Are You Sure?
April 8, 2025
• ... that physician and archaeologist Michele Mercati (8 April 1541 – 25 June 1593) was among the first scholars to recognize prehistoric stone tools as human-made rather than natural or mythologically created thunderstones?
• ... that physicist Heike Kamerlingh Onnes (21 September 1853 – 21 February 1926) discovered superconductivity in 1911, writing in his notebook on April 8: Kwik nagenoeg nul ("Mercury[’s resistance] practically zero [at 3 K].").
• ... that inventor, astronomer, mathematician, clockmaker, and surveyor David Rittenhouse (8 April 1732 – 26 June 1796) was the first Director of the United States Mint, and that Rittenhouse personally struck the new nation's first coins by hand?
"Are You Sure?" is sponsored by Gnomon Chronicles Industries.
