Buzz
Dark matter particles do not emit, reflect, or absorb light. Despite this, although we are unable to observe dark matter directly and its nature remains a puzzle, scientists estimate it constitutes roughly 26 percent of the observable universe. This estimate comes from observing how dark matter’s gravitational effects interact with other celestial bodies. Much like wind shaping the branches of a tree, dark matter remains unseen, yet its influence on the cosmos is undeniable. From these clues, researchers are crafting compelling theories about dark matter that, if proven, could radically alter our comprehension of the universe.
10. Dark Matter Could Potentially Lead to Mass Extinctions
Michael Rampino, a professor of biology at New York University, suggests that Earth's passage through the galactic disk (the region of the Milky Way where we reside) may have triggered mass extinction events on our planet. This is believed to have occurred because the Earth's movement disrupted the orbits of comets in the distant Oort Cloud, which, in turn, increased the heat in the Earth's core.
The Sun, along with its planets, completes an orbit around the center of the Milky Way approximately every 250 million years. As part of this journey, the Sun passes through the galactic disk roughly every 30 million years. Rampino believes that Earth's passage through this disk aligns with comet impacts and mass extinction events on Earth, such as the event 65 million years ago when an asteroid is thought to have wiped out the dinosaurs. Another theory suggests that volcanic eruptions were already thinning out the dinosaur population before the asteroid's fatal blow.
Rampino's theory fits perfectly with the idea of unusual volcanic activity and an asteroid strike coinciding with Earth's journey through the galactic disk. 'As Earth moves through the disk, the dark matter concentrated there interferes with the orbits of comets that typically remain far away in the outer solar system,' Rampino explained. 'This disturbance causes comets, which would usually travel at immense distances from Earth, to veer off course and collide with the planet.' While some argue that the dinosaurs perished due to an asteroid and not a comet, about 4 percent of the Oort Cloud is made up of asteroids, which adds up to approximately eight billion asteroids drifting out there.
Furthermore, Rampino posits that each time Earth passes through the galactic disk, dark matter accumulates within the planet's core. As the dark matter particles annihilate each other, they generate intense heat, which could trigger volcanic eruptions, alter sea levels, create mountains, and cause other geological events that significantly impact life on Earth.
9. The Milky Way Could Be A Massive Wormhole
Could it be that we are residing in a colossal tunnel that offers a shortcut through the universe?
According to Einstein's general theory of relativity, a wormhole is a region where space and time are warped, creating a shortcut to a faraway part of the universe. Astrophysicists from the International School for Advanced Studies in Trieste, Italy, suggest that dark matter in our galaxy might be arranged in such a way that a stable wormhole could exist in the heart of the Milky Way. These researchers propose that it might be time to reconsider what dark matter truly is—perhaps it’s simply another dimension.
Professor Paulo Salucci stated, 'If we combine the map of dark matter in the Milky Way with the latest big bang model to explain the universe, and hypothesize the presence of space-time tunnels, we find that our galaxy could indeed contain one of these tunnels, and it could even span the entire galaxy. But that’s not all—we could potentially traverse this tunnel, as our calculations suggest that it could be navigable. It’s much like the one we saw in the recent movie Interstellar.'
While it remains a theory, scientists are convinced that dark matter could be the key to unlocking the creation and observation of wormholes. To date, no natural wormholes have been found.
8. The Discovery of Galaxy X
Galaxy X, also referred to as the dark matter galaxy, is a largely invisible dwarf galaxy that could be creating strange ripples in the cold hydrogen gas at the outer edge of the Milky Way’s disk. Thought to be a satellite galaxy of the Milky Way, Galaxy X contains a cluster of four Cepheid variable stars, which are used as markers to measure cosmic distances. The rest of the galaxy is invisible, as it is composed primarily of dark matter. However, the powerful gravitational influence of this dark matter likely causes the observed ripples. Without the gravitational force exerted by dark matter, it would be highly improbable for four Cepheid variable stars to be located so closely together in space, rather than drifting apart.
'The discovery of the Cepheid variables confirms that our method of locating dark-matter-dominated dwarf galaxies is effective,' explained astronomer Sukanya Chakrabarti. 'This could ultimately help us uncover the composition of dark matter. Additionally, it demonstrates that Newton’s theory of gravity holds true even at the farthest reaches of a galaxy, and there is no need to alter our understanding of gravity.'
7. The Disintegration of the Higgs Boson into Dark Matter
The Standard Model of particle physics, developed in the 1970s, is a set of theories that predicts the existence of all known subatomic particles and their interactions. With the discovery of the Higgs boson in 2012 (also called the 'God particle'), the Standard Model was considered complete. However, this model doesn’t account for everything, particularly dark matter, the force that binds galaxies together. Additionally, some scientists believe that the Higgs particle’s mass is too low to explain certain phenomena.
This led researchers at Chalmers University of Technology to propose a novel model grounded in supersymmetry, which assigns a heavier superpartner to every known particle in the Standard Model. According to this theory, a small fraction of Higgs particles decay into a photon (a light particle) and two gravitinos (dark matter particles). 'If this model proves accurate, it would dramatically transform our understanding of the fundamental building blocks of nature,' stated Christoffer Petersson of Chalmers. The model will be tested at the Large Hadron Collider in Switzerland.
6. Dark Matter in the Sun
Depending on the method used to analyze the Sun, the quantity of elements heavier than hydrogen or helium fluctuates by 20–30 percent. These elements can be detected by analyzing the light spectrum they emit, much like a unique fingerprint, or by observing how they influence sound waves traveling through the Sun, causing slight variations in its brightness. The enigmatic discrepancy between these two measurements is referred to as the solar abundance problem.
Accurate measurements of these elements are crucial for understanding the Sun's chemical makeup, density, and temperature. This will also allow us to better understand the structure and behavior of other stars, their planets, and even galaxies.
For years, scientists struggled to come up with a viable solution. Then, astroparticle physicist Aaron Vincent and his team proposed that dark matter in the Sun's core could provide the answer. After conducting numerous simulations, they developed a theory that seemed to hold up. However, it involved a unique form of dark matter, known as 'weakly interacting asymmetric dark matter,' which can exist as either matter or antimatter, but not both.
By measuring gravity, scientists have determined that a halo of dark matter surrounds the Sun. Asymmetric dark matter particles, which contain very little antimatter, can endure contact with normal matter and accumulate in the Sun’s core. These particles are also thought to absorb energy at the Sun's center, subsequently transferring that heat to the outer layers, which may explain the solar abundance issue.
'The main benefit of asymmetric dark matter is that a significant amount of it can accumulate in the Sun as it moves through the dark matter cloud that surrounds the Milky Way,' explained Vincent. 'If the dark matter were self-annihilating, it would vanish before it could transport a substantial amount of heat from the Sun's core.'
5. Dark Matter May Be Macroscopic
Scientists at Case Western Reserve have questioned whether dark matter is being searched for in the correct places. They propose that dark matter might not be composed of small, exotic particles such as WIMPs (weakly interacting massive particles). Instead, it could consist of macroscopic objects, possibly ranging from a few ounces to as large as an asteroid. These researchers have confined their theory of where to search based on existing observations in space. This has led them to believe that the Standard Model of particle physics may hold the answer, without the need for a new model of dark matter.
The researchers have named their proposed dark matter objects 'macros.' They are not suggesting that WIMPs or axions (weakly interacting low-mass particles) should be completely discarded, but rather that the search for dark matter should be expanded to include additional possibilities. There are types of matter that don’t strictly fall into the categories of ordinary or exotic, which have not yet been fully explored but could still be consistent with the Standard Model.
'The scientific community largely dismissed the idea that dark matter could consist of more familiar matter in the late '80s,' explained physics professor Glenn Starkman. 'We ask, was that conclusion entirely correct, and how can we be certain that dark matter isn’t more ordinary stuff—matter that could be composed of quarks and electrons?'
4. GPS Detection Of Dark Matter
Two physicists have proposed an innovative method of detecting dark matter using GPS satellites. They suggest that dark matter may not be made up of particles, as commonly assumed, but could instead be disturbances in the fabric of space-time. 'Our research explores the possibility that dark matter is organized as a vast, gas-like collection of topological defects, or energy cracks,' said Andrei Derevianko from the University of Nevada. 'We propose to detect these defects, or dark matter, by observing the disruption they cause as they pass through us, using a network of highly sensitive atomic clocks. Essentially, we envision using the GPS system as the largest man-made detector for dark matter.'
The researchers are currently analyzing data from 30 GPS satellites to test the validity of their hypothesis. If dark matter behaves like a gas, Earth will pass through it while orbiting the galaxy. In a manner similar to wind, clumps of dark matter will sweep by Earth and its satellites, occasionally causing GPS clocks in space and on the ground to lose synchronization for roughly three minutes. Scientists will be able to monitor any discrepancies with precision, detecting differences as small as one-billionth of a second.
3. The Gamma Ray Signature
Until recently, the detection of dark matter relied solely on observing its gravitational influence on other celestial objects. However, scientists now believe that gamma rays might provide a more direct signal of the invisible presence of dark matter in the universe. In a groundbreaking development, researchers may have detected the first gamma ray signature from Reticulum 2, a newly discovered dwarf galaxy located near the Milky Way.
Gamma rays are high-energy electromagnetic radiation that emanates from the dense centers of galaxies. If dark matter is indeed composed of WIMPs, these particles would produce gamma rays when they annihilate each other upon contact. However, gamma rays can also be generated by other cosmic phenomena, such as black holes and pulsars. If scientists can rule out these other potential sources, any remaining gamma rays might be attributed to dark matter. This is the hypothesis being tested.
Scientists speculate that most dwarf galaxies have little to no gamma ray sources other than dark matter, which could make up as much as 99 percent of a dwarf galaxy. This is why researchers from Carnegie Mellon, Brown, and Cambridge universities were particularly excited by the gamma ray signals detected from Reticulum 2.
Matthew Walker from Carnegie Mellon University remarked, 'The gravitational detection of dark matter offers very limited insight into its particle behavior.' He continued, 'But now we might have a non-gravitational detection that reveals dark matter behaving as a particle, which is a holy grail of sorts.' While it's still possible that unidentified sources of gamma rays exist in dwarf galaxies, the recent discovery of nine potential dwarf galaxies near the Milky Way provides an exciting opportunity for further investigation into this dark matter detection theory.
2. Dark Matter May Have Caused Ripples In The Galactic Disk
When we gaze into the vast expanse of space from Earth, we observe that the stars abruptly end about 50,000 light-years from the galactic center. For a long time, this was considered the boundary of our galaxy. Beyond that, we didn't detect anything of significance until we observed the Monoceros Ring of stars about 15,000 light-years further out, extending above the galactic plane. Some scientists speculated that these stars had been torn away from another galaxy.
However, a new analysis of data from the Sloan Digital Sky Survey has revealed that the Monoceros Ring is, in fact, part of the Milky Way. This discovery means that our galaxy is at least 50 percent larger than previously thought, expanding its diameter from the estimated 100,000–120,000 light-years to an impressive 150,000–180,000 light-years.
From our vantage point on Earth, we cannot see the connection between the Monoceros Ring and the rest of the galaxy due to the ripples in the galactic disk. It's akin to watching waves in the ocean from the shore. As a wave rises, it obstructs your view of the ocean beyond, leaving only glimpses of higher waves. Similarly, although the shape of the galaxy partially blocks our line of sight, we can still see the Monoceros Ring as if it's the crest of a higher wave.
This finding alters our understanding of the Milky Way's structure. 'In essence, what we discovered is that the Milky Way's disk is not simply a flat plane of stars, but rather it is corrugated,' explained Heidi Newberg from the Rensselaer School of Science. 'As the disk extends outward from the Sun, we observe at least four distinct ripples. Although our data covers only a portion of the galaxy, we anticipate that this pattern will be present throughout the entire disk.'
Much like the ripples that form when a stone is dropped into a pond, scientists speculate that these ripples in our galaxy might have been caused by a lump of dark matter or a dwarf galaxy passing through the Milky Way’s disk. If this hypothesis holds true, these ripples could provide scientists with a unique opportunity to examine the distribution of dark matter across the galaxy.
1. Dark Energy May Be Eating Dark Matter
Recent studies suggest that dark energy might be consuming dark matter as the two interact, potentially slowing the growth of galaxies and ultimately leading to a universe that could be nearly devoid of matter. It is possible that dark matter is decaying into dark energy, although this has yet to be confirmed. The European Union's Planck spacecraft has provided precise data on the universe's physical composition: 4.9 percent ordinary matter (including humans), 25.9 percent dark matter, and 69.2 percent dark energy.
Neither dark matter nor dark energy can be directly observed. Both terms remain poorly understood, even within the scientific community. They serve more as placeholders, representing phenomena we believe are occurring but cannot fully explain yet. As a result, these terms remain somewhat vague until further understanding is achieved.
Dark matter attracts, while dark energy pushes away. Dark matter is considered the structural foundation or framework upon which galaxies and their components are built. Its gravitational influence is thought to hold galaxies together, ensuring that stars remain bound within their respective systems. Gravity’s strength decreases with distance, and increases when objects are closer together.
In contrast, dark energy is the force responsible for the accelerating expansion of the universe, pushing distant galaxies further away from us. As dark energy causes this repulsion, gravity weakens in the vast expanse of space, leading to the realization that space's expansion is accelerating rather than slowing due to gravity, as was once believed.
'Since the late 1990s, astronomers have been convinced that something is causing the expansion of our universe to speed up,' said Professor David Wands from the University of Portsmouth. 'The simplest explanation was that empty space, or the vacuum, had an energy density known as a cosmological constant. However, increasing evidence suggests that this simple model fails to account for all the astronomical data available today, particularly in terms of the slower-than-expected growth of cosmic structures, galaxies, and clusters of galaxies.'
This transfer of energy is happening solely on the dark side. Ordinary matter, such as ourselves, is not being consumed by dark energy.
