Mind & Body: how people think, sense and work
You spend your whole life inside one mind and one body, and almost none of it examining how either runs. How do you know that other people have thoughts of their own? What is your brain doing when it decides you are afraid, or certain, or full? This hub gathers those explanations — some of it settled science, some of it genuinely open, each labelled honestly for which it is.
Settled where it’s settled, honest where it isn’t
Part of this territory is textbook: the route a sound takes to become hearing is well understood. Part of it is not — how much of another creature’s inner life we can ever really know is still argued over by serious researchers. Around’s rule is to say which is which, rather than smoothing a live debate into false confidence.
Where to start
The first guide is theory of mind: your everyday skill of treating other people as having beliefs and knowledge of their own, and reasoning about what they do not know. It underlies lying, teaching, empathy and getting a joke — and it turns out to be a specific ability that switches on at a particular age, which makes it a good place to see how the mind assembles itself.
Last reviewed 10 July 2026
Understand it
Your everyday ability to treat others as having their own beliefs and knowledge — and to reason about what they do not know.
Guide The false-belief task: the experiment behind theory of mindThe classic experiment that pinpoints when children can hold someone else's mistaken belief apart from the truth.
Guide Why your own voice booms when you block your earsWhy sealing your ear canal makes your own voice sound loud and hollow — the everyday face of bone conduction.
Guide Two accounts of how you read other people's mindsThe two leading accounts of mind-reading — running an inner theory versus simulating the other person — and where they disagree.
Guide How a tuning fork finds the cause of hearing lossHow two quick tuning-fork tests separate a blockage in the outer or middle ear from a problem in the cochlea or nerve.
Guide How solar panels convert sunlight into electricityPhotons knock electrons loose in silicon, creating an electric current.
Guide How GPS determines your exact locationGPS satellites broadcast time; your device triangulates your position.
Guide How WiFi transmits data wirelesslyWiFi converts data into radio signals that travel between devices and routers.
Guide How vaccines train your immune systemVaccines teach your body to recognize and fight off specific pathogens.
Guide How batteries store and release electrical energyChemical reactions inside a battery push electrons through an external circuit.
Guide How encryption keeps your data secureEncryption turns readable data into ciphertext that only authorized parties can decode.
Guide What is neuroplasticity?How the brain rewires itself through experience and recovery.
Guide How does the placebo effect work?Why a sugar pill can make you feel better.
Guide How do sleep cycles work?The stages of sleep and what happens in each.
Guide What are mirror neurons?How the brain mirrors others' actions and emotions.
Guide What is cognitive dissonance?The discomfort of conflicting beliefs and how we resolve it.
Guide How does the brain process pain?The neural pathways that create the experience of pain.
Guide What is net neutrality?The principle that ISPs must treat all online data equally, without blocking or throttling.
Guide What does 'carbon footprint' mean?Total greenhouse gas emissions caused by a person, product, or activity.
Guide What does 'open source' actually mean?Software code anyone can freely use, modify, and share under a permissive license.
Guide What is end‑to‑end encryption?Encryption where only the sender and receiver can read messages; the provider cannot.
Guide What does 'bias in AI' actually mean?Systematic errors in AI outputs that unfairly discriminate, usually from biased training data.
Guide What is greenwashing?Misleading claims about environmental friendliness to attract eco‑conscious consumers.
Guide How does a touchscreen work?Capacitive and resistive touchscreens sense touch differently.
Guide How does a QR code work?QR codes store information using patterns of squares and error correction.
Guide How does a compass work?A compass needle aligns with Earth's magnetic field to indicate north.
GuideFollow the rabbit hole
One idea leads to the next. Start anywhere.
- What is compound interest?A plain explanation of compound interest, why it accelerates, and why it matters for anyone saving or borrowing.
- How compound interest worksThe four moving parts — principal, rate, frequency and time — and how each one changes what you end up with.
- The compound interest formula, explainedWhat FV = P(1 + r/n)^(nt) actually says, term by term, with a worked calculation you can follow.
- The Rule of 72A mental shortcut for how long money takes to double — how it works, how accurate it is, and where it breaks down.
- Compound interest and inflation: real returnsWhy the growth you see is not the growth you get, and how to think about returns after inflation.
- Why compound interest makes pensions workHow decades of compounding do most of the work in a pension, and why starting earlier beats contributing more.
Questions people ask
At what age do children develop theory of mind?
Most children start passing the standard false-belief test — reasoning about what someone else wrongly believes — at around age four. Simpler forms of tracking what others want or look at appear much earlier, in infancy. Researchers still debate what each step really shows.
Do animals have theory of mind?
It is genuinely contested. Some great apes and other species show signs of tracking what another individual can see or knows, but whether they represent others’ beliefs the way humans do is disputed rather than settled.
How do people afford houses in Dublin?
People afford houses in Dublin when their private resources and trade-offs add up: income, savings, mortgage borrowing, family help, a previous sale, or choosing a smaller home or longer commute. Theory of mind matters because you cannot see what another buyer knows or has: their deposit, debts, job security, support from family, or limits set by a lender. So one person’s purchase is not proof that the same home is affordable for everyone; it may reflect information and support you cannot see.
Natural English equivalent of the Ukrainian phrase "one thing doesn't interfere with the other"?
A natural English equivalent is “one doesn’t stop the other”, or more formally, “they’re not mutually exclusive.” It means the ideas, choices, or facts can sit together without conflict: accepting one does not make the other impossible.
Convert english to sinhala?
සූර්ය පැනල් විදුලිය නිපදවන්නේ හිරුඑළියේ ෆෝටෝන සිලිකන් සෛලවලට වැදී, ඉලෙක්ට්රෝන නිදහස් කර විදුලි ධාරාවක් ඇති කිරීමෙනි. මේ ක්රියාව ප්රකාශ-වෝල්ටීය බලපෑම ලෙස හැඳින්වේ. නිදහස් වූ ඉලෙක්ට්රෝන පැනලයේ පරිපථය හරහා ගලා යන අතර, එම විදුලිය නිවසක උපකරණ ක්රියාත්මක කිරීමට හෝ බැටරියක් ආරෝපණය කිරීමට භාවිතා කළ හැක.