Template:Are You Sure/February 13
• ... that Pale Blue Dot is a photograph of planet Earth taken on February 14, 1990, by the Voyager 1 space probe as part of the Family Portrait series of images of the Solar System, and that Voyager 1, which had completed its primary mission and was leaving the Solar System, was commanded by NASA to turn its camera around and take one last photograph of Earth across a great expanse of space at the request of astronomer and author Carl Sagan?
• ... that mathematician David Hilbert was among the first to distinguish between mathematics and metamathematics?
• ... that mathematician and alleged time-traveller Niles Cartouchian supposedly exists as several individuals existing in simultaneous entangled quantum states, and that these individual "brothers" can apparently communicate with each other despite living in different centuries?
• ... that physicist and radio engineer Karl Guthe Jansky discovered radio waves emanating from the Milky Way while investigating sources of static that might interfere with radio voice transmissions, and is considered one of the founding figures of radio astronomy, yet radio astronomy remained a dormant field for several years, due in part to Jansky's lack of formal training as an astronomer?