Botanists on a field trip, collecting plant specimens in a herbarium press.

Herbarium

---

A herbarium is a building that contains a collection of dried plant samples commonly referred to as plant specimens. Herbaria are responsible for maintaining the extensive collection of pressed, dried plant voucher specimens mounted on boards and labelled for scientific studies.

Thousands of herbarium plant specimens have been collected all around the world. These specimens are dried and carefully mounted on cardboard sheets along with the information relating to who collected them and where and when they were collected. The specimens are filed in shelves in large cupboards according to which plant family they belong to.

Herbarium plant specimens are used to describe species. Each specimen represents how a specific plant species looks like in the different areas where it has been collected.

They also inform us about the distribution of individual species over time. The species distribution is plotted on a map. Each specimen of a specific plant species is represented by a dot on a map.

Great White Shark (Carcharodon carcharias)

---

The Great white sharks are the largest known predatory fish and are probably South Africa's most famous shark family, playing a significant role at the top of the marine food chain. The Great white sharks are found worldwide in temperate and subtropical waters. In South Africa, Great whites are most frequent in False Bay, Gansbaai, Mossel Bay and Bird Island in Algoa Bay. They have a large torpedo-shaped, streamlined body and for steering and balancing they use their caudal and pectoral fins. They cruise seamlessly through water for long periods of time but can swim very fast in order to catch prey. The back of their bodies have a grey colour and the front of their body is white. The mix of these two colours acts a protective camouflage when they hunt for prey, they are able to blend in with their surrounding environment and remain unnoticeable.

The great white shark has no parental care. At birth the pups (baby sharks) are as long as an adult male (1.5m) are able to look after themselves and hunt for their own food. Pups feed on fish, cephalopods like squid and octopus. Many pups do not survive the first twelve months as they get preyed upon by bigger predators including other great white sharks. Adult great white sharks feed on bony fish and sea mammals (mainly sea lions, seals and dolphins).

They have no movable eyelids but protect their eyes by rolling them backwards when feeding. The teeth of the Great White are large, with a jagged edge like a saw or similar to the blades of a saw or sharp bread knife edges. Despite having 300 teeth, they do not chew their food but rip their prey into small-sized pieces that are swallowed whole. The hunting of Great white sharks for their fins, teeth and as trophies in South African waters is prohibited as they are listed as Vulnerable species on the International Union for Conservation of Nature (IUCN) Red List of threatened species.

The South African Institute for Aquatic Biodiversity (SAIAB) supports research on white Great white sharks. The Great white is among the 22 species of sharks tagged through SAIAB’s Acoustic Tracking Array Platform (ATAP) to gather more information on shark movements and population size. Information gathered by ATAP researchers is also used to facilitate the most effective protection of this species as well as the fragile marine ecosystems in which they live in by informing the government on critical areas they use as their habitat – government is then able to develop what is known as Marine Protected Areas (MPAs). MPAs are areas of the coastline or ocean that are specially protected for the benefit of people and the marine animals living there by not allowing certain activities such as fishing in those areas.

The SAIAB’s National Fish Collection has 5 catalogued specimens, 5 jaws of the Great White shark including the only record of the albino great white shark. The SAIAB’s National Aquatic Biobank has about 20 tissue samples of Great white sharks and these form part of the resource for researchers who study the naming, defining and classifying fish based on their shared characteristics.

Southern Right Whale

---

Hanging from the ceiling in the Marine Hall at Bayworld Museum in Gqeberha, is the 20 metre long, complete and articulated skeleton of a southern right whale, Eubalaena australis. This was only the second marine mammal specimen collected by the museum. It arrived in 1901. At that time there was still an open boat whaling industry in Algoa Bay. When whales were sighted in the bay from the hills surrounding the then Port Elizabeth (now the city of Gqeberha), small boats would set off from the shore. This was a dangerous business, with whalers using hand-launched harpoons to kill the whales. Many lost their lives. If successful, the dead whale would be towed back to shore to be dismembered by one of the various whaling firms based in the Bay. On the 12th of November 1901, a whaling boat from the firm, the Messina Brothers, brought back this whale. The skeleton was likely cleaned at the whaling station before being transferred to the museum. And this skeleton has travelled with the museum over the years, being displayed wherever the museum was located. 120 years later, it still continues to make people wonder and inspire scientific curiosity, in older researchers, or eager schoolchildren alike.

The southern right whale is a baleen whale. Baleen whales sieve planktonic creatures from the water using "whalebone" in their mouths. Southern right whales feed almost entirely on zooplankton, particularly krill. They feed just beneath the water's surface, holding their mouths partially open and continuously skimming water as they swim. To catch their prey, they strain the water through their long baleen plates. The baleen of a southern right whale can be up to 2.8 m long and is made up of 220-260 baleen plates.

The southern right whale, is listed as "endangered" by CITES, and is protected by all countries with known breeding populations (Argentina, Australia, Brazil, Chile, New Zealand, South Africa and Uruguay).

Fungi

---

Fungi are all around us, in the soil, our bodies and the air, but are often too small to be seen with the naked eye. There are 120,000 classified types of fungi. Scientists estimate that there are 2.2 – 3.8 million species in total, including mushrooms, yeast, lichens, rust, and mold.

Fungi are non-motile, heterotrophic (no chlorophyll), unicellular (yeast) or filamentous (fungus), reproduce by means of spores, consist of long thread-like structures known as hyphae that form a mesh-like structure called mycelium.

Some play an important role in the decomposition of organic material and nutrient cycling in nature, while others form symbiotic relationships with plants. Others are plant or animal pathogens or endophytes (living inside a plant). They also serve as a food source for a large variety of organisms, including humans.

They occur in most habitats from the Arctic to Antarctica, from high mountain tops to desert sand. Some even lives in marine and fresh water environments. More than 90% of the estimated 3.8 million fungi in the world are currently unknown to science.

Did you know?
1. A fungus lives in symbioses with algae and this beneficial lifeform is called a lichen.
2. Fungi are in a kingdom of their own but are closer to animals than plants.
3. They have chemicals in their cell walls shared with lobsters and crabs.
4. There is evidence to suggest that yeasts - a type of fungus - were being used to produce the alcoholic drink mead as long ago as 9,000 years ago.
5. Products made from fungi can be used as replacements for polystyrene foam, leather and building materials.
6. DNA studies show that there are thousands of different fungi in a single sample of soil, many of which are unknown and hidden.
7. They are 2-10µm in size.
8. A huge underground fungus that is one of the largest living organisms on the planet. It spanned at least 0.37 square kilometres .It was estimated in 1980 to be at least 1500 years old and weighed at least 100,000 kilograms.
9. Fungi affects every part of your life, what you eat, what you wear, what you do and your mood.
10. Mycorrhizal fungus forms an essential symbiotic relationship with plant roots. Mycorrhizal fungi help tree and shrub roots find water and nutrients. In return, the roots give the fungi carbon, carbohydrates, and other nutrients.
11. Mushrooms and other fungi release an incredible amount of spores into the atmosphere every year, and contributing up to 50 million tonnes of particulates.

The embryos in the Bernard Price Institute collection of Karoo vertebrates at the Evolutionary Studies Institute of the University of the Witwatersrand.
Photo: Ilse van der Merwe, NSCF

Dinosaur Eggs with Embryos

---

Eggs with embryos belonging to the southern African dinosaur Massospondylus were discovered in 1978 from a road cut-away in the Golden Gate National Park in the Free State.

A clutch of six eggs was removed but these were surrounded by a rock matrix. The scientists believed that attempting to remove the eggs would damage them. Xrays revealed the presence of embryos, but these remained hidden until 2005 when these eggs were carefully partially prepared out of the rock. Once the detail of the structure of the embryos was revealed, scientists were able to improve their understanding about the development of this remarkable dinosaur.

These dinosaurs lived in the early Jurassic, between 200 and 183 million years ago. measured around 4 metres in length and weighing around 1000 kilogrammes, though some sources estimate its length as high as 6 metres. It had a slender body, a long neck, and a relatively small head.

Most recently, Wits scientists (Chapelle et al., 2021) utilised the high-powered and intense energy of the European Synchrotron Radiation Facility (ESRF), located at Grenoble in France to unscramble the embryonic development of dinosaurs. These embryos are in the Bernard Price Institute collection of Karoo vertebrates at the Evolutionary Studies Institute (ESI) of the University of the Witwatersrand.

Mercury

---

Mercury, the closest planet to the Sun, is a fascinating world of extremes. It's the smallest planet in our solar system, with a diameter just a bit larger than Earth's Moon. Despite its diminutive size, Mercury is a fiery planet, experiencing temperatures that range from scorching hot to freezing cold. During the day, when Mercury faces the Sun, temperatures can soar up to a blistering 800 degrees Fahrenheit (430 degrees Celsius). However, at night, when Mercury turns away from the Sun, temperatures plummet to a bone-chilling minus 290 degrees Fahrenheit (minus 180 degrees Celsius).

Mercury is a rocky planet with a heavily cratered surface, resembling the surface of Earth's Moon. Its surface features include vast plains, towering cliffs, and deep craters formed by impacts from asteroids and comets. The planet's lack of atmosphere means there is no protection from these impacts or from the Sun's intense radiation.

Despite its proximity to the Sun, Mercury is not the hottest planet in our solar system. That title goes to Venus, the second planet from the Sun. However, Mercury does have the greatest temperature variation between its day and night sides, making it one of the most extreme environments in our solar system.

Venus

---

Venus, often called Earth's "twin" due to its similar size and composition, is a mysterious and inhospitable world. It is the second planet from the Sun and is often referred to as the "morning star" or the "evening star" because it is one of the brightest objects in the night sky. Despite its beauty when viewed from Earth, Venus is a hostile planet with surface temperatures hot enough to melt lead.

The surface of Venus is shrouded in thick clouds of sulfuric acid, making it impossible to see the planet's surface with the naked eye. These clouds trap heat from the Sun, creating a runaway greenhouse effect that has caused Venus to become the hottest planet in our solar system, even hotter than Mercury.

Beneath its toxic atmosphere, Venus has a rocky surface with vast plains, towering mountains, and deep valleys. It is home to numerous volcanoes, including the massive Maxwell Montes, which is the highest mountain on Venus. The planet's surface is littered with volcanic features, indicating a history of volcanic activity.

Despite its extreme conditions, scientists are intrigued by Venus and continue to study its atmosphere and surface using spacecraft and telescopes. Understanding Venus could provide valuable insights into the processes that shape rocky planets and help scientists better understand the potential for life beyond Earth.

Earth

---

Earth, our home planet, is a unique and vibrant world teeming with life. It is the third planet from the Sun and the only planet in our solar system known to support life. Earth's surface is covered in vast oceans, lush forests, towering mountains, and sprawling deserts, creating a diverse and dynamic environment.

One of the most remarkable features of Earth is its atmosphere, which is composed primarily of nitrogen and oxygen. This atmosphere acts as a protective shield, filtering out harmful solar radiation and regulating the planet's temperature. Earth's atmosphere also plays a crucial role in the water cycle, weather patterns, and climate regulation.

The surface of Earth is divided into several major landmasses, including continents and islands, which are surrounded by vast oceans. These landmasses are constantly shifting and changing due to processes like plate tectonics and erosion, shaping the planet's landscape over millions of years.

Earth is also home to a staggering array of life forms, from microscopic bacteria to towering trees and majestic animals. The diversity of life on Earth is unparalleled, with millions of species inhabiting every corner of the planet, from the depths of the ocean to the highest mountains.

In addition to its natural beauty and biodiversity, Earth is also unique in its ability to sustain life. The presence of liquid water, moderate temperatures, and a stable atmosphere make Earth the perfect habitat for a wide variety of organisms, including humans. Protecting and preserving Earth's delicate balance is essential for the continued survival of life on our planet.

The Moon

---

The Moon, Earth's only natural satellite, is a fascinating and mysterious world that has captivated humans for thousands of years. It orbits around Earth at a distance of about 238,855 miles (384,400 kilometers) and is about one-quarter the size of Earth. The Moon has a rocky surface covered in craters, mountains, and plains, with no atmosphere to protect it from meteoroids and solar radiation.

One of the most striking features of the Moon is its phases, which change as it orbits around Earth. These phases, from a full moon to a new moon and back again, are caused by the relative positions of the Moon, Earth, and Sun. The Moon's gravity also affects Earth's tides, causing them to rise and fall in a predictable pattern.

The Moon has played a crucial role in human history and culture, inspiring myths, legends, and scientific inquiry. It has been the target of numerous spacecraft and missions, including the Apollo missions, which brought humans to the lunar surface for the first time. Today, the Moon continues to be a focus of scientific research and exploration, with plans for future missions to return humans to the lunar surface and establish a permanent presence there.

Mars

---

Mars, often called the "Red Planet" due to its rusty hue, is a cold and barren world with a fascinating history. It is the fourth planet from the Sun and is about half the size of Earth. Mars has intrigued scientists for centuries with its potential for harboring life and its similarities to Earth.

The surface of Mars is covered in reddish-brown soil and is dotted with impact craters, volcanoes, and vast plains. One of the most prominent features of Mars is Olympus Mons, the largest volcano in the solar system, which stands nearly three times taller than Mount Everest. Mars also has a massive canyon system called Valles Marineris, which stretches for over 2,500 miles (4,000 kilometers) and is deeper than the Grand Canyon.

Despite its barren appearance, Mars has captured the imagination of scientists and explorers alike. Evidence from spacecraft and rovers suggests that Mars was once a warmer and wetter planet with rivers, lakes, and possibly even oceans. Scientists continue to search for signs of past or present life on Mars, studying its geology, atmosphere, and climate to unravel the planet's mysteries.

In recent years, Mars has become a focus of human exploration, with numerous missions planned to study the planet and prepare for future human missions. NASA's Perseverance rover, launched in 2020, is currently exploring the surface of Mars, searching for signs of ancient microbial life and collecting samples for return to Earth. The exploration of Mars holds the promise of answering fundamental questions about the potential for life beyond Earth and the future of human space exploration.

Jupiter

---

Jupiter, the largest planet in our solar system, is a gas giant with a mesmerizing appearance and a host of fascinating features. It is the fifth planet from the Sun and is more than twice as massive as all the other planets combined. Jupiter's massive size and strong gravitational pull make it a dominant force in the solar system, influencing the orbits of nearby objects and protecting the inner planets from potential impacts.

One of the most striking features of Jupiter is its colorful bands of clouds, which are made up of ammonia crystals and other compounds. These bands of clouds swirl around the planet, creating mesmerizing patterns and storms that can last for centuries. The most famous of these storms is the Great Red Spot, a massive storm system that has been raging for over 300 years and is larger than Earth itself.

Beneath its thick atmosphere, Jupiter has a core made of rock and metal surrounded by layers of hydrogen and helium gas. Despite its massive size, Jupiter has no solid surface, so if you were to try to land on the planet, you would simply fall through its atmosphere until you reached its core.

Jupiter is also home to a diverse array of moons, with over 70 known moons orbiting the planet. The four largest moons – Io, Europa, Ganymede, and Callisto – are known as the Galilean moons and were discovered by the astronomer Galileo Galilei in 1610. These moons are each unique worlds with their own geology and atmosphere, and they continue to fascinate scientists with their potential for harboring life.

Saturn

---

Saturn, known for its majestic rings, is the sixth planet from the Sun and the second largest in our solar system. It is a gas giant like Jupiter, composed mostly of hydrogen and helium, with a small rocky core at its center. Saturn's most distinctive feature is its rings, which are made up of billions of icy particles ranging in size from tiny grains to large chunks. These rings extend thousands of kilometers from the planet's surface and are visible even from Earth with a small telescope.

Beneath its rings, Saturn has a thick atmosphere with colorful bands of clouds, similar to Jupiter. The planet's atmosphere is primarily composed of hydrogen and helium, with traces of other gases like methane and ammonia. Saturn's atmosphere is also home to powerful storms, including a hexagonal-shaped storm near its north pole.

Saturn has a diverse collection of moons, with over 80 known moons orbiting the planet. The largest of these moons is Titan, which is larger than the planet Mercury and is the only moon in the solar system with a dense atmosphere. Titan's atmosphere is primarily composed of nitrogen, with traces of methane and other gases, making it an intriguing target for future exploration.

In addition to Titan, Saturn's moons include Enceladus, which has geysers of water vapor erupting from its surface, and Mimas, which has a large crater resembling the "Death Star" from Star Wars. These moons, along with Saturn's rings, make it one of the most captivating objects in the night sky.

Uranus

---

Uranus, the seventh planet from the Sun, is an ice giant with a mysterious and enigmatic atmosphere. It is the third largest planet in our solar system and is tilted on its side, with its axis of rotation nearly parallel to its orbit around the Sun. This unique orientation gives Uranus its distinctive appearance and causes extreme seasonal variations as it orbits the Sun.

Uranus has a thick atmosphere composed primarily of hydrogen and helium, with traces of methane that give it a blue-green color. The planet's atmosphere is marked by high-speed winds that can reach speeds of up to 560 miles per hour (900 kilometers per hour). Uranus also has a system of faint rings and a collection of moons, the largest of which is named Titania.

Despite its unique features, Uranus is one of the least explored planets in our solar system, with only one spacecraft – Voyager 2 – having visited the planet in 1986. The limited data collected by Voyager 2 has left many questions unanswered, including the origin of Uranus' unusual tilt and the composition of its atmosphere. Future missions to Uranus could provide valuable insights into the history and evolution of our solar system.

Neptune

---

Neptune, the eighth and farthest planet from the Sun, is a frigid and distant world with a dynamic and turbulent atmosphere. It is the fourth largest planet in our solar system and is composed primarily of hydrogen and helium, with traces of methane that give it a blue color. Neptune's atmosphere is marked by powerful storms, including the Great Dark Spot – a massive storm system similar to Jupiter's Great Red Spot.

Neptune has a system of faint rings and a collection of moons, the largest of which is named Triton. Triton is unique among Neptune's moons because it orbits the planet in a retrograde direction, opposite to the planet's rotation. Triton is also one of the coldest objects in our solar system, with surface temperatures that can plunge to minus 391 degrees Fahrenheit (minus 235 degrees Celsius).

Despite its remote location, Neptune has been visited by only one spacecraft – Voyager 2 – which flew by the planet in 1989. Voyager 2 provided valuable data about Neptune's atmosphere, rings, and moons, but many questions remain unanswered. Future missions to Neptune could provide insights into the planet's composition, weather patterns, and geological features.

The Milky Way

---

The Milky Way, our home galaxy, is a vast and majestic cosmic structure that stretches across the night sky like a shimmering river of stars. Named for its hazy appearance as seen from Earth, the Milky Way is a spiral galaxy composed of billions of stars, stellar remnants, gas, and dust, bound together by gravity.

At the heart of the Milky Way lies a dense region known as the galactic bulge, where stars are densely packed and stellar densities are highest. Surrounding the bulge is a flattened disk of stars, gas, and dust, which extends outward in a spiral pattern. Spiralling arms of stars and interstellar material spiral outwards from the central bulge, creating the iconic spiral arms that give the galaxy its distinctive appearance.

Our solar system resides in one of the Milky Way's spiral arms, known as the Orion Arm or Local Spur. From our vantage point within the galaxy, we peer outward into the vast expanse of space, observing the stars, nebulae, and other celestial objects that populate our cosmic neighbourhood.

The Milky Way is a dynamic and evolving entity, with stars orbiting the galactic centre in elliptical, circular, and spiral trajectories. Over billions of years, these stars interact with one another, forming stellar clusters, binary systems, and occasionally, catastrophic events such as supernovae and black hole mergers.

Moreover, the Milky Way is not alone in the cosmos but is part of a larger cosmic web of galaxies, clusters, and superclusters, bound together by the force of gravity. As we peer deeper into space with telescopes and observatories, we uncover the vastness of the universe and our place within it.

Studying the Milky Way provides insights into the formation, evolution, and dynamics of galaxies, shedding light on the processes that shape the cosmos. It allows us to probe the mysteries of dark matter and dark energy, understand the origins of stars and planets, and explore the potential for life beyond Earth.

Our Galaxy

---

Our galaxy, known as the Milky Way, is a spectacular celestial phenomenon that enchants observers with its vastness and beauty. It spans an immense distance of about 100,000 light-years and comprises billions of stars, along with interstellar gas and dust. A stunning spiral galaxy, the Milky Way boasts a mesmerising structure, with a central bulge surrounded by a flattened disk of stars, gas, and dust. Radiating outwards from the bulge are magnificent spiral arms, each adorned with stellar clusters, nebulae, and other celestial wonders.

Nestled within one of these spiral arms, our solar system finds its home. From our position within the galaxy, we are afforded a breathtaking view of the cosmos, as we peer into the depths of space and marvel at the myriad stars and galaxies that populate our galactic neighbourhood.

The Milky Way is a dynamic and ever-evolving entity, with stars tracing graceful orbits around its centre. Over eons of time, these stars interact, forming clusters, binary systems, and occasionally experiencing cataclysmic events such as supernovae and black hole mergers.

Furthermore, the Milky Way is not an isolated entity but rather part of a vast cosmic ensemble, bound together by the force of gravity. As we explore the universe with increasingly powerful telescopes and instruments, we gain insights into the interconnectedness of galaxies and the intricate tapestry of the cosmos.

Studying our galaxy opens a window into the mysteries of the universe, offering clues about its origins, evolution, and ultimate fate. It allows us to ponder the enigmatic phenomena of dark matter and dark energy, contemplate the formation of stars and planets, and speculate about the possibility of life beyond our solar system.

In conclusion, the Milky Way stands as a testament to the grandeur and complexity of the universe, inspiring wonder and curiosity in all who contemplate its splendour. By studying our galaxy, we embark on a journey of discovery, deepening our understanding of the cosmos and our place within it.

The Sun

---

The Sun is the star at the centre of our Solar System. It is by far the most important source of energy for life on Earth. The interactions between the Sun and Earth drive the seasons, ocean currents, weather, climate and calendar.

The Sun is 75% hydrogen and 25% helium. It’s energy comes from the fusion of hydrogen into helium. Its diameter is about 1.39 million kilometres (864 000 miles), or 109 times that of Earth, and its mass is about 330,000 times that of Earth.

The Sun currently fuses about 600 million tons of hydrogen into helium every second, converting 4 million tons of matter into energy every second producing light and heat. It takes light just over 8 minutes to travel the 150 000 000 km (93 000 000 miles) from sun to earth. Of the approximately 1 500 W/m2 of energy that reaches earth only 1 000 W/m2 reaches the ground.

Our sun’s class and size make it a yellow dwarf star. It formed approximately 4.6 billion years ago. It accounts for about 99.86% of the total mass of our solar system. The rest flattened into an orbiting disk from which the planets formed. The sun’s gravity holds our solar system together, keeping everything from the biggest planets to the smallest particles of debris in its orbit.

Electric currents in the Sun generate a magnetic field that is carried out through the solar system by the solar wind—a stream of electrically charged gas blowing outward from the Sun in all directions.

There are billions of stars like our Sun in just our Milky Way galaxy alone.

Jets

---

Have you ever looked up at the sky and seen a plane flying incredibly fast, leaving a white trail behind it? That's probably a jet!

Jets are powerful aircraft powered by jet engines. Unlike old propeller planes, jets work using a brilliant scientific principle called jet propulsion. The engine sucks in air at the front, squeezes it tightly with compressors, mixes it with fuel, and sets it on fire. The burning gases explode out of the back at extremely high speed. According to Newton's third law ("for every action, there is an equal and opposite reaction"), this backward force pushes the plane forward at amazing speeds — often faster than the speed of sound!

Modern passenger jets like the Airbus A350 or Boeing 787 can fly from Johannesburg to London in about 11 hours. In South Africa, jets are used for commercial flights, military defence (like the South African Air Force's Gripen fighter jets), and even medical emergencies.

From a STEM point of view, jets are incredible achievements. Aerospace Engineers design the wings, fuselage, and overall shape of the plane. Mechanical Engineers work on the powerful jet engines and landing gear. Avionics Engineers create the complex electronic systems, navigation, and flight computers. Materials Scientists develop special lightweight but super-strong materials that can survive the enormous heat and pressure inside a jet engine.

Jets show us how science and engineering can push the limits of what's possible. They help connect people across the world, deliver goods quickly, and protect our country. Next time you see a jet soaring high above the clouds, remember: behind that smooth flight is decades of physics, mathematics, chemistry, and brilliant engineering!

Robots

---

Have you ever watched a robot move, talk, or build something and thought, "That's so cool!"? Robots are machines that can perform tasks automatically, sometimes even thinking and making decisions on their own.

A robot is usually made up of sensors (to "see" or "feel"), a brain (a computer), motors or muscles (to move), and a body. Some robots work in factories assembling cars, others explore the ocean floor, help doctors in surgery, or clean your house. The most advanced ones, like humanoid robots, can walk, talk, and even learn from experience using Artificial Intelligence.

The word "robot" comes from a Czech word meaning "forced labour." The first modern industrial robots appeared in the 1960s. Today, South Africa uses robots in mining, car manufacturing, and even in agriculture to pick fruit or monitor crops.

From a STEM point of view, robots are one of the best examples of combined sciences. Mechanical Engineers design the moving parts and strong structures. Electrical Engineers and Electronics Engineers build the wiring and power systems. Mechatronics Engineers bring everything together — mechanics, electronics, and computer control. Computer Engineers and Data Scientists create the software and artificial intelligence that allow robots to think and learn.

Robots are changing our world — they do dangerous jobs, boring repetitive tasks, and helpful roles like assisting elderly people or teaching children. In the future, robots will likely help solve big problems like healthcare shortages and climate change.

Sailboat

---

Have you ever looked at the ocean and imagined gliding across the water powered only by the wind? That's the beauty of a sailboat!

A sailboat is a watercraft that uses wind to move. Instead of engines, it has large pieces of fabric called sails attached to tall masts. When wind blows into the sails, it creates force that pushes the boat forward. Sailboats have been used for thousands of years — from ancient Egyptian and Phoenician traders to the great explorers who sailed around the world.

In South Africa, with our long coastline and strong winds, sailing is both a sport and a way of life. Many people sail for fun in places like Cape Town, Durban, and the Garden Route. Traditional wooden boats and modern racing yachts can both be seen along our shores.

Sailing is full of real science. Physicists study how wind interacts with sails through aerodynamics. Mechanical Engineers design strong masts, winches, and hull shapes that cut through waves efficiently. Navigators and Marine Engineers use mathematics and technology to plot courses using stars, GPS, and weather data. Even Environmentalists appreciate sailboats because they use clean, renewable wind power instead of burning fuel.

Learning to sail teaches many important skills: teamwork, problem-solving, responsibility, and respect for nature. Next time you see a sailboat leaning into the wind with its sails full, remember: behind that graceful movement is centuries of science, engineering, and courage!

Steam Engine

---

Have you ever wondered what powered the very first trains, factories, and big ships before electricity and diesel? The answer is the incredible steam engine!

A steam engine is a machine that converts heat energy into mechanical movement. It works by burning coal (or wood) to boil water in a large boiler. When the water turns into high-pressure steam, it pushes against pistons inside cylinders. These pistons move back and forth, which then turns wheels or drives machinery. The famous "choo-choo" sound and puffs of smoke you see on old trains come from steam being released.

The steam engine was one of the most important inventions of the Industrial Revolution. Scottish engineer James Watt greatly improved it in the 1700s, making it powerful enough to run factories and locomotives. In South Africa, steam engines played a huge role in transporting gold, diamonds, coal, and people across the country during the late 1800s and 1900s.

From a STEM point of view, the steam engine is a perfect example of applied science. Mechanical Engineers designed the pistons, boilers, and safety valves. Physicists studied heat, pressure, and energy conversion. Civil Engineers built railway lines and bridges strong enough for these heavy machines. Even Chemical Engineers worked on better fuels and water treatment.

The steam engine taught the world how to turn heat into useful work and laid the foundation for all modern engines — from cars to power stations. Next time you see an old steam train chugging along, remember: you're looking at one of the inventions that changed the world forever!

Tank

---

Have you ever seen a massive, heavily armoured vehicle with a big cannon rolling across the ground? That's a tank — one of the most powerful machines ever built for land warfare.

A modern tank is a heavily protected fighting vehicle designed to dominate the battlefield. It has thick armour to protect the crew, powerful tracks instead of wheels so it can move over rough terrain, and a large rotating turret with a powerful cannon. Inside, a team of 3 to 4 crew members works together — a commander, gunner, loader, and driver.

The first tanks appeared during World War I in 1916. The British called them "tanks" as a secret code name so enemies wouldn't know what they were building. Today's tanks use composite armour, night vision, laser rangefinders, and even computer systems that help them aim accurately while moving.

From a STEM point of view, tanks are incredible examples of engineering. Mechanical Engineers design the engine, tracks, and suspension. Materials Scientists develop super-strong but lightweight armour. Electrical Engineers and Electronics Engineers create the communication systems, sensors, and fire control computers. Mechatronics Engineers bring all these systems together seamlessly.

While tanks were created for war, the engineering behind them has also helped develop better engines, stronger materials, and advanced sensors used in peaceful machines like tractors and rescue vehicles. Next time you see a tank, remember: it's not just a weapon — it's a masterpiece of human engineering and teamwork.

Cave People

---

Have you ever wondered what life was like for humans thousands of years ago? Long before houses, cars, or smartphones, early humans lived as cave people!

Around 40,000 to 100,000 years ago, our ancestors — including early Homo sapiens and Neanderthals — often lived in caves. Caves offered natural protection from rain, cold, wild animals, and extreme weather. These ancient people were skilled hunters, gatherers, and artists. They made tools from stone, bone, and wood, created fire for cooking and warmth, and painted beautiful pictures of animals on cave walls — famous examples can be found in South Africa's Cederberg and Drakensberg mountains.

The discovery of fire was one of their greatest achievements — it helped them cook food, stay warm, and scare away predators. Over time, they developed language, music, and rituals. From a STEM point of view, cave people were early scientists and engineers. They understood physics when making spears and arrows, chemistry when creating pigments for rock art, and biology when tracking animals and using medicinal plants.

South Africa is very special because it has some of the oldest evidence of modern human behaviour in the world, including tools and art found in caves like Blombos and Pinnacle Point. Modern Archaeologists, Paleontologists, and Anthropologists study these cave sites to learn how ancient humans lived, migrated, and survived.

Next time you see a cave or rock shelter, remember: our ancestors were smart, creative, and tough. They used science and teamwork to survive — and everything we have today started with their curiosity and ingenuity.

Locomotive Train

---

Have you ever heard the loud whistle and seen clouds of smoke from an old-fashioned train chugging along the tracks? That's the magic of the old steam train!

Before electric and diesel trains, powerful steam locomotives ruled the railways. These mighty machines were invented in the early 1800s and became the backbone of transport during the Industrial Revolution. In South Africa, old steam trains played a huge role in connecting mines, farms, and cities. They carried gold, coal, passengers, and goods across our vast country, helping to build the nation we know today.

How did they work? A steam train burns coal to heat water in a big boiler. The boiling water turns into high-pressure steam, which pushes pistons that make the wheels turn. The loud "choo-choo" sound and white smoke are caused by steam being released. These trains were loud, smoky, and needed a team to keep them running — a driver, fireman, and guards.

Many old steam trains in South Africa, like the famous Red Devil or the Union Limited, are still preserved and sometimes run as heritage trips for tourists. From a STEM point of view, old trains are fantastic examples of engineering. Mechanical Engineers designed the boilers, pistons, and wheels. Civil Engineers built the railway lines, bridges, and tunnels. Industrial Engineers worked out how to move large amounts of goods efficiently.

Old trains teach us about innovation, hard work, and how science changed the way people travel and trade. Next time you see a heritage steam train, listen to its whistle — it's a powerful symbol of human ingenuity and South Africa's railway history!

Microscope

---

Have you ever wondered how scientists can see things that are too small for our eyes? The answer is the microscope — one of the most important tools in science!

A microscope is an instrument that magnifies tiny objects so we can study them in detail. The word "microscope" comes from two Greek words: mikros meaning "small" and skopein meaning "to look at." A basic school microscope can magnify up to 400 times, while powerful electron microscopes can magnify objects more than a million times!

Microscopes let us explore a hidden world. With them, we can see the cells in our bodies, the bacteria that cause diseases, the structure of a leaf, or the tiny details on an insect's wing. In agriculture, scientists use microscopes to study soil organisms, plant diseases, and pests. In medicine, they help doctors identify illnesses. In forensics, they are used to analyse evidence in crimes.

Modern microscopes are very advanced. Some are connected to computers so we can take photos and videos of what we see. There are also stereo microscopes for looking at larger 3D objects, and electron microscopes that use beams of electrons instead of light for incredibly sharp images.

From a STEM point of view, the microscope is a perfect example of applied science. Physicists and Engineers design better lenses and lighting systems. Biologists and Microbiologists use them to understand living things at the smallest level. Next time you look through a microscope, remember: you are using a powerful tool that has helped us discover vaccines, understand diseases, and explore the tiny building blocks of life!

Insects

---

Insects are small air-breathing arthropods (such as ants, beetles, butterflies, bees) with a three-part body (head, thorax and abdomen), three pairs of jointed legs, typically one or two pairs of wings, compound eyes and two antennae.

Insects are the most diverse group of animals; they include more than a million described species and represent more than half of all known living organisms and over 90% of the animal life forms on Earth. Insects are found in nearly all land environments, but only a few species reside in the oceans. Insects perform a vital role in supporting other life forms and ecosystems; pollination, soil aeration, processing of nutrients and as part of the overall food chain.

Entomology is the study of insects and their relationship to humans, the environment, and other organisms. Entomologists contribute to such diverse fields as agriculture, chemistry, biology, human/animal health, molecular science, and even criminology and forensics.

Plant-parasitic nematode feeding types.

Nematology

---

Nematodes, also known as roundworms and eelworms, are one of the most diverse and abundant groups of animals on earth. They are found on every continent and in almost every habitat known to man. Nematodes in the soil are microscopic organisms and can very rarely be seen with the naked eye. There are many different kinds of nematodes and they are divided into groups based on what they eat. Herbivorous nematodes (plant-parasitic nematodes), feed on all different parts of a plant. These nematodes are sometimes referred to as the bad nematodes because they can cause damage to agricultural crops and they make it difficult to grow the food we eat.

But there are also beneficial nematodes, the so called good guys, which can be beneficial to humans because they are essential for soil health. These nematodes are also divided into different groups. Bacterivores (nematodes that eat bacteria), fungivores (nematodes that eat fungi), predators (nematodes that eat other microscopic animals including other nematodes) and omnivores (nematodes that eat plants and animals). These nematodes play an essential role in the soil food web because not only do they eat the other organisms in the soil, but they are also food for many of the other animals also found in the soil. Nematodes are also important in nutrient cycling in the soil, enabling plants to take up nutrients and ensuring plant growth. In the soil environment there are millions of nematodes from all the different feeding groups.

Head stationary despite body movement

Chicken

---

Chickens (Gallus gallus domesticus) are domesticated birds that are kept as livestock. Humans consume chicken meat as well as eggs as a common part of their diet. Chickens are the most widely kept domestic birds with scientists estimating that there are over 23 billion chickens in existence.

Hens (female chickens usually over a year old) lay a clutch of around 10-12 eggs (one egg a day over the course of around two weeks). The hen incubates the eggs by keeping them warm and safe until they hatch, about 21 days later. Chicken are omnivorous birds.

Chickens can keep their heads stable even when their bodies are moving. They have evolved this ability because their eyes cannot remain fixed on an object in front of them while they are moving, so instead, they must keep their heads still to keep the focus on an object. Although they have functional wings, they cannot fly for more than a few seconds at a time.

Chickens have a lifespan of around 5 -10 years. Through DNA studies, some scientists believe that they are the closest living relative to the Tyrannosaurus Rex.

Chicken feathers are commonly used to create bedding items such as pillows and duvets. and also used to stuff upholstery,

Cattle

---

Cattle (Bos taurus) are livestock animals that are commonly raised for their meat, for milk (from cows) and for their hides which are used to make leather items. Cattle are common all over the world, and scientists estimate that there are over 1.5 billion heads of cattle in existence.

Cattle belong to the group of animals called ruminants . They have a fascinating digestive system that is adapted to take nutrients from grass, which does not have a high nutritional value. Their stomachs have four compartments, and when grazing, cattle can regurgitate their food (which is now called cud) to chew it down into smaller pieces.

Some breeds of cows are kept specifically for their ability to produce milk that humans can consume, rather than for meat production. The most well-known dairy breeds are Holstein Friesian, Jersey and Ayrshire breeds. Special machines have been designed to automate the laborious milking process.

Typically cattle have a lifespan of 18 to 22 years and weigh around 1 100 kg.

A sac spider, Cheiracanthium species, that can be found on different crops. Photograph by Peter Webb.

Spider

---

Spiders are one of the most common predator groups in South African agricultural ecosystems. This means they are abundant predators occurring on various crops, including orchards. They are considered to be natural control agents against pests and mites occurring on crops.

How are spiders able to help control pests and mites?
- Spiders are present on crops throughout the year. Their lifespan, that vary from species to species, have instars or juveniles stages that actively feed as predators. Food consumption decreases only before and during ecdysis. Ecdysis is the process where the spiders moult and shed their exoskeletons.

- The fact that spiders are usually polyphagous helps them to act as a natural control agents for pests and mites. Polyphagus means that spiders feed on a variety of available prey. They do not feed on adult prey only, but on different stages of the insect or mite. Research has shown that spiders are often some of the first predators to arrive and colonise a newly planted crop, which is important as many pests attack in the early stages of the crop during the growing season.

- Different species of spiders are found in different microhabitats. Wandering spiders live on the ground and they feed mainly on ground-living insects and larvae hibernating in the soil. The plant-dwelling spiders are present on the stems, foliage, bark or flowers of plants. Many of them are active hunters and move around in search of prey. A number of web-building spiders spin their webs between the leaves and branches, under the bark and even over the leaf surfaces. They will prey on insects that come into contact with the silk threads of their webs.

- As predators, spiders have a two-fold effect. Not only do they feed directly on their prey, but their presence also causes indirect mortality. For example, the presence of foraging spiders can disturb insect larvae, which then drop from the plant and die, or are exposed to predation by ground dwelling predators. The webs spun over the leaves also seem to make them less suitable for oviposition and feeding by pests.

Bird

---

Birds are some of the most active and interesting animals on any farm.

The Pigeon (or Dove) is a gentle, smooth-feathered bird often kept on farms. Pigeons are smart and famous for their homing ability — they can find their way back home even from very long distances. Farmers sometimes raise them for meat or simply enjoy watching them fly. They mainly eat seeds and grains scattered on the ground.

Then there's the Crow, a large, glossy black bird known for being very clever. Crows are excellent problem-solvers and have been seen using tools in the wild. On the farm, they eat leftover grains, insects, and small animals, which helps clean up the area. However, they can also be mischievous and sometimes pull up newly planted seeds or eat young crops, so farmers have to manage them carefully.

Birds like these play important roles in the farm ecosystem. They help control insect numbers and spread seeds. Some birds, like pigeons, have been used by humans for thousands of years as messengers.

From a STEM point of view, birds are fascinating to study. Biologists research their behaviour, migration patterns, and how they interact with crops. Agronomists and Agricultural Technicians learn how to encourage helpful birds while gently discouraging those that damage harvests. Environmentalists watch bird populations because they are good indicators of the health of the land and air.

Next time you visit a farm or see birds flying overhead, take a closer look. Whether it's a soft cooing pigeon or a loud cawing crow, each bird has its own story. Understanding farm birds helps us learn how science, nature, and farming work together to create a balanced environment.

Crow

---

Have you ever seen a big, shiny black bird strutting around the farm or flying over the fields? That's the Crow!

Crows are large, intelligent birds that are very common on South African farms. They have glossy black feathers, strong beaks, and sharp eyes. Crows belong to the same family as ravens and are known for being one of the smartest birds in the world. Some scientists even say crows can solve puzzles and remember human faces!

On the farm, crows play a mixed role. They help by eating insects, leftover grains, and small pests that could damage crops. However, they can also be a bit naughty — they sometimes pull up newly planted seeds or eat young plants. Farmers have to find smart ways to keep them away from certain fields without harming them.

Crows are amazing to watch. They live in groups called murders and communicate with each other using many different calls. They build strong nests high up in trees and are very protective of their babies. In South Africa, you'll often see them in maize fields, around farmyards, or near rubbish areas looking for food.

From a STEM point of view, crows are fascinating. Biologists study their clever behaviour and problem-solving skills. Agricultural Technicians and Agronomists learn how to manage them so they don't damage crops while still letting them help control insect pests. Even Environmentalists watch crows because they are good indicators of the health of the land.

Next time you see a crow cawing loudly on a fence or flying over the farm, remember: it's not just a black bird. It's a smart, hardworking part of the farm ecosystem. Understanding animals like the crow helps us learn how science, farming, and nature all work together.

Lizard

---

Have you ever spotted a quick, sun-loving creature darting across the rocks or walls on a farm? That's a lizard!

Lizards are small reptiles that are very common on South African farms, especially in warmer areas like Limpopo, Mpumalanga, and the Eastern Cape. They have dry, scaly skin, four legs, and long tails that can sometimes break off and grow back — a clever trick to escape from predators!

Most lizards on farms are harmless to humans and actually very helpful. They spend their days basking in the warm sunshine to heat up their bodies because they are cold-blooded. At night or when it's cool, they hide under rocks, in cracks, or under leaves. Their favourite food? Insects! They eat flies, beetles, caterpillars, and many other pests that can damage crops. This makes them natural pest controllers for farmers.

There are many different kinds of lizards in South Africa, from tiny geckos that can walk on walls to larger ones like the rock monitor (leguaan). Some can change colour slightly to blend in with their surroundings — a skill called camouflage.

From a STEM perspective, lizards are fascinating. Biologists study how they survive in different environments. Agricultural Technicians and Agronomists appreciate them because they reduce the need for chemical pesticides. Environmentalists see lizards as important signs of a healthy ecosystem — if lizards are thriving, it usually means the area has good biodiversity.

Next time you see a lizard soaking up the sun or chasing an insect, take a moment to watch it. These speedy little reptiles are a small but important part of farm life. They show us how every creature, even the small ones, plays a role in nature's balance.

Donkey

---

Have you ever seen a strong, patient animal with big ears and a calm personality working hard on a farm? That's the Donkey!

Donkeys (Equus asinus) have been helping humans for thousands of years. In South Africa, they are still important on many farms, especially in rural and drier areas. They are tough, sure-footed animals that can carry heavy loads, pull carts, and walk long distances even when there isn't much food or water around.

Donkeys have long ears that help them hear very well and stay cool in hot weather. They are known for being stubborn, but this is actually a smart survival skill — they won't do something if they think it's dangerous. They are very strong for their size and can survive on poor-quality grass and bushes that other animals might refuse to eat.

On the farm, donkeys are used for many jobs. They carry water, firewood, and crops. Some farmers use them to guard sheep and goats because donkeys are brave and will chase away predators like jackals or dogs. They are also gentle and can be ridden by children.

From a STEM point of view, donkeys teach us a lot. Zoologists and Biologists study their behaviour, strength, and how they adapt to tough conditions. Agricultural Technicians and Agronomists look at how donkeys can still be useful in modern farming, especially in areas where tractors are too expensive or the land is too rough. Environmentalists appreciate donkeys because they have a small environmental footprint — they eat less and need less water than horses or tractors.

Next time you see a donkey standing quietly in a field, remember: this hardworking animal has been a reliable partner to farmers for centuries. Understanding donkeys shows us how science helps us work with animals in smart and respectful ways.

Frog

---

Have you ever heard loud croaking near a farm dam or pond at night? That's the sound of a frog!

Frogs are amphibians — animals that live both in water and on land. In South Africa, they are very common around farm ponds, wetlands, and damp areas. They have smooth, moist skin, big eyes, and powerful back legs made for jumping. Most frogs start life as tadpoles swimming in water, then grow legs and lungs as they turn into adults.

Frogs are super helpful on farms. They are excellent pest controllers because they eat huge numbers of insects like flies, mosquitoes, beetles, and caterpillars. A single frog can eat hundreds of pests every night! This means farmers need fewer chemical sprays, which is better for the environment.

From a STEM point of view, frogs are important bioindicators — their presence tells us a lot about the health of the environment. Biologists and Zoologists study how they survive in different habitats. Environmentalists monitor frog populations because they are among the first animals to be affected by pollution or climate change. Agronomists appreciate them as a natural, chemical-free pest control system.

Next time you hear frogs croaking near a farm, remember: those sounds mean the ecosystem is healthy. Frogs show us how science, nature, and farming can all work together for a better environment.

Sheep

---

Have you ever seen a fluffy white animal grazing quietly in a field? That's a sheep!

Sheep are one of the most common farm animals in South Africa. They are gentle, social animals that usually live in groups called flocks. Farmers raise sheep mainly for two things: wool and meat (called lamb or mutton). Their thick, soft wool is used to make warm jerseys, blankets, socks, and even carpets.

Sheep have a special stomach with four parts that helps them digest tough grass. They spend most of their day grazing and chewing cud — bringing food back up to chew it again. This makes them very good at turning poor-quality grass into meat and wool.

In South Africa, sheep are farmed in many provinces, especially in the Karoo, Free State, and Eastern Cape. Some breeds, like the Merino, are famous worldwide for producing very fine, soft wool. Other breeds are raised mainly for meat because they grow quickly.

From a STEM point of view, sheep farming involves a lot of science. Agronomists plan the best grazing rotations so the grass stays healthy. Soil Scientists check that the land has the right nutrients. Veterinarians make sure the sheep stay healthy and protected from diseases. Geneticists breed stronger sheep that produce more wool or grow faster.

Sheep are also good for the environment when managed properly. They help control bush and weeds, and their manure naturally fertilises the soil.

Next time you see a flock of sheep, remember: these quiet, woolly animals are part of a big agricultural system. Understanding sheep shows us how biology, farming, and technology work together to produce food and clothing we use every day.

Goat

---

Have you ever watched a curious animal climbing rocks or eating almost anything in sight? That's a goat!

Goats are tough, clever, and adventurous farm animals. In South Africa, they are very popular, especially in drier areas like the Karoo, Limpopo, and Eastern Cape. Farmers raise goats for milk, meat, and sometimes to clear land because they eat bushes and weeds that other animals avoid.

Goats are known for being very agile — they can climb steep hills, jump over fences, and even stand on their hind legs to reach leaves high up in trees. They have rectangular pupils that give them excellent side vision to spot danger. Goats are also very social and love to live in small groups.

One of the coolest things about goats is how hardy they are. They can survive on poor-quality food and need less water than cows or sheep. This makes them perfect for areas where grass is scarce. Their milk is easier for some people to digest than cow's milk and is often turned into cheese or yoghurt.

From a STEM point of view, goats are fascinating. Agronomists study the best ways to manage grazing so goats don't overeat the land. Soil Scientists check how goat manure helps improve soil fertility. Geneticists breed stronger goats that produce more milk or resist diseases. Veterinarians and Agricultural Technicians help keep goat herds healthy and productive.

Next time you see a goat climbing or chewing on a tough bush, remember: these hardy animals are important helpers on many South African farms. They teach us about resilience, smart farming, and how science helps us work with nature.

Pig

---

Have you ever seen a smart, pink animal with a curly tail and a big snout rooting around in the mud? That's a pig!

Pigs are highly intelligent farm animals. In South Africa, they are raised mainly for meat — pork, bacon, sausages, and ham. They are social creatures that live in groups and have an excellent sense of smell. Their snout is like a built-in tool that they use to dig in the soil looking for roots, insects, and anything tasty.

Pigs don't sweat like humans do, so they roll in mud to cool down and protect their skin from the sun. Contrary to what many people think, pigs are actually very clean animals when given enough space — they usually keep their sleeping area separate from their toilet area.

On farms, pigs grow quickly. A piglet can weigh over 100 kg in just six months! Farmers must give them a balanced diet of grains, vegetables, and special feed so they stay healthy. In South Africa, pig farming is an important industry that provides jobs and affordable protein for many families.

From a STEM point of view, pigs are fascinating. Agronomists and Agricultural Technicians study the best feeding methods and housing systems. Veterinarians work hard to prevent diseases like African Swine Fever. Geneticists breed pigs that grow faster, produce more meat, and resist illnesses. Environmental Engineers design better waste management systems because pig manure can be turned into valuable fertiliser or even biogas for energy.

Next time you eat bacon or pork, remember the clever pig behind it — and all the STEM minds working to raise them responsibly.

Duck

---

Have you ever seen a bird with a waddling walk, webbed feet, and a loud "quack"? That's a duck!

Ducks are water-loving birds commonly found on South African farms, especially near ponds or dams. They have waterproof feathers, flat bills, and webbed feet that make them excellent swimmers. Farmers raise ducks for their eggs, meat, and sometimes for natural pest control in wet areas.

Ducks are fun to watch. They spend a lot of time in water, dipping their heads to find small fish, snails, insects, and water plants. This makes them very useful on farms because they eat pests that could damage crops or spread disease. Their loud quacking is a familiar sound around many farmyards!

There are different types of ducks. Some are raised mainly for meat, while others are better egg layers. In South Africa, ducks are often kept in small flocks. They need access to clean water for swimming and drinking, plus shelter at night to protect them from predators like jackals or eagles.

From a STEM point of view, ducks are interesting to study. Biologists and Zoologists research their behaviour, swimming ability, and role in the farm ecosystem. Agronomists and Agricultural Technicians look at how ducks can help control pests naturally, reducing the need for chemicals. Environmentalists appreciate ducks because they show how integrating animals with water systems can create a healthier, more balanced farm.

Next time you hear a loud quack near a farm pond, remember: these waddling birds are doing important work — eating pests, providing eggs and meat, and showing us the value of a healthy farm ecosystem.

Centipede / Millepede

---

Centipedes are fast-moving, carnivorous arthropods belonging to the class Chilopoda. Despite their name suggesting 100 legs, centipedes can have anywhere from 30 to 354 legs, always in an odd number of pairs. They are found on every continent except Antarctica, thriving in soil, leaf litter, rotting logs, and dark, moist environments.

Centipedes are predators that play an important role in controlling populations of insects, spiders, and other small invertebrates. They use a pair of modified front legs called forcipules to inject venom into their prey, immobilising it before feeding. This makes them valuable natural pest controllers in gardens and agricultural environments.

In farming and soil ecosystems, centipedes contribute to soil health by feeding on decomposers and other soil organisms, helping to regulate nutrient cycling. Larger centipede species, such as the giant desert centipede (Scolopendra heros), can reach lengths of over 20 centimetres, while smaller garden species are only a few centimetres long.

While centipedes are generally beneficial in outdoor environments, their venom can cause painful reactions in humans if handled. Farmers and field workers are advised to wear gloves when working in soil or around compost heaps where centipedes are commonly found. Understanding centipedes helps us appreciate the complexity of soil ecosystems and the role of predatory invertebrates in maintaining agricultural balance.

Grasshopper

---

Grasshoppers are herbivorous insects belonging to the order Orthoptera, found on every continent except Antarctica. They are recognised by their powerful hind legs, adapted for leaping, and their chewing mouthparts designed to consume plant material. Over 11,000 species of grasshopper exist worldwide, making them one of the most diverse insect groups on Earth.

In agricultural settings, grasshoppers can be both ecologically important and economically damaging. Under normal conditions, they contribute to nutrient cycling by consuming plant matter and returning nutrients to the soil through their waste. However, under certain conditions, some species can form massive swarms known as locusts, which can devastate entire crop fields within hours.

Grasshoppers undergo incomplete metamorphosis, passing through egg, nymph, and adult stages. Females lay their eggs in soil pods, which hatch in spring when conditions are warm enough. The nymphs resemble small adults and moult several times before reaching full maturity. Their life cycle is closely tied to seasonal temperature and rainfall patterns.

Farmers monitor grasshopper populations carefully, particularly during dry years when outbreaks are more likely. Control methods include biological agents such as parasitic fungi, targeted insecticides, and habitat management. Understanding grasshopper behaviour is essential for protecting crops and maintaining food security in vulnerable regions.

Fly

---

Flies belong to the order Diptera, meaning "two wings", and represent one of the largest insect orders with over 160,000 known species. They are found in virtually every habitat on Earth and play complex roles in ecosystems and agriculture, acting as both pollinators and pests depending on the species.

In agriculture, flies have a dual nature. Some species, such as hoverflies, are important pollinators of crops and wildflowers. Others, like the fruit fly (Drosophila) and blowfly, can damage stored produce and livestock. Certain fly larvae, called maggots, decompose organic matter and help recycle nutrients back into the soil, which is beneficial for soil fertility.

Flies undergo complete metamorphosis through four stages: egg, larva (maggot), pupa, and adult. This life cycle can be completed in as little as seven days in warm conditions, which is why fly populations can increase rapidly during summer months. Female flies lay their eggs near food sources such as decaying matter, animal waste, or ripe fruit.

Controlling fly populations on farms is important for both animal health and food hygiene. Flies can transmit diseases and parasites to livestock, reducing productivity. Integrated pest management strategies include sanitation, biological controls, and targeted insecticides. Despite their reputation, flies are ecologically essential and studying them provides valuable insights into disease transmission and ecosystem function.

Mantis

---

Mantises are predatory insects belonging to the order Mantodea, with over 2,400 species found across tropical and temperate regions worldwide. They are instantly recognisable by their triangular heads, large compound eyes, and distinctive raptorial front legs, which they hold in a prayer-like posture — earning them the common name praying mantis.

Mantises are ambush predators, relying on camouflage and patience to catch prey. They can rotate their heads 180 degrees, giving them exceptional binocular vision for tracking moving targets. Once prey is within reach, they strike with lightning speed, their spiked forelegs snapping shut to grip the victim. They feed on a wide range of insects including flies, grasshoppers, moths, and even small vertebrates.

In agriculture, mantises are considered highly beneficial insects. They act as natural biological control agents, reducing populations of harmful pest insects without the need for chemical pesticides. Some farmers deliberately introduce mantises into crops as part of integrated pest management programmes. However, mantises are indiscriminate hunters and will also prey on beneficial insects such as bees and butterflies.

Mantises undergo incomplete metamorphosis with three stages: egg, nymph, and adult. The female lays her eggs in a protective foam casing called an ootheca, which hardens to shield the eggs through winter. Their fascinating biology and predatory precision have made mantises the subject of significant scientific research into visual processing and predatory mechanics.

Butterfly

---

Butterflies are winged insects belonging to the order Lepidoptera, which they share with moths. There are approximately 20,000 known species of butterfly, found on every continent except Antarctica. They are distinguished by their large, often colourful wings covered in tiny scales, and their coiled proboscis used for sipping nectar.

Butterflies are among the most important pollinators in both natural ecosystems and agricultural environments. As they feed on flower nectar, pollen attaches to their bodies and is transferred between plants, enabling fertilisation and fruit production. Many crops, including sunflowers, tomatoes, and various berry crops, benefit from butterfly pollination alongside bees and other insects.

Butterflies undergo complete metamorphosis through four remarkable stages: egg, caterpillar (larva), chrysalis (pupa), and adult. The caterpillar stage is entirely focused on feeding and growth, while the adult stage is dedicated to reproduction. The transformation inside the chrysalis, where the caterpillar's body is completely reorganised into a butterfly, is one of nature's most extraordinary processes.

Declining butterfly populations worldwide are considered a key indicator of ecosystem health. Habitat loss, pesticide use, and climate change are the primary threats. Farmers who adopt wildflower margins, reduce chemical inputs, and maintain hedgerows can support butterfly populations significantly. Protecting butterflies means protecting the broader web of life that sustains productive agriculture.

Bee

---

Bees are flying insects closely related to wasps and ants, belonging to the order Hymenoptera. With over 20,000 known species, bees are found on every continent except Antarctica and are considered the most important pollinators on Earth. The honeybee (Apis mellifera) is the most well-known species and has been kept by humans for thousands of years for its honey and pollination services.

Bees are essential to global food production. It is estimated that approximately one third of all food consumed by humans depends either directly or indirectly on bee pollination. Crops such as almonds, apples, blueberries, avocados, and many vegetables rely on bees to transfer pollen between flowers, enabling fruit and seed development.

Honeybees live in highly organised colonies of up to 80,000 individuals, led by a single queen. Worker bees collect nectar and pollen, which they bring back to the hive. Nectar is converted into honey through enzymatic processes and evaporation, providing the colony with an energy-rich food store through winter. The waggle dance performed by worker bees is a sophisticated communication system used to share the location of food sources.

Bee populations worldwide are under significant threat from habitat loss, pesticide exposure, disease, and climate change. The decline of bees poses a serious risk to agricultural productivity and wild plant diversity. Farmers, scientists, and governments are working together on strategies to protect and restore bee populations, including reducing pesticide use, planting pollinator-friendly habitats, and supporting beekeeping practices.

Ant

---

Ants are social insects of the family Formicidae, belonging to the order Hymenoptera alongside bees and wasps. With over 20,000 described species, ants are among the most successful organisms on Earth, found on every continent except Antarctica. They are estimated to make up 15–25% of all terrestrial animal biomass, reflecting their extraordinary ecological dominance.

Ants live in highly organised colonies ranging from a few dozen to millions of individuals. Each colony is divided into castes — the queen (responsible for laying eggs), workers (sterile females who forage, build, and defend), and males (whose sole role is reproduction). This division of labour makes ant colonies remarkably efficient and adaptable to changing environments.

In agriculture, ants play a complex and varied role. Many species are beneficial: they aerate soil through tunnelling, decompose organic matter, disperse seeds, and prey on harmful pest insects. However, certain species such as fire ants and leafcutter ants can cause significant damage by attacking crops, livestock, and farm infrastructure, or by farming aphids that damage plants.

Soil aeration by ants improves water infiltration and root development in crops, making them important contributors to soil health. Scientists study ant colonies to better understand collective intelligence, chemical communication through pheromones, and ecosystem engineering. Managing ant populations on farms requires understanding which species are present and whether their impact is net beneficial or harmful.

Sedimentary Rocks

---

Sedimentary rocks are formed at or near the Earth’s surface by the accumulation and compaction of sediment or the precipitation from solution at normal surface temperatures. The lithification (literally “turning into stone”) process typically occurs slowly over time and depends on the chemistry of the sediments, the groundwater passing through the sediment, and how quick or deep the deposition process takes place.

Sedimentary rocks are produced by weathering (breaking down) of preexisting rocks, followed by the transportation and deposition of the weathering products. The weathered material is then eroded by either wind, ice, or water, and deposited in lakes and oceans. The erosion process grinds down rocks into smaller fragments. During transportation, fluids (water or wind) sort out the materials by separating heavier particles from lighter particles. The deposited materials undergo cementation, compaction and other solidification processes to form sedimentary rocks. Sedimentary rocks often have distinctive layering/bedding.

Sedimentary rocks can be classified as Clastic, Chemical or Biochemical:

• Clastic sedimentary rocks are rocks composed of fragments (or detritus) derived from the mechanical breaking down of older rocks. Examples of clastic sediments include gravel, sand, silt and mud; these are lithified into conglomerate, sandstone, siltstone and mudstones.
• Biochemical sedimentary rocks are those rocks derived from living organisms. When plant and animal organisms die, their remains can accumulate in particular environments to become sedimentary rocks. Examples include biochemical limestone, biochemical chert, dolomite, coal, etc.
• Dissolved chemical particles, such as sodium and chlorine get into the groundwater and other bodies of water – rivers, lakes, pans, and oceans. When the concentration gets too high, the ions recombine by chemical precipitation to form minerals that can accumulate to form chemical sedimentary rocks. These include evaporites such as salt and gypsum (calcium sulphate) beds, travertine (calcium carbonate), and cherts (very fine-grained silica).

Rock Types

---

Rocks are all around us, making up the Earth’s crust, from the mountains we climb to the pebbles on the beach. In geology, rocks are grouped into three main types: igneous, sedimentary, and metamorphic. Each type forms in a unique way and tells a story about the Earth’s history. Let’s explore these rock types in a way that’s easy to understand!

Igneous rocks are born from fire—well, sort of! The word “igneous” comes from a Latin word meaning “fire.” These rocks form when molten rock, called magma or lava, cools and hardens. Magma is found deep inside the Earth, where it’s super hot. When a volcano erupts, the lava that flows out cools and becomes solid, forming igneous rocks like basalt. If the magma cools slowly underground, it forms rocks like granite, which has big crystals you can see with your eyes. Igneous rocks are tough and often used for building things like roads or statues because they’re so strong.

Sedimentary rocks are like nature’s scrapbooks. They form when bits of other rocks, minerals, or even remains of plants and animals pile up over time and get squashed together. Imagine sand on a beach or mud in a riverbed—over millions of years, these bits, called sediments, get pressed and cemented into solid rock. Examples include sandstone, made from sand, or limestone, which often has shells or coral in it. Sedimentary rocks are special because they can contain fossils, which are clues about life long ago, like dinosaur bones or ancient plants. They usually form in layers, so when you see a cliff with stripes, you’re looking at sedimentary rocks!

Metamorphic rocks are the transformers of the rock world. They start as one type of rock—igneous, sedimentary, or even another metamorphic rock—but change because of intense heat, pressure, or both, deep inside the Earth. This process is like baking a cake: the ingredients change to become something new. For example, limestone can turn into marble, a beautiful rock used for sculptures or fancy buildings. Another example is slate, which comes from shale and is used for roof tiles because it splits into thin sheets. Metamorphic rocks don’t melt during this change; they just get reshaped and recrystallised.

Each rock type has its own role in the Earth’s story. Igneous rocks show us how the Earth’s fiery insides work, sedimentary rocks give us a peek into the past with their layers and fossils, and metamorphic rocks reveal how the Earth’s forces can transform things. Next time you’re hiking in the Drakensberg or strolling along a Cape Town beach, have a look at the rocks around you. Can you guess which type they are? By studying rocks, we learn about the Earth’s history, from volcanoes to ancient oceans, and how our planet keeps changing.

In South Africa, we’re lucky to have all three rock types. The Karoo has lots of sedimentary rocks with dinosaur fossils, while the Witwatersrand’s metamorphic rocks hide gold! Igneous rocks, like those from ancient volcanoes, are also scattered across our land. Rocks are more than just stones—they’re pieces of the Earth’s puzzle, waiting for you to explore!

The Rock Cycle

---

Rocks might seem like they never change, but they’re part of a slow, amazing process called the rock cycle. This is how rocks transform from one type to another over millions of years, like a recycling system for the Earth’s crust. The rock cycle involves igneous, sedimentary, and metamorphic rocks, and it’s driven by forces like heat, pressure, and weathering. Let’s take a journey through the rock cycle to see how it works, using examples you might spot in South Africa!

The rock cycle starts with igneous rocks, which form when molten rock, called magma or lava, cools and hardens. Imagine a volcano erupting near Johannesburg long ago—its lava cools into basalt, an igneous rock. If this rock stays underground, it might cool slowly into granite, like the rocks around Paarl. These igneous rocks are the starting point, but they don’t stay the same forever.

Over time, igneous rocks get broken down by weathering. Rain, wind, and temperature changes chip away at the rock, turning it into tiny bits like sand or mud. For example, granite boulders in the Karoo might break into smaller pieces. These bits get carried away by erosion, like when a river sweeps sand downstream. Eventually, the bits settle in a new place through deposition, maybe at the bottom of a lake or the sea near Durban. Over millions of years, these layers pile up, get squashed, and stick together to form sedimentary rocks, like sandstone or shale. If you visit the Karoo, you might see these layered rocks, some with fossils of ancient creatures!

But the cycle doesn’t stop there. Sedimentary rocks can get buried deep in the Earth’s crust, where they face intense heat and pressure. This transforms them into metamorphic rocks. For example, limestone, a sedimentary rock, can turn into marble if it’s squeezed and heated deep underground. In the Witwatersrand, shale turned into slate, which helped hide gold deposits! Metamorphic rocks are like rocks that got a makeover, with new textures and minerals.

Metamorphic rocks can change even more. If they get pushed deeper into the Earth, they might melt into magma again. This magma can rise, cool, and form new igneous rocks, starting the cycle all over. For example, ancient metamorphic rocks in Namaqualand could melt and become new granite underground. The rock cycle is like a loop with no beginning or end—rocks keep changing from one type to another.

The rock cycle is powered by geoprocesses like plate tectonics, which moves the Earth’s crust, and weathering, which breaks rocks down. It’s super slow, taking millions of years, but it’s always happening. To picture it, imagine a rock in the Drakensberg: it might start as igneous, break into sediment, become sedimentary rock, get transformed into metamorphic rock, and maybe even melt back into magma one day. The rock cycle shows us that the Earth is always changing, recycling its materials to create new landscapes. Next time you’re exploring a rocky outcrop or a beach, think about the incredible journey those rocks have been on—they’re part of the Earth’s big recycling adventure!

Different plates of the world

Example of plate break-up or rifting

Plate Tectonics

---

Plate tectonics is a scientific theory that explains how the Earth’s surface is made up of large plates that move slowly over time. These plates are made up of the Earth’s crust and upper mantle; these two layers comprise the lithosphere. The lithosphere sits on top of a partially molten layer of mantle rock called the asthenosphere. The movement of the lithospheric plates is caused by convection currents in the asthenosphere.

Many different geological events such as earthquakes, volcanic eruptions and mountain building are caused by the movement of these plates. For example, when two plates collide, one plate can be forced under the other in a process called subduction. The descending plate can melt and cause volcanic eruptions. When two plate are jammed together, they can release a huge amount of energy when the stress is relieved, giving rise to earthquakes.

The theory of plate tectonics has revolutionised our understanding of the Earth and its processes. It helps us to understand why certain geological events happen in certain places, and how the Earth’s surface features has changed over time, especially the positions of the continents.

Diagrams showing the formation of metamorphic rocks from both sedimentary and igneous types of rocks adapted from Earle (2019)

The types of metamorphic rock (right) adapted from Stephen and Stefan (2016).

Metamorphic Rocks

---

What are they? Metamorphic rocks are types of rocks which form because of transformation or change of pre-existing rocks in response to high pressure, heat, and/or hot mineral fluids. The parent rock undergoing transformation can originally have been sedimentary or igneous, and even metamorphic; this transformation process is termed metamorphism, from the Greek word ‘metamorphosis’ that means ‘to change form’. Metamorphism occurs deep in the Earth where temperatures range from ~250 ℃ to over 850 ℃ and pressures up to 300 MPa (megapascal). The setting where there are suitable conditions to form metamorphic rocks is where the tectonic plates that comprise the Earth’s crust meet. The tectonic plates collide to form mountain ranges, such as the Himalayas, Alps, and Rocky Mountains, where high pressures squeeze and deform the rocks.

Types of Metamorphism
There are two types of metamorphism, contact and regional metamorphism. Contact metamorphism occurs when a parent (original) rock encounters heat generated from a magma body that intrudes into it. The magma is formed deep in the Earth. The heat metamorphoses or bakes the rocks next to the intrusion, in the process forming new minerals in the metamorphic rock. With regional metamorphism, the entire original rock sequence, usually sedimentary and/or volcanic, is deeply buried by overlying rocks. The burial subjects the rocks to great pressures and high temperatures, causing metamorphism on a regional scale. This results in a suite of different metamorphic rocks that forms from the original ones.

Types of Metamorphic rocks
Metamorphic rocks can form from original sedimentary and igneous rocks, and sometimes even metamorphic ones. Sedimentary shales and sandstones give different types of schists and quartzites when metamorphosed, while volcanic basalts, rhyolites and tuffs will change to mafic (iron and magnesium-rich) and felsic (sodium and potassium-rich) schists and gneisses. These metamorphic rocks usually show a striped appearance, termed a foliation, that is caused by deformation due to high pressures. The platy minerals such as biotite and chlorite stack up to form the foliation. Quartzites are usually not foliated because they do not contain many platy minerals. Sedimentary limestones, made up of coral and shell fragments, metamorphose into different types of marble.

Metamorphic rocks have a variety of different uses, including building and paving stones, roof tiles, artworks, and garden decorations.

Landslides

---

A landslide is defined as the movement of a mass of rock, debris, earth, or soil down a slope. Landslides occur when the gravitational pull on a rock mass on a sloping surface exceeds the shear strength (resistance to shearing) of the materials that form the the rock mass on the slope. Shear strength is dependent mainly on two factors: frictional strength and cohesive strength. Frictional strength is the resistance to movement between the slope material’s interacting constituent particles, and cohesive strength is the bonding between the particles.

Coarse particles such as sand grains have high frictional strength but low cohesive strength whereas the opposite is true for clays which are composed of fine particles. Another factor that affects the shear strength of a slope-forming material is the spatial disposition of its constituent particles referred to as sediment fabric.

Landslides are caused by rain, earthquakes, volcanoes or other factors that weaken the rock mass and make the slope unstable. Geologists sometimes describe landslides a type of mass wasting; this denotes any down-slope movement of soil and rock under the direct influence of gravity.

Shear stresses can be built up within a slope by several processes including oversteepening of the base of the slope by natural erosion or excavation, and loading of the slope such as by an inflow of water or a rise in the groundwater table. Short-term stresses, such as those caused by earthquakes and rainstorms, can also contribute to the activation of landslides.

Human activities such as agriculture and construction can increase the risk of a landslide. Irrigation, deforestation, excavation and water leakage are some common activities that can help destabilise or weaken a slope.

Figure 2: Cross section showing the formation of both volcanic (extrusive) and plutonic (intrusive) igneous rocks (Nelson, G.B.,2023).

Figure 1:
Left: Modern-day basaltic pahoehoe lava flow on Hawaii (scientiafantastica.wixsite.com).
Right: A 3-billion-year-old basaltic pahoehoe lava flow in Kwa-Zulu Natal, South Africa (David Russo, 2022).

Igneous Rocks

---

Igneous rocks are rocks which form as the result of cooling and solidification of molten rock or magma. The term “igneous” comes from the Latin word ‘ignis’ which means fire. Igneous rocks can be divided into two main groups depending on where they form. If magma reaches the surface of the earth and erupts from a volcano, the erupting molten rock known as lava then flows onto the surface of the Earth (Figure 1) where it cools rapidly to form rocks that are called extrusive or volcanic igneous rocks (Figure 2). Due to the rapid cooling, there is no time for large mineral crystals to grow in these rocks. Examples of such rocks are basalt and rhyolite.

If magma is injected and cools within the surface of the Earth, the resulting igneous rocks that form are known as intrusive or plutonic igneous rocks (Figure 2). These rocks form over longer times and cool slower than their extrusive counterparts and therefore have enough time to grow larger mineral crystals. Examples of such rocks are gabbro and granite.

Igneous rocks play a vital role in a country’s economy as they contain many types of mineral deposits needed to build the modern world.

The 90 000 km2 Bushveld Complex in South Africa hosts the world’s largest deposit of platinum group metals (PGMs), chromium and vanadium as well as large amounts of titanium.

A rare volcanic rock known as kimberlite (named after the town of Kimberley) in South Africa is a major source of diamonds. When the magma which formed these rocks travelled to the surface, it carried diamonds that formed deep within the earth along with it.

Igneous rocks also are responsible for creating some of South Africa’s famous tourist destinations. The Drakensberg Mountains were formed as a result of massive eruptions of lava onto the Earth’s surface which cooled to form basaltic rock.

The Pilanesberg National Park is found within the centre of what was once a massive volcano where both the intrusive and some of the extrusive rocks of that volcano can be seen today.

Volcanoes

---

Volcanoes are fascinating natural phenomena that have captivated humans for centuries. They are formed when molten rock, known as magma, rises to the Earth's surface, often accompanied by ash, gases, and lava flows.

Volcanoes can occur at convergent plate boundaries, where tectonic plates collide, or at hotspots, where plumes of hot mantle rock rise from deep within the Earth's interior. When a volcano erupts, it releases tremendous energy and can spew ash, gases, and lava into the surrounding area.

Volcanoes play a crucial role in shaping the Earth's surface and influencing its climate. They release gases and aerosols that can have both cooling and warming effects on the atmosphere. Volcanic eruptions can also create new landforms, such as islands and volcanic mountains.

While volcanoes can be awe-inspiring, they can also pose risks to human populations living nearby. Volcanic eruptions can cause ashfall, mudflows, and pyroclastic flows, which are fast-moving avalanches of hot gas and volcanic debris.

The largest volcano on Earth is Mauna Loa in Hawaii. It rises about 9,144 meters (30,000 feet) from its base on the ocean floor, making it taller than Mount Everest when measured from its base to its summit.

Geological Processes

---

Have you ever wondered why mountains are so tall, why rivers carve valleys, or why earthquakes shake the ground? These are all caused by geological processes, which are the natural forces and actions that shape the Earth’s surface and what’s beneath it. Geological processes are like the Earth’s way of constantly redecorating itself, and they happen both above and below the ground. Let’s dive into some of these amazing processes that make our planet so dynamic!

One major geoprocess is weathering. This is when rocks break down into smaller pieces because of things like wind, rain, or temperature changes. Imagine a big rock on a hill in the Free State. When it gets hot, the rock expands, and when it cools at night, it shrinks. Over time, this makes cracks, and bits break off. Water can also seep into these cracks, freeze, and split the rock further. There’s also chemical weathering, where rainwater, which is slightly acidic, can dissolve rocks like limestone, creating caves like the Cango Caves in the Western Cape.

Another important geoprocess is erosion. This happens when wind, water, or ice carry away the broken bits of rock from weathering. For example, rivers like the Orange River flow fast and pick up sand and pebbles, carving out valleys or canyons over time. Waves crashing on Durban’s beaches also erode cliffs, shaping the coastline. Erosion moves material from one place to another, like a delivery truck for the Earth’s surface.

Deposition is what happens after erosion. It’s when the bits of rock, sand, or mud carried by wind, water, or ice settle in a new place. Think of a river slowing down as it reaches the sea, dropping sand and mud to form a delta. The Tugela River sometimes does this, creating new land where it meets the ocean. Deposition builds up layers that can eventually turn into sedimentary rocks.

Then there’s plate tectonics, a massive geoprocess that shapes the Earth on a huge scale. The Earth’s crust is made of giant plates that float on a hot, semi-liquid layer below. These plates move slowly—about as fast as your fingernails grow! When they crash into each other, they can form mountains like the Drakensberg. When they pull apart, they create valleys or even new ocean floors. Earthquakes, like the ones felt sometimes in the Western Cape, happen when plates grind past each other. Volcanoes, though rare in South Africa now, are also part of this process, as magma escapes where plates meet or split.

Finally, soil formation is a geoprocess that happens slowly but is super important. Soil forms when rocks break down and mix with organic stuff like dead plants and animals. This creates the fertile ground where crops grow, like the maize fields in Mpumalanga. Geoprocesses work together to shape the Earth we see today, from the flat Highveld to the rugged Cape Fold Mountains. They’re always happening, even if we don’t notice, changing the land bit by bit. Next time you’re outside, look for signs of these processes—maybe a cracked rock, a riverbank, or a sandy beach—and you’ll see the Earth at work!

A graphical illustration of the relationship between Geological Time (Hadean at 4.5 Ga) and the Explosion of Life in the Cambrian 542 Ma (from Marshak, 2011 Figure 12.15). Not to scale

Geological Time

---

As humans we are familiar with the concept of time and its relationship to history, but human history, measured in centuries, decades and years is very different from Earth history. The latter is measured in millions to billions of years and measured using geological or deep time.

The “calendar” used to record events in Earth history is called the Geological Time Scale. On this scale, geological time is subdivided into units of descending length called Eons, Eras, Periods, and Epochs. Each unit of time is defined by specific events and changes that took place on Earth, such as the formation of the planet, global scale events related to plate tectonics, the evolution of life as recorded by the fossil record, and within that record, mass extinctions such as the demise of the dinosaurs 65 million years ago. The current epoch, the Holocene, began 120 000 years ago at the end of the last Ice Age, and represents the time during which all human civilisation developed (from geologyscience.com)

One way of grasping the concept of geological time is to scale it down into one human year. In this model, the origin of the Solar System and Earth at 4.57 billion years ago (4.57 Ga (billion years)) is represented by January 1, and the present year by the last tiny fraction of a second on New Year’s Eve. Each day of the year represents 12.5 million years of geological time; each hour about 500,000 years and each second 145 years. Based on this, the oldest rocks known to date (3.96 Ga) formed in early February, the explosion of life (542 million years ago) started in late October, the dinosaurs became extinct on December 25th (65 million years ago), Homo sapiens appear at 23:00 on December 31st and ALL recorded history takes place in the last 30 secs of the year (from Marshak, 2011)

Earthquakes

---

An earthquake is a sudden shake of the ground caused by seismic waves that pass through the crust of the Earth. The Earth’s crust is made of several huge and a few smaller fragments that fit together as in a gigantic jigsaw puzzle; these fragments are called tectonic plates. Most major earthquakes occur at the margins of these plates that are called plate boundaries. For the past 2.8 billion years, tectonic plates have been sliding across the Earth’s surface above a partially molten of mantle rocks underneath the crust.

The plate boundaries are usually rugged and defined by faults (a fracture or zone of fractures between two blocks of rock). Occasionally, two tectonic plates get stuck together along the fault plane separating them. If one of the plates continues to move relative to the other plate, a large amount of stress energy builds up on the fault plane. Once the moving plate has moved for a distance large enough to get unstuck, the Earth’s crust responds by snapping, fracturing, and slipping along the fault. The rocks on either side of the fault plane are displaced relative to each other.

The huge amount of energy that was built on the fault plane is suddenly released in the form of seismic energy waves that travel through the entire Earth. When these seismic waves propagate through the crust, they shake the ground and anything on it violently. This results in the destruction of infrastructure, and causes fatalities, injuries and environmental damage that lead to economic instabilities in the countries affected. Unfortunately, earthquakes cannot be accurately predicted and stopped. Many methods have been attempted to predict earthquakes and most of these tests have not been successful. With that said, since earthquakes are here to stay as a natural phenomenon, we will depend on smarter scientists in the future to devise new methods that will help us predict earthquakes more accurately and thus save lives.

Mountain

---

Mountains are rocky geological features on a landscape that are created through the tectonic movement of the surface of the earth or even through volcanic activity.

Tectonic formations occur when parts of the earth’s crust press up against each other and raise the surface into a mountain. Volcanic activity can form peaks when molten rock (magma) from the earth’s mantle erupts and pushes through the earth’s crust. The magma then piles up to create a mountain, usually conical in shape.

The landscape is then shaped over millions of years by the flow of ice and water that cut through the mountains forming ‘U’ and ‘V’-shaped valleys respectively.

Studying the structure of mountains and their rock types can tell us much about the history of the formation of the earth.

Groups of people who live in mountainous areas may adapt to the different weather conditions and altitudes. As you climb up a mountain, the air becomes thinner. Some peoples, who have lived at high altitude for many generations, have physically adapted to have expanded lungs so they can breathe easier even with the lower oxygen levels.