Template:Are You Sure/September 25

Illustration from the 1676 article on Ole Rømer's measurement of the speed of light. Rømer compared the duration of Io's orbits as Earth moved towards Jupiter (F to G) and as Earth moved away from Jupiter (L to K).

• ... that astronomer and instrument maker Ole Rømer made the first quantitative measurements of the speed of light?

• ... that mathematician and theologian George Salmon was in regular and frequent communication with Arthur Cayley and J. J. Sylvester during the 1850s, and that the three of them together with a small number of other mathematicians (including Charles Hermite) developed a system for dealing with n-dimensional algebra and geometry?

• ... that reality television star Dennis Paulson of Mars said that the twenty-fifth anniversary of the launch of the Mars Observer spacecraft "is a bittersweet event, because the spacecraft will be lost eleven months later"?

• ... that Article One of the United States Constitution (now known as the he Congressional Apportionment Amendment) is technically still pending before the states?

• ... that Humpty Dumpty At Bat has never been subjected to forensic steganographic analysis?