Template:Are You Sure/January 26

• ... that mathematician János Bolyai was one of the founders of non-Euclidean geometry, which helped to free mathematicians to study abstract concepts irrespective of any possible connection with the physical world?

• ... that engineer and inventor John Logie Baird, one of the inventors of the mechanical television, demonstrated the first working television system on this day in 1926, and that Baird also invented the first purely electronic color television picture tube?

• ... that mathematician Richard Courant believed that the existence of a physical solution does not obviate mathematical proof, and that he wrote "Empirical evidence can never establish mathematical existence — nor can the mathematician's demand for existence be dismissed by the physicist as useless rigor. Only a mathematical existence proof can ensure that the mathematical description of a physical phenomenon is meaningful."?

• ... that the Flying Diner (also known as the Flying Lunch Car) is the only diner adapted for flight, and that it serves short-order breakfast and lunch in flight?