Constellations are younger than continents

Stellar lifetimes and constellations

• Betelgeuse’s supernova timing is highly uncertain. Direct supernova observations are sparse and mostly extragalactic, with little pre-explosion data.
• Estimates in the thread range from “any moment in the next 10,000 years” with a roughly flat distribution, to “within the next 100,000 years.”
• Orion’s bright stars are cited as very young (6–12 million years), with total lifespans of only tens of millions of years, so they change on timescales comparable to noticeable continental drift.
• There is a minor contradiction: one comment says Orion is recognizable long enough to see continents change; another claims Orion is still older than most hominids. The relationship between Orion’s age and hominid timelines is unclear in the thread.

Visualizing changing skies

• Multiple tools and media are mentioned for seeing constellation evolution and 3D structure: GAIA motion animations, classic TV explanations, and modern and legacy astronomy simulators (including FLOSS options).
• Users report a strong impression when seeing constellations distort over tens of thousands of years or from different vantage points in the galaxy.

Mythology, precession, and constellations as constructs

• Constellations are framed as human groupings imposed on physically unrelated stars, like weekdays on the natural day–night cycle.
• Discussion of precession links mythic “ages” and changing solstice/equinox positions in zodiac signs, with suggested correlations across multiple ancient mythologies.
• Some see this as fertile ground for connecting astronomical change to religious and historical shifts, including classical texts hinting at new “ages.”

Comparative timescales and “fun facts”

• Numerous comparisons: Polaris as North Star is younger than the Roman Empire and has changed over time due to precession; earlier pole stars differed.
• Sharks predate trees, constellations, and probably Polaris; Saturn’s rings are noted as likely younger than sharks.
• The number of trees on Earth may exceed the number of stars in the Milky Way, though future deforestation might change this; some argue deforestation has already peaked.
• The Appalachian Mountains are described as older than Saturn’s rings, dinosaurs, trees, and even bones, inspiring awe and “terror.”

Cosmology and galaxy structure debates

• One subthread explores the Sun’s limited number of orbits around the galaxy and how few revolutions are needed to form spiral structure.
• A detailed explanation is given of spiral arms as density waves, star motion through arms, and the role of dark matter in galaxy rotation curves.
• This prompts a dispute over mainstream cosmology: one side distrusts big bang and dark matter models, preferring plasma/electric-universe ideas; others defend mainstream cosmology as the product of a century of global work best matching observations so far.
• There is argument over “independent thought” vs. evidence-based consensus, and caution against being persuaded by alternative theories that don’t match data.

Pleiades, vision, and the age of stories

• A paper is cited suggesting that many cultures’ “seven” Pleiades myths reflect an earlier epoch when two now-blended stars were separable by eye; some interpret this as preserving a tens-of-thousands-of-years-old story.
• Counterarguments:
  • Good eyesight and dark skies can still resolve seven or more stars today, so no need for extremely ancient memory.
  • The human bias toward the number seven is common, and many Pleiades stories worldwide differ in details, star counts, or don’t group them at all; emphasizing matching stories may be cherry-picking.
  • Aboriginal stories can be very old (10,000+ years) but stretching to ~100,000-year continuity is seen as speculative.
• A related tangent discusses eyesight: premodern people likely had fewer vision problems like myopia, aiding star resolution; classic vision tests using close double stars are recalled.

Supercontinents and deep time

• Participants note that Pangaea is only the latest in a series of supercontinents; several earlier ones are named in external references.
• Multicellular life appears comparatively late in that sequence.
• A literary aside relates fictional “Ages” to rough spans of a few thousand years, contrasted with geological and cosmological scales.

Human expansion and interstellar culture

• Some imagine humanity eventually spreading by “hitchhiking” to other stars, with the caveat of avoiding self-destruction first.
• Interstellar communication would be extremely slow, implying that distant human colonies’ languages and cultures would diverge, potentially becoming hostile to each other.
• One idea is to deliberately engineer tools (e.g., machine-mediated upbringing, standardized language via AI systems) to reduce cultural drift and keep a galaxy-spanning society coherent.