Blog topic
Science articles
Why Earth has seasons, why scientists use models, the water and carbon cycles, fair tests, eclipses, peer review, weather fronts and how to read data and graphs. These are the pieces about how science is done, which sit underneath every other subject on the site.
39 explainers, newest first. Each one ends with real questions from the unit that teaches it, so you can read the explanation and then check whether it stuck.
These are the readable companion to the Science track, which holds 18 units and 2,321 practice questions. If you are starting the subject rather than looking something up, the study guide is the better place to begin.
Why Are There Seven Days in a Week? Babylon, the Planets and a Cycle Nobody Owns
The week has no basis in astronomy, unlike the day, month and year. Where the seven-day cycle came from, why the days are named for planets, and why it stuck.
September 15, 20264 min readHow Does Fog Form? A Cloud That Touches the Ground
Fog is a cloud whose base is on the ground, made when air near the surface is cooled to its dew point. The main kinds, and why some places get so much.
September 15, 20265 min readHow Does Sunscreen Work? Filters, Factors and What the Number Means
Sunscreen stops ultraviolet light reaching the skin by absorbing it in molecules or scattering it. What UVA and UVB do, and what SPF measures.
September 15, 20264 min readWhat Is the Coriolis Effect? Why Storms Spin, Winds Curve and Bath Water Does Not Care
The Coriolis effect is the apparent deflection of anything moving across a rotating Earth, curving winds and currents. Why it happens.
September 15, 20265 min readWhat Is the Difference Between Weather and Climate?
Weather is what the atmosphere is doing today; climate is what it usually does over decades. Why a cold week says nothing about warming, and why it matters.
September 14, 20264 min readWhat Is Entropy? Why Things Fall Apart and Time Runs One Way
Entropy counts how many ways the parts of a system can be arranged without changing how it looks. Why it always rises, and why it gives time a direction.
September 14, 20265 min readHow Do Tornadoes Form? The Spinning Storms of the Great Plains
A tornado is a column of spinning air from a thunderstorm to the ground. The rotating storms that make them, why the Plains get so many, and the EF scale.
September 14, 20265 min readHow Do Snowflakes Form? Why Every One Has Six Sides
A snowflake grows from a speck of dust in a cloud as water vapour freezes onto it. Why the shape is always six-fold, and what decides stars versus needles.
September 14, 20264 min readWhy Do We Have Leap Years? The Calendar Catching Up With the Sun
A year is not a whole number of days, so every calendar drifts unless corrected. Why February gets an extra day, why 1900 did not, and how a pope fixed it.
September 14, 20264 min readHow Does Anaesthetic Work?
The difference between local and general anaesthesia, what happens to consciousness, and why the mechanism is still not fully understood.
August 28, 20266 min readWhat Is the Scientific Method? A Practical Step-by-Step Guide
Learn how questions, hypotheses, tests, evidence, analysis, and revision work together in real scientific investigations.
August 17, 20266 min readWhy Do Stars Twinkle? How Earth's Atmosphere Bends Starlight
Learn how moving layers of Earth's atmosphere bend starlight and make distant stars appear to flicker, brighten, and shift.
August 17, 20265 min readWhy Is the Ocean Salty? Where Sea Salt Comes From
Learn how weathering, rivers, seafloor processes, and evaporation leave dissolved ions behind and build the oceans' salinity.
August 17, 20265 min readHow Do Auroras Form? Why the Sky Glows Near the Poles
Learn how charged particles, Earth's magnetic field, and gases high in the atmosphere create glowing curtains of light.
August 17, 20265 min readHow Do Geysers Erupt? Heat, Water, and Pressure Underground
Learn how do geysers erupt as groundwater is heated under pressure, flashes into steam, and drives a repeating burst of hot water from underground.
August 17, 20265 min readStates of Matter: Solids, Liquids, Gases, and Changes
States of matter describe how particles are arranged and move. Learn solids, liquids, gases, melting, boiling, freezing, and condensation simply.
August 14, 20265 min readHow Does Lightning Form? From Storm Cloud to Flash
Learn how charge separates inside storm clouds, why electric fields grow, and what happens during a lightning flash.
August 14, 20265 min readHow Do Tides Work? The Moon, Sun, and Moving Oceans
Learn how the Moon and Sun create tidal forces, why most coasts get changing water levels, and what spring and neap tides mean.
August 14, 20266 min readWhat Is Radioactivity? Unstable Nuclei and Radiation Explained
Learn why unstable atomic nuclei decay, what alpha, beta, and gamma radiation are, and how half-life describes decay.
August 14, 20266 min readWhat Is Surface Tension? Why Liquid Surfaces Act Like a Skin
Learn how attractions between liquid molecules shape droplets, support small objects, and change when soap is added.
August 14, 20266 min readHow Fossils Form: From Living Organism to Evidence in Rock
How fossils form depends on burial, preservation, and geological change. Learn about mineral replacement, moulds, casts, trace fossils, and fossil bias.
August 14, 20266 min readWhy Do We Have Day and Night? Earth's Rotation Explained
Learn how Earth's rotation turns places toward and away from the Sun, creating the daily cycle of light and darkness.
August 14, 20266 min readHow Do Rainbows Form? How Sunlight and Water Make Colour
Learn how refraction, reflection, and dispersion inside water droplets separate sunlight into the colours you see in the sky.
August 14, 20266 min readHow Clouds Form: From Water Vapour to Droplets and Ice
Learn how clouds form when rising air cools, water vapour condenses onto tiny particles, and countless droplets or ice crystals become visible together.
August 13, 20265 min readHow the Nitrogen Cycle Works: From Air to Soil and Back
Learn how the nitrogen cycle works through fixation, nitrification, plant uptake, decomposition, and denitrification, with a simple step-by-step explanation.
August 13, 20265 min readHow the Rock Cycle Changes Earth's Materials
The rock cycle connects igneous, sedimentary and metamorphic rocks through melting, cooling, weathering, burial and heat. Any rock type can change when conditions around it change.
August 8, 20265 min readHow Earthquakes Are Located and Measured
Earthquakes release energy as seismic waves that travel through Earth. Scientists use wave arrival times, instruments and magnitude scales to locate events and compare their size.
August 8, 20265 min readHow Sound Travels Through Matter
Sound is a mechanical wave produced by vibrations. Particles pass the disturbance through solids, liquids and gases, while frequency and amplitude shape what you hear.
August 5, 20265 min readHow Scientists Measure Uncertainty
Every measurement has limits, even when it is taken carefully. Scientists describe uncertainty so results can be interpreted, compared and improved honestly.
August 5, 20265 min readHow the Ozone Layer Protects Life
Stratospheric ozone absorbs much of the Sun's harmful ultraviolet radiation. Human-made chemicals damaged this protective layer, and international action has helped it begin a slow recovery.
August 4, 20265 min readHow Weather Fronts Change the Sky
A weather front is a boundary between air masses with different temperatures and moisture. Warm, cold, stationary and occluded fronts create different patterns of cloud, rain and temperature change.
July 29, 20265 min readHow the Carbon Cycle Connects Air, Land and Ocean
Carbon moves between the atmosphere, living things, soils, oceans and rocks. Fast biological exchanges and slow geological processes together form the carbon cycle.
July 29, 20265 min readHow the Greenhouse Effect Keeps Earth Warm
Greenhouse gases absorb and re-emit infrared energy, keeping Earth's surface warmer than it would otherwise be. Human emissions strengthen this natural effect and change the planet's energy balance.
July 29, 20265 min readHow Solar and Lunar Eclipses Happen
Eclipses happen when the Sun, Earth and Moon line up closely enough for one body to enter another shadow. The Moon's tilted orbit explains why this does not happen every month.
July 26, 20265 min readHow Scientific Peer Review Works
Peer review asks other specialists to examine a study before publication. It can improve methods and explanations, but it is a quality check rather than a guarantee of perfect truth.
July 26, 20265 min readWhy Earth Has Seasons
Seasons come from Earth's tilted axis, not from large changes in distance from the Sun. The tilt changes the angle and length of daylight through the year.
July 24, 20265 min readWhy Scientists Use Models to Understand the Unseen
Scientific models make huge, tiny, distant, or complex systems easier to study. They are useful tools, but they are never perfect copies of reality.
July 24, 20265 min readHow the Water Cycle Moves Water Around Earth
Water changes form and travels between oceans, air, land and living things. The water cycle is one connected system powered mainly by sunlight and gravity.
July 24, 20265 min readHow Fair Tests Help Scientists Find Clear Answers
A fair test changes one important factor while keeping other conditions as steady as possible. Controls, repeated trials and careful measurements help separate real effects from coincidence.
July 24, 20265 min read