hackertube.io

Ptolemy and Homer (Simpson)

Santiago Ginnobili · demo · Watch on YouTube

Recreational & visual mathInformation theory & signal processingCosmology & astrophysics

What it is

A short animation reconstructing a planet's looping orbit using Ptolemy's epicycles and deferents, with the epicycles tracing out the face of Homer Simpson. It shows how enough circles can reproduce nearly any shape.

Why Hacker News recommends it

HN uses it as a vivid demonstration that Fourier series and epicycles can fit anything, and as a warning about models with too much wiggle room.

  • 3 people recommended it
  • 3 different months
  • 0 strong recommendations
  • first 2013, last 2022

What HN commenters said

  1. “These guys are one of the reasons I love mathematics. Check this out too”

    Math video that exemplifies love of mathematics.

    TheMakeA, 2013-11 · Recommendation · in “Fourier Toy”

  2. “the reconstruction of Homer Simpson's face”

    Reconstructs Homer Simpson's face with Fourier epicycles, a convincing demo of Fourier transforms.

    JadeNB, 2015-10 · Recommendation · in “Fourier visualised”

  3. “This is my favourite visualisation of this fact”

    Visualizes how epicycles can fit any periodic orbit via Fourier series.

    jordigh, 2016-10 · Recommendation · in “Opposition to Galileo was scientific, not just religious”

Excerpts from Hacker News comments, linked to the originals. Summaries and labels were written by a language model from those comments.

Topics: epicycles, fourier series, ptolemy, overfitting, visualization

Also recommended by the same people