The Sun’s magnetic field reverses every eleven years. There have been a quartet of a million reversals since predecessor Homo Habilis emerged and they haven’t killed us yet - Jocelyn Bell-Burnell
Sometimes the best way to answer a question or questions is as directly as possible. Is there a limit to how strong a magnetic field can be? The shortest, and simplest answer to the question, is no.
There is absolutely no limit to how strong a magnetic field can be, but the stronger a field is, the stranger things around that magnetic field can and do get.
What Is A Magnetic Field?
A magnetic field is, quite simply, an area around a magnet that creates magnetic force.
However, the magnetic fields that most astrophysicists refer to when they talk about them are created by moving electric charges that create planetary and solar magnetic fields that can trap ions, radiation, and an atmosphere within the area surrounding a planet.
Earth’s magnetic field is mostly generated by the moving electrical current created by its liquid outer core, and without it, our planet wouldn’t have an atmosphere, and life couldn’t exist.
Mars, our long dead and the second nearest planetary neighbor doesn’t have a magnetic field and many scientists have theorized that the catastrophic incident that led to Mars being stripped of its atmosphere was directly related to the destruction of its magnetic field.
Magnetic fields cause a moving electric charge to move sideways by pushing it away from them. The stronger a magnetic field is, the greater the effect that it has on electrical charges, which will move in a continuous spiral pattern when they are trapped by a permanent magnetic field.
One of the best and easiest to see examples of this movement is the way that the sun’s plasma moves across its surface, which is due to the force exerted by the stars magnetic field
How Do You Measure a Magnetic Field?
One of the ways in which a magnetic field is measured is with a unit called a Gauss, which was named after the nineteenth-century German mathematician, Carl Friedrich Gauss.
Earth’s magnetic field at its surface averages around half a gauss, while a strong fridge magnet usually measures around one hundred gauss.
Knowing how a magnetic field is measured is important, as the gauss is the unit of measurement that physicists use to determine the strength of large magnetic fields.
How Many Gauss Is Too Many?
As we’ve already mentioned, theoretically, there is no limit to how strong a magnetic field can be. But the stronger a field is, the stronger and stranger the effect that it has on the electrical charges around, and thus the electrons and atoms surrounding, it is.
The larger and stronger a magnetic field is, the more violent the effect that it has on the electrical charges that surround it is, and as they’re pushed away with more force, they spiral ever faster, and the faster they spiral, the tighter their movement becomes.
Everything in the universe is made up of atoms, and every atom has an electrical charge, thanks to the electrons that orbit their nuclei.
So anything that’s exposed to a strong magnetic field will react accordingly, and as the atoms that the object is made up of spiral faster and faster, they begin to deform and will eventually break apart.
When a magnetic field reaches half a million gauss, the objects around it are ripped apart by the effect that it has on the electrical charge (and the atoms) that it is made from.
If a physicist or an engineer were able to make a machine capable of generating a magnetic field measuring half a million gauss, it would exist for milliseconds before being torn apart by the very force that it created.
Going beyond that measurement, if a magnetic field that measured one billion gauss was somehow created, it would transform the shape of the atoms around it, stretching them to an infinite point, and fundamentally altering the building blocks of creation in the process.
Can A Magnetic Field That Strong Exist?
While it would be impossible to generate that sort of magnetic force on the surface of Earth or any other planet, the universe is a mysterious and wonderful place, and physicists believe that impossibly strong magnetic fields that exceed the aforementioned billion gauss measurement do exist.
When the magnetic field of a dying star exceeds one billion gauss after that star has gone Nova ( which happens when a star burns up all its energy and explodes) it creates a highly magnetized form of neutron star composed entirely of superconducting protons called a magnetar.
While flashes of magnetars have been briefly glimpsed, it wasn’t until January 2021 that scientists were granted the opportunity to actually study one at length when a magnetar was detected in a galaxy one hundred and fourteen million light-years away from our own.
Magnetic Fields And Black Holes
Einstein's General Theory of Relativity expounded the idea that when a force strong enough is exerted on space-time, it bends and warps the space-time around it to create a black hole.
So, theoretically, a magnetic field that was strong enough could warp space-time and by doing so, could create a black hole.
The beautiful irony of that idea, which according to the laws of physics as we understand them is entirely possible, is that the magnetic field that created the singularity, would then be confined within it, as the gravity of the black hole would prevent that magnetic field escaping that point in space-time.
An entirely theoretical idea, a magnetic monopole would be created when a strong enough magnetic field reacted with the nothingness (having destroyed all matter around it due to the way in which that matter reacted upon being exposed to the field) that surrounded it.
The magnetic monopoles, if they were proven to be more than a theoretical idea, would, in turn, react with the only other force present, the magnetic field that created then, and would substantially weaken it, which would place a theoretical limit on the strength that a magnetic field could reach before it begins to react upon, and weaken itself.
But as the existence of magnetic monopoles has yet to be proved, there is as modern science and the laws of physics currently understand the nature of the universe, no physical limit to how strong a magnetic field can be.