That Day – The Sky in History

About

Why was the night the Titanic sank so dark? What was the bright star outside Van Gogh's window? What did Song dynasty astronomers see over Kaifeng in 1054? That Day is a collection of stories about real moments in history, each with a question that only the sky can answer. HOW IT WORKS • Read the puzzle: a short scene from history, and a question. • See the sky: the real sky above that place at that minute, calculated on your iPhone. Look around, follow the hints and move time forward or back. • Find the answer: the story explains what the sky shows, with the historical sources. 29 STORIES Art, history, literature and science, from 490 BC to 1969: • The moonless night of the Titanic • The guest star of 1054 over Kaifeng • Van Gogh's Starry Night and Moonrise • Monet's Impression, Sunrise • Bashō setting out on The Narrow Road to the Deep North • Su Shi's Red Cliff and his Mid-Autumn moon • Paul Revere's ride, the Moon landing, the discovery of Neptune, and more A REAL SKY, NOT AN ILLUSTRATION The Sun, Moon and planets are calculated with Astronomy Engine to about one arcminute. 5,044 stars and all 88 constellations come from a modern catalogue. The app handles the Julian calendar and ancient dates, and each story explains where the limits of the calculation matter. CAREFULLY SOURCED Every story lists its sources, from ship inquiries and observatory records to Chinese and Korean histories. All images are public domain. Where historians disagree, the story says so. QUIET BY DESIGN • One purchase, no in-app purchases, no ads, no subscription • No account and no data collected • Works fully offline • English, Simplified Chinese, Traditional Chinese, Japanese and Spanish