Jan 27, 2025 07:03 PM
There’s more than just gravity at work in the Solar System
https://www.universetoday.com/170611/the...ar-system/
EXCERPT: In the paper authored by David Jewitt from the University of California he explores other forces that shape our Solar System. Gravity certainly describes the motion of planetary mass bodies but there are other forces that impart forces upon smaller bodies that are susceptible to their effects. These forces include, but are not limited to recoil (as per Newton’s third law of motion that every action has an equal and opposite reaction,) torque from mass loss, radiation pressure and more.... (MORE - details)
How a popular model of cosmic life and intelligence got it wrong
https://bigthink.com/13-8/how-a-popular-...-it-wrong/
KEY POINTS: The “Hard Steps Model” argues that intelligence is exceedingly rare in the Universe. The model reaches that conclusion by assuming that the timescale for the appearance of intelligence (driven by evolutionary processes) and the timescale for a planet’s habitability (determined by astrophysical factors) are entirely unrelated. Physicist Adam Frank outlines why he thinks the logic behind the Hard Steps Model is flawed. (MORE - details)
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Still, even if you take into account the co-evolution of a planet and its biosphere, it can take billions of years -- barring some world that near-miraculously has ideal conditions from the start. (And orange dwarf and red dwarf stars have a main sequence far longer than our yellow dwarf sun.) And it's not a given that intelligence ineluctably falls out of evolution sooner or later. The cherry-picking optimism about complex life and intelligence being scattered all over the galaxy has been around far longer than newer trends toward pessimism (granting the latter is similarly laden with its own eager presuppositions).
https://www.universetoday.com/170611/the...ar-system/
EXCERPT: In the paper authored by David Jewitt from the University of California he explores other forces that shape our Solar System. Gravity certainly describes the motion of planetary mass bodies but there are other forces that impart forces upon smaller bodies that are susceptible to their effects. These forces include, but are not limited to recoil (as per Newton’s third law of motion that every action has an equal and opposite reaction,) torque from mass loss, radiation pressure and more.... (MORE - details)
How a popular model of cosmic life and intelligence got it wrong
https://bigthink.com/13-8/how-a-popular-...-it-wrong/
KEY POINTS: The “Hard Steps Model” argues that intelligence is exceedingly rare in the Universe. The model reaches that conclusion by assuming that the timescale for the appearance of intelligence (driven by evolutionary processes) and the timescale for a planet’s habitability (determined by astrophysical factors) are entirely unrelated. Physicist Adam Frank outlines why he thinks the logic behind the Hard Steps Model is flawed. (MORE - details)
- - - - - - - - - - - - - -
Still, even if you take into account the co-evolution of a planet and its biosphere, it can take billions of years -- barring some world that near-miraculously has ideal conditions from the start. (And orange dwarf and red dwarf stars have a main sequence far longer than our yellow dwarf sun.) And it's not a given that intelligence ineluctably falls out of evolution sooner or later. The cherry-picking optimism about complex life and intelligence being scattered all over the galaxy has been around far longer than newer trends toward pessimism (granting the latter is similarly laden with its own eager presuppositions).