Episode Summary
Executive Summary: This StarTalk episode explores time from multiple angles: astronomy, calendars, culture, relativity, and modern technology. Neil deGrasse Tyson, Chris Hardwick, Matt Myra, and guests Tony Aveni and timekeeping experts explain how humans built calendars from celestial cycles, why leap seconds matter, how Earth’s rotation is changing, and why 2012 Maya apocalypse fears were overblown. The show ends by tying timekeeping to climate change and the need for action.
Main Topics: Human timekeeping and calendars (Priority: 5/5): The discussion traces timekeeping from moons and sundials to the Julian and Gregorian calendars, explaining why calendars are based on the Sun and seasonal cycles rather than the Moon alone. Maya calendar and 2012 apocalypse fears (Priority: 5/5): Tony Aveni argues that the Maya were not predicting the end of the world in 2012; their inscriptions focus on deep time, lineage, and history rather than future catastrophe. Leap seconds, atomic time, and Earth’s rotation (Priority: 5/5): The episode explains why Earth is an imperfect clock, how leap seconds keep atomic time aligned with solar time, and why removing them could create major technological problems. Relativity and the nature of time (Priority: 4/5): The hosts discuss Einsteinian time dilation, acceleration, and how motion changes aging, contrasting physical time with subjective human perception. Culture, religion, and apocalyptic thinking (Priority: 4/5): The conversation links Western obsession with apocalypse and synchronized time to religion, cultural anxiety, and technological dependence. Climate change and long-term planetary change (Priority: 5/5): In the closing segment, the discussion shifts to climate change, ocean heat uptake, carbon dioxide, and the urgency of responding before long-term damage compounds.
Key Arguments: Calendars arose from observing the Sun, seasons, and celestial cycles; lunar counting alone was insufficient for agricultural life. The Gregorian calendar corrected drift caused by the Julian calendar, which had overcompensated less accurately for Earth’s actual orbit. The Maya calendar was cyclical and historically rooted, not a prophecy of global destruction in 2012. Leap seconds are necessary because Earth’s rotation is not constant, and removing them would eventually make civil time drift away from solar time. Earth’s rotation is affected by tides, atmospheric motion, ice rebound, and mass redistribution, so it is not a perfect timekeeping system. Relativity shows that time is physically affected by speed and acceleration, not just by human perception. Western culture’s fixation on apocalypse and synchronization is tied partly to religion and modern technological dependence. Climate change is real, human-caused, and dangerous primarily because of its speed; ocean heat and sea-level rise are major risks.
Data Points: Gregorian calendar correction: 10 days - Pope Gregory’s reform corrected the drifting spring equinox by removing 10 days. Julian calendar introduction: 45 BC - Julius Caesar introduced the Julian calendar with a leap day. Maya long-count start: 3114 BC - The Maya calendar cycle discussed in the 2012 controversy began in 3114 BC. Maya ritual calendar length: 260 days - Aveni says the Maya 260-day calendar relates to human gestation and a 13x20 system. Human gestation-linked year in pre-Roman Empire: 307-day year - Aveni mentions an earlier year length based on cattle gestation. Apparent solar time variation: about 20 minutes - A sundial can differ from a watch by roughly this much over the year. Leap seconds added since 1972: 23 - Tyson notes that 23 abrupt leap seconds have been added since 1972. GPS-dependent smartphones: 500 million - The GPS system affected by leap-second policy is described as driving 500 million smartphones. Projected time to accumulate an hour of leap seconds: about 500 years - Rob Seaman estimates the current leap-second rate would total an hour in about 500 years. Indy 500 relativistic aging effect: 10^-27 seconds - Aveni/ Tyson mention the winner ages by an extremely tiny amount due to speed/acceleration. Earth’s natural day length in isolation: around 28-30 hours - The body’s intrinsic cycle is described as longer than 24 hours. Climate warming persistence: at least 100 years - Even if emissions stopped now, warming would continue for roughly a century or more.
Pivotal Quotes: "The Mayans didn't know anything about the future, certainly nothing about 2012." — Tony Aveni: He rejects the popular apocalypse interpretation of the Maya calendar. "Earth sucks as a timekeeping device." — Neil deGrasse Tyson: A humorous summary of why Earth’s rotation, tides, and mass shifts complicate precise timekeeping. "The sooner we get to work the better." — Steve Soder: Closing climate-change warning emphasizing urgency and delayed benefits.
Implications: Listeners are reminded that time is both a physical measurement and a cultural construct. Accurate timekeeping underpins GPS, aviation, and software, while climate change demands immediate collective action because delays compound long-term harm.