Beta· We’re publicly testing the first module, Gravity & Relativity.

Deeply Hidden Things
The curriculum

Twelve Big Ideas. Thirty-six lessons. One year.

Each Big Idea is three lessons — Discover, Go Deeper, Use It — and every lesson ends on what is still hidden.

The order is set by what has to be understood first, not by subject tidiness. The particle picture comes early because fluids and chemistry and everything biological need it. Chemistry comes before biology, always, because DNA is a molecule. And the year closes on quantum mechanics, at exactly the unfinished gap that Big Idea 01 pointed at in week three.

Big Idea 01 is designed and free. The lesson player is being built in this repository. The rest of the year is drafted and coming next.

01
Free · designed
02

Heat & Molecules

Why does anything feel hot?

Heat stops being a substance and becomes motion. Collects the debt Big Idea 01 opened when it said air was made of something.

DiscoverThe Invisible JiggleHot isn’t a thing you have. It’s how hard your bits are wobbling.Go DeeperThe One-Way StreetHeat only ever spreads out. Nothing gets tidy on its own.Use ItWhy Your Coat Doesn’t Warm YouInsulation doesn’t add heat. It slows the leak.
In production
03

Fluids & Flight

Why does anything float?

You are standing at the bottom of an ocean of air. The Use It lesson takes a familiar textbook picture of wings and finds a better one.

DiscoverWhy Does Anything Float?Floating isn’t about being light. It’s about being lighter than what you push out of the way.Go DeeperThe Air Is HeavyIt presses on you from every side, all the time, and you never notice.Use ItHow a Wing Holds a Plane UpAnd why the famous shortcut isn’t the whole story.
In production
04

Light

What is light, actually?

Light has a speed, it is the same for everybody, and that is the strangest fact in physics.

DiscoverWhat Is Light Made Of?Two answers, both partly right, and an argument that lasted centuries.Go DeeperThe Race Nothing Can WinNo matter how fast you chase it, light leaves at the same speed.Use ItLooking Backwards in TimeEverything you see is the past. Look far enough and it is a very old past.
In production
05

Electricity & Magnetism

What is a magnet doing to empty space?

Where this whole project came from: a four-year-old handed a compass, and a needle that moved with nothing touching it.

DiscoverThe Push You Can Feel Through NothingEinstein’s compass, arriving on purpose.Go DeeperThe Space Itself Is Doing SomethingA field is not a picture of the answer. It is the answer.Use ItEvery Motor You OwnElectricity and magnetism turn out to be the same thing wearing two hats.
In production
06

Signals

How does a voice cross an ocean?

You do not send the voice. You send a wave, and bend it into the shape of the voice.

DiscoverSending a Message With Nothing In BetweenNo wire, no string, no air. And it still arrives.Go DeeperRiding the WaveHow you hide a voice inside something that is not a voice.Use ItThe Internet Is Light In a PipeGlass threads on the sea floor, flashing faster than you can count.
In production
07

Chance & Evidence

How do we tell a real pattern from a convincing one?

The methods Big Idea, placed at the midpoint on purpose — it needs examples to work on, and by now there are plenty.

DiscoverThe Coin That Looks RiggedRandomness looks lumpy. Lumpy does not mean rigged.Go DeeperThe Pattern-Finding BrainYour brain finds patterns whether or not they are there. That’s a gift, and it’s also why we measure.Use ItReading a Number in the NewsFour questions to ask before you believe a statistic.
In production
08

Atoms & Bonds

Why does anything stick to anything?

Almost everything about a material comes down to what its outermost electrons are doing.

DiscoverWhat Holds Stuff Together?Why a rock is a rock and water is not.Go DeeperSharing and StealingTwo ways atoms can hold hands, and everything that follows from the difference.Use ItWhy Plastic Stretches and Glass ShattersLong tangled chains bend. Rigid grids snap.
In production
09

DNA

How does a body know how to build itself?

The mistakes in the copying are not a flaw in the system. The mistakes are where everything came from.

DiscoverThe Instructions Inside YouEvery cell carries the whole book, and reads only its own page.Go DeeperCopying Without Mistakes (Mostly)And why the “mostly” is the most important word in biology.Use ItWhy You Look Like Your FamilyAnd why you do not look exactly like them.
In production
10

Energy in Living Things

Where does your dinner actually go?

You are burning, right now, slowly and carefully and on purpose.

DiscoverYou Are Burning Right NowThe same reaction as a fire, run a hundred thousand times more gently.Go DeeperThe Tiny Engines in Every CellThere are machines inside you, and they have moving parts.Use ItWhy You Have To Keep EatingBecause of the one-way street from Big Idea 02. Nothing runs for free.
In production
11

Origins of Life

How did stuff become alive?

The Big Idea with the most open questions in the whole year, and it should feel that way.

DiscoverWhat Does “Alive” Even Mean?The definition is genuinely still being argued. That’s part of the adventure.Go DeeperThe First CopySomewhere, something made a copy of itself for the first time.Use ItLooking For Life Somewhere ElseWhat we are actually looking for, and how we would know.
In production
12

Quantum

What is everything made of, really?

The year ends where Big Idea 01 left off — at the unfinished gap between Einstein’s rules and the rules for tiny things.

DiscoverThe Experiment That Broke EverythingTwo slits, and a result nobody could explain away.Go DeeperNot Knowing Isn’t the Same as Not DecidedThe hardest and most careful distinction in the year.Use ItThe Computer In Your PocketEvery transistor you own is built on this.
In production

Four synthesis projects sit at the quarter boundaries — after Big Ideas 03, 06, 09 and 12 — each one needing concepts from at least two different Big Ideas to finish.