The computer BESK and an early attempt to simulate galactic dynamics

TL;DR

This paper discusses the early development of galactic dynamics simulations, highlighting Holmberg's 1941 light-bulb experiment and subsequent computer-based N-body simulations, including the author's contributions.

Contribution

It provides historical context and technical details of early galactic N-body simulations, emphasizing the transition from light-bulb experiments to computer models.

Findings

Holmberg's 1941 light-bulb experiment simulated galaxy interactions.

First computer-based N-body simulations of galaxies were performed in the 1950s.

The paper includes a description of the early simulation movie and its significance.

Abstract

The first N-body simulation of interacting galaxies, even producing spiral arms, was performed by Erik Holmberg in Lund (1941), not with a numerical computer, but by his arrangement of movable light-bulbs and photocells to measure the luminosity at each bulb and thereby estimate the gravitational force. A decade later, and with the arrival of the first programable computers, computations of galactic dynamics were performed, which were later transferred into a N-body simulation movie. I present here the background details for this work with a description of the important elements to note in the movie which may be retrieved at http://ttt.astro.su.se/~po .