If you’re interested in physics, you’ve likely heard of nuclear fusion - the process of fusing two smaller atomic nuclei into one heavier nucleus that releases a vast amount of energy. We’ve been able to do it since 1934, when scientists including Ernest Rutherford bombarded isotopes of hydrogen with light nuclei and caused them to fuse into more massive nuclei. We know that this fusion-released energy would be incredibly useful to use commercially, to power our homes and factories and everything else without having to use polluting fossil fuels that release greenhouse gases into the atmosphere. So why has nuclear fusion not been used widespread for the power grid like nuclear fission (the opposite process which involves splitting heavier nuclei into lighter ones)? Why is it joked about the fact that commercial nuclear fusion has supposedly been “just 30 years away” for decades now? What’s the holdup? Well, the issues are more difficult to solve than we might have thought when fusion was first proposed by American chemist William Draper Harkins in 1915. 

Taking into account all that, it might start to feel impossible to design a reactor that can be both hot and cold enough for all the components at the same time, as well as not breaking under the pressure of fusion. This isn’t even taking into account the cost that it would take to build hundreds of these machines across the globe to shift our power grid from being fossil fuels based to being fusion based. Nevertheless, do not despair! While it is true that the struggle to actually build something to utilise all these hypothetical benefits that fusion would offer us has been an uphill battle, scientists are making progress every day! It may seem tough to believe that fusion is genuinely on the horizon when optimistic predictions have been saying the same thing for years now, but with new developments such as achieving a net energy gain at the Lawrence Livermore Laboratory in 2022, it seems likely that within our lifetimes we will see the introduction of fusion reactors for commercial purposes. The large difficulties that have held up progress: the colossal amounts of energy that need to be put in to make it viable, temperature issues, the fact that we have not been able to sustain the reactions for long, are slowly being solved. Less than three years ago in 2023, the largest and most advanced tokamak to date, the JT-60SA, was unveiled - a collaboration between Japan and the European Union, having already achieved its first plasma earlier that same year. In January of 2025, China announced that it had been able to sustain steady plasma containment for 18 minutes, and just a month later France beat even that with a 22-minute stable confinement. 

While it might be funny to joke about the perpetual “30 years away” fusion, it may end up being true this time after all! The obstacles of implementing these big scientific ideas into reality cannot be ignored, it’s important to remember that progress doesn’t happen all at once, and that one day clean, efficient energy available universally could be the new normal. 

You wake up one morning in a joyful mood. After having breakfast, you decide to take a walk in the local park. While in the park, someone ahead of you trips and falls, badly injuring themselves. There are 2 scenarios. In the first, there are many people walking around you. In the second scenario it's just you and the injured person alone. In which scenario would you most likely act? 

The truth is, a lot goes on in your head before you actually act. First you must register the event. You’d think now it's time to act, but no. Many decisions are made before you do anything. After becoming aware of the event, your brain decides whether or not it's an emergency. Then you consider whether it really is your responsibility. Next, you analyse whether you are actually able to assist. Finally, you ask yourself, do you actually implement action? If you eventually do decide to help, it's only after all these questions have been successfully answered. 

Take the first scenario. There are about 10 people all around, near the injured person. At the same time, every single person is processing their response, trying to stay calm and looking at everyone else. Everyone is stuck, doing the same thing, misinterpreting each other, and not perceiving it as an emergency. This is called pluralistic ignorance. This means that everyone incorrectly believes that their belief is different from all others. What this leads to is individuals rejecting your own views, so as to fit in. You were standing there. You had seen the injured person. You yourself thought it was an emergency, but you do nothing, because everyone else is doing the same thing, stood there. You do nothing because you're scared you've misunderstood the situation and you’ll embarrass yourself. What if they are not hurt? You'll be judged if that happens. In that moment, the potential negatives, including legalities (if you hurt the other person in helping them), embarrassment and a personal sense of shame outweigh the positives, which is a sense of good mood, (you've just possibly saved someone else's life). Since there are so many people there, you feel the responsibility isn't just on you. This is called diffused responsibility. But everyone will see this the same way, right? Everyone will share that little bit of responsibility. This means nobody acts, because nobody feels that they have enough responsibility for them to have to act. So the more people around, the less likely a single individual is to act in an emergency situation.

So how can all this be evidenced? In 1968, psychologists Bibb Latané and John Parley tested this very idea. The two men recruited participants under the guise of a completely different study. As all the participants sat in a room, waiting for the experiment to begin, smoke started to fill the room. They looked at how long it took to notice the smoke, as well as to act. 

The results showed that a higher percentage of participants noticed the smoke within 5 seconds when alone, compared to with others. This result was the same for taking action. 

The percentage of people taking action was higher in a group of three compared to when there were two confederates sitting passively (the Confederates have been told what to do). This is the case of pluralistic ignorance. As nobody else was reacting, the one lone participant was more likely to suppress their belief that there was an emergency. This experiment completely compliments the bystander effect, showing us how this plays out in real life. 

In 1964, Kitty Genovese was murdered. 37 people witnessed this event. Not one person reacted or even called the police. Not to make you feel scared or anything, but this is a very real demonstration, not just an experiment, that the bystander effect is very real, and people's reactions can determine someone's fate. 

Magnetism dwells in almost every part of our lives. It’s in the sound systems in our phones, it’s in the bird-migration paths which sweep the skies overhead, and is even theorised to affect the brain waves of humans. Much of the general population may attribute the enigmatic nature of this quiet, profound force to a lack of knowledge on their part. However, what if I was to tell you that magnetism is just that: enigmatic, and in many ways mysterious and somewhat inexplicable to even the scientific elites of the modern day. As Professor Hannah Fry puts it, magnetism is our ‘most familiar mystery’. But why is this so? And what exactly is this beautiful, alluring property of our universe? 

Originally, in about 206 BC, the Chinese used lodestones, and other magnetised pieces of iron, as tools for feng-shui. This is the practice of tactically placing and orienting cities, houses, streets and even furniture in order to yield the greatest spiritual benefit. They believed that the life energy in all things, ‘Qi’, flowed in the direction that the lodestones pointed and therefore they often oriented their houses in this direction. 

A luopan compass used to practice feng shui | A map depicting ancient Magnesia

In reality, what they were really doing was orientating their houses along the lines of the Earth’s magnetic field. Recognising the fact that the lodestones always pointed in the same direction, some time later, the Chinese began to use magnetism in order to navigate. The compass soon spread across Europe as well. Christopher Columbus used it when he crossed the Atlantic Ocean, noting that the compass deviated slightly from exact north, which was indicated by the stars. Previously, people had believed that either the ‘North Star’, Polaris, or a gigantic magnetic island located on the north pole was what spun the needle of a compass. In 1600, the physician to Queen Elizabeth I, William Gilbert, proposed a radically different explanation: the entire Earth was magnetic, and its magnetic poles deviated slightly from its geographical ones (the points defining either end of the axis about which the Earth spins). Turns out, Gilbert was right. This was the first big discovery in the study of magnetism.

The second came in the early 1800s, when scientists such as Faraday, Ørsted and Ampère worked together to conclude that there was a distinct relationship between magnetism and electricity. The magnetic force was pretty much a force between electric currents. Electric current is the flow of charged particles, such as electrons, through a conductor or through space. Parallel electric currents flowing in the same direction seemed to attract each other, whereas those flowing in opposite directions seemed to repel each other. 

Parallel currents exert a magnetic force on each other

Using this logic, Ampère also guessed that iron atoms must contain miniature electric currents and this was what gave iron its magnetism. Broadly speaking, he was correct. The magnetism of an atom or molecule depends on a combination of both the orbit of electrons around the nucleus of an atom (this creates tiny loops of current, and with that a magnetic field), and the nature of a quantum property of its electrons called spin. If the magnetisms (more specifically, magnetic moments) of each atom in a substance are aligned in the same direction, the material is said to be strongly magnetic. If equal numbers of the atoms are aligned magnetically in opposite directions, the magnetism can cancel out, and the material is said to be weakly magnetic. However, these strongly magnetic materials only become actual magnets once they enter the field of another existing magnet.

If you didn’t understand that, it’s okay. It was a very over-simplified explanation of magnetism. Moreover, much of the full explanation for magnetism lies in quantum electrodynamics, and this region of physics in itself is still not entirely understood by scientists to this very day. In fact, even once you get down to the very nitty-gritty of magnetism and what causes it (in a quantum mechanical sense), you reach a level where one must accept that it just is. That magnetism is a fundamental ingredient of our universe and we cannot push our realm of human understanding further than this simple statement. In my eyes, this makes it all the more magical. Just as characters in fantasy books accept the laws of magic simply because that’s the way they are, scientists must accept that magnetism has all of its fascinating, awesome and beautiful effects simply because that's just the way it is. There’s an elegance to this acceptance. It reminds us that we, as humans, live in a universe that is infinitely more complex than we can ever fathom. It is this inferiority to the universe that unites us all, and grounds us in the long lineage of our humanity.

And humans have been bowing down to the cosmos since the dawn of time. When the Algonquin people, indigenous people of North America, looked up at the sky on a cold, dark night and witnessed a huge dance of glowing, colourful flames, they believed that they were seeing fire made by their creator, Nanahbozho. They believed it was a sign he was watching over them. What they were really seeing was the northern lights (aurora borealis). Long before we understood that these, too, were an effect of magnetism, people had always associated them with great spiritual meaning. Many Scandinavian countries, along with Japan, associated them with childbirth, often as a positive symbol of an easy birth or successful children. In Norse mythology, the aurora was believed to be ‘Bifrost Bridge’, a glowing arch which led those fallen in battle to their final resting place, Valhalla. These are all fascinating stories and once stood before the true majesty of the aurora, one can easily see how our ancestors came up with such mystical ideas. However, what is the scientific explanation for this magical show of light? And how is it caused by magnetism?

A Pictogram of Nanabozho on Mazinaw Rock, Bon Echo Provincial Park, Ontario | The northern lights (aurora borealis) 

People first began to think that the aurora was caused by magnetism since it occurred most frequently around the Earth’s magnetic poles, very far south or very far north. The Earth’s magnetic field lines curve around the entire Earth, and enter the planet at either pole. Therefore, the density of these magnetic field lines are greatest at the poles, and the strength of the magnetic field is too. Now, the aurora has everything to do with a phenomenon called solar wind. The outermost layer of the sun, the corona, is extremely hot. This extreme heat tears electrons from their atoms, turning the corona into a ‘soup’ of free ions and electrons, a gas called plasma. But this plasma is much too hot for the sun’s gravity to hold it captive. Instead, it is constantly expanding away from the sun, being blown off it in magnificent gales, filling the entire solar system with fast moving, very hot electrons and ions. This is solar wind. And it would be very harmful to us if not for the Earth’s magnetic field. The gigantic, magnetised shield around us diverts the flow of solar wind, resulting in a cavity of calm around the Earth, known as a ‘magnetosphere’. This has been one of the most crucial factors in the formation of life on Earth. We would quite literally not be here without it. 

The Earth’s magnetosphere

However, although the magnetosphere diverts most particles, it does not divert all of them, and some of them get trapped in our atmosphere. This is what gives us the aurora borealis. These ions and electrons of the solar wind are, due to their charged quality, guided along the Earth’s magnetic field lines like beads on a wire. Therefore, they become most concentrated at the poles. When these fast moving particles collide with oxygen and nitrogen in our atmosphere, they induce a process called excitation. Essentially, this is the heating up of the gas molecules. Once they ‘cool back down’ again, they release a photon of light. With nitrogen and oxygen, the main colours of light these emit are green, blue, purple and pink. On nights where there is a particularly high bout of solar activity, this is the light we see in the night sky.

However, not only does the Earth’s magnetic field put on breathtaking light shows and shield us from harmful solar wind, it also helps many animals across the world with navigation. This idea first started being explored in the late 1900s. Experiments were carried out by scientists such as W. Merkel and W. Wiltschko, who did multiple variations of caging birds and creating artificial magnetic fields around them. This resulted in birds adjusting their course in line with the new magnetic field. It seemed the birds were using magnetic fields to guide themselves. Soon enough, evidence started piling up that there was a direct link between the precise migration routes taken by many species, and the Earth’s magnetic field.

This in itself is an incredible fact, but what’s even more unbelievable is that some animals, such as robins, may even be able to see the magnetic field. Scientists have found that a protein called cryptochrome located in the eye of birds (having been mostly observed in robins) may be one of the secrets to magnetoreception, the sense which allows animals to sense the Earth’s magnetic field. It is theorised that this protein is able to absorb (specifically blue) light and thus excite an electron, causing it to form a radical pair. This is a quantum mechanical state in which a pair of electrons become sensitive to changes in a magnetic field. What’s even more amazing is that this works because the electron in one eye is quantum entangled with that in the other. Very simply, this means that what happens to one particle happens to the other. If you want this process explained a little better, I would highly recommend this youtube video. In my opinion, this is the pinnacle of clever evolution. A bird has evolved not only to be able to possibly see magnetic fields, but this has also arisen from a complex quantum mechanism within the bird’s eye! How amazing is that?

A diagram illustrating the process of magnetoreception in cryptochromes | a robin

But robins aren’t the only species which have demonstrated magnetoreception, and light-sensitive cryptochromes are not the only system of magnetoreception we have discovered. Remember magnetite? Well, researchers have found the presence of magnetite in loggerhead turtles and pigeons which may measure the intensity of the magnetic field in their current location. Moreover, cells sensitive to electric activity are thought to be present in rays and sharks, and are confirmed to be in the ear canals of pigeons. These cells respond to the magnetic field through magnetic induction; when a pigeon moves its head, it moves it through the Earth’s magnetic field. As discussed earlier, moving a conductor through a magnetic field creates an electrical current. This means that when a pigeon moves its head, electrical signals are created in its ear canals. These are then sent to the brain, alerting it of its position in the magnetic field. Signs of magnetoreception have also been observed in mole-rats, woodmice, insects such as honeybees, ants and termites, amphibians like newts, foxes and even the huge humpback whale. 

I can guess what you’re thinking. Do humans share this remarkable ability as well? In 2019, a team of scientists led by Professor Joseph Kirschvink investigated this idea. They found that, once a subject was placed in a box and exposed to an artificially created magnetic field, a change in brain waves was detected. There was a slight drop in alpha waves emitted by the participants brain, and this change is linked to the brain processing information. This means that, yes, there is some evidence to suggest that humans may have a long-forgotten magnetic navigation ability. However, the evidence is controversial and is yet to be reproduced by other research groups. Although Kirschvink feels very passionately about humans’ magnetoreception, there is not yet any resounding evidence that we have this skill.

A depiction of Kirschvink’s experiment on human magnetoreception | An extremely rare albino humpback whale

So, the Earth has a magnetic field which has many fascinatingly wonderful effects. But, why is this so? What causes the Earth’s magnetic field? Today, scientists are pretty certain that our magnetic field occurs due to convection currents in the Earth’s molten iron outer core. The outer core of our planet is currently in the process of solidifying. It is this process which drives convection currents in the core, hence creating electric currents, and with them a magnetic field which stretches far out into space. 

However, the interesting part is that although we may know what fuels the magnetic field in the present day, what started it is a mystery. I find that so incredibly exciting; the Earth’s magnetic field has a massive influence on all that we know and all that we have ever known. It is a key feature of our planet, it is the reason we are here today. Every day, we wake up on top of one giant magnet, and yet, we truly have no clue what has caused that. As far as we know, the planet’s core only began to solidify roughly 1 billion years ago but there is strong evidence to suggest that the field existed at least 3.5 billion years ago. We know this partly through the study of ancient rocks. As rocks cool and form, the electrons within the rock minerals align themselves with the surrounding magnetic field. Once these rocks cool past a certain temperature called the Curie temperature, they cease to be magnetic and are quite literally set in stone. Through studying the orientation of these electrons, researchers can determine the strength and orientation of the magnetic field at the time. The location of the poles has been known to wander slightly throughout history, due to fluctuations in the convection currents of the outer core. They have even been shown to flip. Complete pole-reversals of the magnetic field (where north becomes south and south becomes north) have been observed every 200,000 years or so. By this logic, we are actually around 580,00 years overdue for a pole reversal. But don’t worry, if it does happen any time soon, it won’t happen overnight, and is instead expected to take a few thousand years. When exactly the poles will next switch, along with why we even have them in the first place are both fields of active research in the continuous quest to better understand magnetism.

The interior of the Earth | The wandering of the poles shown by paleomagnetism

Thousands of years ago, when the Inuits of the far north looked up at the night sky and saw huge, undulating ribbons of light, they believed it was a gift from the gods. The ancient Chinese used to believe the Earth’s magnetic field harbored the life force in all things, Qi. Humans have been making magnetism synonymous with magic for thousands of years. Why should we stop today? What is the fundamental nature of magnetism? How come our entire planet is magnetised? How do the creatures around us, big and small, use this invisible force exactly to find their way? These are all unanswered questions. These are big gaps of uncertainty. And in life, uncertainty leaves room not just for discovery, but also for magic. Although, we don’t have to stop there. Why should we stop viewing something as magical once it can be explained? The concept that robins may be able to actually see the Earth’s magnetic field, and use it to navigate, is nothing short of mind-blowing. Neither is the idea that our planet is engulfed in a gigantic field of force that shields us from harmful solar wind. What if we start viewing magic not as anything mysterious or inexplicable necessarily, but as anything filled with awe? As anything that instills wonder in us? As do many parts of the scientific world, in my eyes, the phenomena of magnetism does a great deal of that.

AI refers to the simulation of human intelligence through machines that are programmed to think, learn, and solve problems like humans. They replicate the multi-layered neural pathways in human brains in order to produce meaningful analyses of data. The objective is that these algorithms are to be capable of analysing, learning and comprehending data without explicit programming. The ongoing developments in AI are relevant to healthcare because they represent the potential of improved diagnostics through automated systems capable of processing patients far faster than the average human.

AI in diagnostics

AI has the ability to analyse images such as X-rays, MRIs and CT scans. This can increase efficiency of analysis due to their removal of the potential for human error. Moreover, AI has both a higher capacity for knowledge than humans and a perfect memory- without the drawbacks of human memory it can instantly recall anything it has previously learned, increasing the chance of diagnosis for more obscure or rare ailments. It can also recognise patterns between symptoms highly efficiently, allowing it to detect diseases such as cancer and Alzheimer's very early on. Studies have even proved that AI can have greater accuracy than doctors when it comes to making diagnoses. Despite these benefits, certain challenges such as data privacy and algorithmic bias can pose serious caveats that need to be considered as this technology advances.

Personalised treatment

Predictive modelling can help to assess how a patient may react to certain treatments and optimise plans to their personal needs. The data analysis skills built into the core of these AI models can customize treatments based on a patient's specific genetics and ensure a smooth transition into and cooperation with their lifestyle. Doses of drugs can also be optimised by AI in order to personalise medication plans.

Streamlining healthcare options

AI can also help to make the currently heavily overworked healthcare system more efficient by automating administrative tasks such as the scheduling of appointments and billing. This also reduces operational costs and improves efficiency so that more money can be focused where it’s really needed such as fixing outdated equipment and solving underpayment for overworked doctors and nurses. AI chatbots have also been introduced in some institutions in order to answer queries about patient symptoms. This helps to prioritise in-person appointments for those nursing more serious ailments who would require more immediate attention. This also frees up more time for healthcare professionals to spend with patients who have the most urgent need for extended care.

Possible drawbacks

A big concern in terms of the use of an AI engine in healthcare is the data privacy of patients, especially since they would have to turn to an external AI algorithm. This distrust stems from the fact that this AI would most likely be sourced from a developer that has experienced major data leaks in the past decade. Additionally, AI suffers from algorithmic bias, a term meaning that it both reflects the values of the humans who created its code and can pick up biases from the data it uses to learn. This can lead to inappropriate treatment recommendations or misdiagnosis for certain groups. There would also need to be clear regulatory frameworks set in place before it could be used in practice. They would need to undergo rigorous testing, validation, and constant monitoring in order to ensure their safety and infallibility. The introduction of Artificial Intelligence would also introduce a myriad of ethical implications because the amount of water, energy and electricity AI data centres use grosses a heavy carbon footprint each year.