The BrainSnail Blog

Small, practical ideas for learning more with less stress. Study tips, memory tricks and the science of slow and steady.

846 articles · page 2 of 36

chemistrybleach

How Does Bleach Work? Chlorine, Oxygen and the Chemistry of Taking Colour Away

Bleach removes colour and kills germs by oxidation, breaking the bonds that absorb light and the proteins microbes need. Why not to mix it.

September 15, 20265 min read
philosophyepicureanism

What Is Epicureanism? Pleasure, Friendship and a Garden in Athens

Epicurus taught that pleasure is the goal of life and that the greatest pleasure is freedom from pain and fear. What he said, and why his name became an insult.

September 15, 20265 min read
language and literaturesurnames

Where Do Surnames Come From? Trades, Fathers, Places and Nicknames

Most European surnames were fixed between the twelfth and sixteenth centuries from four sources, and a name still says which. What the commonest ones mean.

September 15, 20265 min read
food and cookingpickling

How Does Pickling Preserve Food? Salt, Acid and the Microbes on Your Side

Pickling keeps food by making it too acidic for the microbes that spoil it, with vinegar or by letting bacteria make the acid. The two methods, and the science.

September 15, 20265 min read
mathmatrices

What Is a Matrix? Grids of Numbers That Rotate, Solve and Rank

A matrix is a grid of numbers that acts on vectors, the machine behind graphics, search rankings and neural networks. How they multiply, and why.

September 15, 20265 min read
astronomykuiper belt

What Is the Kuiper Belt? Pluto's Neighbourhood and the Edge of the Planets

The Kuiper Belt is a ring of icy bodies beyond Neptune, Pluto the largest, left from the solar system's birth. What is out there, and how it was found.

September 15, 20265 min read
animals and naturesharks

How Do Sharks Sense Their Prey? Smell, Electricity and a Line Along the Body

Sharks find prey with senses humans lack, including detectors of the electric fields all animals give off. How each sense works, and what the myths got wrong.

September 15, 20265 min read
historypetra

What Is Petra? The Rose City the Nabataeans Cut From Rock

Petra is a city in Jordan whose tombs and temples were cut into sandstone cliffs by Arab traders two thousand years ago. Who built it, and how it was lost.

September 15, 20265 min read
musicequal temperament

Why Is a Piano Slightly Out of Tune on Purpose? Equal Temperament Explained

No tuning of twelve notes can make every interval pure, so a piano is tuned with every interval slightly wrong by the same amount. Why the maths forces it.

September 15, 20265 min read
psychologycognitive load

What Is Cognitive Load? Why the Mind Can Hold Only So Much at Once

Cognitive load is the demand a task places on working memory, which holds only a few items at a time. The three kinds of load, and how to design around it.

September 15, 20264 min read
sportsrowing

How Does Rowing Work? Oars, Levers and the Longest Stroke

A rowing boat moves because the oar is a lever that pushes water backward and the boat forward, and a crew wins by rowing in time. The physics of the stroke.

September 15, 20265 min read
prehistoric lifetitanoboa

What Was Titanoboa? The Thirteen-Metre Snake of the Palaeocene

Titanoboa was a snake as long as a bus and as thick as a person that lived in Colombian swamps after the dinosaurs. How its size was estimated, and its meaning.

September 15, 20264 min read
dinosaurstaxonomy

How Are Dinosaurs Named? Latin, Greek and the Rules of Giving a Fossil a Name

Every dinosaur has a two-part scientific name, coined by whoever describes it under rules that go back to 1758. Where the names come from, and the errors.

September 15, 20264 min read
law and citizenshipplea bargain

What Is a Plea Bargain? Why Most Criminal Cases Never Reach a Trial

A plea bargain is an agreement in which the accused pleads guilty for a lighter charge or sentence, and it settles nine cases in ten in America. How it works.

September 15, 20265 min read
religionsermon on the mount

What Is the Sermon on the Mount? The Core of Jesus's Teaching in One Speech

The Sermon on the Mount is three chapters of Matthew in which Jesus sets out the ethics of his kingdom, from the Beatitudes to the Lord's Prayer. What it says.

September 15, 20265 min read
historycoal

Why Did the Industrial Revolution Run on Coal? Steam, Iron and the Fuel Under Britain

Britain industrialised first partly because it sat on coal that was cheap, shallow and close to the sea. How coal replaced wood, powered steam and made iron.

September 15, 20265 min read
technologylighthouses

How Do Lighthouses Work? Lenses, Rhythms and the Keepers Who Left

A lighthouse turns a small lamp into a beam seen 30 kilometres away with a lens from 1822, and tells sailors which it is by its rhythm. How the optics work.

September 15, 20265 min read
chemistryperfume

How Is Perfume Made? Notes, Fixatives and the Chemistry of Scent

A perfume is a solution of scented molecules in alcohol, built so that light ones open and the heaviest last for hours. Where the materials come from.

September 15, 20265 min read
food and cookingpasta

How Is Pasta Made? Durum, Dies and Why the Shape Matters

Dried pasta is two ingredients, hard wheat and water, pressed through a die and dried slowly; fresh pasta adds egg. Why durum, and what the shapes are for.

September 15, 20265 min read
astronomyspace weather

What Is Space Weather? Solar Storms and the Grid They Could Knock Out

Space weather is the flow of particles and magnetic fields from the Sun that buffets the Earth, giving auroras or blackouts. What flares and ejections do.

September 15, 20265 min read
animals and natureelephants

How Do Elephants Communicate? Rumbles Below Hearing, Feet That Listen and Names

Elephants talk in rumbles too low for people to hear, felt through the ground kilometres away, and they appear to use names. What the calls carry.

September 15, 20264 min read
mathvectors

What Is a Vector? Arrows, Coordinates and the Mathematics of Direction

A vector is a quantity with both size and direction, drawn as an arrow and written as a list of numbers. How they add, and why physics and computing use them.

September 15, 20265 min read
language and literaturefree verse

What Is Free Verse? Poetry Without Metre and What Holds It Together

Free verse is poetry that keeps no regular metre or rhyme, and it is the dominant form of the last century. Where it came from, and what holds it together.

September 15, 20265 min read
historyplague of justinian

What Was the Plague of Justinian? The First Pandemic

In 541 AD bubonic plague reached Constantinople and killed perhaps a fifth of the eastern Roman Empire within two years. Where it came from, and what it did.

September 15, 20265 min read

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