Library

Find out how to work out the power of an electrical appliance and the energy it uses, so you can finally understand your electricity bill and the Joule effect.

From Kepler’s elliptical orbits to modern geostationary satellites: understand the mechanics governing the motion of planets and spacecraft, including calculations of velocity, period and energy.

Find out how to work out the speed of a moving object, the difference between average speed and instantaneous speed, and how to read a distance-time graph like a real physicist.

Discover how a computer arranges a list of numbers in order, from the simplest method to the most efficient. You'll compare the methods step by step using diagrams.

Explore the binary tree structure, from basic vocabulary to the binary search tree (BST). You will learn to insert, search, traverse (pre-order, in-order, post-order) and measure the height of a tree, with large diagrams to visualize each step.

Modelling a network: vertices, edges, directed or weighted graphs. Two ways to represent them in memory, and the two fundamental traversals (breadth-first and depth-first) illustrated step by step.

Install the essential basics of the Python language: your first program, variables and data types. A concrete and reassuring first step into programming.

Learn how to make your programs take decisions using if / elif / else, and how to repeat actions with for and while loops. Two essential pillars for building useful programs.

Learn to break your code into reusable blocks using functions: parameters, return values, and variable scope. An essential step toward writing clearer, easier-to-fix programs.

Discover two essential data structures: the list, for storing values in order, and the dictionary, for associating a key with a value. Everything you need to organize your programs' data properly.

Understand the principle of a function that calls itself, from the indispensable base case to the call stack, through classic examples such as the factorial and the Fibonacci sequence.

How to store thousands of pieces of information without ever losing or duplicating them, and how to speak to them in the universal language of databases: SQL.

Discover why atoms bond together to form molecules or crystals, and learn to distinguish covalent bonds from ionic bonds using Lewis structures.

Understand how a gas's pressure, volume, temperature, and amount of substance are linked by a single equation, and learn to calculate one from the others.

Discover how a chemical reaction releases or absorbs energy, and learn to precisely calculate this energy using bond energies. A detour through the combustion of methane shows you how thermochemistry explains the calorific value of fuels.

Understand how a galvanic cell turns a spontaneous redox reaction into usable electric current, by physically separating the oxidizing agent and the reducing agent. Through the Daniell cell, discover the anode, the cathode, the direction of current, and learn to calculate the voltage delivered.

Understand how a fluid exchanges pressure energy, kinetic energy and potential energy along a streamline, and discover the applications (Venturi, Pitot, Torricelli) as well as the limitations of this fundamental result in fluid mechanics.

An object can be both at rest and in motion: it all depends on who is observing it! Discover the concept of a reference frame – the key to describing any motion correctly.

Find out how the eye forms images, why certain vision problems occur, and how magnifying glasses, microscopes and telescopes push the boundaries of our vision.

The little padlock in your browser: what it really guarantees, what it doesn’t guarantee, and how a secure connection is established in a matter of milliseconds.

Your browser accepts millions of websites it has never seen before. How does it decide which ones to trust? How certificates and certificate authorities work – and their vulnerabilities.

What is the difference between ‘encrypted’ and ‘end-to-end encrypted’? What the server can see, what it cannot see, and how modern messaging services protect both the past and the future.

The weakest link is usually neither the algorithm nor the key, but the way in which it is selected at random. Why unpredictability is difficult to achieve, and what happens when it is lacking.

Delve into the dynamics of an RC circuit to understand how a capacitor stores and then releases energy, and master the differential equation that governs all analogue electronics.