As we move from late autumn into the winter months, the weather has become noticeably colder, and soon we will undoubtedly be seeing some frost and ice on the ground in the chilly mornings. These glacial additions to a morning walk to school can quickly become somewhat of a skiddy annoyance for anyone as clumsy as I am, and more than once I have ended up flat on my face as the pavement became a temporary ice rink. But have you ever stopped to think about what actually makes ice so slippery and difficult to walk on? There’s actually some very interesting physics behind it!

In the 1850s, British chemist and physicist Michael Faraday suggested that ice is actually not completely solid, but is coated with a very thin layer of water despite being at temperatures below freezing (0°C). This explains why objects can slide around on its surface with very little friction despite the ice appearing as a solid surface. Nowadays, over 150 years later, this turned out to be a surprisingly accurate prediction. Scientists have recently suggested that through a process called “premelting”, a tiny film of molecules that act like a liquid can form on the top of the solid ice surface, where the molecules are not arranged in rigid structures as in a solid. In fact, they are arranged in a disorganised random layer of particles that can move over each other and that objects can glide over smoothly.

Ice is normally thought of as being a “crystalline” solid, which means that its molecules have a clear, ordered 3D pattern. However, this ice crystal will be in layers when it naturally forms on the ground, and the top layer can become a strange arrangement of H2O molecules that is neither fully solid nor liquid called a “quasi-liquid” when it is at temperatures ranging from 0 to ~ -40°C. The particles are less tightly bonded to each other and can therefore move around almost like the atoms in normal water. 

This quasi-liquid acts as a lubricant as the molecules can move around more freely than in a solid, but still retain a little bit of that form that we saw in the crystalline ice. In a sense, when you skate or slip on the surface of ice, you aren’t in contact with a solid, but instead gliding over a moving layer of water molecules! That process is the reason why ice that is extremely cold, for example below -35°C is not as slippery and is much easier to walk on, because there is less premelting and less of a mobile layer for objects to slide over.

When you go ice skating at winter wonderland this festive season, think about all the fascinating physics you’re demonstrating while doing it! 

Think you know about how to cure a hiccup, stop a cold or lose weight fast? Think again. Behind every “miracle cure” or “ancient remedy” lies a surprising truth and some of them might even shock you. We’ve all heard sayings like “cracking your knuckles give you arthritis” or “if you eat carrots you can see in the dark” but how many are actually true? It’s time to put some of the most common medical myths under the microscope and find out what’s fact and what’s fiction. 

Pop goes the myth 

Pop goes your knuckles, pop goes this myth! You may think this repetitive cracking of your fingers will lead to arthritis but, despite what your grandma says, it’s completely harmless. So what is that popping noise? Gas bubbles! A lot of people think that the noise you hear is your joints getting damaged which leads to arthritis over time, a painful condition that affects your joints. However, the sound actually comes from tiny gas bubbles that form and burst in the fluid inside your joints called synovial fluid. When you stretch or pull your fingers, the pressure change is making the bubbles pop which is the noise you hear.  Now you may not believe me, but scientists have studied this myth for decades and there is no evidence that knuckle cracking causes any long-term damage so if you don’t believe me believe them! Did you know, one doctor, Dr Donald Unger, even cracked his knuckles on only one of his hands for over 50 years and found no difference between them! He later won the Ig Nobel Prize for his unusual experiment which proves that it doesn’t cause any damage. So go ahead, crack away guilt free- pre-warning though, you probably won’t get an Ig Nobel Prize for it.

Cold hard lies

Pluck and panic

Ever feared that tugging a single grey hair will double your worries? Science says relax, it’s time to bust that myth! Many people worry that plucking one grey hair will cause it to multiply, making their hair go grey faster. It’s a common warning passed down through parents, friends and even beauty advice columns. Let’s debunk this myth: plucking a grey hair does not make more grey hair grow back. When you pull out one hair the follicle may grow new hair in its place but it’s still just one hair. If the new hair is grey, it’s because of genetics and natural ageing, not because you pulled the old one out. Did you know grey hair is produced when your hair follicle stops producing pigment? This process is gradual and depends on genetics, stress and aging, but not plucking. However, if you pluck too much, you can actually damage the follicles which stops the hair from growing at all. Pluck one grey hair and it won’t double your worries…. but keep tugging and you might just end up with a bald spot to stress about instead.

Hiccup hack?

Everyone’s tried it before; “Hold your breath and your hiccups will magically go away”. Spoiler: they don’t. Many people think that holding your breath or drinking water upside down or even being startled can magically make those persistent hiccups disappear. These “hacks” have been passed down through families and appear in countless advice columns. Hiccups are actually caused by involuntary spasms of the diaphragm, the muscles that help you breathe. While holding your breath can sometimes interrupt the spasm temporarily, it doesn’t reliably cure hiccups; most hiccups stop on their own within a few minutes. Some people have hiccups that last for days, weeks or even months and even though this is very rare, it shows that simple tricks like holding your breath aren’t a guaranteed cure. So next time someone tells you to hold your breath to fix a hiccup you can say it’s not that simple. Sometimes the best cure is just… patience!

Sweet lies 

Believe it or not, too much sugar will not make kids bounce off the walls like jelly beans. Studies have shown that sugar doesn’t actually make you hyperactive. Energy spikes are usually from excitement, environment or (if with children) just being kids. Fun fact: researchers even tested kids at birthday parties and found no difference in behaviour between those who had sugary sweets and those who didn’t, so next time someone blames the cupcakes for a kid's zoomies you know it's the celebration not the sugar!

Calorie Chaos 

Think that having Christmas dinner one week and skipping dinner the next will magically melt away pounds, or that eating at night makes you gain more weight than in the day? That’s calorie chaos talking and it’s mostly myths. Calories are just the unit of energy! Weight changes depending on the balance between what you consume and what you’ve burned, not the time on the clock. Fun fact: research shows that people who eat late don’t actually gain more weight. It’s total calories and activities that matter the most. Another myth is that certain fat burning foods can mount pounds on their own. Sadly, broccoli won’t turn into a six pack! So next time someone swears by extreme diets or late night rules remember it’s the mass of energy not magic that rules your body. Eat smart, move more and don’t buy the hype!

Fact over fiction 

From popping knuckles to cold weather, grey hairs, hiccups and sugar. It turns out that many “health facts” we’ve always believed to be true are… well, myths. Science shows that germs, genetics and natural body processes are usually the culprits, not the spooky warnings passed down from parents, friends or old wives tales. Remember not every ‘fact’ is a fact, some are just myths in disguise. So go ahead, eat your candy, pop your knuckles, and laugh at the nonsense! If you go along and believe in every health tip, you’ll end up shivering, hiccuping and avoiding cupcakes all day. Science says relax!

I’m sure most of you have heard of ‘runner’s high’. Only the lucky among us will have experienced it. ‘Runner’s high’ is the feeling of euphoria you are supposed to get after running for a while. Words can barely do it justice; it’s the moment when your whole body feels unstoppable, your legs light as air. It’s when the white-hot feeling of glimmering possibility surges through your veins, and every trouble in your life dissolves into the sure-and-steady rhythm of your feet, beating against the ground. The experience is almost otherworldly and it’s what makes running, for many, so addictive. However, aside from runner’s high, how good is running, really?

Studies show, the answer is very good. In fact, according to Redbull, along with swimming, running is one of the best sports for your body and mind. One huge benefit of running is the longevity it encourages. The study Running as a Key Lifestyle Medicine for Longevity, found that runners have a 25-40% reduced risk of premature mortality, live approximately three years longer than non-runners, and that running will do more for your longevity than any other form of exercise. There’s many reasons as to why this is the case. 

One is that running improves your cardiovascular fitness immensely. The more you run, the stronger your heart becomes, meaning it can pump out more blood, and thus more oxygen, with each heartbeat. In turn, this reduces your resting heart rate, which correlates with better cardiovascular fitness.

Moreover, have you ever heard that running will wreck your knees? Weaken your joints? This is a complete myth and a very common misconception about running. In fact, running (with proper form) even strengthens your joints. A study published in the Journal of Orthopaedic & Sports Physical Therapy concluded that recreational runners had a much lower occurrence of osteoarthritis, a degenerative disease affecting the joints, in the hip and knee when compared with non-runners. Not only that but, as found by the European Journal of Applied Physiology, recreational runners have a reduced concentration of cytokine—proteins which cause inflammation in the knee—than recreational runners.

Throughout September this year, I ran more regularly than I have ever done before in preparation for the Cardiff Half Marathon. Usually, as school starts and the weather gets colder, I get a blocked nose and a sore throat like everyone else. This year, I haven’t been ill once. Until researching for this article, I had always attributed that to other factors. I now know that the statistics show otherwise; it is running that has improved my life once again. Research shows that running at least 5 days a week can lower your risk of upper respiratory tract infections by 43%. This is because running strengthens your immune system, partly because the increased blood flow of running helps to remove toxins and distribute nutrients around the body more efficiently.

However, the benefits of running do not stop at your physical health. There is scientific proof that running changes how your brain works for the better. As reported in the Frontiers in Human Neuroscience, a study was conducted in which the brains of young, competitive distance runners were scanned. When compared with control participants, the runners showed greater connectivity between the frontal-parietal network, responsible for cognitive control, and neural regions involved in working memory and self-control.

Running is also one of creation’s best stress relievers. A study conducted by the running brand Asics measured the brain waves of individuals before and after a 20-minute run. They found that even this short run led to a 58% reduction in levels of cognitive stress. Another study found that running just 15 minutes per day can lower your chances of developing depression by roughly 26%. It is unsurprising that running has such a positive effect on your mental health. In 2015, researchers found that running results in better emotional management, as reported in the study Acute Aerobic Exercise Helps Overcome Emotion Regulation Deficits. There are several other factors at play here too: Being in nature and getting some fresh-air, improving your self-esteem, having some routine, feeling a sense of community and improving your relationship with food are all by-products or running which make significant differences to your mental health.   

But these aren’t the only reasons running results in better mental health. Another element is the mysterious ‘runner’s high’, the magical, euphoric sensation you are supposed to get a couple of miles into your run. If you thought this was caused by the rush of endorphins (‘happy hormones’) resulting from aerobic exercise, you are not alone. So did almost every scientist until the late nineties. Although endorphins are very good and can help prevent muscles from feeling pain, recent studies prove that their molecules are actually too big to pass through into the brain. This is making many scientists believe that it is in fact endocannabinoids, another group of biochemicals, which is responsible for this experience. These lipid molecules act on the endocannabinoid system, the same system affected by the active compound in cannabis. That’s right; weed. That means a ‘runner's high’ is actually very similar to a high induced by drugs except much safer, healthier, more respectable and usually less intense. Recent results suggest it can even be as addictive, since it is also linked to the dopamine (another ‘happy hormone’) circuit, although it does not take ‘as big a wallop on that circuit as, say, cocaine and nicotine’, says neuroscientist Cecilia Hillard. The long term effects of runners high on your body’s system are still being investigated. One thing we know for certain is that they are definitely beneficial. At the moment, the use of endocannabinoids is being explored as a means to treat PTSD, anxiety and depression. 

Running benefits almost every single part of your body. And no wonder; running is more than just a modern sport, it’s an ancestral calling. No matter what you’re convinced you’re capable of, human bodies–including yours—are built for endurance running. Before the invention of weapons, early man would hunt their prey by chasing them for days on end until the animal collapsed of exhaustion. Intelligence is not our only outstanding trait. Although animals like cheetahs are faster, observation shows that humans can run for longer than quite literally any other animal in the world. 

We were all born to run and our body rewards us for it—in pretty much every way it can. Running is one of the most accessible sports and will honestly change your life, as it has mine. So what’s stopping you from lacing up those trainers?