Cosmology Archives

August 28, 2014December 23, 2015 by Shannon Hall

What Lit up the Universe? Astronomers May be on the Brink of an Answer

A computer model shows one scenario for how light is spread through the early universe on vast scales (more than 50 million light years across). Astronomers will soon know whether or not these kinds of computer models give an accurate portrayal of light in the real cosmos. Credit: Andrew Pontzen/Fabio Governato

Most scientists can see, hear, smell, touch or even taste their research. But astronomers can only study light — photons traveling billions of light-years across the cosmos before getting scooped up by an array of radio dishes or a single parabolic mirror orbiting the Earth.

Luckily the universe is overflowing with photons across a spectrum of energies and wavelengths. But astronomers don’t fully understand where most of the light, especially in the early universe, originates.

Now, new simulations hope to uncover the origin of the ultraviolet light that bathes — and shapes — the early cosmos.

“Which produces more light? A country’s biggest cities or its many tiny towns?” asked lead author Andrew Pontzen in a press release. “Cities are brighter, but towns are far more numerous. Understanding the balance would tell you something about the organization of the country. We’re posing a similar question about the universe: does ultraviolet light come from numerous but faint galaxies, or from a smaller number of quasars?”

Answering this question will give us a valuable insight into the way the universe built its galaxies over time. It will also help astronomers calibrate their measurements of dark energy, the mysterious agent that is somehow accelerating the universe’s expansion.

The problem is that most of intergalactic space is impossible to see directly. But quasars — brilliant galactic centers fueled by black holes rapidly accreting material — shine brightly and illuminate otherwise invisible matter. Any intervening gas will absorb the quasar’s light and leave dark lines in the arriving spectrum.

“Because they can be seen at such great distances, quasars are a useful probe for finding out the properties of the universe,” said Pontzen. “Distant quasars can be used as a backlight, and the properties of the gas between them and us are imprinted on the light.

Multiple clouds of intervening hydrogen gas leave a “forest” of hydrogen absorption lines in the quasar’s spectrum. But, crucially, not all gas in the universe contributes to these dark lines. When hydrogen is bombarded by ultraviolet light, it becomes ionized — the electron separates from the proton — which renders it transparent.

So the pattern of absorption lines visible in a quasar’s spectrum map out the location of neutral and ionized regions in between the quasar and the Earth.

This pattern will tell astronomers the main contributing light source in the early universe. Quasars are fairly limited in number but individually extremely bright. If they caused most of the radiation, the pattern will be far from uniform, with some areas nearly transparent and others strongly opaque. But if galaxies, which are far more numerous but much dimmer, caused most of the radiation, the pattern will be very uniform, with evenly spaced absorption lines.

Current samples of quasars aren’t quite big enough for a robust analysis of the subtle differences between the two scenarios. But Pontzen and colleagues show that a number of new surveys should shed light on the question.

The team is hopeful the DESI (Dark Energy Spectroscopic Instrument) survey, which will look at about a million distant quasars in order to better understand dark energy, will also show the distribution of intervening gas.

“It’s amazing how little is known about the objects that bathed the universe in ultraviolet radiation while galaxies assembled into their present form,” said coauthor Hiranya Peiris. “This technique gives us a novel handle on the intergalactic environment during this critical time in the Universe’s history.”

The paper was published Aug. 27 in the Astrophysical Journal Letters and is available online.

August 15, 2014December 23, 2015 by Jason Chu

Parallel Universes and the Many-Worlds Theory

Are you unique? In your perception of the world, the answer is simple: you are different than every other person on this planet. But is our universe unique? The concept of multiple realities — or parallel universes — complicates this answer and challenges what we know about the world and ourselves. One model of potential multiple universes called the Many-Worlds Theory might sound so bizarre and unrealistic that it should be in science fiction movies and not in real life. However, there is no experiment that can irrefutably discredit its validity.

The origin of the parallel universe conjecture is closely connected with introduction of the idea of quantum mechanics in the early 1900s. Quantum mechanics, a branch of physics that studies the infinitesimal world, predicts the behavior of nanoscopic objects. Physicists had difficulties fitting a mathematical model to the behavior of quantum matter because some matter exhibited signs of both particle-like and wave-like movements. For example, the photon, a tiny bundle of light, can travel vertically up and down while moving horizontally forward or backward.

Such behavior starkly contrasts with that of objects visible to the naked eye; everything we see moves like either a wave or a particle. This theory of matter duality has been called the Heisenberg Uncertainty Principle (HUP), which states that the act of observation disturbs quantities like momentum and position.

In relation to quantum mechanics, this observer effect can impact the form – particle or wave – of quantum objects during measurements. Future quantum theories, like Niels Bohr’s Copenhagen interpretation, use HUP to state that an observed object does not retain its dual nature and can only behave in one state.

Multiverse Theory — Artist concept of the multiverse. Credit: Florida State University

In 1954, a young student at Princeton University named Hugh Everett proposed a radical supposition that differed from the popular models of quantum mechanics. Everett did not believe that observation causes quantum matter to stop behaving in multiple forms.

Instead, he argued that observation of quantum matter creates a split in the universe. In other words, the universe makes copies of itself to account for all the possibilities and these duplicates will proceed independently. Every time a photon is measured, for instance, a scientist in one universe will analyze it in wave form and the same scientist in another universe will analyze it in particle form. Each of these universes offers a unique and independent reality that coexists with other parallel universes.

If Everett’s Many-Worlds Theory (MWT) is true, it holds many ramifications that completely transform our perceptions on life. Any action that has more than one possible result produces a split in the universe. Thus, there are an infinite number of parallel universes and infinite copies of each person.

These copies have identical facial and body features, but do not have identical personalities (one may be aggressive and another may be passive) because each one experiences a separate outcome. The infinite number of alternate realities also suggests that nobody can achieve unique accomplishments. Every person – or some version of that person in a parallel universe – has done or will do everything.

Moreover, the MWT implies that everybody is immortal. Old age will no longer be a surefire killer, as some alternate realities could be so scientifically and technologically advanced that they have developed an anti-aging medicine. If you do die in one world, another version of you in another world will survive.

The most troubling implication of parallel universes is that your perception of the world is never real. Our “reality” at an exact moment in one parallel universe will be completely unlike that of another world; it is only a tiny figment of an infinite and absolute truth. You might believe you are reading this article at this instance, but there are many copies of you that are not reading. In fact, you are even the author of this article in some distant reality. Thus, do winning prizes and making decisions matter if we might lose those awards and make different choices? Is living important if we might actually be dead somewhere else?

Some scientists, like Austrian mathematician Hans Moravec, have tried to debunk the possibility of parallel universes. Moravec developed a famous experiment called quantum suicide in 1987 that connects a person to a fatal weapon and a machine that determines the spin value, or angular momentum, of protons. Every 10 seconds, the spin value, or quark, of a new proton is recorded.

Based on this measurement, the machine will cause the weapon to kill or spare the person with a 50 percent chance for each scenario. If the Many-World’s Theory is not true, then the experimenter’s survival probability decreases after every quark measurement until it essentially becomes zero (a fraction raised to a large exponent is a very small value). On the other hand, MWT argues that the experimenter always has a 100% chance of living in some parallel universe and he/she has encountered quantum immortality.

When the quark measurement is processed, there are two possibilities: the weapon can either fire or not fire. At this moment, MWT claims that the universe splits into two different universes to account for the two endings. The weapon will discharge in one reality, but not discharge in the other. For moral reasons, scientists cannot use Moravec’s experiment to disprove or corroborate the existence of parallel worlds, as the test subjects may only be dead in that particular reality and still alive in another parallel universe. In any case, the peculiar Many-World’s Theory and its startling implications challenges everything we know about the world.

Sources: Scientific American

August 12, 2014December 23, 2015 by Shannon Hall

How did Supermassive Black Holes Grow so Massive so Quickly?

Artist concept of matter swirling around a black hole. (NASA/Dana Berry/SkyWorks Digital)

Black holes one billion times the Sun’s mass or more lie at the heart of many galaxies, driving their evolution. Although common today, evidence of supermassive black holes existing since the infancy of the Universe, one billion years or so after the Big Bang, has puzzled astronomers for years.

How could these giants have grown so massive in the relatively short amount of time they had to form? A new study led by Tal Alexander from the Weizmann Institute of Science and Priyamvada Natarajn from Yale University, may provide a solution.

Black holes are often mistaken to be monstrous creatures that suck in dust and gas at an enormous rate. But this couldn’t be further from the truth (in fact the words “suck” and “black hole” in the same sentence makes me cringe). Although they typically accumulate bright accretion disks — swirling disks of gas and dust that make them visible across the observable Universe — these very disks actually limit the speed of growth.

First, as matter in an accretion disk gets close to the black hole, traffic jams occur that slow down any other infalling material. Second, as matter collides within these traffic jams, it heats up, generating energy radiation that actually drives gas and dust away from the black hole.

A star or a gas stream can actually be on a stable orbit around the black hole, much as a planet orbits around a star. So it is quite a challenge for astronomers to think of ways that would make a black hole grow to supermassive proportions.

Luckily, Alexander and Natarajan may have found a way to do this: by placing the black hole within a cluster of thousands of stars, they’re able to operate without the restrictions of an accretion disk.

Black holes are generally thought to form when massive stars, weighing tens of solar masses, explode after their nuclear fuel is spent. Without the nuclear furnace at its core pushing against gravity, the star collapses. While the inner layers fall inward to form a black hole of only about 10 solar masses, the outer layers fall faster, hitting the inner layers, and rebounding in a huge supernova explosion. At least that’s the simple version.

A small black hole gains mass: Dense cold gas (green) flows toward the center of a stellar cluster (red cross in blue circle) with stars (yellow); the erratic path of the black hole through the gas (black line) is randomized by the surrounding stars Prof. Tal Alexander’s research is supported by the European Research Council. — The erratic path of the black hole through the gas (black line) is randomized by the surrounding stars (yellow circles). Meanwhile, dense cold gas (green arrows) flows toward the center of the cluster (red cross). Credit: Weizmann Institute of Science.

The team began with a model of a black hole, created from this stellar blast, embedded within a cluster of thousands of stars. A continuous flow of dense, cold, opaque gas fell into the black hole. But here’s the trick: the gravitational pull of many nearby stars caused it to zigzag randomly, preventing it from forming an accretion disk.

Without an accretion disk, not only is matter more able to fall into the black hole from all sides, but it isn’t slowed down in the accretion disk itself.

All in all, the model suggests that a black hole 10 times the mass of the Sun could grow to more than 10 billion times the mass of the Sun by one billion years after the Big Bang.

The paper was published Aug. 7 in Science and is available online.

August 6, 2014December 23, 2015 by Nancy Atkinson

“Theory of Everything:” Trailer for Movie about Stephen Hawking Now Available

Still of Felicity Jones and Eddie Redmayne in 'The Theory of Everything.' Via IMBd and Focus Features.

Who says science and love (and science and the arts) don’t go together? A new movie set to premiere in November 2014 will feature the life story of physicist Stephen Hawking and focuses on his relationship with Jane Wilde, the art student he fell in love with while studying at Cambridge in the 1960s. “The Theory of Everything” also depicts Hawking’s genuius amid the diagnosis of a fatal illness at age 21 and how he has survived. From the movie blurb:

Little was expected from Stephen Hawking, a bright but shiftless student of cosmology, given just two years to live following the diagnosis of a fatal illness at 21 years of age. He became galvanized, however, by the love of fellow Cambridge student, Jane Wilde, and he went on to be called the successor to Einstein, as well as a husband and father to their three children. Over the course of their marriage as Stephen’s body collapsed and his academic renown soared, fault lines were exposed that tested the lineaments of their relationship and dramatically altered the course of both of their lives.

The movie stars Eddie Redmayne as Hawking and Felicity Jones as Jane, and is from Focus Films. See the full cast and info at IMBd.

July 10, 2014December 23, 2015 by Bob King

Merging Giant Galaxies Sport ‘Blue Bling’ in New Hubble Pic

In this new Hubble image shows two galaxies (yellow, center) from the cluster SDSS J1531+3414 have been found to be merging into one and a "chain" of young stellar super-clusters are seen winding around the galaxies'?? nuclei. The galaxies are surrounded by an egg-shaped blue ring caused by the immense gravity of the cluster bending light from other galaxies beyond it. Credit: NASA/ESA/Grant Tremblay

On a summer night, high above our heads, where the Northern Crown and Herdsman meet, a titanic new galaxy is being born 4.5 billion light years away. You and I can’t see it, but astronomers using the Hubble Space Telescope released photographs today showing the merger of two enormous elliptical galaxies into a future heavyweight adorned with a dazzling string of super-sized star clusters.

The two giants, each about 330,000 light years across or more than three times the size of the Milky Way, are members of a large cluster of galaxies called SDSS J1531+3414. They’ve strayed into each other’s paths and are now helpless against the attractive force of gravity which pulls them ever closer.

A few examples of merging galaxies. NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University), K. Noll (STScI), and J. Westphal (Caltech)

Galactic mergers are violent events that strip gas, dust and stars away from the galaxies involved and can alter their appearances dramatically, forming large gaseous tails, glowing rings, and warped galactic disks. Stars on the other hand, like so many pinpoints in relatively empty space, pass by one another and rarely collide.

Elliptical galaxies get their name from their oval and spheroidal shapes. They lack the spiral arms, rich reserves of dust and gas and pizza-like flatness that give spiral galaxies like Andromeda and the Milky Way their multi-faceted character. Ellipticals, although incredibly rich in stars and globular clusters, generally appear featureless.

The differences between elliptical and spiral galaxies is easy to see. M87 at left and M74, both photographed with the Hubble Space Telescope. Credit: NASA/ESA — The differences between elliptical and spiral galaxies is easy to see. M87 at left and M74, both photographed with the Hubble Space Telescope. What look like stars around M87 are really globular star clusters. Credit: NASA/ESA

But these two monster ellipticals appear to be different. Unlike their gas-starved brothers and sisters, they’re rich enough in the stuff needed to induce star formation. Take a look at that string of blue blobs stretching across the center – astronomers call it a great example of ‘beads on a string’ star formation. The knotted rope of gaseous filaments with bright patches of new star clusters stems from the same physics which causes rain or water from a faucet to fall in droplets instead of streams. In the case of water, surface tension makes water ‘snap’ into individual droplets; with clouds of galactic gas, gravity is the great congealer.

Close up of the two elliptical galaxies undergoing a merger. The blue blobs are giant star clusters forming from gas colliding and collapsing into stars during the merger. Click for the scientific paper on the topic. Credit: NASA/ESA/Grant Tremblay — Close up of the two elliptical galaxies undergoing a merger. The blue blobs are giant star clusters forming from gas colliding and collapsing into stars during the merger. Click to read the scientific paper on the topic. Credit: NASA/ESA/Grant Tremblay

Nineteen compact clumps of young stars make up the length of this ‘string’, woven together with narrow filaments of hydrogen gas. The star formation spans 100,000 light years, about the size of our galaxy, the Milky Way. Astronomers still aren’t sure if the gas comes directly from the galaxies or has condensed like rain from X-ray-hot halos of gas surrounding both giants.

The blue arcs framing the merger have to do with the galaxy cluster’s enormous gravity, which warps the fabric of space like a lens, bending and focusing the light of more distant background galaxies into curvy strands of blue light. Each represents a highly distorted image of a real object.

Simulation of the Milky Way-Andromeda collision 4 billion years from now

Four billion years from now, Milky Way residents will experience a merger of our own when the Andromeda Galaxy, which has been heading our direction at 300,000 mph for millions of years, arrives on our doorstep. After a few do-si-dos the two galaxies will swallow one another up to form a much larger whirling dervish that some have already dubbed ‘Milkomeda’. Come that day, perhaps our combined galaxies will don a string a blue pearls too.

June 26, 2014December 23, 2015 by Tim Reyes

Has the Cosmology Standard Model become a Rube Goldberg Device?

Artists illustration of the expansion of the Universe (Credit: NASA, Goddard Space Flight Center)

This week at the Royal Astronomical Society’s National Astronomy Meeting in the UK, physicists are challenging the evidence for the recent BICEP2 results regarding the inflation period of the Universe, announced just 90 days ago. New research is laying doubt upon the inclusion of inflation theory in the Standard Cosmological Model for understanding the forces of nature, the nature of elementary particles and the present state of the known Universe.

Back on March 17, 2014, it seemed the World was offered a glimpse of an ultimate order from eons ago … actually from the beginning of time. BICEP2, the single purpose machine at the South Pole delivered an image that after analysis, and subtraction of estimated background signal from the Milky Way, lead its researchers to conclude that they had found the earliest remnant from the birth of the Universe, a signature in ancient light that supported the theory of Inflation.

BICEP2 Telescope at twilight at the South Pole, Antartica (Credit: Steffen Richter, Harvard University) — BICEP2 Telescope at twilight at the South Pole, Antarctica (Credit: Steffen Richter, Harvard University)

Thirty years ago, the Inflation theory was conceived by physicists Alan Guth and Andei Linde. Guth, Linde and others realized that a sudden expansion of the Universe at only 1/1000000000000000000000000000000000th of a second after the Big Bang could solve some puzzling mysteries of the Cosmos. Inflation could explain the uniformity of the cosmic background radiation. While images such as from the COBE satellite show a blotchy distribution of radiation, in actuality, these images accentuate extremely small variations in the background radiation, remnants from the Big Bang, variations on the order of 1/100,000th of the background level.

Note that the time of the Universe’s proposed Inflationary period immediately after the Big Bang would today permit light to travel only 1/1000000000000000th of the diameter of the Hydrogen atom. The Universe during this first moment of expansion was encapsulated in a volume far smaller than the a single atom.

Emotions ran very high when the BICEP2 team announced their findings on March 17 of this year. The inflation event that the background radiation data supported is described as a supercooling of the Cosmos however, there were physicists that simply remained cool and remained contrarians to the theory. Noted British Physicist Sir Roger Primrose was one who remained underwhelmed and stated that the incredible circular polarization of light that remained in the processed data from BICEP2 could be explained by the interaction of dust, light and magnetic fields in our own neighborhood, the Milky Way.

Illustration of the ESA Planck Telescope in Earth orbit (Credit: ESA)

Now, new observations from another detector, one on the Planck Satellite orbiting the Earth, is revealing that the contribution of background radiation from local sources, the dust in the Milky Way, is appearing to have been under-estimated by the BICEP2 team. All the evidence is not yet laid out but the researchers are now showing reservations. At the same time, it does not dismiss the Inflation Theory. It means that more observations are needed and probably with greater sensitivity.

So why ask the question, are physicists constructing a Rube Goldberg device?

Our present understanding of the Universe stands upon what is called “the Standard Model” of Cosmology. At the Royal Astronomical Society meeting this week, the discussions underfoot could be revealing a Standard Model possibly in a state of collapse or simply needing new gadgets and mechanisms to remain the best theory of everything.

Also this week, new data further supports the discovery of the Higg’s Boson by the Large Hadron Collider in 2012, the elementary particle whose existence explains the mass of fundamental particles in nature and that supports the existence of the Higgs Field vital to robustness of the Standard Model. However, the Higgs related data is also revealing that if the inflationary period of the Universe did take place, then if taken with the Standard Model, one can conclude that the Universe should have collapsed upon itself and our very existence today would not be possible.

A Rube Goldberg Toothpaste dispenser as also the state of the Standard Model (Credit: R.Goldberg)

Dr. Brian Green, a researcher in the field of Super String Theory and M-Theory and others such as Dr. Stephen Hawking, are quick to state that the Standard Model is an intermediary step towards a Grand Unified Theory of everything, the Universe. The contortion of the Standard Model, into a sort of Rube Goldberg device can be explained by the undaunting accumulation of more acute and diverse observations at cosmic and quantum scales.

Discussions at the Royal Astronomical Society meeting are laying more doubts upon the inflation theory which just 90 days ago appeared so well supported by BICEP2 – data derived by truly remarkable cutting edge electronics developed by NASA and researchers at the California Institute of Technology. The trials and tribulations of these great theories to explain everything harken back to the period just prior to Einstein’s Miracle Year, 1905. Fragmented theories explaining separately the forces of nature were present but also the accumulation of observational data had reached a flash point.

Today, observations from BICEP2, NASA and ESA great space observatories, sensitive instruments buried miles underground and carefully contrived quantum experiments in laboratories are making the Standard Model more stressed in explaining everything, the same model so well supported by the Higg’s Boson discovery just two years ago. Cosmologists concede that we may never have a complete, proven theory of everything, one that is elegant; however, the challenges upon the Standard Model and inflation will surely embolden younger theorists to double the efforts in other theoretical work.

For further reading:
RAS NAM press release: Should the Higgs Boson Have Caused our Universe To Collapse?
We’ve Discovered Inflation!: Now What?
Cosmologists Cast Doubt on Inflation Evidence
Are the BICEP2 Results Invalid? Probably Not

June 4, 2014December 23, 2015 by Elizabeth Howell

Move Over, Gravity: Black Hole Magnetic Fields May Have Powerful Pull

Artist rendering of a supermassive black hole. Credit: NASA / JPL-Caltech.

It’s oft-repeated that black holes are powerful gravity wells, because they represent a dense concentration of matter in one location. But what about their magnetic fields? A new study suggests that this force could be at least as strong as gravity in supermassive black holes, the singularities that lurk in the center of many galaxies.

Simulations of magnetic fields of gas falling into these beasts suggest that this action — if the gas carries a magnetic field — makes the field stronger until it equals gravity.

Magnetic fields can affect properties such as how luminous black holes appear (in radio) and how powerful the jets emanating from the singularity are. The scientists speculate that when you see bright jets from a black hole, this could imply a strong magnetic field indeed.

A computer simulation of gas (yellow) falling into a black hole, and jets emanating from the singularity. Credit: Alexander Tchekhovskoy (LBNL)

“Surprisingly, the magnetic field strength around these exotic objects is comparable to the magnetic field produced in something more familiar: a magnetic resonance imaging (MRI) machine that you can find in your local hospital,” the Max Planck Institute for Radio Astronomy stated.

“Both supermassive black holes and MRI machines produce magnetic fields that are roughly 10,000 times stronger than the Earth’s surface magnetic field, which is what guides an ordinary compass.”

New information on how strong the magnetic fields was based on recent work with the Very Long Baseline Array, a networked group of radio telescopes in the United States. Specifically, the information came from a program named MOJAVE (Monitoring Of Jets in Active galactic nuclei with VLBA Experiments) that looks at jets around several hundred supermassive black holes.

The researchers emphasized that more observational research will be needed to supplement the simulations. The work will be published today in Nature. Leading the research was Mohammad Zamaninasab, a past researcher at Max Planck.

Source: Max Planck Institute for Radio Astronomy

May 19, 2014December 23, 2015 by Brian Koberlein

Are the BICEP2 Results Invalid? Probably Not.

Galactic radio loops, with BICEP2 region indicated. Credit: Philipp Mertsch

Recently rumors have been flying that the BICEP2 results regarding the cosmic inflationary period may be invalid. It all started with a post by Dan Falkowski on his blog Resonaances, where he claimed that the BICEP2 had misinterpreted some data, which rendered their results invalid, or at least questionable. The story was then picked up by Nature’s Blog and elsewhere, which has sparked some heated debate.

So what’s really going on?

For those who might not remember, BICEP2 is a project working to detect polarized light within the cosmic microwave background (CMB). Specifically they were looking for a type of polarization known as B-mode polarization. Detection of B-mode polarization is important because one mechanism for it is cosmic inflation in the early universe, which is exactly what BICEP2 claimed to have evidence of.

Part of the reason BICEP2 got so much press is because B-mode polarization is particularly difficult to detect. It is a small signal, and you have to filter through a great deal of observational data to be sure that your result is valid. But you also have to worry about other sources that look like B-mode polarization, and if you don’t account for them properly, then you could get a “false positive.” That’s where this latest drama arises.

In general this challenge is sometimes called the foreground problem. Basically, the cosmic microwave background is the most distant light we can observe. All the galaxies, dust, interstellar plasma and our own galaxy is between us and the CMB. So to make sure that the data you gather is really from the CMB, you have to account for all the stuff in the way (the foreground). We have ways of doing this, but it is difficult. The big challenge is to account for everything.

A map of foreground polarization from the Milky Way. Credit: ESA and the Planck Collaboration

Soon after the BICEP2 results, another team noted a foreground effect that could effect the BICEP2 results. It involves an effect known as radio loops, where dust particles trapped in interstellar magnetic fields can emit polarized light similar to B-mode polarization. How much of an effect this might have is unclear. Another project being done with the Planck satellite is also looking at this foreground effect, and has released some initial results (seen in the figure), but hasn’t yet released the actual data yet.

Now it has come to light that BICEP2 did, in fact, take some of this foreground polarization into account, in part using results from Planck. But since the raw data hadn’t been released, the team used data taken from a PDF slide of Planck results and basically reverse-engineered the Planck data. It is sometimes referred to as “data scraping”, and it isn’t ideal, but it works moderately well. Now there is some debate as to whether that slide presented the real foreground polarization or some averaged polarization. If it is the latter, then the BICEP2 results may have underestimated the foreground effect. Does this mean the BICEP2 results are completely invalid? Given what I’ve seen so far, I don’t think it does. Keep in mind that the Planck foreground is one of several foreground effects that BICEP2 did account for. It could be a large error, but it could also be a rather minor one.

The important thing to keep in mind is that the BICEP2 paper is still undergoing peer review. Critical analysis of the paper is exactly what should happen, and is happening. This type review used to be confined to the ivory towers, but with social media it now happens in the open. This is how science is done. BICEP2 has made a bold claim, and now everyone gets to whack at them like a piñata.

The BICEP2 team stands by their work, and so we’ll have to see whether it holds up to peer review. We’ll also have to wait for the Planck team to release their results on B-mode polarization. Eventually the dust will settle and we’ll have a much better handle on the results.

May 5, 2014December 23, 2015 by Shannon Hall

Unprecedented Images of the Intergalactic Medium

Comparison of Lyman alpha blob observed with Cosmic Web Imager and a simulation of the cosmic web based on theoretical predictions. Credit: Christopher Martin, Robert Hurt - See more at: http://www.caltech.edu/content/intergalactic-medium-unveiled-caltechs-cosmic-web-imager-directly-observes-dim-matter#sthash.3bs0Xl3d.dpuf

An international team of astronomers has taken unprecedented images of intergalactic space — the diffuse and often invisible gas that connects and feeds galaxies throughout the Universe.

Until now, the structure of intergalactic space has mostly been a matter for theoretical speculation. Advanced computer simulations predict that primordial gas from the Big Bang is distributed in a vast cosmic web — a network of filaments that span galaxies and flow between them.

This vast network is impossible to see alone. In the past astronomers have looked at distant quasars — supermassive black holes at the centers of galaxies which are rapidly accreting material and shining brightly — to indicate the otherwise invisible matter along their lines of sight.

While distant quasars may reveal the otherwise invisible gas, there’s no information about how that gas is distributed across space. New images, however, from the Cosmic Web Imager are revealing the webs’ filaments directly, allowing them to be seen across space.

The first filaments observed by the Cosmic Web Imager are in the vicinity of two ancient but bright objects: the quasar QSO 1549+19 and a so-called Lyman alpha blob (yes, this is a technical term for a huge concentration of hydrogen gas) in the emerging galaxy cluster SSA22. These objects are bright, lighting up the intervening galactic space and boosting the detectable signal.

Image of quasar (QSO 1549+19) taken with Caltech's Cosmic Web Imager, showing surrounding gas (in blue) and direction of filamentary gas inflow. Credit: Christopher Martin, Robert Hurt - See more at: http://www.caltech.edu/content/intergalactic-medium-unveiled-caltechs-cosmic-web-imager-directly-observes-dim-matter#sthash.3bs0Xl3d.dpuf — Image of quasar (QSO 1549+19) taken with Caltech’s Cosmic Web Imager, showing surrounding gas (in blue) and direction of filamentary gas inflow.
Image Credit: Christopher Martin, Robert Hurt

Both objects date back to two billion years after the Big Bang, in a time of rapid star formation in galaxies. Observations show a narrow filament, about one million light-years across flowing into the quasar, which is likely fueling the growth of the host galaxy.

There are three filaments flowing into the Lyman alpha blob. “I think we’re looking at a giant protogalactic disk,” said lead author Christopher Martin from the California Institute of Technology in a press release. “It’s almost 300,000 light-years in diameter, three times the size of the Milky Way.”

The Cosmic Web Imager on board the Hale 200 inch telescope is a spectrographic imager, taking pictures at many different wavelengths simultaneously. This allows astronomers to learn about objects’ composition, mass and velocity.

“The gaseous filaments and structures we see around the quasar and the Lyman alpha blob are unusually bright,” said Martin. “Our goal is to eventually be able to see the average intergalactic medium everywhere. It’s harder, but we’ll get there.”

Both papers (“Intergalactic Medium Observations with the Cosmic Web Imager: I. The Circum-QSO Medium of QSO 1549+19 and Evidence for a Filamentary Gas Inflow” and “Intergalactic Medium Observations with the Cosmic Web Imager: II. Discovery of Extended, Kinematically-linked Emission around SSA22 Ly-alpha Blob 2”) have been published in the Astrophysical Journal.

April 24, 2014December 23, 2015 by Shannon Hall

Why Inflation Didn’t Get the Same Hype as the Higgs

Shown here are the actual B-mode polarization patterns provided by the BICEP2 Telescope. Image Credit: Harvard-Smithsonian Center for Astrophysics

Last month astronomers provided evidence that the universe underwent a brief but stupendous expansion at the very beginning of time. It was a landmark discovery. And while the media worldwide gleamed with fantastical headlines, I’m left overwhelmed with the feeling that it didn’t quite get the spotlight it deserves.

The day of the announcement was ablaze with excitement. When I first started to cover the news, I told my mother I was writing on something that was bigger than the Higgs boson. That was the best way I could explain the significance of this monumental discovery to someone with very little physics knowledge in a text message.

But inflation didn’t get the same hype as the Higgs. Why?

Scientific results are mostly tangible. The Higgs boson was created in a 27-kilometer ring of superconducting magnets designed to boost the energy of particles — marking the world’s largest and most powerful particle accelerator. There’s something about this experiment that we can wrap our minds around, even when the particle itself remains elusive. The $10 billion effort has 6,000 researchers working hard to control the system.

But we can’t control the universe. We can’t ask two galaxies to collide; We can’t speed up stellar evolution; And we can’t pull a nearby star a little closer to take a peek at its circling exoplanet. Instead we stand on our cosmic platform and wait for the light from various happenings to reach us. Once it does, we dig through that light — collecting photons in different filters or spreading them across a spectrum of wavelengths — reaping every last bit of knowledge possible.

Astronomical research is complex and abstract. But it’s what we love about it.

The vast cosmic arena — with its unimaginable vistas of time and space — is laid out in the small specks of light on the celestial sphere. By collecting this light we have placed ourselves within the cosmos. We know the universe began with the Big Bang nearly 13.8 billion years ago. We know that dark matter binds massive galaxy clusters together and that dark energy is causing the universe to accelerate rapidly. It’s truly phenomenal that so much can be learned from the study of light.

Still, there’s a fundamental difference between observing the direct light emitted from distant stars and galaxies and observing a slight polarization pattern on the cosmic microwave background — the radiation released 380,000 years after the Big Bang when photons were able to travel freely across the cosmos.

The result threw open a new window on the birth of the universe. To be more precise, it let us peer back at the moment that took place a mere trillionth of a trillionth of a trillionth of a second after the Big Bang. But it takes so many steps (potentially as many steps as seconds from then until now) to grasp this hazy and mind-boggling concept. It will stretch your ideas of space and time to their limits.

Not only does this result succeed in showing the universe in its infancy, explaining the origin of cosmic structure and providing evidence for the last untested prediction of Albert Einstein’s General Theory of Relativity (gravity comes in discrete packets like light), but it makes an even wilder prediction.

The model likely produces not just one universe, but rather an ensemble of universes: an endless series of big bangs that continue to pop up eternally. Our universe may just be one bubble out of a vast cosmic ocean of others.

Astronomy is moving further toward the abstract. Both in how we collect data and the scientific results we carefully and slowly unearth from that data.

I find this awe-inspiring. But while astronomers are finding ingenious and creative methods to further understand the phenomenal universe in which we live, science journalists and educators are going to have to follow suit. We need to act not as translators but as guides who map scientific knowledge, finding paths through vast amounts of abstract information and analyzing key points along the way. Only then will inflation trump the Higgs and the abstract become tangible.

But honestly I’m still ruminating on this question so all additional thoughts are welcome.