Dwarf galaxies tip the scales in favor of dark matter over modified gravity

An international team of researchers led by the Leibniz Institute for Astrophysics Potsdam (AIP) has shed light on a decades-long debate about why galaxies spin faster than expected—and whether this behavior is caused by invisible dark matter or by a collapse of gravity on cosmic scales.


Led by the AIP in collaboration with the University of Surrey, the University of Bath, Nanjing University in China, the University of Porto in Portugal, Leiden University in the Netherlands, and Lund University in Sweden, the study analyzed stellar velocity data from 12 of the smallest and faintest galaxies in the universe to put rival theories to the test.

READ MORE...

Dark Matter and Dark Energy Don’t Exist, New Study Claims

A new study argues that dark matter and dark energy might be illusions caused by the universe’s forces fading over time.

For many years, scientists have thought that dark matter and dark energy make up most of the cosmos. A new study, however, challenges that long-held belief by proposing that these mysterious components might not exist at all. Instead, what appears to be dark matter and dark energy could actually result from the gradual weakening of the universe’s fundamental forces as it grows older.

The research, led by Rajendra Gupta, an Adjunct Professor in the Department of Physics at the University of Ottawa, suggests that if the core strengths of nature’s forces (like gravity) change slowly across time and space, they could account for the puzzling behaviors astronomers see—such as how galaxies rotate, evolve, and how the universe continues to expand.

READ MORE...

Scientists Create Levitating Disk That Requires No External Power

Okinawa Institute of Science and Technology (OIST) scientists have achieved a levitation breakthrough by creating a virtually frictionless, macroscopic levitating disk, which requires no external power to magically float above a series of rare-earth magnets.


The researchers behind the historic achievement believe their levitating disk, which resists magnetic eddy forces that can reduce its sensitivity, could be adapted to sensors designed to measure extremely small forces. These include interactions of dark matter and dark energy, as well as those found in the quantum realm.

READ MORE...

Theories on dark matter's origins point to 'mirror world' and universe's edge

Two recent studies by Professor Stefano Profumo at the University of California, Santa Cruz, propose theories that attempt to answer one of the most fundamental open questions in modern physics: What is the particle nature of dark matter?


Science has produced overwhelming evidence that the mysterious substance, which accounts for 80% of all matter in the universe, exists. Dark matter's presence explains what binds galaxies together and makes them rotate. 

Findings such as the large-scale structure of the universe and measurements of the cosmic microwave background also prove that something as-yet undetermined permeates all that darkness.

READ MORE...

We've discovered a door to a hidden part of reality – what's inside?

The discovery of a new door to a hidden part of reality, as described in a recent New Scientist article, could potentially reveal new particles or even deeper insights into the fundamental nature of reality. While the exact contents of this hidden realm are unknown, physicists speculate it might house particles like axions or non-Abelian anyons, which could be crucial for understanding dark matter or developing quantum computing.


Here's a more detailed breakdown:
New Particles:
The article highlights the possibility of finding new particles, possibly like those predicted by theoretical physics but not yet observed in experiments like the Large Hadron Collider (LHC), according to New Scientist.

Deepening Our Understanding of Reality:
Beyond specific particles, this discovery could shed light on the fundamental nature of reality, challenging existing theories about what constitutes a "particle" and potentially revealing deeper layers of the universe's structure.

Quasiparticles:
The article mentions quasiparticles, which are emergent properties of many-body systems that behave like particles. Non-Abelian anyons, a type of quasiparticle, are particularly interesting because of their potential to be used in quantum computing.

Dark Matter and Dark Energy:
The discovery might also offer clues about dark matter and dark energy, mysterious components of the universe that make up a significant portion of its mass and energy but remain largely unknown.

Speculative Imagination:
The search for these hidden realms and their potential contents relies on a combination of theoretical predictions, experimental data, and imaginative thinking.

Scientists develop nuclear clock method to detect dark matter using thorium-229

For nearly a century, scientists around the world have been searching for dark matter—an invisible substance believed to make up about 80% of the universe's mass and needed to explain a variety of physical phenomena. Numerous methods have been used in attempts to detect dark matter, from trying to produce it in particle accelerators to searching for cosmic radiation that it might emit in space.

Yet even today, very little is known about this matter's fundamental properties. Although it operates in the background, dark matter is believed to influence visible matter, but in ways so subtle that they currently cannot be directly measured.

Scientists believe that if a nuclear clock is developed—one that uses the atomic nucleus to measure time with extreme precision—even the tiniest irregularities in its ticking could reveal dark matter's influence. Last year, physicists in Germany and Colorado made a breakthrough toward building such a clock, using the radioactive element thorium-229.

READ MORE...

Dark Matter Could Be Evolving, And The Implications Are Profound

For a while now, there has been a problematic mystery at the heart of the standard cosmological model.


Although all observations support the expanding Universe model, observations of the early period of the cosmos give a lower rate of acceleration than more local observations. We call it the Hubble tension problem, and we have no idea how to solve it.


Naturally, there have been several proposed ideas: what if general relativity is wrong; what if dark matter doesn't exist; what if the rate of time isn't uniform; heck, what if the entire Universe rotates.

READ MORE...

New Theory Suggests Dark Matter Is Frozen Relics of Light-Speed Particles

In an ongoing quest to guess the secret behind the Universe's excess in gravity, two researchers from Dartmouth College in the US have proposed a chilling union between massless particles soon after the Big Bang.


For the better part of a century it's been frustratingly clear that estimates of the Universe's visible mass have failed to account for the way galaxies rotate, pointing to slow-moving clumps of matter we can't see. This stuff has been dubbed ' dark matter'.


Even as researchers whittle away at the list of properties describing this cold and silent corner of physics, its identity and origins remain elusive.

READ MORE...

Researcher proposes first-time model that replaces dark energy and dark matter in explaining nature of the universe

Dr. Richard Lieu, a physics professor at The University of Alabama in Huntsville (UAH), a part of The University of Alabama System, has published a paper in the journal Classical and Quantum Gravity that proposes a universe built on steps of multiple singularities rather than the Big Bang alone to account for the expansion of the cosmos.

The new model forgoes the need for either dark matter or dark energy as explanations for the universe's acceleration and how structures like galaxies are generated.

The researcher's work builds on an earlier model hypothesizing that gravity can exist without mass.

READ MORE...

Gravity is the spawn of entropy

For centuries, scientists have been trying to unify two fundamental theories – Einstein’s general theory of relativity, which describes gravity and cosmic scales, and quantum mechanics, which governs the world of particles. But their incompatibility remains one of the unsolved problems of modern physics. The breakthrough may come from a new concept of quantum gravity, which arises from entropy – chaos in a system. This idea not only brings us closer to a “Theory of Everything” but also offers a solution to the mysteries of dark matter and dark energy, which make up 95% of the Universe. The study is published in the journal Physical Review D.

READ MORE...

Dark Matter and Gravity

Key Takeaways

1. Out there in the Universe, it isn’t just normal matter that’s present, but dark matter as well: a mysterious, invisible substance that, as far as we can tell, gravitates, but doesn’t interact through any other means.
2. When we look at the gravitational effects that massive objects have on space, we find dark matter forms a diffuse, halo-and-filament-like network of structure.
3. Normal matter, however, collapses into stars, galaxies, planets, and much more. If dark matter gravitates, and does so the same as normal matter does, then what prevents it from collapsing?

Here in our Universe, it may be the normal matter that we can directly detect, measure, manipulate, experiment with, and observe, but it’s the dark matter that represents most of the mass in the Universe. 

Whereas all the “stuff” that the planets, stars, gas, plasma, and dust are composed of represents about 4.9% of the total energy in the Universe, the mysterious dark matter — whose nature is unknown but for which the observational astrophysical evidence is overwhelming — makes up a whopping 27% of the cosmic energy budget. 

Only dark energy, making up 68% of the Universe, is more important from an energy density perspective.     READ MORE...

What the Euclid Space Telescope Sees

The Euclid Space Telescope has revealed the "first page" of the cosmic atlas it is building. The section of the map of the cosmos being built by Euclid was released on Monday (Oct. 15), and it features tens of millions of stars within the Milky Way and around 14 million distant galaxies beyond our own.


The vast cosmic mosaic was constructed from 260 Euclid observations collected between March 25 and April 8, 2024 and contains 208 gigapixels of data. The region charted is around 500 times as wide as the full moon appears in the sky over Earth.

Perhaps most astoundingly, the mosaic accounts for just 1% of the total survey Euclid will conduct over the next six years as it tracks the shapes, distances and movements of galaxies as far as 10 billion light-years away. Not only will this result in the largest 3D map of the cosmos ever created, but the vast scale of this map will help scientists investigate the mysteries of dark matter and dark energy, sometimes collectively known as the "dark universe."     READ MORE...

Dark Matter Does Not Exist

For centuries, scientists have grappled with the fundamental forces that govern our universe, chief among them being gravity, and more recently, dark matter.

Gravity is the invisible force that attracts objects with mass towards each other, playing a crucial role in shaping the cosmos, from the formation of galaxies to the orbits of planets.

However, as our understanding of the universe has expanded, so too have the mysteries surrounding it.

Dark matter dilemma
One of the most perplexing of these mysteries is the concept of dark matter, a hypothetical form of matter that is believed to make up a significant portion of the universe’s total mass.

Unlike ordinary matter, which we can see and interact with directly, dark matter does not emit, absorb, or reflect light, making it invisible to telescopes and other detecting instruments.  READ MORE...

Disputed Dark Matter Claim

Inside the hall that will house the large scintillator counter. Yemilab is built 1,000 metres underground in an old mine. Credit: Kangsoon Park and Eunkyung Lee





It’s a mystery that has had physicists scratching their heads for more than 20 years. The DAMA/LIBRA experiment at the Gran Sasso National Laboratory (LNGS) near L’Aquila, Italy, has been recording an annual fluctuation of light flashes in its detector that appears to be a sign of dark matter. But no one has been able to definitively replicate the findings.

But beneath a mountain in Jeongseon, South Korea, researchers are scaling up an experiment that could finally lay the controversial dark-matter claim to rest. In June, researchers will finish installing a revamped detector in a brand-new facility called Yemilab. If all goes to plan, the upgraded COSINE-100 experiment will be running by August, says Hyun Su Lee, a physicist at the Institute for Basic Science (IBS) in Daejeon, South Korea.

Dark matter is thought to account for 85% of mass in the Universe, but because it barely interacts with ordinary matter and doesn’t interact at all with light, it is notoriously difficult to observe directly. Several research teams have tried to catch a glimpse of the elusive substance, but only the DAMA/LIBRA experiment has claimed to have seen it for real.     READ MORE...

Ultra Light Particles

Astronomers have a problem. Stars and galaxies dance to an unexpected tune, their motion seemingly governed by six times the matter that can be seen. Scientists believe that the Universe is filled with a form of dark matter that far exceeds the amount of ordinary matter. There’s only one problem: There is no direct evidence for the existence of dark matter.

Over the past 50 years, physicists have tried to detect dark matter, to no avail. Many options have been considered, ranging from subatomic particles to unseen black holes. For the past few decades, the theoretical physics community has favored the idea that dark matter is made of stable particles with a mass somewhere between the mass of a proton and a few thousand times greater.

However, a group of physicists at Fermi National Accelerator Laboratory and the University of Chicago have explored a very different mass range. These scientists are looking for dark matter particles that are trillions or even quadrillion times lighter than the more traditional searches.      READ MORE...

Dark Matter to Visible Light

Explorations in dark matter are advancing with new experimental techniques designed to detect axions, leveraging advanced technology and interdisciplinary collaboration to uncover the secrets of this elusive component of the cosmos.

A ghost is haunting our universe. This has been known in astronomy and cosmology for decades. Observations suggest that about 85% of all the matter in the universe is mysterious and invisible. These two qualities are reflected in its name: dark matter.    READ MORE...

The Universe & Dark Matter

Physicists have long theorized that our universe may not be limited to what we can see. By observing gravitational forces on other galaxies, they've hypothesized the existence of "dark matter," which would be invisible to conventional forms of observation.


Pran Nath, the Matthews Distinguished University Professor of physics at Northeastern University, says that "95% of the universe is dark, is invisible to the eye."


"However, we know that the dark universe is there by [its] gravitational pull on stars," he says. Other than its gravity, dark matter has never seemed to have much effect on the visible universe.    READ MORE...

Dark Matter Hiding in Collider's Particle Jets

A new search for dark matter has turned up empty handed — but, in a silver lining, the effort provided important limits that will help future experiments narrow down the hunt for this elusive substance.

Most astronomers believe that dark matter accounts for 85 percent of all mass in the universe, and that its existence would explain the apparent extra gravity detectable around galaxies and within huge galaxy clusters. However, so far, no one has been able to identify what dark matter is made of.    READ MORE...

Matter in the Universe

Most matter in the universe cannot be seen — but its influence on the largest structures in space can.

Astronomers estimate that roughly 85% of all the matter in the universe is dark matter, meaning only 15% of all matter is normal matter. Accounting for dark energy, the name astronomers give to the accelerated expansion of the universe, dark matter makes up roughly 27% of all the mass energy in the cosmos, according to CERN (the European Organization for Nuclear Research).

Astronomers have a variety of tools to measure the total amount of matter in the universe and compare that to the amount of "normal" (also called "baryonic") matter. The simplest technique is to compare two measurements.

The first measurement is the total amount of light emitted by a large structure, like a galaxy, which astronomers can use to infer that object's mass. The second measurement is the estimated amount of gravity needed to hold the large structure together. 

When astronomers compare these measurements on galaxies and clusters throughout the universe, they get the same result: There simply isn't enough normal, light-emitting matter to account for the amount of gravitational force needed to hold those objects together.

Thus, there must be some form of matter that is not emitting light: dark matter.

Different galaxies have different proportions of dark matter to normal matter. Some galaxies contain almost no dark matter, while others are nearly devoid of normal matter. But measurement after measurement gives the same average result: Roughly 85% of the matter in the universe does not emit or interact with light.  READ MORE...

Neutrinos and Dark Matter

PNNL chemist Isaac Arnquist examines ultra-low radiation copper cables specially created for sensitive physics detection experiments. Credit: Andrea Starr, Pacific Northwest National Laboratory



Ultra-low radiation cables reduce background noise for neutrino and dark matter detectors.

Imagine trying to tune a radio to a single station but instead encountering static noise and interfering signals from your own equipment. That is the challenge facing research teams searching for evidence of extremely rare events that could help understand the origin and nature of matter in the universe. 

It turns out that when you are trying to tune into some of the universe’s weakest signals, it helps to make your instruments very quiet.

Around the world, more than a dozen teams are listening for the pops and electronic sizzle that might mean they have finally tuned into the right channel. These scientists and engineers have gone to extraordinary lengths to shield their experiments from false signals created by cosmic radiation. 

Most such experiments are found in very inaccessible places—such as a mile underground in a nickel mine in Sudbury, Ontario, Canada, or in an abandoned gold mine in Lead, South Dakota—to shield them from naturally radioactive elements on Earth. 

However, one such source of fake signals comes from natural radioactivity in the very electronics that are designed to record potential signals.

Ultra-low radiation cables reduce background noise for neutrino and dark matter detectors.

Imagine trying to tune a radio to a single station but instead encountering static noise and interfering signals from your own equipment. That is the challenge facing research teams searching for evidence of extremely rare events that could help understand the origin and nature of matter in the universe. 

It turns out that when you are trying to tune into some of the universe’s weakest signals, it helps to make your instruments very quiet.

Around the world, more than a dozen teams are listening for the pops and electronic sizzle that might mean they have finally tuned into the right channel. These scientists and engineers have gone to extraordinary lengths to shield their experiments from false signals created by cosmic radiation. 

Most such experiments are found in very inaccessible places—such as a mile underground in a nickel mine in Sudbury, Ontario, Canada, or in an abandoned gold mine in Lead, South Dakota—to shield them from naturally radioactive elements on Earth. 

However, one such source of fake signals comes from natural radioactivity in the very electronics that are designed to record potential signals.  READ MORE...