Universe Today
The Early Universe was Hot, Dense, and Soupy
MIT physicists have observed the first clear evidence that quarks create a wake as they speed through quark-gluon plasma, confirming the plasma behaves like a liquid.
Cosmology
The study of the universe as a whole
Recent Articles
-
-
The Answer is Written in the Stars
Astronomers have turned to some of the oldest stars in our Galaxy to tackle one of cosmology's most stubborn puzzles and their answer might surprise you. By analysing precise age data for more than 200,000 Milky Way stars, researchers have placed the age of the universe at around 13.6 billion years. It's a deceptively simple idea that the universe cannot be younger than the stars it contains. What they found doesn't just give us a number, it adds a compelling new dimension to a decades long argument that has divided the scientific world.
-
Illinois and UChicago Physicists Develop a New Method for Measuring Cosmic Expansion
A team of astrophysicists, cosmologists, and physicists has developed a novel way to compute the Hubble constant using gravitational waves. As our capability to observe gravitational waves improves in the future, this new method could be used to make even more accurate measurements of the Hubble constant, bringing scientists closer to resolving the Hubble tension.
-
The Universe's Most Extraordinary Construction Site
Astronomers have discovered a extraordinary celestial construction site hiding behind a natural magnifying glass in space and what they've found is unlike anything seen before. A cluster of at least 11 galaxies, all building stars at a ferocious rate in the early universe, has been caught in the act of becoming one of the most massive structures in the universe.
-
How giant galaxies could form just 1.4 billion years after the Big Bang
The existence of massive, elliptical galaxies in the early universe has puzzled astronomers for two decades. An international team led by Nikolaus Sulzenauer and Axel WeiĂ from the Max Planck Institute for Radio Astronomy (MPIfR) used data from the Atacama Large Millimeter/submillimeter Array (ALMA) to shed light on this open question of galaxy formation. They studied one of the most spectacular galaxy aggregations in great detail and published their results in the current issue of The Astrophysical Journal.
-
Searching Out Missing Links in Galaxy Evolution
How do galaxies evolve? When did they start forming? Those are questions astronomers and cosmologists are working to answer. The standard path includes early bright starforming activity, a middle age, and then a quiescent old age where they stop making stars. That changes if the galaxy happens to collide with another one, because that spurs new bouts of starbirth. It's been this way since stars and galaxies first began forming, slightly less than a billion years after the Big Bang.
-
Why Cosmic âDark Matterâ Is Living On Borrowed Time
A plethora of newly discovered baryonic (or normal) dark matter signals the first step toward the end of dark matter theory. Or so say the authors of a new paper just accepted by the journal Physical Review D.
-
Ancient Massive Stars Enriched Early Clusters and Birthed First Black Holes
The early Universe was a busy place. As the infant cosmos exanded, that epoch saw the massive first stars forming, along with protogalaxies. It turns out those extremely massive early stars were stirring up chemical changes in the first globular clusters, as well. Not only that, many of those monster stars ultimately collapsed as black holes.
-
Is Dark Energy Actually Evolving?
Dark energy is one of those cosmological features that we are still learning about. While we canât see it directly, we can most famously observe its effects on the universe - primarily how it is causing the expansion of the universe to speed up. But recently, physicists have begun to question even that narrative, pointing to results that show the expansion isnât happening at the same rate our math would have predicted. In essence, dark energy might be changing over time, and that would have a huge impact on the universeâs expansion and cosmological physics in general. A new paper available in pre-print on arXiv from Dr. Slava Turyshev, who is also famously the most vocal advocate of the Solar Gravitational Lens mission, explores an alternative possibility that our data is actually just messy from inaccuracies in how we measure particular cosmological features - like supernovae.
-
Are there Hidden Dimensions to the Universe? Part 4: Looking Past the Universe
So we did that. And we found nothing. So far, with all of our experiments around the world, we find no evidence of missing momentum, and no signs of towers of gravitons slipping away into hidden dimensions.
-
Are there Hidden Dimensions to the Universe? Part 3: The Graviton Tower
To test it, I want you to imagine rolling up a piece of paper into a tight cylinder. Or, if you happen to be near a source of paper, doing it in real life. The analogy works either way.
-
Are there Hidden Dimensions to the Universe? Part 2: The Hierarchy Problem
The problem that large extra dimensions just might solve is called the hierarchy problem, and itâs one of the nastiest outstanding problems in modern physics.
-
Are there Hidden Dimensions to the Universe? Part 1: Kaluza and Klein
I always say that one of the things that separates real science from pseudoscience is that while in both youâre allowed to say whatever crazy idea pops into your mind, in real science youâre obligated to take that idea seriously.
-
Is the Universe Older Than We Think? Part 4: The Changing Lambda-scape
Isnât the FLRW metric way generic? It lays out the basic assumptions and tells us how the universe should behave, but it doesnât say WHAT the universe is made of.
-
Is the Universe Older Than We Think? Part 3: Timescape
The FLRW metric is a model. And you know the saying, all models are wrong, but some are useful.
-
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.
-
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.
-
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.
-
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 âgrow upâ faster than expected.
-
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.