Magnetism from the iron filing to the planetary dynamo. Four orders of magnitude in one toolkit.
An interactive magnetism lab teaching one move: the same dipole physics appears at every scale from a desktop bar magnet to the magnetosphere shield that protects Earth from solar wind. Same equations. Different r. Wildly different consequences.
Pedagogically a sibling to the Stimulated Emission Bridge in 4.10.39 (Gigamaser) and the Terracotta-daylight-ceiling reframe in 4.4.10 (The Other Side). Same physics, different scale is becoming an OPA signature pedagogical move.
Panel 3 paleomagnetic timeline rebuilt with 4-lane collision-aware label staggering, leader lines from each event dot to its label, shortened names for the crowded right cluster (B-M Reversal, Cobb Mtn., G-M Reversal), and a taller canvas (200 px vs 130). Caught by Travis: labels were stacking on top of each other on the right side of the log scale.
Section 4.9.4e — joins the OPA Browser Physics Lab Suite (4.9.4a Chladni Plate, 4.9.4b Acoustic Levitation, 4.9.4c Ripple Tank, 4.9.4d Double-Slit Interference). College IX, Stephens Science Center.
Built by Travis Jenkins (User Zero) with Claude. The four-scales framing — bar magnet to magnetosphere via horseshoe and Earth's pole — was User Zero's. The capstone cartoon is User Zero's own artwork, drawn after the February 19, 2026 AI Impact Summit in New Delhi.
The magnetic dipole field equation is taught in every undergraduate electromagnetism course. Jackson's Classical Electrodynamics (1962, still canonical) is the standard reference. The force between two coaxial dipoles falls as 1/r⁴ (Griffiths, Introduction to Electrodynamics, Ch. 6).
The International Geomagnetic Reference Field (IGRF) is the open dataset maintained by IAGA. NOAA's National Centers for Environmental Information (NCEI) hosts the historical pole positions. The North Magnetic Pole has drifted from northern Canada toward Siberia, accelerating from ~10 km/yr in the late 20th century to ~55 km/yr around 2000, slowing back to ~35 km/yr now. The current global field weakens at ~5% per century.
Paleomagnetic reversals are documented in the Geomagnetic Polarity Timescale (Cande & Kent, 1995; updated since). The last full reversal — Brunhes-Matuyama — was ~780,000 years ago. Partial excursions (e.g., Laschamp, ~42,000 years ago) are the best-modeled near-reversal events.
NASA's Magnetospheric Multiscale (MMS) mission provides the modern in-situ measurements. The bow shock / magnetopause / magnetotail structure is documented in Kivelson & Russell's Introduction to Space Physics (1995). The atmospheric-stripping-without-field result is from Mars: the MAVEN mission (2014–present) measured the rate at which Mars loses atmosphere to solar wind in the absence of a global magnetic field.
The conference moment captured in the cartoon is a documented public event covered by multiple news outlets:
Altman later said he was "confused" and thought it was "the open clock." Amodei has not commented publicly as of this lab's filing date.
The AI industry dynamics underlying the capstone are covered in canon at: 4.4.2 (Business Case Study: AI App Wars), 4.5.3 (DCV Case Study: Truth, Power, and Public Discourse), 4.8.7 (Corporate Hypocrisy: LinkedIn + Anthropic source-code leak), and 4.19.1 (International Affairs & Diplomacy, Building 19 — the natural home for cross-listing the summit event itself).