Noone honestly knew the answer to "How I wonder what you are." when Twinkle Twinkle Little Star was written in 1806.

Tim Swast on February 9, 2019:

Noone honestly knew the answer to "How I wonder what you are!" when Twinkle Twinkle Little Star was written (1806). Not until 1838, when Friedrich Bessel first measured the distance to 61 Cygni. #TIL from Our Mathematical Universe by Max Tegmark.