# Calibration curve · Concept > The correction that turns a radiocarbon measurement into a calendar date. Source: https://mysteriesdept.com/concepts/CPT0DECW019N8HS/calibration-curve Publisher: Mysteries Department Licence: CC BY 4.0 (credit Mysteries Department and link the page) --- [Concepts](https://mysteriesdept.com/concepts)Calibration curve Concept · archaeometry · in 9 mysteries # Calibration curve The correction that turns a radiocarbon measurement into a calendar date. [Voynich Manuscript](https://mysteriesdept.com/mysteries/voynich-manuscript)[Pictish symbol stones](https://mysteriesdept.com/mysteries/pictish-symbols)[Tabby's star (KIC 8462852)](https://mysteriesdept.com/mysteries/tabbys-star) The atmosphere's carbon-14 has not been constant, so a raw radiocarbon age is matched against a curve built from tree rings and other dated records to give a calendar range. Where the curve is flat, a tight measurement gives a wide date; where it wiggles, several ranges are possible. Many arguments on this site about a date are arguments about where a sample falls on the curve. ## Where it comes up **[Voynich Manuscript](https://mysteriesdept.com/mysteries/voynich-manuscript)** Small neural classifiers trained on the T39 simulations give a posterior over every period-cipher setting; checked by simulation-based calibration against rejection ABC before it is used on the herbal sections. [Neural posterior estimation for the period-cipher family, with simulation-based calibration](https://mysteriesdept.com/methods/MTH0DCF1J196PST/neural-posterior-estimation-for-the-period-cipher-family)[A calibrated posterior over period-cipher settings pins down spacing and the line layer, not the key's size](https://mysteriesdept.com/mysteries/voynich-manuscript/evidence/EVD0DCHSNX5R3VX/a-calibrated-posterior-over-period-cipher-settings-pins-down) **[Pictish symbol stones](https://mysteriesdept.com/mysteries/pictish-symbols)** The authors' decision tree separated their own calibration corpora of known writing and non-linguistic systems. [The authors' decision tree separated their own calibration corpora of known writing and non-linguistic…](https://mysteriesdept.com/mysteries/pictish-symbols/evidence/EVD0CQHAKQC6HA2/the-authors-decision-tree-separated-their-own-calibration) **[Tabby's star (KIC 8462852)](https://mysteriesdept.com/mysteries/tabbys-star)** [The century fade is a calibration artefact of plate photometry.](https://mysteriesdept.com/mysteries/tabbys-star/answers/ANS0D8E7HPY1BFW/the-century-fade-is-a-calibration-artefact-of-plate) **[1979 Vela incident](https://mysteriesdept.com/mysteries/vela-incident)** [Laser calibration tests showed the bhangmeters operating nominally.](https://mysteriesdept.com/mysteries/vela-incident/evidence/EVD0CW4X33P2S9R/laser-calibration-tests-showed-the-bhangmeters-operating) **[Late Bronze Age collapse](https://mysteriesdept.com/mysteries/bronze-age-collapse)** [128 high-precision 14C measurements on Gordion tree-ring decades and the wiggle-match (Manning et al. 2010)](https://mysteriesdept.com/datasets/DAT0D4654MW78RA/128-high-precision-14c-measurements-on-gordion-tree-ring) **[Younger Dryas impact hypothesis](https://mysteriesdept.com/mysteries/younger-dryas-impact)** Recommended calibration of the Baffin Bay dates gives younger ages outside the Younger Dryas, and one core has a non-boundary peak as large as the boundary peak in another. [Recommended calibration of the Baffin Bay dates gives younger ages outside the Younger Dryas, and one core…](https://mysteriesdept.com/mysteries/younger-dryas-impact/evidence/EVD0D51XRXT584N/recommended-calibration-of-the-baffin-bay-dates-gives) **[Phosphine in the clouds of Venus](https://mysteriesdept.com/mysteries/venus-phosphine)** [The feature is an artefact of baseline fitting and calibration, not a property of Venus.](https://mysteriesdept.com/mysteries/venus-phosphine/answers/ANS0CQY1XNA2472/the-feature-is-an-artefact-of-baseline-fitting-and)[ALMA's standard calibration was unsuitable for so bright a target and had to be revised.](https://mysteriesdept.com/mysteries/venus-phosphine/evidence/EVD0CQY1X5P6K79/almas-standard-calibration-was-unsuitable-for-so-bright-a)[The team reports the line at about 5 sigma in ALMA data reprocessed with the revised calibration.](https://mysteriesdept.com/mysteries/venus-phosphine/evidence/EVD0CQY1VPT5C0Z/the-team-reports-the-line-at-about-5-sigma-in-alma-data)[The team reports the feature in data reduced with revised calibration and in new JCMT data.](https://mysteriesdept.com/mysteries/venus-phosphine/evidence/EVD0CQY1YCR5FCM/the-team-reports-the-feature-in-data-reduced-with-revised)[ALMA project 2018.A.00023.S, Venus in Band 6, 5 March 2019](https://mysteriesdept.com/datasets/DAT0CQY24G22YT7/alma-project-2018-a-00023-s-venus-in-band-6-5-march-2019) **[Dead Sea Scrolls: dating, scribes and provenance](https://mysteriesdept.com/mysteries/dead-sea-scrolls-dating)** [A re-examination of the calibrations found they do not support the later chronology.](https://mysteriesdept.com/mysteries/dead-sea-scrolls-dating/evidence/EVD0D484RHA4SK3/a-re-examination-of-the-calibrations-found-they-do-not) **[Mars methane puzzle](https://mysteriesdept.com/mysteries/mars-methane)** [ExoMars TGO ACS data (PSA bundle em16_tgo_acs)](https://mysteriesdept.com/datasets/DAT0D7EY6G425AP/exomars-tgo-acs-data-psa-bundle-em16-tgo-acs) ## Methods that use it 1 [Neural posterior estimation for the period-cipher family, with simulation-based calibration](https://mysteriesdept.com/methods/MTH0DCF1J196PST/neural-posterior-estimation-for-the-period-cipher-family) Voynich Manuscript MTH ## Cite it ``` Mysteries Department. (2026). Calibration curve [Concept CPT0DECW019N8HS]. https://mysteriesdept.com/r/CPT0DECW019N8HS ``` Key **CPT** 0DECW019N8HS Record Concept Field Archaeometry Related [Radiocarbon dating](https://mysteriesdept.com/concepts/CPT0DECW013KR34/radiocarbon-dating) Version 2 Added by [apollo](https://mysteriesdept.com/u/apollo) **How this page is made.** The definition is the site's, in its own words. “Where it comes up” is read from the answers, methods and evidence that name the concept. Related concepts [Radiocarbon dating](https://mysteriesdept.com/concepts/CPT0DECW013KR34/radiocarbon-dating) The record Every record is open data. Take this one as JSON, with its links and its history. [JSON](https://mysteriesdept.com/api/v1/records/CPT0DECW019N8HS)