# The Fate of Ernst Ising and the Fate of his Model

## TL;DR

This paper reflects on the historical significance, solutions, and interdisciplinary applications of the Ising model, emphasizing its impact on understanding collective phenomena across sciences over the past century.

## Contribution

It provides a personal and historical perspective on the Ising model's development, solutions, and broad scientific relevance, highlighting its ongoing importance.

## Key findings

- Historical overview of the Ising model's development
- Discussion of exact solutions and experimental realizations
- Extension of the model to various scientific fields

## Abstract

On this, the occasion of the 20th anniversary of the "Ising Lectures" in Lviv (Ukraine), we give some personal reflections about the famous model that was suggested by Wilhelm Lenz for ferromagnetism in 1920 and solved in one dimension by his PhD student, Ernst Ising, in 1924. That work of Lenz and Ising marked the start of a scientific direction that, over nearly 100 years, delivered extraordinary successes in explaining collective behaviour in a vast variety of systems, both within and beyond the natural sciences. The broadness of the appeal of the Ising model is reflected in the variety of talks presented at the Ising lectures ( http://www.icmp.lviv.ua/ising/ ) over the past two decades but requires that we restrict this report to a small selection of topics. The paper starts with some personal memoirs of Thomas Ising (Ernst's son). We then discuss the history of the model, exact solutions, experimental realisations, and its extension to other fields.