Cosmology Archives

March 22, 2013December 23, 2015 by David Dickinson

Meet Hopper: A Key Player in the Planck Discovery Story

The cabinets containing the Grace Hopper Cray XE6 supercomputer. (Credit: LBNL/Dept of Energy).

Behind every modern tale of cosmological discovery is the supercomputer that made it possible. Such was the case with the announcement yesterday from the European Space Agencies’ Planck mission team which raised the age estimate for the universe to 13.82 billion years and tweaked the parameters for the amounts dark matter, dark energy and plain old baryonic matter in the universe.

Planck built upon our understanding of the early universe by providing us the most detailed picture yet of the cosmic microwave background (CMB), the “fossil relic” of the Big Bang first discovered by Penzias & Wilson in 1965. Planck’s discoveries built upon the CMB map of the universe observed by the Wilkinson Microwave Anisotropy Probe (WMAP) and serves to further validate the Big Bang theory of cosmology.

But studying the tiny fluctuations in the faint cosmic microwave background isn’t easy, and that’s where Hopper comes in. From its L2 Lagrange vantage point beyond Earth’s Moon, Planck’s 72 onboard detectors observe the sky at 9 separate frequencies, completing a full scan of the sky every six months. This first release of data is the culmination of 15 months worth of observations representing close to a trillion overall samples. Planck records on average of 10,000 samples every second and scans every point in the sky about 1,000 times.

That’s a challenge to analyze, even for a supercomputer. Hopper is a Cray XE6 supercomputer based at the Department of Energy’s National Energy Research Scientific Computing center (NERSC) at the Lawrence Berkeley National Laboratory in California. Named after computer scientist and pioneer Grace Hopper, the supercomputer has a whopping 217 terabytes of memory running across 153,216 computer cores with a peak performance of 1.28 petaflops a second. Hopper placed number five on a November 2010 list of the world’s top supercomputers. (The Tianhe-1A supercomputer at the National Supercomputing Center in Tianjin China was number one at a peak performance of 4.7 petaflops per second).

One of the main challenges for the team sifting through the flood of CMB data generated by Planck was to filter out the “noise” and bias from the detectors themselves.

“It’s like more than just bugs on a windshield that we want to remove to see the light, but a storm of bugs all around us in every direction,” said Planck project scientist Charles Lawrence. To overcome this, Hopper runs simulations of how the sky would appear to Planck under different conditions and compares these simulations against observations to tease out data.

“By scaling up to tens of thousands of processors, we’ve reduced the time it takes to run these calculations from an impossible 1,000 years to a few weeks,” said Berkeley lab and Planck scientist Ted Kisner.

But the Planck mission isn’t the only data that Hopper is involved with. Hopper and NERSC were also involved with last year’s discovery of the final neutrino mixing angle. Hopper is also currently involved with studying wave-plasma interactions, fusion plasmas and more. You can see the projects that NERSC computers are tasked with currently on their site along with CPU core hours used in real time. Maybe a future descendant of Hopper could give Deep Thought of Hitchhiker’s Guide to the Galaxy fame competition in solving the answer to Life, the Universe, and Everything.

Also, a big congrats to Planck and NERSC researchers. Yesterday was a great day to be a cosmologist. At very least, perhaps folks won’t continue to confuse the field with cosmetology… trust us, you don’t want a cosmologist styling your hair!

March 21, 2013December 23, 2015 by John Williams

Planck’s Cosmic Map Reveals Universe Older, Expanding More Slowly

Like archaeologists sifting through the dust of ancient civilizations, scientists with the ESA Planck mission today showed a map of the oldest light in the Universe. The first cosmology results of the mission suggest our Universe is slightly older and expanding more slowly than previously thought.

Planck’s new estimate for the age of the Universe is 13.82 billion years.

The map also appears to show more matter and dark matter and less dark energy, a hypothetical force that is causing an expansion of the Universe.

“We are measuring the oldest light in the Universe, the cosmic microwave background,” says Paul Hertz, director of astrophysics with NASA. “It is the most sensitive and detailed map ever. It’s like going from standard television to a new high definition screen. The new details have become crystal clear.”

Overall, the cosmic background radiation, the afterglow of the Universe’s birth, is smooth and uniform. The map, however, provides a glimpse of the tiny temperature fluctuations that were imprinted on the sky when the Universe was just 370,000 years old. Scientists believe the map reveals a fossil, an imprint, of the state of the Universe just 10 nano-nano-nano-nano seconds after the Big Bang; just a tiny fraction of the time it took to read that sentence. The splotches in the Planck map represent the seeds from which the stars and galaxies formed.

The colors in the map represent different temperatures; red for warmer, blue for cooler. The temperature differences being only 1/100 millionth of a degree. “The contrast on the map has been turned way up,” says Charles Lawrence, the US project scientist for Planck at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

Planck, launched in 2009 from the Guiana Space Center in French Guiana, is a European Space Agency mission with significant contribution from NASA. The two-ton spacecraft gathers the ancient glow of the Universe’s beginning from a vantage more than 1 million miles from Earth.

735692main_pia16874-43_946-710 — This graphic shows the evolution of satellites designed to measure the light left over from the Big Bang that created our Universe about 13.8 billion years ago. Called the cosmic background radiation, the light reveals information about the early Universe. The three panels show the same 10-square-degree patch of sky as seen by NASA’s Cosmic Background Explorer, or COBE, NASA’s Wilkinson Microwave Anisotropy Probe, or WMAP, and Planck. Planck has a resolution about 2.5 times greater than WMAP. Credit: NASA/JPL-Caltech/ESA

This is not the first map produced by Planck. In 2010, Planck produced an all-sky radiation map. Scientists, using supercomputers, have removed not only the bright emissions from foreground sources, like the Milky Way, but also stray light from the satellite itself.

As the light travels, matter scattered throughout the Universe with its associated gravity subtly bends and absorbs the light, “making it wiggle to and fro,” said Martin White, a Planck project scientist with the University of California, Berkeley and the Lawrence Berkeley National Laboratory.

“The Planck map shows the impact of all matter back to the edge of the Universe,” says White. “It’s not just a pretty picture. Our theories on how matter forms and how the Universe formed match spectacularly to this new data.”

“This is a treasury of scientific data,” said Krzysztof Gorski, a member of the Planck team with JPL. “We are very excited with the results. We find an early Universe that is considerably less rigged and more random than other, more complex models. We think they’ll be facing a dead-end.”

An artists animation depicting the “life” of a photon, or a particle light, as it travels across space and time from the beginning of the Universe to the detectors of the Planck telescope. Credit: NASA

Planck scientists believe the new data should help scientists refine many of the theories proposed by cosmologists that the Universe underwent a sudden and rapid inflation.

February 23, 2013April 26, 2016 by Dan Majaess

Nearby Ancient Star is Almost as Old as the Universe

A billion years after the big bang, hydrogen atoms were mysteriously torn apart into a soup of ions. Credit: NASA/ESA/A. Felid (STScI)).

A metal-poor star located merely 190 light-years from the Sun is 14.46+-0.80 billion years old, which implies that the star is nearly as old as the Universe! Those results emerged from a new study led by Howard Bond. Such metal-poor stars are (super) important to astronomers because they set an independent lower limit for the age of the Universe, which can be used to corroborate age estimates inferred by other means.

In the past, analyses of globular clusters and the Hubble constant (expansion rate of the Universe) yielded vastly different ages for the Universe, and were offset by billions of years! Hence the importance of the star (designated HD 140283) studied by Bond and his coauthors.

“Within the errors, the age of HD 140283 does not conflict with the age of the Universe, 13.77 ± 0.06 billion years, based on the microwave background and Hubble constant, but it must have formed soon after the big bang.” the team noted.

Metal-poor stars can be used to constrain the age of the Universe because metal-content is typically a proxy for age. Heavier metals are generally formed in supernova explosions, which pollute the surrounding interstellar medium. Stars subsequently born from that medium are more enriched with metals than their predecessors, with each successive generation becoming increasingly enriched. Indeed, HD 140283 exhibits less than 1% the iron content of the Sun, which provides an indication of its sizable age.

HD 140283 had been used previously to constrain the age of the Universe, but uncertainties tied to its estimated distance (at that time) made the age determination somewhat imprecise. The team therefore decided to obtain a new and improved distance for HD 140283 using the Hubble Space Telescope (HST), namely via the trigonometric parallax approach. The distance uncertainty for HD 140283 was significantly reduced by comparison to existing estimates, thus resulting in a more precise age estimate for the star.

Age estimate for HD 140283 is 14.46+-0.80 Gyr. On the y-axis is the star's pseudo-luminosity, on the x-axis its temperature. An evolutionary track was applied to infer the age (credit: adapted by D. Majaess from Fig 1 in Bond et al. 2013, arXiv). — HD 140283 is estimated to be 14.46+-0.80 billion years old. On the y-axis is the star’s pseudo-luminosity, on the x-axis its temperature. Computed evolutionary tracks (solid lines ranging from 13.4 to 14.4 billion years) were applied to infer the age (image credit: adapted from Fig 1 in Bond et al. 2013 by D. Majaess, arXiv).

The team applied the latest evolutionary tracks (basically, computer models that trace a star’s luminosity and temperature evolution as a function of time) to HD 140283 and derived an age of 14.46+-0.80 billion years (see figure above). Yet the associated uncertainty could be further mitigated by increasing the sample size of (very) metal-poor stars with precise distances, in concert with the unending task of improving computer models employed to delineate a star’s evolutionary track. An average computed from that sample would provide a firm lower-limit for the age of the Universe. The reliability of the age determined is likewise contingent on accurately determining the sample’s metal content. However, we may not have to wait long, as Don VandenBerg (UVic) kindly relayed to Universe Today to expect, “an expanded article on HD 140283, and the other [similar] targets for which we have improved parallaxes [distances].”

As noted at the outset, analyses of globular clusters and the Hubble constant yielded vastly different ages for the Universe. Hence the motivation for the Bond et al. 2013 study, which aimed to determine an age for the metal-poor star HD 140283 that could be compared with existing age estimates for the Universe. The discrepant ages stemmed partly from uncertainties in the cosmic distance scale, as the determination of the Hubble constant relied on establishing (accurate) distances to galaxies. Historical estimates for the Hubble constant ranged from 50-100 km/s/Mpc, which defines an age spread for the Universe of ~10 billion years.

Age estimates for globular clusters were previously larger than that inferred for the Age of the Universe from the Hubble constant (NASA, R. Gilliland (STScI), D. Malin (AAO)) — Age estimates for the Universe as inferred from globular clusters and the Hubble constant were previously in significant disagreement (image credit: NASA, R. Gilliland (STScI), D. Malin (AAO)).

The aforementioned spread in Hubble constant estimates was certainly unsatisfactory, and astronomers recognized that reliable results were needed. One of the key objectives envisioned for HST was to reduce uncertainties associated with the Hubble constant to <10%, thus providing an improved estimate for the age of the Universe. Present estimates for the Hubble constant, as tied to HST data, appear to span a smaller range (64-75 km/s/Mpc), with the mean implying an age near ~14 billion years.

Determining a reliable age for stars in globular clusters is likewise contingent on the availability of a reliable distance, and the team notes that “it is still unclear whether or not globular cluster ages are compatible with the age of the Universe [predicted from the Hubble constant and other means].” Globular clusters set a lower limit to the age of the Universe, and their age should be smaller than that inferred from the Hubble constant (& cosmological parameters).

In sum, the study reaffirms that there are old stars roaming the solar neighborhood which can be used to constrain the age of the Universe (~14 billion years). The Sun, by comparison, is ~4.5 billion years old.

The team’s findings will appear in the Astrophysical Journal Letters, and a preprint is available on arXiv. The coauthors on the study are E. Nelan, D. VandenBerg, G. Schaefer, and D. Harmer. The interested reader desiring complete information will find the following works pertinent: Pont et al. 1998, VandenBerg 2000, Freedman & Madore (2010), Tammann & Reindl 2012.

January 31, 2013December 23, 2015 by Evan Gough

Book Review: Unraveling the Universe’s Mysteries

“Unraveling the Universe’s Mysteries” is Louis A. Del Monte’s contribution to the world of science writing. If you haven’t heard of him, don’t be surprised. He’s not a prolific author or researcher, but worked in the development of microelectronics for the US companies IBM and Honeywell before forming a high-tech e-marketing agency.

The book lives up to its title and long subtitle: “Explore sciences’ most baffling mysteries, including the Big Bang’s origin, time travel, dark energy, humankind’s fate, and more.” It covers string theory, the Big Bang, dark matter, dark energy, time travel, the existence of God, and other mysterious aspects of our Universe. Del Monte also discusses artificial intelligence, the end of the Universe, and the mysterious nature of light. These subjects have all been covered in great detail by other authors in other books. How does Del Monte’s treatment of these subjects stand up in comparison?

Not great, in my opinion. The writing is somehow uninviting. The book reads more like a textbook or a lecture than it does a science book for an interested audience. It’s somewhat dry, and the writing is kind of heavy. After looking into Del Monte’s background, it becomes clear why. He’s an engineer, and his background is in writing technical papers.

This book is a bit of a puzzle, as is the author himself. I’ve mentioned the problems with the writing, but there are other issues. In one instance Del Monte references a study from the Journal of Cosmology. If you haven’t heard of that journal, it’s come under heavy criticism for its peer-review process, and isn’t highly regarded in science circles. The Journal of Cosmology seems to be a journal for people with an axe to grind around certain issues more than a healthy part of the science journal community. To be quoting studies from it is a bit of a black mark, in my opinion.

In another instance, he opens the chapter on Advanced Aliens with a quote from “Chariot of the Gods”, that old book/documentary from the 1970’s that just won’t seem to die, no matter how discredited it is. The main thrust of “Chariot of the Gods” is that human civilisation got a technological boost from visitations by advanced aliens. Readers can judge for themselves the wisdom of quoting “Chariot of the Gods” in a science book.

The publisher bills the book as “a new theory to explain one of cosmology’s most profound mysteries, the accelerated expansion of the universe,” and that Del Monte “presents an original solution to Einstein’s equations of special relativity.” But without conducting peer reviewed research, the validity of his theory comes into question.

If I seem puzzled by this book, it’s because I am. Del Monte seems to be a bit of an outsider when it comes to writing about astronomy and cosmology. He has no background in it. There’s nothing wrong with that in principle; there’s always room for new perspectives in science. But I can’t help thinking that he could’ve benefited from working more closely with an experienced editor.

Readers will get something out of this book; it’s an interesting discussion of the mysterious aspects of our Universe. But it’s also a somewhat strange book. For those of you who decide to read it, you’re in for an interesting read.

For more information about Louis Del Monte, see his website.

December 11, 2012December 23, 2015 by Nancy Atkinson

Stephen Hawking and CERN LHC Team Each Win $3 Million Prize

Stephen Hawking visited the Large Hadron Collider’s underground tunnel at Europe’s CERN particle physics research center in 2006. Hawking and seven CERN researchers receiving multimillion-dollar prizes from the Fundamental Physics Prize Foundation. Image credit: CERN

Two $3,000,000 special physics prizes have been awarded to Stephen Hawking and to seven scientists who led the effort to discover a Higgs-like particle at CERN’s Large Hadron Collider. The Fundamental Physics Prize Foundation, backed by Russian billionaire Yuri Milner announced the awards today, saying that Hawking is honored for his discovery of Hawking radiation from black holes “and his deep contributions to quantum gravity and quantum aspects of the early universe,” and that the prize money for the European Organization for Nuclear Research, or CERN, is being shared among a scientist who administered the building of the $10 billion Large Hadron Collider and six physicists who directed two teams of 3,000 scientists each.

The $3 million Fundamental Physics Prize is awarded annually by the nonprofit Fundamental Physics Prize Foundation to recognize “transformative advances in the field.” The $3 million prize may also be given at any time outside the formal nomination process “in exceptional cases,” according to the Foundation. When the Foundation’s prize intentions were announced in July of this year, Milner said, “I hope the new prize will bring long overdue recognition to the greatest minds working in the field of fundamental physics, and if this helps encourage young people to be inspired by science, I will be deeply gratified.”

The Foundation said the seven were being honored “for their leadership role in the scientific endeavor that led to the discovery of the new Higgs-like particle by the ATLAS and CMS collaborations at CERN’s Large Hadron Collider.” They will share the $3 million prize equally.

The laureates include Lyn Evans, a Welsh scientist who serves as the LHC’s project leader; Peter Jenni amd Fabiola Gianotti of the LHC’s ATLAS collaboration; and Michel Della Negra, Tejinder Singh Virdee, Guido Tonelli and Joe Incandela of the CMS collaboration.

“It is a great honour for the LHC’s achievement to be recognised in this way,” said CERN Director General Rolf Heuer in a statement. “This prize recognizes the work of everyone who has contributed to the project over many years. The Fundamental Physics Prize underlines the value of fundamental physics to society, and I am delighted that the Foundation has chosen to hold its first award ceremony at CERN.”

“I am very much pleased with the decisions of the Selection Committee,” commented Yuri Milner. “I hope that the prizes will bring further recognition to some of the most brilliant minds in the world and the great accomplishments they have produced.”

“Choosing this year’s recipients from such a large pool of spectacular nominations was a very difficult task,” said Nima Arkani-Hamed, a member of the Selection Committee. “The selected physicists have done transformative work spanning a wide range of areas in fundamental physics. I especially look forward to future breakthroughs from the first recipients of the New Horizons in Physics Prize.”

The laureates of 2013 New Horizons in Physics Prize are:

Niklas Beisert for the development of powerful exact methods to describe a quantum gauge theory and its associated string theory;

Davide Gaiotto for far-reaching new insights about duality, gauge theory, and geometry, and especially for his work linking theories in different dimensions in most unexpected ways;

Zohar Komargodski for his work on the dynamics of four-dimensional field theories. In particular, his proof of the “a-theorem” has solved a long-standing problem, leading to deep new insights.

Each of the laureates will receive $100,000.

Sources: Fundamental Physics Prize Foundation, IOP, CERN

December 7, 2012April 26, 2016 by Jason Major

Do We Really Need Dark Matter?

Hubble mosaic of massive galaxy cluster MACS J0717.5+3745, thought to be connected by a filament of dark matter. Credit: NASA, ESA, Harald Ebeling (University of Hawaii at Manoa) & Jean-Paul Kneib (LAM)

Even though teams of scientists around the world are at this very moment hot on the trail of dark matter — the “other stuff” that the Universe is made of and supposedly accounts for nearly 80% of the mass that we can’t directly observe (yet) — and trying to quantify exactly how so-called “dark energy” drives its ever-accelerating expansion, perhaps one answer to these ongoing mysteries is maybe they don’t exist at all.

This is precisely what one astronomer is suggesting in a recent paper, submitted Dec. 3 to Astrophysical Journal Letters.

In a paper titled “An expanding universe without dark matter and dark energy” (arXiv:1212.1110) Pierre Magain, a professor at Belgium’s Institut d’Astrophysique et de Géophysique, proposes that the expansion of the Universe could be explained without the need for enigmatic material and energy that, to date, has yet to be directly measured.

In addition, Magain’s proposal puts a higher age to the Universe than what’s currently accepted. With a model that shows a slower expansion rate during the early Universe than today, Magain’s calculations estimate its age to be closer to 15.4 – 16.5 billion years old, adding a couple billion more candles to the cosmic birthday cake.

The benefit to a slightly older Universe, Magain posits, is that it’s not so uncannily close to the apparent age of the most distant galaxies recently found — such as MACS0647-JD, which is 13.3 billion light-years away and thus (based on current estimates, see graphic at right) must have formed when the Universe was a mere 420 million years old.

Using accepted physics of how time behaves based on Einstein’s theory of general relativity — namely, how the passage of time is relative to the position and velocity of the viewer (as well as the intensity of the gravitational field the viewer is within) — Magain’s model allows for an observer located within the Universe to potentially be experiencing a different rate of time than a hypothetical viewer located outside the Universe. Not to be so metaphysical as to presume that there are external observers of our Universe but merely to say that an external point would be a fixed one against which one could benchmark a varying passage of time inside the Universe, Magain calls this universal relativity.

A viewer experiencing universal relativity would, Magain claims, always measure the curvature of the Universe to be equal to zero. This is what’s currently observed, a “flatness problem” that Magain insinuates is strangely coincidental.

By attributing an expanding Universe to dark energy and the high velocities of stars along the edges of galaxies (as well as the motions of galaxy clusters themselves) to dark matter, we may be introducing ad hoc elements to the Universe, says Magain. Instead, he proposes his “more economical” model — which uses universal relativity — explains these apparently accelerating, increasingly expanding behaviors… and gives a bigger margin of time between the Big Bang and the formation of the first galactic structures.

There’s quite a bit of math involved, and since I never claimed to understand physics equations you can check out the original paper here.

While intriguing, the bottom line is that dark energy and dark matter have still managed to elude science, existing just outside the borders of what can be observed (although the gravitational lensing effects of what’s thought to be dark matter filaments have been observed by Hubble) and Magain’s paper is merely putting another idea onto the table — one that, while he recognizes needs further testing and relies upon very specific singular parameters, doesn’t depend upon invisible, unobservable and mysteriously dark “stuff”. Whether it belongs on the table or not will be up to other astrophysicists to decide.

Prof. Magain’s research was supported by ESA and the Belgian Science Policy Office.

At right: Artist’s impression of dark matter (h/t to Steve Nerlich)

Note: this is “just” a submitted paper and has not been selected for publication yet. Any hypotheses proposed are those of the author and are not endorsed by this site. (Personally I like dark matter. It’s fascinating stuff… even if we can’t see it. Want an astrophysicist’s viewpoint on the existence of dark matter? Check out Ethan Siegel’s blog response here.)

December 4, 2012December 23, 2015 by Jason Major

The Brightest Galaxies in the Universe Were Invisible… Until Now

Hubble images of six of the starburst galaxies first found by ESA’s Herschel Space Observatory (Keck data shown below each in blue)

Many of the brightest, most actively star-forming galaxies in the Universe were actually undetectable by Earth-based observatories, hidden from view by thick clouds of opaque dust and gas. Thanks to ESA’s Herschel space observatory, which views the Universe in infrared, an enormous amount of these “starburst” galaxies have recently been uncovered, allowing astronomers to measure their distances with the twin telescopes of Hawaii’s W.M. Keck Observatory. What they found is quite surprising: at least 767 previously unknown galaxies, many of them generating new stars at incredible rates.

Although nearly invisible at optical wavelengths these newly-found galaxies shine brightly in far-infrared, making them visible to Herschel, which can peer through even the densest dust clouds. Once astronomers knew where the galaxies are located, they were able to target them with Hubble and, most importantly, the two 10-meter Keck telescopes — the two largest optical telescopes in the world.

By gathering literally hundreds of hours of spectral data on the galaxies with the Keck telescopes, estimates of their distances could be determined as well as their temperatures and how often new stars are born within them.

“While some of the galaxies are nearby, most are very distant; we even found galaxies that are so far that their light has taken 12 billion years to travel here, so we are seeing them when the Universe was only a ninth of its current age,” said Dr. Caitlin Casey, Hubble fellow at the UH Manoa Institute for Astronomy and lead scientist on the survey. “Now that we have a pretty good idea of how important this type of galaxy is in forming huge numbers of stars in the Universe, the next step is to figure out why and how they formed.”

A representation of the distribution of nearly 300 starbursts in one 1.4 x 1.4 degree field of view.

The galaxies, many of them observed as they were during the early stages of their formation, are producing new stars at a rate of 100 to 500 a year — with a mass equivalent of several thousand Suns — hence the moniker “starburst” galaxy. By comparison the Milky Way galaxy only births one or two Sun-mass stars per year.

The reason behind this explosion of star formation in these galaxies is unknown, but it’s thought that collisions between young galaxies may be the cause.

Another possibility is that galaxies had much more gas and dust during the early Universe, allowing for much higher star formation rates than what’s seen today.

“It’s a hotly debated topic that requires details on the shape and rotation of the galaxies before it can be resolved,” said Dr. Casey.

Still, the discovery of these “hidden” galaxies is a major step forward in understanding the evolution of star formation in the Universe.

“Our study confirms the importance of starburst galaxies in the cosmic history of star formation. Models that try to reproduce the formation and evolution of galaxies will have to take these results into account.”

– Dr. Caitlin Casey, Hubble fellow at the UH Manoa Institute for Astronomy

“For the first time, we have been able to measure distances, star formation rates, and temperatures for a brand new set of 767 previously unidentified galaxies,” said Dr. Scott Chapman, a co-author on the studies. “The previous similar survey of distant infrared starbursts only covered 73 galaxies. This is a huge improvement.”

The papers detailing the results were published today online in the Astrophysical Journal.

Sources: W.M. Keck Observatory article and ESA’s news release.

Image credits: ESA–C. Carreau/C. Casey (University of Hawai’i); COSMOS field: ESA/Herschel/SPIRE/HerMES Key Programme; Hubble images: NASA, ESA. Inset image courtesy W. M. Keck Observatory.

November 28, 2012January 4, 2016 by Nancy Atkinson

Does the Universe Have a Purpose?

An intersection of two of my favorite entities (Minute Physics and Neil deGrasse Tyson) now covers a topic that has been on my mind lately: does the Universe — and therefore humanity — have a purpose?

deGrasse Tyson was asked by the Templeton Foundation to answer this question and poses here that if there is a purpose, the cosmic environment has a strange way of showing it.

What do you think?

Continue reading “Does the Universe Have a Purpose?”

November 20, 2012December 23, 2015 by Jason Major

Hot Gas Bridge Discovered Connecting Galaxy Clusters

An “bridge” of hot gas stretches between galaxy clusters Abell 401 and Abell 399

It may not be good practice to burn bridges but this is one super-heated bridge that astronomers were happy to find: an enormous swath of hot gas connecting two galaxy clusters 10 million light-years apart, and nearly a billion light-years away.

Using ESA’s Planck space telescope, astronomers have identified leftover light from the Big Bang interacting with a filament of hot gas stretching between Abell 401 and Abell 399, two galactic clusters each containing hundreds of individual galaxies.

Launched in May 2009, Planck is designed to study the Cosmic Microwave Background (CMB) — the leftover light from the Big Bang. When this radiation interacts with large-scale cosmic structures, like the hot gas bridging clusters of galaxies, its energy is modified in a specific way. This is referred to as the Sunyaev–Zel’dovich Effect (SZE), and Planck is specifically attuned to finding it.

This, however, is Planck’s first discovery of inter-cluster gas found using the SZ technique.

The temperature of the gas is estimated to be around 80 million degrees C, similar to the temperature of the gas found within the clusters themselves. It’s thought that the gas may be a combination of cosmic web filaments left over from the early Universe mixed with gas from the clusters.

The image above shows the clusters Abell 401 and Abell 399 as seen at optical wavelengths with ground-based telescopes overlaid with the SZE from Planck. The entire bridge spans a distance about the size of two full Moons in the sky.

Book Review: About Time: Cosmology and Culture at the Twilight of the Big Bang

When introducing his book “About Time: Cosmology and Culture at the Twilight of the Big Bang,” author Adam Frank tells us that he is setting out to “unfold the grandest conception of the universe we human beings have been able to imagine and explore. At the same time embracing our most intimate and most personal experience of the world — the very frame of human life.”

“This book is about time, both cosmic and human.”

For those interested in the complex journey of humanity through the cosmos, Frank does not fail in his quest to unravel the unique web of ‘time’ into a thread of understandable science. That is, if you can take a partially solved puzzle and write a book that connects the proverbial dots of known science and cultural anthropology with the partially understood theories of cosmology and related sciences.

Mission accomplished by Frank.

Upon first receiving this book, I was hopeful that Frank would present the material of thousands of years of science in a unique and interesting way; setting his writing apart from the hundreds of other astronomy books I’ve read. Frank, being a seasoned writer and astrophysics professor, did not disappoint. Frank takes you on a conversational journey, filled with real life examples, both personal and historical, to share his view of some of the most multifarious ideas being considered in our galaxy today.

The first few chapters are a review of compound science related to our galaxy, but Frank quickly dives into a discussion of how culture has been affected by the world around it. From there Frank draws a picture from intricate ideas and theories of how society fits in the larger puzzle of cosmology. All while focusing on the measurement of time.

If you are looking to take your perspective of cosmology to a new and deeper level, allow Adam Frank to steal some of your time and read his book “About Time”. Frank will surely have you viewing your society, history, and clock in a whole new perspective. Not to mention putting you on the forefront of scientific theories and cultural progress being considered in the world of cosmology.

Adam Frank is Professor of Astrophysics at the University of Rochester and a regular contributor to Discover and Astronomy magazines, and is the co-founder of National Public Radio’s popular 13:7 Cosmos & Culture blog. He won an American Astronomical Society Prize for his scientific writing. His first book was The Constant Fire: Beyond the Science vs. Religion Debate.