PATREON: https://www.patreon.com/anotherroof CHANNEL: null WEBSITE: https://anotherroof.top/ SUBREDDIT: https://www.reddit.com/r/anotherroof Check out my series on building numbers from the ground up:    • Mathematics from the Ground Up   Okay, we all know 1 isn’t prime. But it wasn’t always that way. It also wasn’t always considered to be a number at all. Join me on a deep dive into mathematical history to see how our concepts of numbers and primes changed over time. A huge thank you to my patrons for keeping the channel alive. Please consider supporting me by following the link above! An enormous thank you to Chris Caldwell et al. for their compilation of sources regarding the history of 1 as a prime. Their work is much more thorough and extensive than my video and covers many, many more examples of 1 defined as prime or otherwise. My video is intended as a rough narrative through line regarding the broad(ish) consensus regarding the status of 1. Having such an extensive list of sources was really helpful when writing. You can find their article here: Caldwell, Chris K. et al. “The History of the Primality of One: A Selection of Sources.” Journal of integer sequences 15.9 (2012). All music by Danijel Zambo. TIMESTAMPS: 00:00 - Intro 01:20 - Antiquity 09:17 - Medieval 13:50 - Modern 23:59 - Outro REFERENCES [1] - Euclid. The Thirteen Books of The Elements, Vol. 2 Books III-IX. Translated by Heiberg. Dover Books on Mathematics, 1956. [2] - Martianus Capella. et al. Martianus Capella and the Seven Liberal Arts. Vol.2, The Marriage of Philology and Mercury. New York ;: Columbia University Press, 1977. [3] - Isidore, and Stephen A. Barney. The Etymologies of Isidore of Seville. Cambridge: Cambridge University Press, 2006. [4] - Khuwārizmĭ, Mu.hammad ibn Mūsá, Robert, and Barnabas. Hughes. Robert of Chester’s Latin translation of al-Khwārizmĭ’s al-Jabr : a new critical edition. Stuttgart: Franz Steiner, 1989. [5] - Stevin, S. The Principal Works of Simon Stevin. Vol.2B. Mathematics. C.V. Swets & Zeitlinger, 1958. [6] - Morland, Samuel. The Description and Use of Two Arithmetick Instruments : Together with a Short Treatise, Explaining and Demonstrating the Ordinary Operations of Arithmetick, as Likewise a Perpetual Almanack and Several Useful Tables : Presented to His Most Excellent Majesty Charles II ... London: Printed and are to be sold by Moses Pitt ..., 1673. [7] - Moxon, Joseph, and Henry Coley. Mathematicks Made Easie, or, A Mathematical Dictionary ... The second edition, corrected and much enlarged by Hen. Coley ... London: Printed for J. Moxon ..., 1692. [8] - Rahn, Johann Heinrich, Thomas Brancker, and John Pell. An Introduction to Algebra. London: Printed by W.G. for Moses Pitt ..., 1668. [9] - C. Goldbach, Letter to Euler dated 7 June 1742. Correspondance math´ematique et physique de quelques c´elebres geometres du XVIIIeme, siecle by P.-H. Fuss, Vol. I, pp. 125–129, Academie Imperiale des Sciences, St.-Petersbourg, 1843. [10] - J. G. Krüger, Gedancken von der Algebra, nebst den Primzahlen von 1 bis 1000000, Lüderwalds Buchhandlung, Halle, 1746. [11] - Euler, Leonhard, and John Hewlett. Elements of Algebra. Trans. John Hewlett. Cambridge: Cambridge University Press, 2009. [12] - Gauss, Carl Friedrich et al. Disquisitiones Arithmeticae. New York: Springer-Verlag, 1986. Print. [13] - Gregory, Olinthus. Mathematics for Practical Men : Being a Common-Place Book of Pure and Mixed Mathematics, Designed Chiefly for the Use of Civil Engineers, Architects and Surveyors. 4th ed / rev. and enl., by Henry Law. London: J. Weale, 1862. [14] - Hardy, G. H. (Godfrey Harold). A Course of Pure Mathematics. 6th ed. Cambridge Eng: The University Press, 1933. [15] - Hardy, G. H. (Godfrey Harold). A Course of Pure Mathematics. Centenary ed. Cambridge: Cambridge University Press, 2008. [16] - Sagan, C. Contact. Simon and Schuster, 1985. [17] - J. B. Andreasen, L.-A. T. Spalding, and E. Ortiz, FTCE: Elementary Education K-6, Cliffs Notes, Wiley, Hoboken, NJ, 2010.