# A prime-number sieve is later attributed to Eratosthenes; it is not a recovered classroom autograph Date: 235 ## The fact Britannica and MacTutor print a prime-finding algorithm later called the sieve of [Eratosthenes](/people/eratosthenes), in which composites are struck from a list of naturals. The public attribution is later (Nicomachus and subsequent mathematical tradition), not a surviving Alexandrian school tablet. Modern programming textbooks that animate the sieve are not his acts. It is one event. ## Context Do not upgrade a later attribution into a dated Mouseion lecture. Do store the received mathematical heading as a knowledge path of medium confidence on authorship, high on the later name of the method. Eratosthenes’s documented role is bounded by other offices and collaborators named in the sources below. Sharing a field with them is not a reason to drop a documented act, and it is not a reason to assign later consequences done in the name after death. Conventional years are c.276–c.194 BCE. Almost no autograph survives. Cleomedes, Strabo, Nicomachus, and later encyclopedias are the public file. Classroom globe reconstructions are not his acts. Contribution is complex. Named person as heading of the dated public instrument. Later editors, museums, printers, or offices share publication. Complex where later carriers are the surviving public file. ## Evidence and sources Britannica’s sieve discussion inside the Eratosthenes life and MacTutor independently describe the algorithm as credited to him in later tradition. Official or archival record: Britannica — Eratosthenes (https://www.britannica.com/biography/Eratosthenes; Encyclopaedia Britannica). ## Significance A later-attributed prime algorithm is a knowledge-access path. It is not a unique coefficient for later computing, and it is not a recovered autograph. ## What is established and what is not Established: later mathematical tradition names a sieve after him. Not established: a third-century BCE autograph of the procedure, or that every later textbook proof is his wording. What would change the picture: a contradictory original with a different date or name, or a measured series that can be argued, with lag and alternatives, as a consequence of this instrument rather than of later institutions. The date is the date of this instrument, not a licence to back-date every later harm or benefit. Established here: a sourced, dated public instrument with a named contribution by Eratosthenes. They are not a public rating. Eratosthenes did not file a later UNESCO form, a later Loeb colophon, or a later museum label as a personal act. A portrait or conventional bust is not this mechanism. Allegation, reconstruction, and established occurrence stay distinct. Do not treat a JavaScript animation as a 235 BCE instrument. Keep the carrier date of later English distinct from the received historical year stored in the date field. Do not read a later English edition as a recovered autograph of Eratosthenes. ## People - Eratosthenes: https://factrail.ai/people/eratosthenes ## Drivers - Digital Learning Access: https://factrail.ai/drivers/edu-digital-learning-access ## Sources - https://www.britannica.com/biography/Eratosthenes - https://mathshistory.st-andrews.ac.uk/Biographies/Eratosthenes/ ## Methodology https://factrail.ai/methodology Canonical: https://factrail.ai/facts/era-sieve-later-attributed