Photons Explain Dark Energy

 

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When it comes to the Universe, there are some things we can be confident are out there based on what we observe. 

We know that the Universe was hotter, denser, and more uniform in the distant past. We know that the stars and galaxies in the Universe have grown up and evolved as the Universe has aged. 

We know that gravitation has formed the large-scale structure in the Universe, and that structure has grown more complex over time. 

And we also know how much normal matter, altogether, is present in the Universe, and that it isn’t sufficient to explain the full suite of the gravitational effects that we see on its own.  READ MORE...

Dark Energy Used to Map Universe

With 5,000 tiny robots in a mountaintop telescope, researchers can look 11 billion years into the past. The light from far-flung objects in space is just now reaching the Dark Energy Spectroscopic Instrument (DESI), enabling us to map our cosmos as it was in its youth and trace its growth to what we see today.


Understanding how our universe has evolved is tied to how it ends, and to one of the biggest mysteries in physics: dark energy, the unknown ingredient causing our universe to expand faster and faster.

To study dark energy's effects over the past 11 billion years, DESI has created the largest 3D map of our cosmos ever constructed, with the most precise measurements to date. This is the first time scientists have measured the expansion history of the young universe with a precision better than 1%, giving us our best view yet of how the universe evolved.  READ MORE...

Deciphering the Dark

Dark energy’s role in propelling the universe’s accelerated expansion presents a pivotal challenge in astrophysics, driving ongoing research and space missions dedicated to uncovering the nature of this mysterious force.

Some 13.8 billion years ago, the universe began with a rapid expansion we call the Big Bang. After this initial expansion, which lasted a fraction of a second, gravity started to slow the universe down. But the cosmos wouldn’t stay this way. Nine billion years after the universe began, its expansion started to speed up, driven by an unknown force that scientists have named dark energy.

But what exactly is dark energy?  The short answer is: We don’t know. But we do know that it exists, it’s making the universe expand at an accelerating rate, and approximately 68.3 to 70% of the universe is dark energy.     READ MORE...

Cosmological Distance Measurements

Measurements of the distance to extragalactic sources allow us to infer the major energy constituents of our Universe.

Two decades ago such measurements revealed that most of the energy in the Universe is in `dark energy’ — a discovery that has had immense implications for fundamental physics. 

Currently there is a 10% discrepancy in cosmic distances inferred with the two most accepted techniques, despite 1-2% errors claimed on both methods, with the model that is most successful at reconciling this discrepancy being an earlier era where something like dark energy was again important. 

Interpreting mild tensions can be challenging and ideally a much more precise measurement would be performed. Such a measurement could also lead to entirely new discoveries.  READ MORE...

New Way to Measure Dark Energy

Researchers have discovered a method to potentially detect and measure dark energy by examining the motion between the Milky Way and Andromeda galaxies. This technique, still in its early stages, can estimate the upper value of the cosmological constant, a simple model of dark energy, which is five times higher than values determined from the early universe.




Researchers from the University of Cambridge have discovered a new way to measure dark energy – the mysterious force that makes up more than two-thirds of the universe and is responsible for its accelerating expansion – in our own cosmic backyard.

The researchers found that it may be possible to detect and measure dark energy by studying Andromeda, our galactic next-door neighbor that is on a slow-motion collision course with the Milky Way.


Since it was first identified in the late 1990s, scientists have used very distant galaxies to study dark energy but have yet to directly detect it. 

However, the Cambridge researchers found that by studying how Andromeda and the Milky Way are moving toward each other given their collective mass, they could place an upper limit on the value of the cosmological constant, which is the simplest model of dark energy. 

The upper limit they found is five times higher than the value of the cosmological constant that can be detected from the early universe.

Although the technique is still early in its development, the researchers say that it could be possible to detect dark energy by studying our own cosmic neighborhood. The results are reported in The Astrophysical Journal Letters.

Everything we can see in our world and in the skies – from tiny insects to massive galaxies – makes up just five percent of the observable universe. 

The rest is dark: scientists believe that about 27% of the universe is made of dark matter, which holds objects together, while 68% is dark energy, which pushes objects apart.  READ MORE...

Dark Energy

Universe Dark Energy-1 Expanding Universe
This diagram reveals changes in the rate of expansion since the universe's birth 15 billion years ago. The more shallow the curve, the faster the rate of expansion. The curve changes noticeably about 7.5 billion years ago, when objects in the universe began flying apart as a faster rate. Astronomers theorize that the faster expansion rate is due to a mysterious, dark force that is pulling galaxies apart.  Credit: NASA/STSci/Ann Feild






One explanation for dark energy is that it is a property of space. Albert Einstein was the first person to realize that empty space is not nothing. Space has amazing properties, many of which are just beginning to be understood. The first property that Einstein discovered is that it is possible for more space to come into existence. 

Then one version of Einstein's gravity theory, the version that contains a cosmological constant, makes a second prediction: "empty space" can possess its own energy. Because this energy is a property of space itself, it would not be diluted as space expands. As more space comes into existence, more of this energy-of-space would appear. 

As a result, this form of energy would cause the universe to expand faster and faster. Unfortunately, no one understands why the cosmological constant should even be there, much less why it would have exactly the right value to cause the observed acceleration of the universe.


Another explanation for how space acquires energy comes from the quantum theory of matter. In this theory, "empty space" is actually full of temporary ("virtual") particles that continually form and then disappear. 

But when physicists tried to calculate how much energy this would give empty space, the answer came out wrong - wrong by a lot. The number came out 10120 times too big. That's a 1 with 120 zeros after it. It's hard to get an answer that bad. So the mystery continues.

Another explanation for dark energy is that it is a new kind of dynamical energy fluid or field, something that fills all of space but something whose effect on the expansion of the universe is the opposite of that of matter and normal energy. 

Some theorists have named this "quintessence," after the fifth element of the Greek philosophers. But, if quintessence is the answer, we still don't know what it is like, what it interacts with, or why it exists. So the mystery continues.  READ MORE...

Space-Time Distortions

Observing time distortions could show whether Einstein's theory of general relativity accounts for the mysteries of dark matter and dark energy.

Scientists could soon test Einstein's theory of general relativity by measuring the distortion of time.


According to new research published June 22 in the journal Nature Astronomy, the newly proposed method turns the edge of space and time into a vast cosmic lab to investigate if general relativity can account for dark matter  -  a mysterious, invisible form of matter that can only be inferred by its gravitational influence on the universe's visible matter and energy -  as well as the accelerating expansion of the universe due to dark energy. The method is ready to be tested on future surveys of the deep universe, according to the study authors.

General relativity states that gravity is the result of mass warping the fabric of space and time, which Einstein lumped into a four-dimensional entity called space-time. According to relativity, time passes more slowly close to a massive object than it does in a mass-less vacuum. This change in the passing of time is called time distortion.

Since its introduction in 1915, general relativity has been tested extensively and has become our best description of gravity on tremendous scales. But scientists aren't yet sure if it can explain invisible dark matter and dark energy, which together account for around 95% of the energy and matter in the universe.  READ MORE...

Dark Energy

This diagram reveals changes in the rate of expansion since the universe’s birth nearly 15 billion years ago. The more shallow the curve, the faster the rate of expansion. The curve changes noticeably about 7.5 billion years ago when objects in the universe began flying apart at a faster rate. Astronomers theorize that the faster expansion rate is due to a force called “dark energy” that is pulling galaxies apart. Credit: NASA/STSci/Ann Feild






Dark Energy Was Always Present, Everywhere and at Every Time


The Force is with us, according to cosmologists working to understand a mysterious “something” that’s making the universe expand. Its name? Dark energy. And, it turns out that it’s been present everywhere throughout cosmic history.

Astronomers have known since the 1920s that the universe is expanding. That understanding began with Edwin Hubble’s groundbreaking observation of a Type I supernova in the Andromeda Galaxy. 

And, astronomy trucked along for many years, using that expansion to measure distances and other parameters in the cosmos. Then, in 1998, something happened. Astronomers discovered that the cosmic expansion is speeding up.

The culprit? This completely not-at-all-understood dark energy force which can’t be seen, but with effects that can be detected. Some explain it as a property of space that causes the universe to expand faster and faster. 

Others suggest that it’s some kind of new energy fluid or a field that fits throughout space, but has an effect on the expansion of the Universe. It could also be something that doesn’t fit our current theories about gravity, and that a new theory of gravity could account for dark energy’s effects.

There’s no consensus yet about which of these theories is correct. However, its discovery immediately raised a bunch of questions, such as, when did the expansion rate accelerate? Will that change, too? Was it the same rate throughout the universe across all time?

Dark Energy, eROSITA, and Galaxy Clusters

To answer those, a group of researchers used something called eROSITA to look at a specific subset of galaxy clusters across time. eROSITA is the main X-ray-sensitive instrument aboard the Spectrum-ROENTGEN-GAMMA (SRG) mission launched in 2019. (Currently, it is shut down due to the ongoing conflict between Russia and Ukraine.) 

One of its jobs is to do a complete all-sky survey in the medium energy X-ray range (up to 10 keV). The data it returns should help probe the nature and ubiquity of dark energy by studying up to 100,000 galaxy clusters and the material between them. It also studies obscured black holes in galaxies and looks at X-ray sources ranging from young stars and supernova remnants to X-ray binaries.

Astronomers I-Non Chieu of Taiwan’s National Cheng Kung University and Matthias Klein, Sebastian Bocquet, and Joseph Mohr at Ludwig Maximilians-Universitat in Munich used eROSITA Final Equatorial Depth Survey (eFEDS) data taken before the shutdown to characterize about 500 low-mass galaxy clusters. 

It’s one of the largest such samples and it “saw” them over the past ten billion years. That’s around 3/4 of the age of the Universe.  READ MORE...

Expansion of Universe Nearing End

The universe is not only expanding, but accelerating that expansion, leading most scientists to anticipate it will keep on growing for a very long time, if not forever. However, a trio of Princeton physicists have challenged this view, presenting a model of the universe in which this expansion is nearly at its end. The universe will start to contract in on itself, they claim, and that could happen surprisingly soon. This is a cosmologist’s “soon”, however, of the order of 100 million years, not something most people would recognize as imminent.

The discovery of acceleration in the expansion of the universe has shaken up cosmology perhaps more than anything else this century. Beforehand the primary debate was whether the universe would expand forever, albeit more slowly, or be dragged back into a “big crunch” as gravity overcame the movement apart.

Acceleration, and the Dark Energy used to explain it, appeared to end the possibility the universe would ever contract again, but a minority of physicists aren't ready to let the idea go. Professor Paul Steinhardt, in particular, has proposed “bouncing” models of the universe. Now Steinhardt and co-authors claim in Proceedings of the National Academy of Sciences that the turning point from expansion to contraction could be close without us being able to tell.

The authors do not assert certainty. They refer to three models of Dark Energy's nature. One of these would see the universe continue to expand faster and faster forever, while a second would see it slow at an unpredictable point, probably far in the future.  READ MORE...

Laniakea Destroyed by Dark Energy

On the largest cosmic scales, planet Earth appears to be anything but special. Like hundreds of billions of other planets in our galaxy, we orbit our parent star; like hundreds of billions of solar systems, we revolve around the galaxy; like the majority of galaxies in the Universe, we’re bound together in either a group or cluster of galaxies. 

And, like most galactic groups and clusters, we’re a small part of a larger structure containing over 100,000 galaxies: a supercluster. Ours is named Laniakea: the Hawaiian word for “immense heaven.”

Superclusters have been found and charted throughout our observable Universe, where they’re more than 10 times as rich as the largest known clusters of galaxies. Unfortunately, owing to the presence of dark energy in the Universe, these superclusters ⁠— including our own ⁠— are only apparent structures. In reality, they’re mere phantasms, in the process of dissolving before our very eyes.

The Universe as we know it began some 13.8 billion years ago with the Big Bang. It was filled with matter, antimatter, radiation, etc.; all the particles and fields that we know of today, and possibly even more. 

From the earliest instants of the hot Big Bang, however, it wasn’t simply a uniform sea of these energetic quanta. Instead, there were tiny imperfections ⁠— at about the 0.003% level ⁠— on all scales, where some regions had slightly more or slightly less matter and energy than average.

In each one of these regions, a great cosmic race ensued. The race was between two competing phenomena:

1. the expansion of the Universe, which works to drive all the matter and energy apart
2. gravitation, which works to pull all forms of energy together, causing massive material to clump and cluster together

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Dark Energy On Earth

DARK ENERGY ISN’T just dark — it's nigh invisible.

Hypothesized by physicists to drive the accelerating expansion of the universe, dark energy has never been directly observed or measured. Instead, scientists can only make inferences about it from its effects on the space and matter we can see.


Finding measurable hints of dark energy’s effects on distance objects — and the shape of space itself — is a major goal of major NASA missions, such as the upcoming Nancy Grace Roman Space Telescope.

But in a new paper published September 15 in the journal Physical Review D a group of cosmologists suggests researchers might not need to peer deep into the cosmos to make second-hand observations of dark energy — it may have been detected right here on Earth.

WHAT’S NEW — In the paper, the researchers claim that hints of dark energy were detected at the Gran Sasso National Laboratory in Italy during an experiment designed to detect dark matter.

The team, comprised mostly of theorists, looked at data from the XENON1T, an experiment designed to detect rare interactions between hypothetical dark matter particles and components of the noble gas xenon held in a special detector.

The odds that dark energy has been detected directly are admittedly low, Jeremy Sakstein, assistant professor of theoretical physics at the University of Hawaii and one of the paper’s authors, tells Inverse.

“There are other explanations for this signal as well,” he says, and at the moment, “we don't know whether it's just a statistical anomaly.”

Statistically, there is a 5 percent chance the detection was an anomaly. The detection of the 2012 discovery Higgs Boson, by comparison, was much more certain — there was only a chance in about 3.5 million that detection was anomalous.  READ MORE...

Offering An Explanation

YALE UNIVERSITY

OXFORD UNIVERSITY

HARVARD UNIVERSITY

PRINCETON UNIVERSITY

Oxford University - The Crown Jewel of Education

If you had a PhD from any of these fine and upstanding universities you would be admired and revered and if you had more than more than one, your admiration might be doubled and you would have a GUARANTEED CHAIR at any university in our tiny little world that we refer to as EARTH in a WILD WILD WEST of a UNIVERSE...

BUT...  no matter how many PhD's you earned and were awarded, you still would not be able to give us a definitive answer as to how our universe was created and if there are other forms of life living out there in distant galaxies or if there has been time traveling aliens who have previously visited our earth...

What you would give us would be a highly educated OPINION...

a mere speculation or conjecture as to what you perceived was real...

and, even if you were in touch with a cosmic consciousness, you would not know how to harness it in such a way that it would provide you with the sum total of all knowledge...

as human beings and even with PhD's we are limited with our knowledge and understandings even though we pretend to students that is not the case at all...

Some now believe that there was a VOID in space and by definition VOIDS are empty of all matter...  yet, these VOIDS were in possession of DARK MATTER AND DARK ENERGY that when EXPLODED created our universe...  and because this dark energy is still around, our universe is continuing to expand into more VOIDS of non existence...

Excuse me for being relatively ignorant as Einstein might have once upon a time said, but this explanation makes no sense, in fact, it seems rather illogical to me that something from nothing could create you and me and all this other stuff around us.

Isn't some kind of CREATOR a more likely possibility...   I mean...  using OCCUM'S RAZOR as a precursor for our thoughts.