StarTalk Radio - Episode Summary: "Things You Thought You Knew - The Ancient Planets"

Podcast Information:

• Title: StarTalk Radio
• Host: Neil deGrasse Tyson
• Co-Host: Chuck Nice
• Episode: Things You Thought You Knew - The Ancient Planets
• Release Date: November 12, 2024
• Description: Astrophysicist Neil deGrasse Tyson and his co-host Chuck Nice delve into the fascinating world of astronomy, blending science with pop culture to unpack the mysteries of the universe.

1. The Sun’s Diameter and Photosphere Explained

Timestamps: 01:14 – 09:24

Discussion Highlights:

• Understanding the Sun and Earth’s Dimensions:

  • Neil deGrasse Tyson begins by contrasting the diameters of the Earth and the Sun. "The diameter of the Earth is about 8,000 miles" (01:57), while the Sun's diameter is approximately 800,000 miles (09:13).
  • Chuck Nice humorously remarks on the simplicity of these facts, setting a lighthearted tone for the discussion.

• The Photosphere and Plasma Edges:

  • The conversation delves into the Sun's photosphere—the visible “surface” where photons escape into space. Neil explains, "The photosphere is a layer of the sun's atmosphere, which is the last point of contact with the photon trying to get out of the sun" (05:14).
  • Chuck questions how a gaseous body like the Sun can have a sharp edge, leading Neil to clarify the nature of plasma and atmospheric layers.

• Visual Perception vs. Physical Reality:

  • Neil emphasizes our "visible light bias," noting that the Sun's diameter appears different when observed in various wavelengths, such as X-rays. "If you look at the sun in X-rays... you see a different diameter" (06:03).

Notable Quotes:

• Neil deGrasse Tyson: "When you look up a numerical answer to a question... depending on what it's answering, the question might not have an actual answer. We just have to sort of set the rule." (03:36)
• Chuck Nice: "That's, you know, you need the high frequency, right?" (03:38)

2. The Intricacies of Leap Days and Calendar Systems

Timestamps: 14:34 – 25:24

Discussion Highlights:

• Why We Have Leap Days:

  • Neil introduces the topic of leap days, questioning the arbitrary nature of February 29th. "People seem to be mystified by it... it seems very arbitrary" (15:01).
  • The co-hosts explore Earth's rotation and revolution, explaining that a solar year is approximately 365 days and 6 hours (16:00). This discrepancy necessitates the addition of a leap day every four years.

• Historical Evolution of Calendars:

  • The conversation traces the development from the Julian to the Gregorian calendar. Neil explains how Pope Gregory XIII corrected the Julian calendar's drift by eliminating 10 days in October 1582 to realign the vernal equinox to March 21st (22:28).
  • Chuck humorously imagines the chaos of suddenly missing days: "October Dominus is Spitter 2. Half the month is gone" (23:09).

• Complexities in Modern Calendar Adjustments:

  • They discuss the further refinement of leap year rules, such as skipping leap days on century years not divisible by 400. "The leap day is a century year divisible by 400, right? No, no, rare. That leap day is." (24:33).

Notable Quotes:

• Neil deGrasse Tyson: "So if we're about 8,000 miles across, right. If you look up the diameter of the sun, it'll give you something like 864,000 miles." (09:13)
• Chuck Nice: "We were the Wanderer all along." (36:15)

3. The Origins of the Days of the Week and Their Planetary Connections

Timestamps: 28:39 – 37:27

Discussion Highlights:

• Ancient Planetary Names:

  • Neil and Chuck embark on an exploration of how the seven days of the week are named after the seven ancient planets. They note that "each day of the week is named for one of those seven planets" (30:52).

• Norse and Roman Influences:

  • The hosts connect each day to its corresponding celestial body and mythological figure:
    • Sunday: Named after the Sun. "Sunday is named after Sunday. The sun." (30:52)
    • Monday: Named after the Moon. "Guess what moon day was named after." (31:34)
    • Tuesday: Named after Mars (Tiw/Tuous in Norse mythology). "Tews will come kick your ass." (32:16)
    • Wednesday: Named after Mercury (Woden in Norse). "Wednesday is Wednesday." (32:09)
    • Thursday: Named after Jupiter (Thor in Norse). "Thor's day." (33:49)
    • Friday: Named after Venus (Frigga in Norse). "Frigga has less sort of poetry for that than I think. Venus." (34:58)
    • Saturday: Named after Saturn. "Saturday. Saturn." (31:27)

• Impact of Copernicus and Planetary Classification:

  • They discuss the shift in planet classification post-Copernicus, reducing the number from seven to five by excluding the Sun and Moon. "We went from seven to five, back up to six." (35:58)
  • Chuck humorously imagines additional planets being added, such as "Planet George" named after King George, highlighting the complexities and cultural influences on planetary naming (36:53).

Notable Quotes:

• Neil deGrasse Tyson: "That's, you know, you need the high frequency, right?" (03:38)
• Chuck Nice: "I'm thinking about that." (16:48)
• Neil deGrasse Tyson: "So the Seven planets. Correct." (35:51)

4. Reflections on Human Perception and Cosmic Scale

Timestamps: 25:24 – 37:27

Discussion Highlights:

• Birthday Celebrations and Orbital Mechanics:

  • Neil muses on the arbitrary nature of celebrating birthdays based on calendar dates rather than precise orbital positions. "Celebrate that moment every year" (25:56).

• Synchronization of Time Zones and Global Celebrations:

  • They touch upon the complexity of global time zones in celebrating events like the New Year. "There's nothing magical about them. We're not all celebrating the new year. Correct." (26:11).

• Cultural and Scientific Intersections:

  • The episode highlights how cultural practices, such as naming days after celestial bodies, are deeply intertwined with scientific understanding and historical contexts.

Notable Quotes:

• Neil deGrasse Tyson: "If you are born on a leap day... the real way to do birthdays is to know exactly where Earth is in its orbit." (25:24)
• Chuck Nice: "That leap day is a century year divisible by 400, right? No, no, rare. That leap day is." (24:33)

5. Conclusion and Final Thoughts

Timestamps: 37:27 – 38:45

Discussion Highlights:

• Recap of Planetary History:

  • Neil summarizes the historical journey of how planets were perceived and classified, emphasizing the dynamic nature of astronomical science and human understanding.

• Closing Remarks:

  • The hosts reiterate the importance of continuous exploration and questioning of established knowledge. Neil concludes with, "There's a lot out there that needs explaining. All right. As always, keep looking up." (37:34).

Notable Quotes:

• Chuck Nice: "We haven't talked about planets in a long time. This is true, right?" (28:39)
• Neil deGrasse Tyson: "This has been StarTalk. Yet another explainer." (37:26)

Key Insights and Takeaways:

1. Scientific Precision vs. Human Perception: The episode underscores the difference between scientifically accurate measurements and human perceptions influenced by observational biases, such as visible light’s limitations.

2. Historical Evolution of Timekeeping: The discussion on leap days reveals the intricate balance between astronomical phenomena and human-made systems like calendars, highlighting the ongoing efforts to synchronize the two.

3. Cultural Influence on Astronomy: The naming of days after ancient planets demonstrates how mythology and culture have historically shaped our understanding and categorization of celestial bodies.

4. Dynamic Nature of Astronomy: The episode illustrates how astronomical classifications have evolved over time, particularly post-Copernicus, reflecting the dynamic and ever-progressing nature of the field.

5. Interconnection Between Science and Daily Life: From leap days to the names of the week, the conversation emphasizes that astronomy and scientific principles are deeply woven into the fabric of everyday human experiences.

Final Note: "Things You Thought You Knew - The Ancient Planets" delves into the intersections of astronomy, history, and culture, offering listeners a comprehensive understanding of how ancient perceptions and modern science intertwine to shape our knowledge of the universe. Neil deGrasse Tyson and Chuck Nice deliver complex concepts with humor and clarity, making this episode both educational and entertaining.

Stay Curious and Keep Looking Up!