Shocked quartz grains are an accepted indicator of crater-forming cosmic impact events, which also typically produce amorphous silica along the fractures. Furthermore, previous research has shown that shocked quartz can form when nuclear detonations, asteroids, and comets produce near-surface or “touch-down” airbursts. When cosmic airbursts detonate with enough energy and at sufficiently low altitude, the resultant relatively small, high-velocity fragments may strike Earth’s surface with high enough pressures to generate thermal and mechanical shock that can fracture quartz grains and introduce molten silica into the fractures. Here, we report the discovery of shocked quartz grains in a layer dating to the Younger Dryas (YD) onset (12.8 ka) in three classic archaeological sequences in the Southwestern United States: Murray Springs, Arizona; Blackwater Draw, New Mexico; and Arlington Canyon, California. These sites were foundational in demonstrating that the extinction or observed population bottlenecks of many megafaunal species and the coeval collapse/reorganization of the Clovis technocomplex in North America co-occurred at or near the YD onset. Using a comprehensive suite of 10 analytical techniques, including electron microscopy (TEM, SEM, CL, and EBSD), we have identified grains with glass-filled fractures similar to shocked grains associated with nuclear explosions and 27 accepted impact craters of different ages (e.g., Meteor Crater, 50 ka; Chesapeake Bay, 35 Ma; Chicxulub, 66 Ma; Manicouagan, 214 Ma) and produced in 11 laboratory shock experiments. In addition, we used hydrocode modeling to explore the temperatures, pressures, and shockwave velocities associated with the airburst of a 100-m fragment of a comet and conclude that they are sufficient to produce shocked quartz. These shocked grains co-occur with previously reported peak concentrations in platinum, meltglass, soot, and nanodiamonds, along with microspherules, similar to those found in ~28 microspherule layers that are accepted as evidence for cosmic impact events, even in the absence of a known crater. The discovery of apparently thermally-altered shocked quartz grains at these three key archaeological sites supports a cosmic impact as a major contributing factor in the megafaunal extinctions and the collapse of the Clovis technocomplex at the YD onset.
Citation: Kennett JP, LeCompte MA, Moore CR, Kletetschka G, Johnson JR, Wolbach WS, et al. (2025)PLoS One 20: e0319840. https://doi.org/10.1371/journal.pone.
Editor: Talaat Abdel Hamid, National Research Centre, EGYPT
Dinosaurs had such an immense impact on Earth that their sudden extinction led to wide-scale changes in landscapes—including the shape of rivers—and these changes are reflected in the geologic record, according to a University of Michigan study.
Scientists have long recognized the stark difference in rock formations from just before dinosaurs went extinct to just after, but chalked it up to sea level rise, coincidence, or other abiotic reasons. But U-M paleontologist Luke Weaver shows that once dinosaurs were extinguished, forests were allowed to flourish, which had a strong impact on rivers.
Weaver and colleagues examined locations throughout the western United States that depicted sudden geologic changes that occurred at the boundary between the age of dinosaurs and the age of mammals.
China has recently unveiled its plan to initiate an experimental verification project to demonstrate and test the effectiveness of its asteroid defense system, and Wu Weiren, one of the country’s top space scientists, stressed the necessity of such project to the Global Times on Sunday, saying that from the perspective of safeguarding the Earth’s safety and the continuation of humanity, building asteroid defense capabilities is a shared task for all humankind, while calling on further international collaborative efforts against the threats posed by asteroid impact.
“As a responsible spacefaring nation, China has the responsibility, obligation, and capability to contribute Chinese wisdom, leverage Chinese strength, and systematically develop an asteroid detection and defense system, working together with the world to protect our planetary home,” Wu said. Wu is the chief designer of China’s lunar exploration program and director and chief scientist of the country’s Deep Space Exploration Laboratory (DSEL).
Wu outlined China’s asteroid exploration and defense system in detail for the first time at the third International Deep Space Exploration Conference, and during the event held from Thursday to Friday in Hefei, East China’s Anhui Province, Wu revealed that in the near future, China will conduct a kinetic impact demonstration and verification mission on an asteroid posing a potential threat to Earth.
Instead of being a mix of water ice, rock and carbon-rich material left over from the formation of the solar system, ‘Oumuamua appears to be almost pure nitrogen ice. And rather than being a compact ball, the visitor is more elongated than any known body in the solar system and starkly different from the interstellar Comets and , the only other known interstellar visitors.
“‘Oumuamua is in a different category of object,” Desch told Space.com by email. “It’s much harder to find, but there are a lot more of them.”
Planets arise from the cloud of gas and dust left over after a star is born. The first few million years are chaotic as the growing worlds jostle for their place around the young star…
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This is the full version of Jan Jekielek’s interview with Max Tegmark. The interview was originally released on Epoch TV on June 3, 2025.
Few people understand artificial intelligence and machine learning as well as MIT physics professor Max Tegmark. Founder of the Future of Life Institute, he is the author of “Life 3.0: Being Human in the Age of Artificial Intelligence.”
“The painful truth that’s really beginning to sink in is that we’re much closer to figuring out how to build this stuff than we are figuring out how to control it,” he says.
Where is the U.S.–China AI race headed? How close are we to science fiction-type scenarios where an uncontrollable superintelligent AI can wreak major havoc on humanity? Are concerns overblown? How do we prevent such scenarios?
CHAPTER TITLES
A debate/discussion on ASI (artificial superintelligence) between Foresight Senior Fellow Mark S. Miller and MIRI founder Eliezer Yudkowsky. Sharing similar long-term goals, they nevertheless reach opposite conclusions on best strategy.
“What are the best strategies for addressing risks from artificial superintelligence? In this 4-hour conversation, Eliezer Yudkowsky and Mark Miller discuss their cruxes for disagreement. While Eliezer advocates an international treaty that bans anyone from building it, Mark argues that such a pause would make an ASI singleton more likely – which he sees as the greatest danger.”
What are the best strategies for addressing extreme risks from artificial superintelligence? In this 4-hour conversation, decision theorist Eliezer Yudkowsky and computer scientist Mark Miller discuss their cruxes for disagreement.
They examine the future of AI, existential risk, and whether alignment is even possible. Topics include AI risk scenarios, coalition dynamics, secure systems like seL4, hardware exploits like Rowhammer, molecular engineering with AlphaFold, and historical analogies like nuclear arms control. They explore superintelligence governance, multipolar vs singleton futures, and the philosophical challenges of trust, verification, and control in a post-AGI world.
Moderated by Christine Peterson, the discussion seeks the least risky strategy for reaching a preferred state amid superintelligent AI risks. Yudkowsky warns of catastrophic outcomes if AGI is not controlled, while Miller advocates decentralizing power and preserving human institutions as AI evolves.
WARNING: AI could end humanity, and we’re completely unprepared. Dr. Roman Yampolskiy reveals how AI will take 99% of jobs, why Sam Altman is ignoring safety, and how we’re heading toward global collapse…or even World War III.
Dr. Roman Yampolskiy is a leading voice in AI safety and a Professor of Computer Science and Engineering. He coined the term “AI safety” in 2010 and has published over 100 papers on the dangers of AI. He is also the author of books such as, ‘Considerations on the AI Endgame: Ethics, Risks and Computational Frameworks’
He explains:
⬛How AI could release a deadly virus.
⬛Why these 5 jobs might be the only ones left.
⬛How superintelligence will dominate humans.
⬛Why ‘superintelligence’ could trigger a global collapse by 2027
⬛How AI could be worse than nuclear weapons.
⬛Why we’re almost certainly living in a simulation.
00:00 Intro.
02:28 How to Stop AI From Killing Everyone.
04:35 What’s the Probability Something Goes Wrong?
04:57 How Long Have You Been Working on AI Safety?
08:15 What Is AI?
09:54 Prediction for 2027
11:38 What Jobs Will Actually Exist?
14:27 Can AI Really Take All Jobs?
18:49 What Happens When All Jobs Are Taken?
20:32 Is There a Good Argument Against AI Replacing Humans?
22:04 Prediction for 2030
23:58 What Happens by 2045?
25:37 Will We Just Find New Careers and Ways to Live?
28:51 Is Anything More Important Than AI Safety Right Now?
30:07 Can’t We Just Unplug It?
31:32 Do We Just Go With It?
37:20 What Is Most Likely to Cause Human Extinction?
39:45 No One Knows What’s Going On Inside AI
41:30 Ads.
42:32 Thoughts on OpenAI and Sam Altman.
46:24 What Will the World Look Like in 2100?
46:56 What Can Be Done About the AI Doom Narrative?
53:55 Should People Be Protesting?
56:10 Are We Living in a Simulation?
1:01:45 How Certain Are You We’re in a Simulation?
1:07:45 Can We Live Forever?
1:12:20 Bitcoin.
1:14:03 What Should I Do Differently After This Conversation?
1:15:07 Are You Religious?
1:17:11 Do These Conversations Make People Feel Good?
1:20:10 What Do Your Strongest Critics Say?
1:21:36 Closing Statements.
1:22:08 If You Had One Button, What Would You Pick?
1:23:36 Are We Moving Toward Mass Unemployment?
1:24:37 Most Important Characteristics.
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You can purchase Dr Roman’s book, ‘Considerations on the AI Endgame: Ethics, Risks and Computational Frameworks’, here: https://amzn.to/4g4Jpa5
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What happens after intelligence explodes beyond human comprehension? We explore a world shaped by superintelligence, where humanity may ascend, adapt — or disappear.
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Credits:
After the Singularity — What Life Would Be Like If A Technological Singularity Happened?
Written, Produced & Narrated by: Isaac Arthur.
Editors: Lukas Konecny.
Select imagery/video supplied by Getty Images.
Music Courtesy of Epidemic Sound http://epidemicsound.com/creator.
Chapters.
0:00 Intro.
3:36 Is the Singularity Inevitable? The Case for Limits and Roadblocks.
8:42 Scenarios After the Singularity.
9:15 Scenario One: The AI Utopia.
10:31 Scenario Two: Digital Heaven.
11:57 Scenario Three: The AI Wasteland.
13:10 Scenario Four: The Hybrid Civilization.
14:48 What Does the Singularity Mean for Us?
16:31 Humanity’s Response: Resistance, Adaptation, or Surrender.
20:22 PRecision.
21:45 The Limits of Superintelligence: Why Even Godlike Minds Might Struggle.
25:48 Humanity’s Role in a Post-Singularity Future.
29:06 The Fermi Paradox and the Silent Singularity.
31:10 Reflections in Pop Culture and History.
32:27 Writing the Future.
Scientists are rethinking the universe’s deepest mysteries using numerical relativity, complex computer simulations of Einstein’s equations in extreme conditions. This method could help explore what happened before the Big Bang, test theories of cosmic inflation, investigate multiverse collisions, and even model cyclic universes that endlessly bounce through creation and destruction.