AI and neural networks

A neural network is a very large number of small adjustments, made until the answers stop being wrong.

What it is

Modern AI is mostly machine learning: instead of writing rules, engineers show a model many examples and adjust its internal weights until its outputs improve. Neural networks, loosely inspired by neurons, are layers of these adjustable connections.

Two ideas carry most of today’s progress. Backpropagation (1986) made it practical to train deep networks, and the transformer architecture (2017) made it possible to train them on vast amounts of text. Language models such as Claude are transformers.

Updated 5 November 2026 · 3 sourced facts

Illustrative model

How a neural network passes a signal

A small network showing inputs, hidden layers and outputs, with a signal moving through the weights.

Source: Nature

A model to explain the idea; not drawn to scale.

Ideas to carry

  1. 1

    Learning, not programming

    The behaviour comes from data and training, not from hand-written rules.

  2. 2

    Attention

    Transformers let every word weigh every other word when building meaning.

  3. 3

    Scale is not understanding

    Bigger models do more, but how much they understand is still debated.

Established What we know

  1. Rumelhart, Hinton and Williams showed in 1986 how back-propagating errors can train multi-layer networks.[1]
  2. The transformer architecture was introduced in the 2017 paper “Attention Is All You Need”.[2]
  3. The 2024 Nobel Prize in Physics went to John Hopfield and Geoffrey Hinton for foundational discoveries enabling machine learning with artificial neural networks.[3]

Interpretation The older lens · Jewish folklore

Jewish folklore’s golem is a made servant that does exactly what it is told, which is why the instructions matter.

Reading

  1. 1986Learning representations by back-propagating errorsRumelhart, Hinton and Williams
  2. 2017Attention Is All You NeedVaswani et al.
  3. 2019Artificial Intelligence: A Guide for Thinking HumansMelanie Mitchell

Neural network after 10 billion examples

“Is this a cat?” — 97% sure it is a fluffy towel

Made in-house, for fun.

Connected subjects, projects and writing

Sources

  1. Learning representations by back-propagating errors Nature, 1986. Checked 5 Nov 2026.
  2. Attention Is All You Need arXiv, 2017. Checked 5 Nov 2026.
  3. The Nobel Prize in Physics 2024 Nobel Prize, 2024. Checked 5 Nov 2026.