I found a 55 year old bug in the first Lunar Lander game (martincmartin.com)

Article summary

The first Lunar Lander game, written in 1969 by a high school senior, contained a 55-year-old bug that was recently discovered. The game's physics simulation used a sophisticated approach, including the Tsiolkovsky rocket equation and a Taylor series expansion, but a missing 'divide by two' in the code led to incorrect results. The bug was found by analyzing the game's optimal fuel burn schedule and comparing it to the theoretical best strategy. The discovery highlights the impressive numerical techniques used in the game, considering the limited resources and knowledge available at the time.

Main themes

• Lunar Lander game
• Vintage computer programming
• Physics simulation
• Numerical computing
• Retro gaming
• Computer science history

What commenters say

• The bug in the Lunar Lander game is impressive to have gone unnoticed for so long, given the game's simplicity and the large number of people who have played it.
• The game's author demonstrated exceptional skill and knowledge of calculus and physics for a high school student in 1969, making the game's creation even more remarkable.
• The discovery of the bug highlights the importance of numerical computing and the challenges of simulating real-world physics in computer games, even with modern technology.
• The game's use of the Tsiolkovsky rocket equation and Taylor series expansion was a sophisticated approach, considering the limited resources and knowledge available at the time, and demonstrates the author's understanding of advanced mathematical concepts.
• The fact that the bug was not noticed earlier suggests that players were more focused on playing the game and having fun, rather than analyzing its underlying physics and mathematics.
• The creation of the Lunar Lander game and the discovery of the bug demonstrate the evolution of computer science and programming over time, with modern developers having more access to resources and knowledge.
• The game's author's use of a non-standard programming language, FOCAL, added to the complexity of the code and may have contributed to the bug going unnoticed for so long.
• The discussion around the bug and the game's physics simulation highlights the ongoing interest in retro gaming and the history of computer science, with many commenters sharing their own experiences and insights.