from Hacker News

The decimal point is 150 years older than we thought

by frasermarlow on 2/21/24, 5:54 PM with 3 comments

• by quuxplusone on 2/21/24, 6:45 PM

  Submitted URL is a newsletter linking to a Nature blurb linking to the actual paper, https://doi.org/10.1016/j.hm.2024.01.001 "Decimal fractional numeration and the decimal point in 15th-century Italy" (Glen Van Brummelen, 2024). That paper's abstract:

  "The earliest known appearance of the decimal point was in the interpolation column of a sine table in Christopher Clavius's Astrolabium (1593) [...] We trace Clavius's use of decimal fractional numeration and the decimal point back to the work of Giovanni Bianchini (1440s), whose decimal system was a distinguishing feature of his calculations in spherical astronomy and metrology."

• by frasermarlow on 2/21/24, 5:54 PM

  Not that I could have placed an age on the decimal point prior to reading this, mind you.