Blog
Why is a rainbow curved? Why does a magnet stick to the fridge but not to wood? Short, sourced, clear articles.
A light-year is not a length of time but a unit of distance: the path light covers in a year, about 9.46 trillion kilometres. We work the sum out step by step, show when the light of the Sun and Sirius set off, and explain why looking at the sky means looking into the past.
5 min read
Solve ten direct-proportion problems in a row and everything feels easy; mix the types in the exam and you get stuck. We explain what interleaved practice is, what the research shows and how to add it to your studying, with examples.
6 min read
A spoonful of yoghurt can turn a whole pan of milk into yoghurt overnight. We explain how two kinds of bacteria turn lactose into lactic acid, why the milk sets, why temperature matters so much, and the hygiene rules for homemade yoghurt.
8 min read
A book completed in Diyarbakir in 1206 describes fifty devices, complete with measurements and drawings. We open up al-Jazari's Elephant Clock step by step, weigh up the 'first robot' claim, and show how medieval engineering drew on Indian, Greek and Baghdad traditions.
8 min read
A handful of garden soil holds more bacteria than there are people on Earth, metres upon metres of fungal threads and hundreds of tiny animals. We meet the crowd that makes soil alive, look at Darwin's earthworms and explain how to make compost safely at home.
8 min read
Why do chickpeas cook so much faster in a pressure cooker? We explain how the boiling point depends on pressure, why water in high-altitude Erzurum does not boil at 100 °C, and the physics behind the rules for using a pressure cooker safely.
9 min read
Drawn on gazelle skin in Gallipoli in 1513 and spotted in Istanbul's Topkapi Palace in 1929, this map preserves traces of a lost map by Columbus. The claim that it shows Antarctica free of ice, however, is a legend. Using the map's own source notes, we look at what it really tells us.
8 min read
Where was the scent hiding before you rubbed that thyme leaf? We explain how plants make essential oils, compounds such as thymol and linalool, steam distillation and the myth that 'natural means harmless', along with the rules for using these oils safely.
8 min read
The crust of fresh bread, roasted coffee, fried köfte (Turkish meatballs)... Behind all their wonderful smells lies the same chemical process: the Maillard reaction. We explain this kitchen chemistry, how it differs from caramelisation, and some common misconceptions.
7 min read
Does a 20 percent price rise followed by a 20 percent discount bring the price back to where it was? We explain percentage formulas, successive discounts, percent vs percentage points and VAT, with shopping examples.
7 min read
When you press a string exactly at its midpoint, why do you hear a higher version of the same note? From Pythagoras's string experiments to frequency ratios and the piano's equal temperament, we explore the maths inside music.
7 min read
Why do all the bulbs go out when one bulb in a series string fails? Why are the sockets in your home wired in parallel? We explain series and parallel circuits using Ohm's law, with a worked example and notes on electrical safety.
10 min read