Universe Today
Is the Universe Older Than We Think? Part 2: Tired Light
This is all based on the assumption that galaxies are receding away from us. And I actually cheated a little.
Cosmology
The study of the universe as a whole
Recent Articles
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Dark Energy Survey Data Reveals the Tightest Estimates Yet on Cosmic Expansion
The Dark Energy Survey Collaboration collected information on hundreds of millions of galaxies across the Universe using the U.S. Department of Energy-fabricated Dark Energy Camera, mounted on the U.S. National Science Foundation VĂctor M. Blanco 4-meter Telescope at CTIO, a Program of NSF NOIRLab. Their completed analysis combines all six years of data for the first time and yields constraints on the Universe's expansion history that are twice as tight as past analyses.
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These Gravitationally Lensed Supernovae Could Resolve The Hubble Tension
Researchers used the JWST to find a pair of strong gravitationally lensed Supernovae. They exploded billions of years ago, and their light is just reaching us now. Because of the lensing, we'll see multiple images of them, separated by years or decades. This could reveal the expansion rate of the Universe, and provide a solution to the Hubble Tension.
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Unveiling the Turbulent 'Teenage Years' of the Universe
Combining data from different telescopes is one of the best ways to get a fuller picture of far-off objects. Because telescopes such as Hubble (visible light), the James Webb Space Telescope (infrared), and the Atacama Large Millimeter Array (radio) each collect data in different wavelengths, they are able to capture distinct features of objects like galaxies that other telescopes cannot observe. A new paper by a large group of authors, headed by Andreas Faisst of Caltech, presented at the American Astronomical Society Meeting last week and published in The Astrophysical Journal Supplement tracks eighteen early galaxies in as broad of a spectrum as those instruments can collect, and most significantly found that they seem to “grow up” faster than expected.
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A New Study Finds a Subtle Dance Between Dark Matter and Neutrinos
Scientists are a step closer to solving one of the universe's biggest mysteries as new research finds evidence that dark matter and neutrinos may be interacting, offering a rare window into the darkest recesses of the cosmos.
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Using Webb, Canadian Astronomers Shed Light on the Milky Way's Turbulent Past
A team of Canadian astronomers has used Webb's observations of "Milky Way twins" in the early Universe to learn more about our galaxy's turbulent youth.
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Astronomers Find the First Compelling Evidence of "Monster Stars" in the Early Universe
Using the James Webb Space Telescope, a team of international researchers has discovered chemical fingerprints of gigantic primordial stars that were among the first to form after the Big Bang.
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The Nancy Grace Roman Space Telescope Will Teach Us A Lot More About Cosmic Voids
The Large-Scale Structure of the Universe features massive filaments where galaxy clusters and superclusters reside. In between these filaments are cosmic voids, vast regions that are nearly empty. The Nancy Grace Roman will map and study 80,000 of these voids to place constraints on Dark Energy drives the expansion of the Universe.
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A New Window on the Expansion of the Universe
Astronomers at the University of Tokyo have used gravitational lensing to measure how fast the universe is expanding, adding weight to one of cosmology's most intriguing mysteries. Their technique exploits the way massive galaxies bend light from distant quasars, creating multiple distorted images that arrive at different times. The measurement supports recent observations showing the universe expands faster than predictions based on the early universe suggest, strengthening evidence that the "Hubble tension" represents genuine new physics rather than experimental error.
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Gravitational Lenses Deliver a Verdict on the Hubble Tension
The Hubble Tension is one of the great mysteries of cosmology. Solving it might require a fundamental change in how we understand the universe - but scientists have to prove it actually exists first. A new paper from a collective of cosmologist researchers known as the TDCOSMO Collaboration adds further fuel to that first with updated measurements of the “Late Universe” measurement of the Hubble Constant using gravitational lenses of quasars, which shows that the Tension might exist after all.
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We Are Moving Through The Universe Faster Than We Thought
We've long known that we move through the Universe relative to the cosmic microwave background, but a new study of radio galaxies finds an even faster result, which could contradict the standard model of cosmology.
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The Knotty Problem of Matter Asymmetry Might Be Solved By Extending Physics
Why is the Universe filled with matter? Why isn't it an equal amount of matter and antimatter? We still don't know the answer, but a new approach looks at the symmetries of extended models of particle physics and finds a possible path forward. It's a knotty problem that may just have a knotty solution.
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The Universe Was Warm Before It Was Bright
There is a period in the Universe known as the cosmic dark ages. It lies between the recombination of the first atoms and the ignition of the first stars, when the Universe was thought to be cold and dark. Now astronomers have looked at the faint glow of atomic hydrogen to find that while the Universe was dark, it wasn't quite as cold as we thought.
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Is the Universe Infinite?
The surface of the Earth is finite. We can measure it. If it was expanding, then its size would grow with time. And once again, good ol’ Earth helps us understand what the universe might be doing beyond our observable horizon.
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Yes, the Universe Can Expand Faster Than Light
An expanding universe complicates this picture just a little bit, because the universe absolutely refuses to be straightforward.
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How to Imagine an Expanding Universe
I honestly don’t have a decent analogy for you to explain how the universe is expanding without a center and without an edge. It just does, whether we can wrap our minds around it or not. But I CAN give you a way to think about it.
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Where Was the Big Bang?
Let’s start out with something that we can say for certain: we live in an expanding universe.
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Astronomers Spot "First Stars" Billions of Years After They Were Supposed to Die
Over the course of billions of years, the universe has steadily been evolving. Thanks to the expansion of the universe, we are able to “see” back in time to watch that evolution, almost from the beginning. But every once in a while we see something that doesn’t fit into our current understanding of how the universe should operate. That’s the case for a galaxy described in a new paper by PhD student Sijia Cai of Tsinghua University’s Department of Astronomy and their colleagues. They found a galaxy formed around 11 billion years ago that appears to be “metal-free”, indicating that it might contain a set of elusive first generation (Pop III) stars.
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Is LCDM Cosmology Doomed?
All of the proposals floating around out there for invoking dynamical dark energy are a little on the weak side. In many cases, they raise more questions than answers.
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What's Driving Dark Energy?
To be fair, all scientific models are in some sense wrong