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The Arrow of Time and How to Reverse It

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Ever wish you could travel backward in time and do things differently? Good news: the laws of physics seem to say traveling backward in time is the same as traveling forwards. So why do we seem to be stuck in this inexorable flow towards the future? It’s time to begin our journey towards really understanding time.

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https://mailchi.mp/1a6eb8f2717d/space… by Matt O’Dowd Written by Matt O’Dowd Graphics by Leonardo Scholzer, Yago Ballarini, & Pedro Osinski Directed by: Andrew Kornhaber Assistant Producer: Setare Gholipour Executive Producers: Eric Brown & Andrew Kornhaber End Credits Music by J.R.S. Schattenberg: / @julesschattenberg Special Thanks to Our Patreon Producers Big Bang Supporters Sean Maddox Marty Yudkovitz Brodie Rao Scott Gray Ahmad Jodeh Radu Negulescu Alexander Tamas Morgan Hough Juan Benet Fabrice Eap Mark Rosenthal David Nicklas Quasar Supporters Justin Lloyd Christina Oegren Mark Heising Vinnie Falco Hypernova Supporters William Bryan L. Wayne Ausbrooks Nicholas Newlin Mark Matthew Bosko Justin Jermyn Jason Finn Антон Кочков Alec S-L Julian Tyacke John R. Slavik Mathew Danton Spivey Donal Botkin John Pollock Edmund Fokschaner Joseph Salomone Matthew O’Connor chuck zegar Jordan Young m0nk Hank S John Hofmann Timothy McCulloch Gamma Ray Burst Daniel Jennings Cameron Sampson Pratik Mukherjee Geoffrey Clarion Astronauticist Nate Darren Duncan Lily kawaii Russ Creech Jeremy Reed Max Bernard Bill Blair Eric Webster Steven Sartore DrJYou David Johnston J. King Michael Barton Christopher Barron James Ramsey Mr T Andrew Mann Jeremiah Johnson fieldsa eleanory Peter Mertz Kevin O’Connell Richard Deighton Isaac Suttell Devon Rosenthal Oliver Flanagan Dawn M Fink Bleys Goodson Darryl J Lyle Robert Walter Bruce B Ismael Montecel Andrew Richmond Simon Oliphant Mirik Gogri David Hughes Mark Daniel Cohen Brandon Lattin Yannick Weyns Nickolas Andrew Freeman Brian Blanchard Shane Calimlim Tybie Fitzhugh Robert Ilardi Astaurus Eric Kiebler Craig Stonaha Martin Skans Michael Conroy Graydon Goss Frederic Simon Greg Smith Sean Warniaha Tonyface John Robinson A G Kevin Lee Adrian Hatch Yurii Konovaliuk John Funai Cass Costello Geoffrey Short Bradley Jenkins Kyle Hofer Tim Stephani Luaan AlecZero Malte Ubl Nick Virtue Scott Gossett Martin J Lollar Dan Warren Patrick Sutton John Griffith Daniel Lyons DFaulk Kevin Warne Andreas Nautsch Brandon labonte Lucas Morgan.

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How To Detect Faster Than Light Travel

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Warp drives may or may not be possible, but if they are then could a distant alien civilization’s warp fields produce gravitational waves that we could see here on Earth? According to a recent study… Actually maybe, at least eventually. And we now know just what to look for and how to look for it.

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It’s about time we discussed an obscure concept in physics that may be more fundamental than energy and entropy and perhaps time itself. That’s right — the time has come for Action.

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Hosted by Matt O’Dowd
Written by Fernando Franco Félix & Matt O’Dowd
Post Production by Leonardo Scholzer, Yago Ballarini, Pedro Osinski, Adriano Leal & Stephanie Faria
GFX Visualizations: Ajay Manuel
Directed by Andrew Kornhaber
Assistant Producer: Setare Gholipour
Executive Producers: Eric Brown & Andrew Kornhaber.

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10 Ancient Space Objects That Existed Before the Universe Itself

All right, let’s go.
Number 10. Methuselah’s Star.
In 2000, a team of astronomers led by Howard Bond at Penn State University pointed the Hubble Space Telescope at a faint star in the constellation Libra and made a discovery that should have been impossible. The star, designated HD 140,283 and later nicknamed Methuselah, appeared to be 14.5 billion years old. The universe itself is only 13.8 billion years old. A star older than the cosmos that contains it shouldn’t exist. Yet there it was, burning quietly just 190 light years from Earth, defying the most fundamental timeline in all of physics.

Challenging a 300-year-old law of friction

Researchers at the University of Konstanz have uncovered a new mechanism of sliding friction: resistance to motion that arises without any mechanical contact, driven purely by collective magnetic dynamics. The study, published in Nature Materials, shows that friction does not necessarily increase steadily with load, as postulated by Amontons’ law—one of the oldest and most fundamental empirical laws of physics—but can instead exhibit a pronounced maximum when internal magnetic ordering becomes frustrated.

For more than three centuries, Amontons’ law has linked friction directly to load, reflecting the everyday experience that heavier objects are harder to move; for example, pushing a heavy piece of furniture requires far more effort than sliding a light chair. This behavior is commonly attributed to tiny deformations of the surfaces in contact under load, which increase the number of microscopic contact points and thereby enhance friction.

In most classical situations, these deformations remain small and do not qualitatively change the internal structure of the materials during sliding. It is therefore not clear whether Amontons’ law will also hold when sliding induces much stronger internal reconfigurations, as can occur in magnetic materials where motion can modify the magnetic order.

Clearest evidence yet that giant planets spin faster than their cosmic lookalikes

For decades, astronomers have struggled to differentiate giant planets from brown dwarfs, a class of objects more massive than planets but too small to ignite nuclear fusion like true stars. Through a telescope, these cosmic lookalikes can have overlapping brightness, temperatures, and even atmospheric fingerprints. The striking similarity leaves astronomers unsure if they have observed an oversized planet or an undersized star. Now, a Northwestern University-led team has uncovered a crucial clue that separates the two: how fast they spin.

In a new study, astrophysicists found the clearest evidence yet that giant planets spin significantly faster than their brown dwarf counterparts. The new results suggest rotation measurements may provide a powerful new diagnostic for classifying these indistinguishable populations and suggest that these two objects evolve differently, perhaps even forming through distinct processes.

The study was published in The Astronomical Journal. It marks the largest survey of spin measurements of directly imaged extrasolar planets and brown dwarfs to date.

Bell-bottoms today, miniskirts tomorrow: Math reveals fashion’s 20-year cycle

Fashion insiders and beauty magazines have long cited the “20-year-rule”—the idea that clothing trends often resurface every two decades. According to Northwestern University scientists, that observation isn’t just anecdotal. It’s a mathematical reality.

In a new study, the Northwestern team developed a new mathematical model showing that fashion trends tend to cycle roughly every 20 years. By analyzing roughly 37,000 images of women’s clothing spanning from 1869 to today, the team found that styles rise in popularity, fall out of favor and then eventually experience renewal. Along with supporting common perceptions about the life cycles of fads, the researchers say these results could help explain how new ideas spread in society.

The study’s lead author, Emma Zajdela, will present these findings on Tuesday, March 17, at the American Physical Society (APS) Global Physics Summit in Denver. Her talk, “Back in Fashion: Modeling the Cyclical Dynamics of Trends,” is part of the session “Statistical Physics of Networks and Complex Society Systems.”

Discrete time crystal acts as a usable sensor for weak magnetic oscillations

The bizarre properties of discrete time crystals could be harnessed to detect extremely subtle oscillations of magnetic fields, physicists in the US and Germany have revealed. Publishing their results in Nature Physics, a team led by Ashok Ajoy at the University of California, Berkeley, show for the first time that these exotic materials could have practical uses far beyond their current status as an impractical curiosity.

Discrete time crystals (DTCs) are an exotic phase of matter which break entirely from the rules which apply to classical materials. Whereas an ordinary crystal is made up of atomic or molecular patterns that repeat at regular intervals in space, DTCs have structures that constantly oscillate in repeating cycles when driven by an external protocol, without ever reaching thermal equilibrium.

“Since their initial experimental demonstrations in 2017, there has been enormous excitement surrounding these states,” explains co-author Paul Schindler at the Max Planck Institute of Complex Systems. “Yet a persistent question has remained unanswered: can this exotic order be harnessed for practical applications?”

Astronomers May Have Seen Colliding Black Holes Trigger a Blaze of Light

A brief blaze of gamma and X-ray light that lit up Earth telescopes in November 2024 may have come from an unexpected source.

Just a few seconds earlier, from the same tiny corner of the sky, LIGO-Virgo-KAGRA had detected the telltale gravitational wave signal of two black holes colliding. These massive events are some of the most extreme in the Universe; even so, they’re not generally expected to produce detectable light.

A team led by astronomer Shu-Rui Zhang of the University of Science and Technology of China has linked the extraordinary detection to an even more extraordinary set of possible circumstances: the collision, the researchers believe, may have taken place in the enormous, roiling disk of dust and gas surrounding a third, supermassive black hole – the host galaxy’s active galactic nucleus (AGN).

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