Ciencia: Teoria de la Realidad · Ciencia: Teoria de la Realidad

Termodinámica aplicada: La entropía en la evolución del universo observable

·1 hr 20 min·6 clips

Babylonian priests who knew their astrology didn't work would install a fake king when the stars predicted the king's death — and then personally kill the fake king to make sure the prophecy came true.

1. Jordi Pereira, author of 'The Universe in a Cup of Coffee,' presents at the Ciutat de les Arts i les Ciències in Valencia during World Space Week, introduced by scientific broadcaster José Antonio Gordillo Martorell. 2. Jordi is a mechanical engineering graduate from the Universitat Politècnica de Catalunya who runs the science blog 'Sofa Science,' launched in 2013 to make science accessible through humor, drawing, and everyday language. 3. The talk's central thesis is that astronomy was not born from wonder but from practical survival necessity — Paleolithic humans needed to predict seasonal changes to time migrations and resource gathering. 4. A 30,000-year-old bone engraved with lunar cycles is cited as the oldest known evidence of sky-watching, with the moon chosen because its phases are easily observable and its cycle is short enough to track. 5. The lunar calendar failed as a seasonal predictor because 29.5 days per lunar cycle does not divide evenly into a solar year, causing the calendar to drift against the seasons over time. 6. In the Valley of Wonders in present-day France, 15,000 Neolithic petroglyphs were found including flags pointing toward the horizon — decoded by archaeologists as a solar position calendar used by mountain-dwelling people to time their winter descent. 7. The ancient Egyptians used the heliacal rising of the star Sirius as a warning that the Nile flood was approaching, allowing them to build protective walls for their villages and livestock. 8. The Egyptians erroneously attributed the Nile's flooding to Sirius itself rather than to rains at Lake Victoria, which led them to worship Sirius as the goddess Sopdet, associated with abundance and fertility. 9. The Babylonians discovered five 'wandering stars' (planets) that moved differently from the background stars, and correctly named them from the Greek aster planetai meaning 'wandering star.' 10. Babylonian priests built elaborate clay-tablet records of planetary positions correlated with events, attempting to predict the future — an early form of astrology — while privately knowing the system was unreliable. 11. When Babylonian star charts predicted a king would die, priests would substitute a fake king (typically a criminal or madman) and then personally execute him afterward to make the prophecy appear to come true. 12. The Greek philosopher Thales of Miletus is identified as the first person to propose rational rather than mythological explanations for natural phenomena, though his specific ideas — that the Earth is a rock floating on an ocean — were largely wrong. 13. Eratosthenes of Alexandria calculated the circumference of the Earth by measuring the different shadow angles cast by vertical sticks in Alexandria and in Syene on the summer solstice, arriving at a figure approximately 26% off from the modern value of 40,000 kilometers. 14. The episode debunks the myth that medieval sailors feared falling off a flat Earth — sailors knew the Earth was round and used the stars to navigate; what Columbus miscalculated was the size of the ocean between Europe and Asia, which he underestimated by a factor of four. 15. The Greek Aristarchus of Samos correctly proposed heliocentrism — that the sun sits at the center of the solar system — centuries before Copernicus, and correctly explained planetary retrograde motion as a perspective effect of Earth's faster orbit. 16. Aristarchus was ignored because Aristotle and Plato had institutionalized geocentrism and declared all celestial bodies perfect and immutable; their followers treated observational contradictions as failures of reality rather than of the theory. 17. The geocentric Ptolemaic model required 55 epicycles (small circles within orbits) to approximate observed planetary motion, and still failed to produce accurate predictions. 18. The talk is delivered in a university lecture style with visual slides, humor, and analogies — Jordi notes he does not drink coffee despite writing a book titled 'The Universe in a Cup of Coffee.' 19. People curious about the history of science, amateur astronomers, and Spanish-speaking listeners who enjoy accessible science communication will find the talk engaging. 20. Listeners who want mathematical rigor, deep telescope mechanics, or cutting-edge astrophysics research will find this talk too introductory.

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