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In this episode of SpaceTime, we uncover exciting new research challenging our understanding of dark matter, reveal hidden treasures beneath the Earth's surface, and explore the potential for life on Titan, Saturn's enigmatic moon.
Modified Newtonian Dynamics: A Dark Matter Alternative
Recent studies suggest that modified Newtonian dynamics (MOND) may serve as a viable alternative to the elusive dark matter hypothesis. This theory, proposed by physicist Mordecai Milgrom, modifies Newton's laws to explain the gravitational behavior observed in galaxies without relying on dark matter. We delve into the latest findings that support MOND, including a novel method for measuring gravity in wide binary star systems, which indicates that gravity may actually be stronger than Newton's predictions under certain conditions.
Earth's Hidden Gold Reserves
A groundbreaking study reveals that Earth's core may contain vast reserves of gold and other precious metals, far beyond what is accessible on the surface. Researchers discovered traces of ruthenium in volcanic rocks from Hawaii, suggesting that these metals originated from the core and are leaking into the mantle. This research opens new avenues for understanding Earth's internal dynamics and the movement of materials from the core to the surface.
Searching for Life's Chemistry on Titan
NASA's upcoming Dragonfly mission aims to investigate the intriguing chemistry of life on Titan, Saturn's largest moon. With its organic-rich environment and unique geological features, Titan presents an opportunity to study prebiotic chemistry in a way that Earth cannot. We explore how Dragonfly will analyze the moon's surface and atmosphere to uncover clues about the processes that may have led to the emergence of life, potentially reshaping our understanding of habitability in the universe.
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✍️ Episode References
Astrophysical Journal
https://iopscience.iop.org/journal/0004-637X
Nature
https://www.nature.com/nature/
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00:00 This is Space Time Series 28, Episode 68 for broadcast on 6 June 2025
01:00 Modified Newtonian dynamics as an alternative to dark matter
12:15 Earth's hidden gold reserves
22:30 Searching for life's chemistry on Titan
30:00 Science report: Ancient tool-making from whale bones and quantum computing breakthroughs