Scientists have discovered a galaxy as it was 13 billion years ago, 800 million years after the Big Bang. It contains possible evidence of the universe’s first stars and is one of the most chemically primitive galaxies observed to date.
The first stars and galaxies are difficult to see because they are so far away and their light is extremely faint. But thanks to the James Webb Space Telescope, we don’t have to remain in the dark about them. This $10 billion observatory was launched in 2021 and can peer back in time to when the first galaxies and stars were forming.
In a paper published in the journal Nature, a team of scientists led by Kimihiko Nakajima, an astronomer at Kanazawa University, Japan, describes how they used the telescope to study a part of the deep universe and discovered a faint galaxy called LAP1-B. “LAP1-B establishes a ‘fossil in the making,’ a direct high-redshift progenitor of the ancient ultra-faint dwarf galaxies observed in the local universe,” they wrote.
An international team of researchers has developed new stellar and supernova models to explain the mysterious elemental abundance patterns left by billions of supernova explosions around the Perseus constellation, which have been difficult to explain with conventional theoretical models, reports three recent studies published in The Astrophysical Journal.
Deep within the Perseus constellation lies one of the most massive structures known to science: the Perseus Cluster. A titan of the cosmos, it anchors over a thousand galaxies within a sea of superheated gas known as the Intracluster Medium (ICM). This gas, glowing fiercely in X-rays, acts as a celestial ledger, recording the chemical “fingerprints” left behind by billions of supernova explosions over billions of years.
However, data from the HITOMI (Astro-H) space telescope revealed a profound mystery. Long-standing theoretical models by researchers need important corrections.
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What if gravity is just entropy in disguise? Professor Erik Verlinde joins me to argue that gravity isn’t a fundamental force—it’s thermodynamic, emerging from quantum information the way gas pressure emerges from molecules bouncing around. We explore why spacetime may be stitched together by entanglement, and how dark energy and dark matter both pop out automatically without extra particles or parameters. Verlinde explains why the cosmological constant problem is a red herring, and why there may be no final theory of physics. When asked where the universe comes from, his answer is one word: chaos.
Guests do not pay to appear. Theories of Everything receives revenue solely from viewer donations, platform ads, and clearly labelled sponsors; no guest or associated entity has ever given compensation, directly or through intermediaries. #science.
TIMESTAMPS: 00:00:00 — Thermodynamic Gravity and Information 00:06:35 — Beyond Effective Field Theory 00:13:08 — Turtles All The Way Down 00:25:41 — Entropy as a Force 00:36:31 — Entanglement and Spatial Connectivity 00:47:31 — Deriving Inertia and F=ma 00:56:41 — De Sitter Space Challenges 01:02:01 — Dark Matter and Milgram 01:11:51 — The Emergence of Time 01:21:01 — Statistical Gravity Fluctuations 01:27:01 — Quantum Computational Complexity 01:36:01 — Physics Intuition and Mentorship 01:47:31 — Beauty, Garbage, and Chaos.
For the past tens of thousands of years, our Solar System has been traversing the local interstellar cloud (LIC), one of the 15 clouds of gas and dust that occupy the Sun’s neighborhood. Dust that might have come from the LIC has been found on Earth’s surface, its interstellar origins earmarked by an iron isotope produced in supernovae (see Synopsis: Seeking Stardust in the Snow). Now more traces of iron-60 (60 Fe) have turned up, this time buried in ancient Antarctic ice [1]. Dominik Koll of the Helmholtz-Zentrum Dresden-Rossendorf in Germany led the team that purified and analyzed the ice. He and his colleagues inferred that the LIC is the likeliest source of the 60 Fe and that the LIC is the result of past supernova activity.
Gas and dust trapped in the layers of Earth’s ice sheets provide a record of past environments. Koll and colleagues took 300 kg of an Antarctic ice core, representing the period 40–80 thousand years ago. They melted the ice, extracted the radionuclides, and used mass spectrometers to identify 60 Fe along with manganese-53. The latter is produced with 60 Fe when cosmic rays strike interplanetary dust. Because the researchers found more 60 Fe than expected from this “local” source, they concluded that the surplus came from beyond the Solar System.
Combining measurements from contemporary Antarctic snow and recent deep-sea sediments, Koll’s team reconstructed the influx of 60 Fe to Earth over the past 80 thousand years. The measured profile showed a very low 60 Fe influx around the time the Solar System entered the LIC, a peak while traversing the cloud, and a gradual decline as it nears the exit. The most direct explanation for the pattern is that the LIC is part of a single supernova remnant, but other explanations are in play.
Researchers have developed a technique to analyze how black holes “ring” when they collide and merge: one of the universe’s most dramatic events. When black holes merge, the collision produces a new, larger black hole that “rings” like a plucked guitar string or a bell while it settles into its final, stable shape. But instead of sound waves, the new black hole rings with gravitational waves: ripples in spacetime first predicted by Albert Einstein.
The new black hole vibrates at a specific set of frequencies, depending on its mass and spin, which help scientists learn about the object formed in the collision.
These vibrations, known as quasinormal modes, are the fingerprint of a black hole. Detecting them is central to testing Einstein’s general theory of relativity in the most extreme gravitational environments in the universe.
New observations and simulations by a research team led by MPE show that a massive binary star near the center of our Galaxy is creating a series of enigmatic gas clouds, compact clumps that help feed the supermassive black hole Sagittarius A*.
Dark matter is thought to make up most of the matter in the universe, but the only way it interacts with its surroundings is through gravity. If two colliding black holes spiral through a dense region of dark matter and merge, gravitational waves rippling across space and time could carry an imprint of that dark matter.
Now, physicists may be able to spot such imprints of dark matter in gravitational waves that are detected on Earth.
Researchers at MIT and in Europe have developed a method that makes predictions for what a gravitational wave should look like if it were produced by black holes that moved through dark matter, rather than empty space. They applied the technique to publicly available gravitational-wave data previously recorded by LIGO-Virgo-KAGRA (LVK), the global network of observatories that detect gravitational waves from black hole mergers and other far-off astrophysical sources.
Gravitational wave researchers working on the world’s most sensitive scientific instruments have found a way to tune their detectors using a process akin to the pitch-correction used in music production.
Scientists at the international LIGO, Virgo and KAGRA (LVK) gravitational wave observatory collaboration have employed the technique, which they call astrophysical calibration, to use gravitational-wave signals to measure the response of their incredibly sensitive instruments.
It enables them to ensure that they can clearly “hear” the sounds of colossal cosmic events like the collision of black holes, even when one gravitational wave detector is slightly out of tune. This is crucial to accurately interpret the signals and find their source location.
The largest-ever survey of physicists from around the world—released today—shows a distinct lack of consensus across many of physics’s most important questions, from the nature of black holes and dark matter, to the still-incomplete unification of Einstein’s theory of gravity with quantum mechanics.
Even the best theory of the universe’s expansion, known as the standard model of cosmology or ΛCDM (Lambda Cold Dark Matter), did not attain majority support. This surprising outcome is perhaps due to results from the Dark Energy Spectroscopic Instrument (DESI) last year, which hinted that dark energy may change over time, in opposition to the standard model’s conviction that dark energy remains constant.
But that wasn’t the only surprising outcome. The survey doesn’t seem to find much agreement anywhere.
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It may be that for every star in the universe there are billions of microscopic black holes streaming through the solar system, the planet, even our bodies every second. Sounds horrible — but hey, at least we’d have explained dark matter.
Want a very deep understanding of Black Holes? Check out the Black Hole playlist: • Black Holes.
