A new detection framework explains how astronomers can isolate extremely slow gravitational wave signals.
By combining subtle distortions in spacetime with observations of unusually bright galactic centers, the study authors have demonstrated a practical method for identifying likely locations of merging supermassive black holes.
A group of US astronomers may have uncovered the first evidence for a dark matter sub-halo lurking just beyond our stellar neighborhood. Reporting their findings in Physical Review Letters, a team led by Sukanya Chakrabarti at the University of Alabama in Huntsville suggests that an unseen clump of dark matter could be subtly tugging on nearby pulsars. If confirmed, the result could shed new light on the elusive nature of dark matter and how it is distributed throughout our galaxy.
Despite never having been observed directly, astronomers estimate that dark matter makes up around 85% of the total mass of the universe. According to the best available cosmological models, this invisible material forms vast, diffuse “halos” that completely envelop the flat disks of galaxies like the Milky Way. These halos, in turn, should be populated by numerous smaller structures known as dark matter sub-halos.
If theoretical predictions are correct, such sub-halos should be abundant throughout the galaxy. Yet even with masses potentially exceeding tens of millions of times that of the sun, their limited gravitational influence on visible matter has so far made them extraordinarily difficult to detect.
“Discovering that Sgr A is rotating at its maximum speed has far-reaching implications for our understanding of black hole formation and the astrophysical processes associated with these fascinating cosmic objects,” Xavier Calmet, a theoretical physicist at the University of Sussex who was not involved in the research, told Live Science in an email.
Related: Black holes: Everything you need to know
A black hole’s spin is different from those of other cosmic objects. Whereas planets, stars and asteroids are solid bodies with physical surfaces, black holes are actually regions of space-time bounded by an outer nonphysical surface called the event horizon, beyond which no light can escape.
Big Bang Thought of the Day by Nobel Laureate Peter Higgs, “The Big Bang made the universe explode into existence. The Higgs boson made it stay.” The universe formed 13.8 billion years ago. But matter could not exist without mass. In 1964, Peter Higgs proposed a solution. His Higgs boson explains why particles gained weight after the Big Bang. Confirmed in 2012 at CERN, it settled decades of cosmic theory conflicts. This discovery reshaped modern physics and cosmology forever.
The Big Bang is often described as the explosive birth of the Universe – a singular moment when space, time and matter sprang into existence.
But what if this was not the beginning at all? What if our Universe emerged from something else – something more familiar and radical at the same time?
In a new paper, published in Physical Review D, my colleagues and I propose a striking alternative. Our calculations suggest the Big Bang was not the start of everything, but rather the outcome of a gravitational crunch or collapse that formed a very massive black hole – followed by a bounce inside it.
Could we build wormholes and travel the galaxy? Exploring stable wormholes, spacetime shortcuts, and the future of interstellar civilization.
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/ discord Credits: Wormhole Stableways – Constructing and Navigating Artificial Shortcuts Through Space Written, Produced & Narrated by: Isaac Arthur Select imagery/video supplied by Getty Images Chapters 0:00 Intro 1:38 What Is a Wormhole? 5:21 Could Wormholes Exist Naturally? 8:49 What Keeps a Wormhole Open? 12:08 Can We Build an Artificial Wormhole? 16:05 How Would You Travel Through One? 20:56 So Where Are We? 25:14 Civilization across the Stableways 30:58 Nebula 32:10 Bridges to Eternity.
Check out Joe Scott’s Oldest & Newest: https://nebula.tv/videos/joescott-old…
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Credits:
Wormhole Stableways – Constructing and Navigating Artificial Shortcuts Through Space.
Written, Produced & Narrated by:
Isaac Arthur.
Select imagery/video supplied by Getty Images.
Chapters.
0:00 Intro.
1:38 What Is a Wormhole?
5:21 Could Wormholes Exist Naturally?
8:49 What Keeps a Wormhole Open?
12:08 Can We Build an Artificial Wormhole?
16:05 How Would You Travel Through One?
20:56 So Where Are We?
25:14 Civilization across the Stableways.
30:58 Nebula.
32:10 Bridges to Eternity.
Entropy is one of the most profound and misunderstood concepts in modern science — at once a physical quantity, a measure of uncertainty, and a metaphor for the passage of time itself. Entropy: The Order of Disorder explores this concept in its full philosophical and scientific depth, tracing its evolution from the thermodynamics of Clausius and Boltzmann to the cosmology of the expanding universe, the information theory of Shannon, and the paradoxes of quantum mechanics.
At the heart of this study lies a critical insight: entropy in its ideal form can exist only in a perfectly closed and isolated system — a condition that is impossible to realize, even for the universe itself. From this impossibility arises the central tension of modern thought: the laws that describe equilibrium govern a world that never rests.
Bridging physics, philosophy, and cosmology, this book examines entropy as a universal principle of transformation rather than decay. It situates the second law of thermodynamics within a broader intellectual landscape, connecting it to the philosophies of Heraclitus, Kant, Hegel, and Whitehead, and to contemporary discussions of information, complexity, and emergence.
Head to https://brilliant.org/Spacetime/ to start learning for free for 30 days. Plus, our viewers get 20% off an annual Premium subscription for unlimited daily access to everything Brilliant has to offer.
Physicists have long believed that detecting the particle of gravity—the graviton—was fundamentally impossible, with the universe itself seeming to block every direct attempt. This episode explores a new generation of clever experiments that may finally let us detect gravity’s particle, and why even succeeding wouldn’t quite mean what we think it does.
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https://mailchi.mp/1a6eb8f2717d/space… the Entire Space Time Library Here: https://search.pbsspacetime.com/ Hosted by Matt O’Dowd Written by Richard Dyer & Matt O’Dowd Post Production by Leonardo Scholzer Directed by Andrew Kornhaber Associate Producer: Bahar Gholipour Executive Producer: Andrew Kornhaber Executive in Charge for PBS: Maribel Lopez Director of Programming for PBS: Gabrielle Ewing Assistant Director of Programming for PBS: Mike Martin Spacetime is a production of Kornhaber Brown for PBS Digital Studios. This program is produced by Kornhaber Brown, which is solely responsible for its content. © 2026 PBS. All rights reserved. End Credits Music by J.R.S. Schattenberg: / multidroideka Space Time Was Made Possible In Part By: Big Bang Alexander Tamas David Paryente Juan Benet Mark Rosenthal Morgan Hough Peter Barrett Santiago Tj Steyn Vinnie Falco Supernova Ethan Cohen Glenn Sugden Grace Biaelcki Mark Heising Stephen Wilcox Tristan Lucian Claudius Aurelius Tyacke Hypernova Alex Kern Ben Delo Cal Stephens chuck zegar David Giltinan Dean Galvin Donal Botkin Gregory Forfa Jesse Cid Dyer John R. Slavik Justin Lloyd Kenneth See Massimiliano Pala Michael Tidwell Mike Purvis Paul Stehr-Green Scott Gorlick Scott Gray Spencer Jones Stephen Saslow Thomas Mouton Zachary Haberman Антон Кочков Daniel Muzquiz Gamma Ray Burst Aaron Pinto Adrien Molyneux Almog Cohen Anthony Leon Arko Provo Mukherjee Ayden Miller Ben McIntosh Bradley Jenkins Bradley Ulis Brandon Lattin Brian Cook Bryan White Chris Liao Christopher Wade Chuck Lukaszewski Collin Dutrow Craig Falls Craig Stonaha Dan Warren Daniel Donahue Daniel Jennings Daron Woods Darrell Stewart David Johnston Doyle Vann Eric Kiebler Eric Raschke Eric Schrenker Faraz Khan Frederic Simon Harsh Khandhadia Ian Williams Isaac Suttell James Trimmier Jeb Campbell Jeremy Soller Jerry Thomas jim bartosh John Anderson John De Witt John Funai John H. Austin, Jr. John591 Joseph Salomone Junaid Ali Kacper Cieśla Kane Holbrook Keith Pasko Kent Durham Koen Wilde Kyle Atkinson Marcelo Garcia Marion Lang Mark Daniel Cohen Mark Delagasse Matt Kaprocki Matthew Johnson Michael Barton Michael Clark Michael Lev Michael Purcell Nathaniel Bennett Nick Hoffenstoffer III Nicolas Katsantonis Paul Wood Rad Antonov Reuben Brewer Richard Steenbergen Robert DeChellis Ross Story Russell Moore SamSword Sandhya Devi Satwik Pani Sean Owen Shane Calimlim SilentGnome Sound Reason Steffen Bendel Steven Giallourakis Terje Vold Thomas Dougherty Tomaz Lovsin Tybie Fitzhugh Vlad Shipulin William Flinn WILLIAM HAY III Zac Sweers.
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