Is the universe ringing like a crystal glass?

The standard view of the expanding universe.

The standard view of the expanding universe.

Many know the phrase “the big bang theory.” There’s even a top television comedy series with that as its title. According to scientists, the universe began with the “big bang” and expanded to the size it is today. Yet, the gravity of all of this matter, stars, gas, galaxies, and mysterious dark matter, tries to pull the universe back together, slowing down the expansion.

Now, two physicists at The University of Southern Mississippi, Lawrence Mead and Harry Ringermacher, have discovered that the universe might not only be expanding, but also oscillating or “ringing” at the same time. Their paper on the topic has been published in the April 2015 issue of the Astronomical Journal.
In 1978 Arno Allan Penzias and Robert Woodrow Wilson received the Nobel prize for their 1964 discovery of the key signature of this theory, the primal radiation from the early universe known as the “cosmic microwave background” (CMB).
“Then in 1998 the finding that the universe was not only expanding, but was speeding up, or accelerating in its expansion was a shock when it was discovered simultaneously by east coast and west coast teams of astronomers and physicists,” said Mead. “A new form of matter, dark energy, repulsive in nature, was responsible for the speed-up. The teams led by Saul Perlmutter, Adam Riess, and Brian Schmidt won the 2011 Nobel Prize in Physics for that discovery.”
According to Mead and Ringermacher, this change from slowing down to speeding up (the transition time) took place approximately 6 to 7 billion years ago. Since then, Mead and Ringermacher say a vast accumulation of high-tech data has verified the theory to extraordinary accuracy.
Figure 1 is a NASA diagram representing the events of the Big Bang from the beginning of time to the present day as described by the current, accepted model known as “Lambda CDM” or Lambda Cold Dark Matter, where the Greek Lambda stands for Einstein’s “cosmological constant”. This cosmological constant is responsible for the acceleration of the universe. The outline of the “bell-shaped” universe represents its expanding size. The transition time is the point in time at which the bell shape shifts from going inward to outward from left to right.

“The new finding suggests that the universe has slowed down and speeded up, not just once, but 7 times in the last 13.8 billion years, on average emulating dark matter in the process,” said Mead. “The ringing has been decaying and is now very small – much like striking a crystal glass and hearing it ring down.”

The universe ringing while expanding.

The universe ringing while expanding.

Figure 2 shows the new finding superposed on the Lambda CDM model of Figure 1. The oscillation amplitude is highly exaggerated, but the frequency is roughly correct. Ringermacher and Mead have determined that this oscillation is not a wave moving through the universe, such as a gravitational wave, but rather it is a “wave of the universe”.
Ringermacher says the discovery was made accidentally when, through their collaboration on dark matter modeling of galaxies, they found a new way of plotting a classic textbook graph describing the scale of the universe against its age (lookback time) that did not depend on one’s prior choice of models of the universe – as was traditional.
“The standard graph, the Hubble diagram, is constructed by astronomers observing the distances of Type 1A Supernovae that serve as “standard candles” for measuring the expansion of the universe,” said Ringermacher. “Analyzing this new plot to locate the transition time of the universe, we found there was more than one such time – in fact multiple oscillations with a frequency of about 7 cycles over the lifetime of the universe. It is space itself that has been speeding up its expansion followed by slowing down 7 times since creation.”
Mead and Ringermacher say this finding must ultimately be verified by independent analyses, preferably of new supernovae data, to confirm its reality. In the meantime, their work into the “ringing” of the universe continues.

Read more at: http://phys.org/news/2015-06-universe-crystal-glass.html#jCp – http://arxiv.org/abs/1502.06140

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Why isn’t the universe as bright as it should be?

Study explains why galaxies don’t churn out as many stars as they should.

A handful of new stars are born each year in the Milky Way, while many more blink on across the universe. But astronomers have observed that galaxies should be churning out millions more stars, based on the amount of interstellar gas available.
Now researchers from MIT, Columbia University, and Michigan State University have pieced together a theory describing how clusters of galaxies may regulate star formation. They describe their framework this week in the journal Nature.
When intracluster gas cools rapidly, it condenses, then collapses to form new stars. Scientists have long thought that something must be keeping the gas from cooling enough to generate more stars — but exactly what has remained a mystery.
For some galaxy clusters, the researchers say, the intracluster gas may simply be too hot — on the order of hundreds of millions of degrees Celsius. Even if one region experiences some cooling, the intensity of the surrounding heat would keep that region from cooling further — an effect known as conduction.
“It would be like putting an ice cube in a boiling pot of water — the average temperature is pretty much still boiling,” says Michael McDonald, a Hubble Fellow in MIT’s Kavli Institute for Astrophysics and Space Research. “At super-high temperatures, conduction smooths out the temperature distribution so you don’t get any of these cold clouds that should form stars.” Continue reading Why isn’t the universe as bright as it should be?

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Chronology of the Universe

What happened at the origin of the universe? How did the Big Bang process unfold? How was matter created? And what was the role of the Higgs boson, which gave mass to other particles? This is the story of the creation of our universe, a narrative that lasts 13.7 billion years, but we have summarized it for you in the three and a half minutes of this spectacular video illustration.

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A 3D Map of the Adolescent Universe

3D map of the cosmic web at a distance of 10.8 billion years from Earth, generated from imprints of hydrogen gas observed in the spectrum of 24 background galaxies behind the volume. This is the first time that large-scale structures in such a distant part of the Universe have been directly mapped. Credit: Casey Stark (UC Berkeley) and Khee-Gan Lee (MPIA). - See more at: http://newscenter.lbl.gov/2014/10/16/a-3d-map-of-the-adolescent-universe/#sthash.FC2wxF0N.dpuf

3D map of the cosmic web at a distance of 10.8 billion years from Earth, generated from imprints of hydrogen gas observed in the spectrum of 24 background galaxies behind the volume. This is the first time that large-scale structures in such a distant part of the Universe have been directly mapped. Credit: Casey Stark (UC Berkeley) and Khee-Gan Lee (MPIA).

cosmic_ctscan_640x423
Read more at newscenter.lbl.gov

Astronomers Discover Largest Structure in the Universe

It’s ten billion light years across and almost as far away but nobody had spotted it…until now

: 283 GRBs with observed redshift (blue) and the 31 GRBs (red) between redshift 1.6 and 2.

283 GRBs with observed redshift (blue) and the 31 GRBs (red) between redshift 1.6 and 2.

What’s the largest structure in the Universe? That’s a question that has intrigued scientists for centuries. Today, they get an answer thanks to astronomers who say they’ve discovered the largest structure ever observed and one that dwarfs the previous record-holder by billions of light years.

Astronomer’s ideas about the universe’s largest structures have changed dramatically in the last 100 years. At the beginning of the 20th century, they began to suspect that stars were clustered together to form “island universes” or galaxies which themselves were separated by vast distances.

The question was eventually settled in the 1920s by Edwin Hubble and others who measured the distance to different galaxies, thereby proving that they were much further away than stars . These galaxies, they thought, were the largest structures in the universe and distributed more or less uniformly throughout space.

It wasn’t until 1989 that astronomers found something even bigger. In the 1970s and 80s, they had begun to systematically measure the distances to large numbers of galaxies and this eventually allowed them to produce a 3D map of them.

To their surprise, the galaxies were not distributed evenly but instead formed filamentary structures with walls and voids. They called the largest of these “the Great Wall”, a structure that is 200 million light years away and some 500 million light years long.

That was puzzling at the time because these walls and voids were too large to have formed through gravitational interactions in the time since the birth of the universe. Of course, astronomers now know that this structure comes from variations in the density of the early universe soon after the Big Bang, caused by quantum fluctuations.

Since then, astronomers have found even larger structures as the technology to look further into the universe improved. In 2003, they discovered the Sloan Great Wall, another wall of galaxies some 1.4 billion light years long and about a billion light years from Earth.

Earlier this year, they spotted a larger structure in the constellation of Leo called the Huge-LQG (Large Quasar Group) . This consists of 73 quasars stretching over a distance of 4 billion light years.

Now I Horvath at the National University of Public Service in Budapest, Hungary, and a couple of pals say they’ve identified something even bigger. Their data is based on gamma-ray bursts, the most energetic events in the universe.

Astronomers think these bursts are emitted by stars as they collapse to form neutron stars or black holes. These bursts are incredibly bright—a typical burst releases about the same energy in a fraction of a second as the Sun will during its entire life time.

Astronomers measure the distance of gamma ray bursts by looking for the optical afterglow of the explosion when it is detected and measuring its redshift. Since 1997, when this technique was first used, they’ve measured the distance to 283 of these bursts and mapped their position within the universe.

Astronomers have always assumed that these explosions are distributed evenly throughout the universe. And for the most part, this looks to be the case.

But Horvath and co say they’ve found a significant irregularity. They say there are far more gamma ray bursts at a distance of about ten billion light years than would be expected if the distribution was uniform.

These gamma ray bursts form a structure that is some ten billion light years in size, significantly larger than even the Huge-LQG. So this thing, presumably another wall of even more distant galaxies, is the new largest structure in the universe.

Of course, there are caveats associated with this new work. The first is the small sample size of just 283 gamma ray bursts of which only 31 make up this new giant structure. Horvath and co say that, statistically, this number of gamma ray bursts should not be grouped together in this way if they are evenly distributed.

That’s a decent pointer that something interesting might be going on here but it is by no means an astronomical slamdunk; more data is desperately needed. “One or two years more of gamma burst observations will hopefully provide the statistics to confirm or disprove this discovery,” they say.

If this tale seems a little familiar, that’s because astronomers have regularly assumed that the objects they can see must be distributed uniformly around the universe. As history has shown time and again, this usually turns out to be wrong. The universe always seems to have structure at every scale.

That may have even more significance. One of the fundamental tenets of cosmology is the Cosmological principle—this holds that the distribution of matter in the universe will appear uniform if viewed from a large enough scale.

This is equivalent to the idea that the universe appears the same to all observers, wherever in the cosmos they may be.

But the evidence, as far as astronomers can gather it, does not back up this idea. At whatever scale they look, large scale structures always seem to emerge.

That doesn’t disprove the Cosmological principle. Indeed, cosmologists are quick to say that the key idea is that the laws of physics must be the same for all observers, not necessarily the large scale structure.

Nevertheless, the possibility that the Cosmological principle may sit on shaky ground will provide many theorists with some interesting food for thought.

Ref: http://arxiv.org/abs/1311.1104 : The Largest Structure Of The Universe, Defined By Gamma-Ray Bursts

Read more at https://medium.com/the-physics-arxiv-blog/267ddcb8057b

A Flight Through the Universe

by the Sloan Digital Sky Survey

This animated flight through the universe was made by Miguel Aragon of Johns Hopkins University with Mark Subbarao of the Adler Planetarium and Alex Szalay of Johns Hopkins.
There are close to 400,000 galaxies in the animation, with images of the actual galaxies in these positions (or in some cases their near cousins in type) derived from the Sloan Digital Sky Survey (SDSS) Data Release 7.
Vast as this slice of the universe seems, its most distant reach is to redshift 0.1, corresponding to roughly 1.3 billion light years from Earth. SDSS Data Release 9 from the Baryon Oscillation Spectroscopic Survey (BOSS), led by Berkeley Lab scientists, includes spectroscopic data for well over half a million galaxies at redshifts up to 0.8 — roughly 7 billion light years distant — and over a hundred thousand quasars to redshift 3.0 and beyond.
http://youtu.be/08LBltePDZw

Secrets Of The Dark Universe: Simulating The Sky

dark matterAn astonishing 99.6% of our Universe is dark. Observations indicate that the Universe consists of 70% of a mysterious dark energy and 25% of a yet-unidentified dark matter
component, and only 0.4% of the remaining ordinary matter is visible.

Understanding the physics of this dark sector is the foremost challenge in cosmology today. Sophisticated simulations of the evolution of the Universe play a crucial task in this endeavor.

This movie shows an intermediate stage in a large simulation of the distribution of matter in the Universe, the so-called cosmic web, accounting for the influence of dark energy. The simulation is evolving 1.1 trillion particles. The movie shows a snapshot of the Universe when it was 1.6 billion years old.