Electrical energy and magnetism have lots in widespread. They’re related by the unified theory of electromagnetism, and are in some ways two sides of the identical coin. Each can exert forces on costs and magnetic fields. A altering electrical discipline creates a magnetic discipline and vice versa. Elementary particles can possess electrical and magnetic properties. However there’s one basic distinction.
Electrical fields are created by electrical costs. There are two varieties of electrical cost. We name constructive and destructive, they usually exist independently. Electrons have only a destructive cost, for instance, whereas protons have a constructive cost. The on a regular basis objects round us are often electrically impartial, nevertheless it’s simple to present objects a slight constructive or destructive cost. Static electrical energy is an effective instance of this.
This isn’t the case with magnetic cost. Like electrical cost, there are two varieties of magnetic cost. For historic causes we name them north and south poles. However these magnetic poles all the time are available in pairs. Each magnet has a north and south pole. In case you break a magnet in half, you don’t separate the poles. As an alternative, you get two smaller magnets, every with a north and south pole. Even magnetic elementary particles have this dipole property. So far as we are able to inform, there are not any magnetic monopoles.
Though we’ve by no means noticed magnetic monopoles, we all know what their properties can be in accordance with electromagnetism. One of many extra shocking penalties is that magnetic monopoles would quantize cost. In case you had a number of electrical and magnetic costs, the electromagnetic discipline they produce would have an angular momentum (rotation) that will depend on the worth of the electrical and magnetic costs. In quantum mechanics, angular momentum is quantized, which implies the costs would even be quantized. The existence of even one magnetic monopole within the universe would clarify why basic particles all the time have an integral worth of the electrical cost. Magnetic monopoles would additionally carry symmetry to electromagnetism. This is without doubt one of the the explanation why models such as string theory predict magnetic monopoles.
The invention of magnetic monopoles would revolutionize our understanding of the universe, so it’s value on the lookout for them the place we are able to. Lately a group seemed for proof of them them in Earth’s magnetic discipline. In precept their concept is easy. If magnetic monopoles exist, they might be trapped by Earth’s sturdy magnetic discipline. This is able to give Earth a magnetic cost, which we must always be capable to measure.
In observe, that is fairly difficult. For his or her examine, the group used six years of public knowledge from the ESA’s Swarm constellation. This can be a assortment of orbiting satellites particularly designed to make a high-resolution map of Earth’s magnetic fields. From this knowledge, the group created a map of our planet’s magnetic discipline strains and utilized a mathematical approach often called Gauss’ Legislation. Consider the Earth surrounded by an imaginary sphere. If there are not any magnetic monopoles, any magnetic discipline line that crosses out of the sphere should additionally cross again into the sphere. If there are magnetic monopoles, then some magnetic discipline strains should cross the sphere with out crossing again. An extra of discipline line crossings would show the existence of magnetic monopoles.
The group discovered that to the bounds of their knowledge there was no proof of extra discipline line crossings. This doesn’t imply that magnetic monopoles don’t exist, simply that there is no such thing as a proof of any being trapped by Earth’s magnetic discipline. So no luck this time, nevertheless it’s an amazing outcome utilizing public knowledge.
Reference: Bai, Yang, Sida Lu, and Nicholas Orlofsky. “Searching for Magnetic Monopoles with the Earth’s Magnetic Field.” arXiv preprint arXiv:2103.06286 (2021).