New Nature Astronomy study suggests dark matter and neutrinos may interact, easing a long-running mismatch in cosmic measurements.
Category: cosmology
Physicists develop new method to measure universe’s expansion rate
We have known for several decades that the universe is expanding. Scientists use multiple techniques to measure the present-day expansion rate of the universe, known as the Hubble constant. These methods are internally consistent and based on the same physics, so all observed values of the Hubble constant should agree. But those that come from early-universe datasets disagree with those that come from late-universe datasets. This problem is known as the Hubble tension and is considered to be one of the most significant open questions in cosmology.
Now a team of astrophysicists, cosmologists, and physicists at The Grainger College of Engineering at the University of Illinois Urbana-Champaign and at the University of Chicago has developed a novel way to compute the Hubble constant using gravitational waves—tiny ripples in the spacetime fabric. The researchers were able to improve upon the accuracy of prior gravitational-wave methods of measuring the Hubble constant. As our capability to observe gravitational waves improves in the future, this new method can be used to make even more accurate measurements of the Hubble constant, bringing scientists closer to resolving the Hubble tension.
Illinois Physics Professor Nicolás Yunes said, “This result is very significant—it’s important to obtain an independent measurement of the Hubble constant to resolve the current Hubble tension. Our method is an innovative way to enhance the accuracy of Hubble constant inferences using gravitational waves.” Yunes is the founding director of the Illinois Center for Advanced Studies of the Universe (ICASU) on the Urbana campus.
Astronomers Witness Unprecedented Cosmic Explosion Linked to a “Missing” Black Hole
The Truth About Wormholes: Einstein’s “Bridge” May Rewrite Time Itself
A newly detected X-ray transient may reveal the first direct evidence of an intermediate-mass black hole consuming a white dwarf.
A newly observed cosmic outburst is giving astronomers a rare glimpse into some of the most extreme processes in the universe.
On July 2, 2025, the China-led Einstein Probe (EP) space telescope identified an extraordinarily bright X-ray source while conducting a routine survey of the sky. What immediately caught scientists’ attention was how rapidly the object’s brightness changed. Its unusual behavior distinguished it from typical high-energy sources and prompted observatories around the world to begin immediate follow-up observations.
One of the biggest stars in the universe might be getting ready to explode
One of the largest known stars in the universe underwent a dramatic transformation in 2014, new research shows, and may be preparing to explode. A study led by Gonzalo Muñoz-Sanchez at the National Observatory of Athens, published in Nature Astronomy today, argues that the enormous star WOH G64 has transitioned from a red supergiant to a rare yellow hypergiant—in what may be evidence of an impending supernova.
The evidence suggests we may be witnessing, in real time, a massive star shedding its outer layers, shrinking as it heats up, and moving closer to the end of its short life.
Scientists Simulated The Big Bang’s Aftermath, And Found The Universe Was Like Soup
Immediately after the Big Bang boomed, the Universe was a trillion-degree ‘soup’ of unimaginably dense plasma. In a breakthrough experiment, researchers have found the first evidence that this exotic primordial goo did actually slosh and swirl like soup.
In slightly more scientific terms, this gooey soup is called quark-gluon plasma, or QGP. It was the first and hottest liquid ever to exist. Predictions suggest it blazed a billion times hotter than the surface of the Sun for a few millionths of a second before it expanded, cooled, and coalesced into atoms.
As detailed in a recent study, a team of physicists from MIT and CERN recreated heavy-ion collisions like those that created the QGP to explore its properties. For example, when a quark flows through the plasma, does it recoil and splash like a cohesive liquid, or does it scatter randomly like a collection of particles?
Using Blender In Real-World Cosmology Research
We recently shared the story of Blender’s role in the adult animated series Il Baracchino, and now, a fascinating new article by Ph.D. student MohammadHossein Jamshidi showcases how he applied Geometry Nodes in his cosmology research.
Cosmology is the study of the universe and its fundamental nature. MohammadHossein Jamshidi, from Shahid Beheshti University in Iran, has also worked as an animation engineer in the game industry since 2012. His initial inspiration to apply Blender to scientific work came from the creative projects of Seanterelle, which led him to experiment with using Geometry Nodes for cosmological computations.
In the article, he shares several ideas and techniques for using Blender in his research, and he believes that these approaches could be applied to other areas of science as well. All the files featured are freely available on this GitHub repository.
The persistence of gravitational wave memory
Neutron stars are ultra-dense remnants of massive stars that collapsed after supernova explosions and are made up mostly of subatomic particles with no electric charge (i.e., neutrons). When two neutron stars collide, they are predicted to produce gravitational waves, ripples in the fabric of spacetime that travel at the speed of light.
Gravitational waves typically take the form of oscillations, periodically and temporarily influencing the universe’s underlying fabric (i.e., spacetime). However, general relativity suggests that for some cosmological events, in addition to the oscillatory displacement of test masses (as produced by the passage of a gravitational wave train), there exists a final permanent displacement of them via a phenomenon referred to as “gravitational wave memory.”
Researchers at the University of Illinois at Urbana-Champaign, the Academy of Athens, the University of Valencia and Montclair State University recently carried out a study exploring the gravitational wave memory effects that would arise from neutron star mergers.
Galen Strawson on Panpsychism
Is there something that it is like to be an electron? That sounds implausible. Yet Galen Strawson believes this is the best explanation of how things are.
Specifically, Galen offers his view on physicalistic panpsychism (though there are non-physicalistic panpsychisms as well). He argues something like this, it seems to me:
First, Galen assumes (very plausibly) that experiential phenomena are real phenomena, opposed to illusory. Now:
1. If radical emergentism is true, then experiential phenomena emerges from wholly and utterly non-experiential phenomena.
2. But experiential phenomena cannot emerge from wholly and utterly non-experiential pheneomena.
3. So radical emergentism is false. [1, 2]
4. If radical emergentism is false, then experiential phenomena must already exist in some sense and to some extent as a feature of physical stuff to give rise to experiential phenomena in an intelligible way.
5. So experiential phenomena must already exist in some sense and to some extent as a feature of physical stuff to give rise to experiential phenomena in an intelligible way. [3, 4]
In other words, consciousness has been a feature of the universe since the Big Bang.
For sustained and scholarly treatment of panpsychism, see Galen Strawson’s paper, \.
How fast is the universe expanding? Supernova could provide the answer
That the universe is expanding has been known for almost a hundred years now, but how fast? The exact rate of that expansion remains hotly debated, even challenging the standard model of cosmology. A research team at the Technical University of Munich (TUM), the Ludwig Maximilians University (LMU) and the Max Planck Institutes, MPA and MPE, has now imaged and modeled an exceptionally rare supernova that could provide a new, independent way to measure how fast the universe is expanding. The studies are published on the arXiv preprint server.
The supernova is a rare superluminous stellar explosion, 10 billion light-years away, and far brighter than typical supernovae. It is also special in another way: the single supernova appears five times in the night sky, like cosmic fireworks, due to a phenomenon known as gravitational lensing.
Two foreground galaxies bend the supernova’s light as it travels toward Earth, forcing it to take different paths. Because these paths have slightly different lengths, the light arrives at different times. By measuring the time delays between the multiple copies of the supernova, researchers can determine the universe’s present-day expansion rate, known as the Hubble constant.