February 25

• 

  1598: John Dee demonstrates the solar eclipse by viewing an image through a pinhole. Two versions from Ashmole and Aubrey give different details of who was present. Dee's Diary only contains the notation, "the eclips. A clowdy day, but great darkness about 9 1/2 maine".

• 

  1857: Botanist and chemist Friedrich Reinitzer born. In late 1880s, experimenting with cholesteryl benzoate, Reinitzer discovered the properties of what would later be called liquid crystals; although the discovery attracted attention, interest soon faded as no practical uses were found at the time.

• 

  1971: Chemist and academic Theodor Svedberg dies. He was awarded the 1926 Nobel Prize in Chemistry for his pioneering use of analytical ultracentrifugation to distinguish pure proteins from one another.

• 

  1972: Mathematician and academic Hugo Steinhaus dies. He discovered mathematician Stefan Banach, with whom he made notable contributions to functional analysis, including the Banach–Steinhaus theorem.

• 

  1999: Chemist Glenn T. Seaborg dies. He shared the 1951 Nobel Prize in Chemistry for the synthesis, discovery, and investigation of transuranium elements.