3Blue1Brown

3Blue1Brown is a maths channel made by Grant Sanderson. The channel has its own website with more of his projects, answers to common questions and ways to get in touch.

The videos cover topics in maths and nearby fields such as physics and computer science. The focus is always on seeing an idea, not just memorising it. Smooth animations build up a concept step by step, and a change of viewpoint often makes a hard problem feel simple. Some videos stand alone, while others form longer series on calculus, linear algebra, differential equations and neural networks.

Some highlights include:

The first chapter of a series on deep learning, showing how a neural network can learn to recognise handwritten digits.

An introduction to Fourier series, starting from how heat flows and ending with pictures drawn by spinning circles.

A visual introduction to the Fourier transform, the tool that lets engineers split a signal into its frequencies.

3Blue1Brown has over 8.6 million subscribers.

This is one of the best places to build real intuition for the maths engineers use every day. Fourier analysis sits behind audio, radio and image processing, so it is a strong way into electronic engineering. The neural network series is a clear starting point for anyone thinking about computer science, AI or robotics. It also makes A level maths and further maths feel more connected to the real world.