I just finished an interview for NHK (Japan’s public broadcast station) about Heber Curtis and his discovery of a polar jet in M87 using the Crossley Telescope at Lick Observatory. At the time he suspected that many of the nebulae he was describing in detail were actually very distant and not part of our own Milky Way galaxy. He debated this with Harlow Shapley in 1920 in “The Great Debate” after which the prominent astronomers of the day agreed with Curtis that these were island universes.