Centuries of the Bristlecone

Overview

Centuries of the Bristlecone is Jonathan Keats’s 5,000-year living-calendar project in (From the archive) Jonathon Keats: Envisioning Deep Time and Anne Heggli, Jonathon Keats, & Adam Csank: Art & Science at the Nevada Bristlecone Preserve. It uses bristlecone growth rather than abstract standardized intervals as its primary temporal signal.

Current Profile

The project is a Long Now-style artwork and timekeeping system at the Nevada Bristlecone Preserve. Dated survey markers are placed around a sapling using an estimated growth rate of about one millimeter per year; the tree reaches them according to its lived conditions rather than a fixed calendar. A related municipal clock, engineered for a proposed 5,000-year lifespan, carries that variable rate into public life in Reno. The current synthesis is therefore broader than a ring calendar: it is an experiment in whether ecological response can become a public standard of accuracy.

Key Characteristics

• The project uses a bristlecone pine as the timekeeping medium.
• It is designed for a 5,000-year horizon rather than a human lifetime.
• Its marks can drift from the Gregorian calendar because tree rings respond to lived environmental conditions.
• It turns calendar disagreement into a philosophical question about which temporal system should be treated as authoritative.
• The source links the proposal to Long Now’s Mount Washington site in eastern Nevada.
• Its municipal-clock branch makes remote tree growth publicly visible through a variable pendulum rate.

Evidence

Living Calendar Medium

• (From the archive) Jonathon Keats: Envisioning Deep Time says Keats introduced the project publicly as a calendar kept according to life on Earth rather than abstract regularity.
• (From the archive) Jonathon Keats: Envisioning Deep Time explains that the proposed stones would be placed around the tree at projected growth intervals and eventually be overturned by the tree.
• Anne Heggli, Jonathon Keats, & Adam Csank: Art & Science at the Nevada Bristlecone Preserve specifies survey markers stamped with future dates around a sapling and an estimated growth rate of about one millimeter per year.

Long Now Site Context

• (From the archive) Jonathon Keats: Envisioning Deep Time says Long Now owns more than 800 acres at Mount Washington in eastern Nevada and that Keats had begun discussing implementation there.
• Anne Heggli, Jonathon Keats, & Adam Csank: Art & Science at the Nevada Bristlecone Preserve places the project within the Nevada Bristlecone Preserve, where tree growth can be read beside NEVCAN’s environmental observations.

Calendar Challenge

• (From the archive) Jonathon Keats: Envisioning Deep Time says the project would fall out of sync with the Gregorian calendar, making calendar correctness a live question rather than a settled convention.
• Anne Heggli, Jonathon Keats, & Adam Csank: Art & Science at the Nevada Bristlecone Preserve distinguishes uniform precision from a living system’s environmental accuracy and says climate and carbon-dioxide responses may speed or slow the tree calendar relative to atomic time.

Municipal Clock

• Anne Heggli, Jonathon Keats, & Adam Csank: Art & Science at the Nevada Bristlecone Preserve says Phil Abernathy and Brittany Nicole Cox engineered a clock tied to bristlecone growth for an intended 5,000-year lifespan, with the Nevada Museum of Art and Long Now making it publicly accessible.

Qualifications

The sources do not establish how tree measurements will control the public clock, how calibration and repairs will remain legible over millennia, or how conservation and site management will handle disturbance. A stated 5,000-year design intention is not evidence that the device or institutional arrangement will survive that long.

What Changed

• The proposal is now grounded in dated survey markers, a sapling growth estimate, and a related municipal clock rather than only a conceptual stone calendar.
• Chronodiversity and environmental accuracy now clarify why variable growth is a feature of the project rather than measurement error.

Relationships

• Jonathan Keats - project originator.
• Long Now - institutional and site collaborator context.
• Ecological Timekeeping - conceptual frame for using living systems as calendars.
• Deep-Time Mental Prosthesis - adjacent role as a tool for imagining millennial accountability.
• Chronodiversity - principle that gives the tree’s variable temporal rate normative significance.
• Nevada Bristlecone Preserve - ecological and institutional setting for the living calendar.