INVISIBLE FORCES
10 Facts About Magnetism That Will Attract Your Attention
Published on April 15, 2024
Credit: Chris Nagahama
Magnetism is one of the fundamental forces of our world, influencing everything from the structure of the universe to the behavior of living organisms. And from guiding migratory birds to powering MRI machines, the deep impact of magnetism on our everyday lives cannot be overstated.
Jump into the rabbit hole of the magnetic realm with these 10 peculiar facts that will leave you positively charged!
Earth's Magnetic Poles Can Swap Places
Credit: Denise Jans
As crazy as it sounds, every few hundred thousand years, Earth's magnetic field flips completely, causing the north and south poles to switch places. This strange phenomenon, known as geomagnetic reversal, has happened hundreds of times in Earth's history. Its cause remains elusive, and there’s no way to predict when the next one might occur. However, while a magnetic reversal could certainly wreak havoc on communication systems and power grids worldwide, it wouldn’t happen overnight, as the process takes several thousands of years.
Magnets Can Levitate Living Creatures
Credit: name_ gravity
You might be familiar with the fact that trains and other large ferrous objects can effortlessly be made to levitate with the aid of magnetism. But did you know that even tiny creatures like frogs and small mammals can be levitated using strong magnetic fields? This is because water is diamagnetic - meaning that it repels magnetic fields - and under the influence of a sufficiently powerful magnetic field, droplets and even living organisms can be made to seemingly float.
The Strongest Magnets in the Universe
Credit: ESO/L. Calçada, CC BY 4.0
Magnetars are neutron stars with incredibly powerful magnetic fields. They can generate magnetic fields a quadrillion times stronger than that of Earth. These extreme magnets can disrupt the electron clouds of atoms from thousands of kilometers away.
It has been suggested that magnetars are the source of fast radio bursts, a strange deep-space phenomenon that resembles intentional radio signals that have puzzled scientists for decades.
Magnetoreception in Animals
Credit: Chris Briggs
Several animals, including bees, sea turtles, and salmon, possess magnetoreception, the ability to sense magnetic fields. They use this ability for navigation, migration, and general orientation. Birds, in particular, use this ability to easily navigate the skies even on cloudy days or at night. Some scientists believe that even humans possess a dormant or semi-subconscious magnetic sense, but research into this exciting field is still in its infancy.
The Sun's Magnetic Influence
Credit: NASA Goddard Space Flight Center, CC BY 2.0
The Sun exerts a tremendous magnetic influence on our planet. Solar flares and sunspots, for example, are caused by intense bursts of magnetic activity on its surface. These eruptions release vast amounts of energy and can seriously affect communication systems on Earth and even weaken the protective effect of our planetary magnetic field.
Magnetism Applied to Health
Credit: National Cancer Institute
Magnetism finds countless applications in medicine, with one of the most successful being MRI or Magnetic Resonance Imaging devices. MRI machines use powerful magnetic fields and radio waves to generate detailed images of the body's internal structures. Since its development in the late 70s, this non-invasive medical imaging technique has revolutionized diagnosis and treatment in healthcare globally.
We Owe Auroras to Magnetism Too
Credit: v2osk
Auroras, also known as the Northern and Southern Lights, are caused by charged particles from the Sun interacting with Earth's magnetic field. The shape and color of auroras are determined by the strength and direction of these magnetic fields. Interestingly, large geomagnetic storms can influence the latitude at which auroras can be observed. During particularly strong historical events, they have been observed as far south as the Mediterranean.
An Efficient Way of Cooling
Credit: Dev Benjamin
Magnetic refrigeration is a cooling technology that exploits the inherent thermal properties of magnetic fields to achieve refrigeration. While the technology has the potential to be more energy-efficient and environmentally friendly compared to traditional refrigeration methods, no commercially viable magnetic refrigerator has been made to this date.
Compass Bacteria
Credit: Adrian Lange
Some bacteria have tiny magnetic crystals inside their bodies, allowing them to align with Earth's magnetic field. This helps them navigate and find optimal environments for survival, such as low-oxygen habitats. However, unlike magnetoreception, this process is more akin to the movement of a compass needle, as the bacteria are forced into alignment rather than choosing to move in a certain direction.
Even Memory Storage Depends on Magnets
Credit: benjamin lehman
Magnetic storage devices, like hard disk drives and magnetic tape, use magnetization to store digital data. This is often accomplished by encoding a signal through small variations in electrical current that embed a proportional magnetic distribution into the storage device. Later, this distribution can be read to faithfully reproduce the original signal. Despite advancements in solid-state storage technology, magnetic storage remains a cost-effective and reliable option for large-scale data storage.