We, and creation itself, actualize the possibilities of the God who sustains the world, towards becoming in the world in a fuller, more deeper way. - R.E. Slater

There is urgency in coming to see the world as a web of interrelated processes of which we are integral parts, so that all of our choices and actions have [consequential effects upon] the world around us. - Process Metaphysician Alfred North Whitehead

Kurt Gödel's Incompleteness Theorem says (i) all closed systems are unprovable within themselves and, that (ii) all open systems are rightly understood as incomplete. - R.E. Slater

The most true thing about you is what God has said to you in Christ, "You are My Beloved." - Tripp Fuller

The God among us is the God who refuses to be God without us, so great is God's Love. - Tripp Fuller

According to some Christian outlooks we were made for another world. Perhaps, rather, we were made for this world to recreate, reclaim, redeem, and renew unto God's future aspiration by the power of His Spirit. - R.E. Slater

Our eschatological ethos is to love. To stand with those who are oppressed. To stand against those who are oppressing. It is that simple. Love is our only calling and Christian Hope. - R.E. Slater

Secularization theory has been massively falsified. We don't live in an age of secularity. We live in an age of explosive, pervasive religiosity... an age of religious pluralism. - Peter L. Berger

Exploring the edge of life and faith in a post-everything world. - Todd Littleton

I don't need another reason to believe, your love is all around for me to see. – Anon

Thou art our need; and in giving us more of thyself thou givest us all. - Khalil Gibran, Prayer XXIII

Be careful what you pretend to be. You become what you pretend to be. - Kurt Vonnegut

Religious beliefs, far from being primary, are often shaped and adjusted by our social goals. - Jim Forest

People, even more than things, need to be restored, renewed, revived, reclaimed, and redeemed; never throw out anyone. – Anon

Certainly, God's love has made fools of us all. - R.E. Slater

An apocalyptic Christian faith doesn't wait for Jesus to come, but for Jesus to become in our midst. - R.E. Slater

Christian belief in God begins with the cross and resurrection of Jesus, not with rational apologetics. - Eberhard Jüngel, Jürgen Moltmann

Our knowledge of God is through the 'I-Thou' encounter, not in finding God at the end of a syllogism or argument. There is a grave danger in any Christian treatment of God as an object. The God of Jesus Christ and Scripture is irreducibly subject and never made as an object, a force, a power, or a principle that can be manipulated. - Emil Brunner

“Ehyeh Asher Ehyeh” means "I will be that who I have yet to become." - God (Ex 3.14) or, conversely, “I AM who I AM Becoming.”

Our job is to love others without stopping to inquire whether or not they are worthy. - Thomas Merton

The church is God's world-changing social experiment of bringing unlikes and differents to the Eucharist/Communion table to share life with one another as a new kind of family. When this happens, we show to the world what love, justice, peace, reconciliation, and life together is designed by God to be. The church is God's show-and-tell for the world to see how God wants us to live as a blended, global, polypluralistic family united with one will, by one Lord, and baptized by one Spirit. – Anon

The cross that is planted at the heart of the history of the world cannot be uprooted. - Jacques Ellul

The Unity in whose loving presence the universe unfolds is inside each person as a call to welcome the stranger, protect animals and the earth, respect the dignity of each person, think new thoughts, and help bring about ecological civilizations. - John Cobb & Farhan A. Shah

If you board the wrong train it is of no use running along the corridors of the train in the other direction. - Dietrich Bonhoeffer

God's justice is restorative rather than punitive; His discipline is merciful rather than punishing; His power is made perfect in weakness; and His grace is sufficient for all. – Anon

Our little [biblical] systems have their day; they have their day and cease to be. They are but broken lights of Thee, and Thou, O God art more than they. - Alfred Lord Tennyson

We can’t control God; God is uncontrollable. God can’t control us; God’s love is uncontrolling! - Thomas Jay Oord

Life in perspective but always in process... as we are relational beings in process to one another, so life events are in process in relation to each event... as God is to Self, is to world, is to us... like Father, like sons and daughters, like events... life in process yet always in perspective. - R.E. Slater

To promote societal transition to sustainable ways of living and a global society founded on a shared ethical framework which includes respect and care for the community of life, ecological integrity, universal human rights, respect for diversity, economic justice, democracy, and a culture of peace. - The Earth Charter Mission Statement

Christian humanism is the belief that human freedom, individual conscience, and unencumbered rational inquiry are compatible with the practice of Christianity or even intrinsic in its doctrine. It represents a philosophical union of Christian faith and classical humanist principles. - Scott Postma

It is never wise to have a self-appointed religious institution determine a nation's moral code. The opportunities for moral compromise and failure are high; the moral codes and creeds assuredly racist, discriminatory, or subjectively and religiously defined; and the pronouncement of inhumanitarian political objectives quite predictable. - R.E. Slater

God's love must both center and define the Christian faith and all religious or human faiths seeking human and ecological balance in worlds of subtraction, harm, tragedy, and evil. - R.E. Slater

Sunday, April 3, 2022

The Basics of Dark Matter & Dark Energy



When a quark collides with its antiquark, the interaction produces energy in the form of moving particles, antiparticles, and energy. Because scientists can detect these particles and energy, they are not the mysterious dark energy.

Does dark energy come from antimatter?

Astronomy: Roen Kelly

RELATED TOPICS: DARK ENERGY


Q: Could the energy produced during matter-antimatter annihilation in the early universe be dark energy? If not, where is that produced energy today?

Michael Lynch
Dallas, Texas

A: Astronomers see galaxies flying away from each other faster than expected. Some sort of energy — dubbed “dark energy” because we cannot identify what it is — must be causing this repulsion. We know that dark energy composes an amazing 68 percent of the universe, so it produces an extremely big effect. Normal matter — like stars, gas, and planets — is only 5 percent of the cosmos.

Scientists believe that the laws of physics are constant everywhere and at all times. Decades of experiments have tested this principle and shown that it is valid. Therefore, we can use our current theory to predict what happened at the Big Bang, even though no one was around to observe the universe’s beginning.

We can study and measure matter-antimatter annihilations in high-energy accelerators. For instance, when quarks interact with antiquarks, we can measure the newly produced particles that have energy we can observe. Thus, the collisions aren’t creating dark energy (we can’t see dark energy; we can only detect its effect). Accelerator experiments also show no hint of dark matter — the mysterious mass that makes up 27 percent of the cosmos.

Physicists believe that the simplest explanation of a scientific question is often the best, so we conclude that throughout the universe, when matter collides with antimatter, the interaction produces the same energy we see on Earth. If the laws of physics are constant over time, we assert that when the cosmos was full of matter and antimatter, starting around one-trillionth of a second after the Big Bang, collisions between them produced the same energy we see and feel every day.

As the universe expanded and cooled, the collisions’ energy went right back to where it came from: matter, antimatter, and energy. For some reason, however, there was one slight asymmetry; the process created more matter than antimatter, which is why we see only matter today. The early universe’s antimatter and matter simply converted into our matter. Thank goodness, too — an astronaut would not want to meet up with antimatter debris.

Howard Matis
Lawrence Berkeley National
Laboratory, California

* * * * * *


Two galaxy clusters collided to create the “Bullet Cluster,” shown here. Normal matter is shown in pink and the rest of the matter is illustrated in blue, revealing that dark matter dominates this enormous cluster. | X-ray: NASA/CXC/CfA/M.Markevitch et al.; Optical: NASA/STScI; Magellan/U.Arizona/D.Clowe et al.; Lensing Map: NASA/STScI; ESO WFI; Magellan/U.Arizona/D.Clowe et al.

What's the difference between dark matter and dark energy?


RELATED TOPICS: DARK MATTER | DARK ENERGY | COSMOLOGY


Our universe is dominated by mysterious and invisible forms of matter and energy that have yet to be fully (or even adequately) understood.

Most of our universe is hidden in plain sight. Though we can’t see or touch it, most astronomers say the majority of the cosmos consists of dark matter and dark energy. But what is this mysterious, invisible stuff that surrounds us? And what’s the difference between dark energy and dark matter? In short, dark matter slows down the expansion of the universe, while dark energy speeds it up.

Dark matter works like an attractive force — a kind of cosmic cement that holds our universe together. This is because dark matter does interact with gravity, but it doesn’t reflect, absorb, or emit light.

Meanwhile, dark energy is a repulsive forcea sort of anti-gravity — that drives the universe’s ever-accelerating expansion.

Dark energy is the far more dominant force of the two, accounting for roughly 68 percent of the universe’s total mass and energy. Dark matter makes up 27 percent. And the rest — a measly 5 percent — is all the regular matter we see and interact with every day.

Dark matter cannot be photographed, but researchers can detect it and map it by measuring gravitational lensing. Its distribution is shown here in the blue overlay of the inner region of Abell 1689, a cluster of galaxies 2.2 billion light-years away. | NASA/ESA/JPL-Caltech/Yale/CNRS

Dark matter

In the 1930s, Swiss-born astronomer Fritz Zwicky studied images of the roughly 1,000 galaxies that make up the Coma Cluster — and he spotted something funny about their behavior. The galaxies moved so fast that they should simply fly apart. He speculated that some kind of “dark matter” held them together.

Decades later, astronomers Vera Rubin and Kent Ford found a similar phenomenon when they studied the rotation rates of individual galaxies. The stars at a galaxy’s outer edge should circle slower than stars near the center. That’s the way planets in our solar system orbit. Instead, they noticed that the stars on a galaxy’s outskirts orbit just as fast — or faster — than the stars closer in. Rubin and Ford had found more evidence that some invisible form of matter is apparently holding the universe together.

“Even stars at the periphery are orbiting at high velocities,” Rubin once explained in an interview with Discover. “There has to be a lot of mass to make the stars orbit so rapidly, but we can’t see it. We call this invisible mass dark matter.”

How did we discover dark matter? What is dark matter made of? How is dark matter different than dark energy? Astronomy’s free downloadable eBook, The Science Behind Dark Matter, contains everything you need to know about the elusive and invisible substance.

Astronomers now have many other lines of evidence that suggest dark matter is real. In fact, the existence of dark matter is so widely accepted that it’s part of the so-called standard model of cosmology, which forms the foundation of how scientists understand the universe’s birth and evolution. Without it, we can’t explain how we got here.

But that lofty status puts pressure on cosmologists to find definitive proof that dark matter exists and that their model of the universe is correct. For decades, physicists all over the world have employed increasingly high-tech instruments to try and detect dark matter. So far, they’ve found no signs of it.

A wide view of the local universe, spanning hundreds of millions of light-years, reveals the clumped and weblike structure of the cosmos, with strands of galaxies and immense voids. The Milky Way is just one of many points that make up the Virgo Supercluster. Rather than just empty, passive spaces, voids may hold clues to understanding dark matter, dark energy and galactic evolution. - Andrew Z. Colvin

Dark Energy

Astronomers have known that our universe is expanding for about a century now. Telescopic observations have shown that most galaxies are moving away from each other, which implies the galaxies were closer together in the distant past. As a result, the evidence piled up for the Big Bang. However, astronomers assumed that the combined gravitational pull of all the cosmos’ stars and galaxies should be slowing down the universe’s expansion. Perhaps it would even someday collapse back in on itself in a Big Crunch.

That notion was thrown out in the late 1990s, however, when two teams of astronomers spotted something that didn’t make any sense. Researchers studying supernovas in the the most distant galaxies discovered that distant galaxies were moving away from us faster than nearby galaxies. The universe wasn’t just expanding — the expansion was speeding up.

“My own reaction is somewhere between amazement and horror,“ astronomer Brian Schmidt, who led one of the two teams, told The New York Times in 1998. “Amazement, because I just did not expect this result, and horror in knowing that it will likely be disbelieved by a majority of astronomers — who, like myself, are extremely skeptical of the unexpected.“

This graphic illustrates how the universe expands over time. | Astronomy: Roen Kelly


But rather than refute it, subsequent observations have only made the evidence for dark energy more robust. In fact, some prominent critics of dark matter still accept the existence of dark energy.

Now, that doesn’t mean researchers know what dark energy is. Far from it. But they can describe its role in the universe, thanks to Albert Einstein’s theory of general relativity. Einstein didn’t know about dark energy, but his equations suggested new space can come into existence. And he also included a fudge factor in relativity called the cosmological constant, which he added — and later regretted — to keep the universe from collapsing inward. This idea allows space itself to have energy. However, scientists have still never actually seen this force on Earth.

Some theoretical physicists think there’s an entire dark realm of particles and forces out there, just waiting to be discovered. Whatever dark energy and dark matter are made of, they seem to be playing tug-of-war with our universe — both holding it together and pulling it apart.

* * * * * *


In 1998, researchers discovered that something was causing the expansion of the universe to speed up. | NASA’s Goddard Space Flight Center Conceptual Image Lab.




The Beginning to the End of the Universe: The mystery of dark energy

by Bruce Dorminey

RELATED TOPICS: DARK ENERGY | COSMOLOGY
This story comes from our special January 2021 issue, "The Beginning and the End of the Universe.” Click here to purchase the full issue.

The universe isn’t just expanding, it’s accelerating.


For almost a century, astronomers have known that the universe is expanding. Space-time is stretching itself out over billions of light-years, carrying the galaxies within it apart, like raisins embedded within a rising loaf of bread.

This steady expansion, pitted against the cosmos’ urge to collapse under its own gravity, means there are two main scenarios for how the universe will eventually end. These scenarios are dubbed the Big Crunch — where gravity overcomes expansion and the Big Bang occurs in reverse — and the Big Freeze — where gravity loses out to the expansion and all matter is isolated by unfathomable distances. (See “The Big Crunch vs. the Big Freeze,” page 50.)

For a while, researchers believed the universe’s fate was leaning toward the final scenario. But, in the late 1990s, astronomers discovered something unexpected that changed our understanding of the future of the universe: The most distant galaxies weren’t just moving away from us. They were accelerating.

A cosmological puzzle

This phenomenon was independently discovered by two teams of astronomers who were measuring distant supernovae to calculate the precise rate at which the universe was expanding, expecting to find it slowing down. Three of these scientists — Saul Perlmutter, Adam Riess, and Brian Schmidt — shared the 2011 Nobel Prize in Physics for their discovery.
The award-winning observations came from a survey of distant type Ia supernovae. Astronomers believe these explosions are triggered when a white dwarf — the dense remnant of a Sun-like star — accretes matter that pushes it over a physical mass limit. That limit is the same for all white dwarfs, making all type Ia supernovae the same true brightness. This property made these supernovae ideal standard distance markers, or standard candles, in the mid-1990s.
The two teams were actually looking back into time for the onset of cosmic deceleration: They were looking for the point in time at which gravity gained the upper hand over the cosmos’ rapid acceleration after the Big Bang. This moment would mark a turnaround, as gravity finally started to slow the rate at which galaxies and clusters of galaxies are pulled away from one another by the expansion of the universe.

Since scientists know the true brightness of the standard candles, they could anticipate how bright these distant supernovae would be if expansion was slowing down. But instead, they found the observed type Ia supernovae were 25 percent fainter than expected, proving that the universe’s expansion isn’t slowing down, but instead is speeding up.

By the end of 1998, both teams had submitted papers detailing their findings to academic journals. Perlmutter’s team published its paper in The Astrophysical Journal and Riess and Schmidt’s team published in The Astronomical Journal.

The conclusion of both: A large percent of the universe is made up of something previously undiscovered and unexpected. And this so-called dark energy is overpowering gravity and pushing space-time apart from within.




A lot of missing pieces

The composition of the universe is surprisingly tricky to pin down. Besides dark energy, space is also filled with an invisible form of matter known as dark matter. Astronomers now know that normal, visible matter makes up just 5 percent of the universe, while enigmatic dark matter and dark energy constitute 26 percent and 69 percent, respectively. In other words, astronomers don’t really understand what about 95 percent of the universe is really made of.
And even decades after their discovery, scientists still know shockingly little about the “dark” forces that rule our universe. “Understanding and measuring dark matter and dark energy is hard,” says Riess. “Imagine bumping around in a dark room, occasionally touching an elephant, having never seen one, and [trying to understand] what it is, what it looks like.”
But the dark room is the size of the universe and instead of touching the elephant, astronomers can only see the effects it has on other objects. Astronomers can see that dark matter gravitationally interacts with visible matter, so they suspect it to be made up of one or more unknown particles. Dark energy could be a fifth fundamental force of the universe. (The known four are: the weak force, the strong force, gravity, and electromagnetism.) But its exact properties are still a mystery, especially since dark energy seems to have randomly turned itself on. Riess says the most recent measurements show that dark energy really kicked off this acceleration about 5 billion to 6 billion years ago, and it’s been the dominant force ever since.

The simplest explanation for dark energy is that it is the intrinsic energy of space itself. Albert Einstein initially introduced such a concept to allow for a flat universe when laying out his theory of relativity. Einstein’s so-called cosmological constant is a repulsive force that counteracts the attractive force of gravity to allow for a universe that neither collapses nor expands. But, in the end, Einstein dismissed his concept after Edwin Hubble observed the universe expanding. The Nobel-winning supernovae work in the 1990s resurrected [Einstein's] cosmological constant and related it to dark energy.

Though astronomers cannot see dark matter directly, they can infer its location from observations. The distribution of dark matter (magenta) in supercluster Abell 901/902 is revealed in this photo by combining a visible light image of the supercluster and a dark matter map of the area. | VISIBLE LIGHT: ESO, C. Wolf (Oxford University, U.K.), K. Meisenheimer (Max-Planck Institute for Astronomy, Heidelberg), and the COMBO-17 collaboration. DARK MATTER MAP: NASA, ESA, C. Heymans (University of British Columbia, Vancouver), M. Gray (University of Nottingham, U.K.), M. Barden (Innsbruck), and the STAGES collaboration.

What lies ahead

To ultimately resolve this dark energy puzzle, Riess says scientists will need more than just measurements. The world’s best theoretical physicists have tried to work out a grand unified theory of physics that fully explains all aspects of the universe. But so far, gravity and quantum physics don’t seem to mesh, despite the fact that theorists believe their unification is essential to any theory that will also explain dark energy.

One thing scientists have been able to figure out, however, is the profound impact dark energy will have on the universe in the distant future.
If the contribution of dark energy grows as the universe ages, the universe will expand progressively faster over time. Other galaxies beyond our Local Group — which will have merged into a single giant galaxy nicknamed Milkomeda — will eventually be whisked out to such great distances that any far-future occupants of our solar system wouldn’t be able to view them.
In fact, Alexei Filippenko, an astronomer at University of California, Berkeley, who has worked with both teams that discovered dark energy, says, “If all records are lost, future civilizations might not ever know about other galaxies.” For them, he says, “[The universe] will be a cold, dark, lonely place.