Journal — Physics
Digital Sidewalk for energy
A proposal from January 2026 to turn home thermal scans into a shared, place-indexed record. It was written, costed, and not built.
The cavity model in the previous entry suggested a product: a phone app that turns a thermal image of a house into a prioritized list of heat leaks with a cost and a return for each fix. The January 2026 specification named it the Home Leak Mapper and sketched an HVAC optimizer to follow.
The flywheel idea
The more interesting part of the proposal was not the app. It was what the app's data could become. If homeowners contributed anonymized scans, indexed to a place at census-block precision and normalized by home type and climate zone, then regional patterns would emerge that no single scan could show. The model would improve with contributions, and the improved model would make each new contribution more useful.
The working name for that loop was a geocache data flywheel, after the practice of leaving records at known locations for others to find. The record schema was written: a scan identifier, scan type, anonymized location, timestamp, climate zone, building type, a processed cavity signature, and the model's outputs.
Why it is filed as "Digital Sidewalk"
This was the first time the sidewalk framework was applied to an environmental record rather than a social one. The community in Jacobs's sense was a neighborhood of houses contributing observations. The movement was scans accumulating over seasons. The safety question was privacy: what precision of location a household could share without becoming identifiable.
That last question is where the proposal did its most durable work. The schema anonymizes to the census block and stores a processed signature rather than the original image. Those two choices reappear, nearly unchanged, in the sensing platform's privacy rules later in 2026.
Status
The Home Leak Mapper was not built. The proposal listed phases and prices, and this journal does not repeat those as current plans. What survived was a habit: before the Lab collects an observation, it writes down where the record lives, how precise it is, and who is allowed to see it.