could potentially cause the formation of a black hole. According to General Relativity, mass and energy will bend spacetime, meaning that if there is enough energy in one area, you could bend spacetime in a way that forms a black hole.
We do not know if this is possible yet, because there is not a way for us to know if there would be another factor inhibiting a magnetic field from becoming that strong.
So, is there a limit to the strength that a magnetic force can be?
According to some theories, there might be a limit to the strength that a magnetic field can reach. This is based on the theory that when a magnetic field becomes too strong, monopoles may be created out of the vacuum.
This means that the magnetic field would be weakened and not be allowed to get any stronger than it is. But this theory is rooted in mystery since scientist are not even sure that monopoles exist.
Therefore, we cannot for sure say that there is a measurable limit to how strong a magnetic field can become.