Is the Big Bang in the Bible?

[Buster's Uncle]

Universe Shouldn't Be Here, According to Higgs Physics
LiveScience.com
By Tia Ghose, Staff Writer  19 hours ago



The BICEP2 telescope in Antarctica, seen at twilight.



The universe shouldn't exist — at least according to a new theory.

Modeling of conditions soon after the Big Bang suggests the universe should have collapsed just microseconds after its explosive birth, the new study suggests.

"During the early universe, we expected cosmic inflation — this is a rapid expansion of the universe right after the Big Bang," said study co-author Robert Hogan, a doctoral candidate in physics at King's College in London. "This expansion causes lots of stuff to shake around, and if we shake it too much, we could go into this new energy space, which could cause the universe to collapse."

Physicists draw that conclusion from a model that accounts for the properties of the newly discovered Higgs boson particle, which is thought to explain how other particles get their mass; faint traces of gravitational waves formed at the universe's origin also inform the conclusion.

Of course, there must be something missing from these calculations.

"We are here talking about it," Hogan told Live Science. "That means we have to extend our theories to explain why this didn't happen."


Bang!

One possible explanation holds that during the fiery flash after the primordial Big Bang explosion, matter raced outward at breakneck speeds in a process known as cosmic inflation. This bent and squeezed space-time, creating ripples known as gravitational waves that also twisted the radiation that passed through the universe, Hogan said.

Though those events would have occurred 13.8 billion years ago, a telescope at the South Pole known as the Background Imaging of Cosmic Extragalactic Polarization (BICEP2) recently detected the faint traces of cosmic inflation in the background microwave radiation that pervades the universe: in particular, characteristic twisted or curled waves called the B-mode pattern. (Other scientists have already begun to question the findings, saying the results may just be from dust in the Milky Way.)

But gravity wasn't the only force at play in the early universe. A ubiquitous energy field, called the Higgs field, permeates the universe and gives mass to the particles that trudge through the field. Scientists found the telltale sign of that field in 2012, when they discovered the Higgs boson and then determined its mass.

With a greater understanding of cosmic inflation's properties and the Higgs boson mass, Hogan and his colleague, Malcolm Fairbairn, who is also a physicist at King's College London, tried to recreate the conditions of cosmic inflation after the Big Bang.

What they found was bad news for, well, everything. The newborn universe should have experienced an intense jittering in the energy field, known as quantum fluctuation. Those jitters, in turn, could have disrupted the Higgs field, in essence rolling the entire system into a much lower energy state that would make the collapse of the universe inevitable.


Missing ingredient

So if the universe shouldn't exist, why is it here?

"The generic expectation is that there must be some new physics that we haven't put in our theories yet, because we haven't been able to discover them," Hogan said.

One leading possibility, known as the theory of supersymmetry, proposes that there are superpartner particles for all the currently known particles, and perhaps more-powerful particle accelerators could find these particles, Hogan said.

But the theory of cosmic inflation is still speculative, and some physicists hint that what looked like primordial gravitational waves to the BICEP2 telescope may actually be signals from cosmic dust in the galaxy, said Sean Carroll, a physicist at the California Institute of Technology and author of "The Particle at the End of the Universe: How the Hunt for the Higgs Boson Leads Us to the Edge of a New World" (Dutton Adult, 2012).

If the details of cosmic inflation change, then Hogan and Fairbairn's model would need to adapt as well, Carroll told Live Science. Caroll was not involved in the study.

Interestingly, this isn't the first time that physicists have said the Higgs boson spells doom for the universe. Others have calculated that the Higgs boson's mass would lead to a fundamentally unstable universe that could end apocalyptically in billions of years.

The mass of the Higgs boson, about 126 times that of the proton, turns out to be "right on the edge," in terms of the universe's stability, Carroll said. A little bit lighter, and the Higgs field would be much more easily perturbed; a little heavier, and the current Higgs field would be incredibly stable.

Hogan will present his findings Tuesday (June 24) at the Royal Astronomical Society meeting in Portsmouth, England, and the study was published May 20 in the journal Physical Review Letters.

http://news.yahoo.com/universe-shouldnt-according-higgs-physics-220219618.html

[Buster's Uncle]

Higgs quest deepens into realm of 'New Physics'
AFP
By Mariette Le Roux  13 hours ago



A worker walks past equipment at CERN's Large Hadron Collider, during maintenance works on July 19, 2013 in Meyrin, near Geneva (AFP Photo/Fabrice Coffrini)



Paris (AFP) - Two years after making history by unearthing the Higgs boson, the particle that confers mass, physicists are broadening their probe into its identity, hoping this will also solve other great cosmic mysteries.

Sifting through mountains of experimental data, they have now pieced together a partial sketch of the evasive boson's traits and behaviour.

But, some of them admit to be puzzled.

The better they become acquainted with the Higgs at the infinitely small quantum level, the further the experts seem from explaining certain cosmic-scale questions, like dark matter.

"The observed characteristics of the Higgs boson, such as its mass, interaction strengths and life-time, provide very powerful constraints on our understanding of the more fundamental theory," Valya Khoze, director of the Institute for Particle Physics Phenomenology (IPPP) at Durham University, told AFP.

From next year, scientists will smash sub-atomic particles at ever higher-speeds in the upgraded Large Hadron Collider (LHC) near Geneva, which announced the Higgs discovery on July 4, 2012.

Not only will they hope for new particles to emerge, but also for the Higgs to show signs of, well, weirdness.

So far, the Higgs has conformed well to the traits predicted in the Standard Model of particle physics, the mainstream theory of how our Universe is constructed.

Too well, for some.

The model has weaknesses in that it doesn't explain dark matter or dark energy, which jointly make up 95 percent of the Universe. Nor is it compatible with the theory of gravity.

Scientists have proposed alternative theories to explain the inconsistencies -- like supersymmetry which postulates the existence of a "sibling" for every particle in the Universe and may explain dark matter and dark energy.

No proof of such symmetric particles has been found at the LHC, currently in sleep mode for an 18-month overhaul to super-boost its power levels.

Supersymmetry, additionally, predicts the existence of at least five types of Higgs boson, and physicists will thus be watching the LHC Higgs closely for signs of behaviour inconsistent with the Standard Model.


- 'New Physics' -

"It would give us a very good hint that there is physics there beyond the Standard Model and that there's new, additional physics coming soon," said Dave Charlton, who heads the ATLAS experiment at the LHC.

"It could help to explain many of the other problems we have in physics at the moment."

The LHC is a facility of the European Organisation for Nuclear Research (CERN) which celebrated its 60th anniversary on Tuesday.

The Higgs boson is a cornerstone of the Standard Model, a theory developed in the early 1970s to explain the five percent of the Universe composed of visible matter and energy, all carried by fundamental particles.

But some of the boson's newly discovered properties have left physicists scratching their heads.

For starters, they don't understand how it can have such a small mass.

Nor is the evidence consistent for the role it played in the development of the early Universe after the Big Bang -- issues that may be resolved by so-called New Physics the experts hope will follow soon.

When the LHC fires up again next year, scientists will be on the lookout for new particles, including other types of Higgs, and possible "invisible decays" of the boson to indicate the presence of dark matter.

"All of the particles of the Standard Model have now been discovered," said Charlton.

"If we see new particles, it's something new... if we see new particles, it will point to something whether it is supersymmetry or some other new theory.

"It will tell us that the Standard Model is broken, that there is something else."

Charlton said we may never know if the Higgs found at the LHC was exactly the Standard Model version or something that just resembles it.

Themis Bowcock, particle physics head at the University of Liverpool, said confirmation of several Standard Model predictions over the past two years have placed a new focus on what is not yet known.

"It allows us to step back and view the boundaries of our knowledge with a keener eye," he told AFP.

"We realise we have mastered our closest and most obvious challenges, but like a 15th century navigator we are motivated to venture beyond our mapped lands to discover the missing 95 percent -- the New World."

http://news.yahoo.com/higgs-quest-deepens-realm-physics-035140731.html

[Buster's Uncle]

'Revolutionary' Physics: Do Sterile Neutrinos Lurk in the Universe?
LiveScience.com
By Tia Ghose, Staff Writer  2 hours ago


The detector for the MicroBooNe is gently lowered into place.



A completely new subatomic particle — one so reclusive and strange that it passes undetected through ordinary matter — could be lurking in the universe.

If so, a detector set to turn on later this year could find the first convincing evidence for the particle, called a sterile neutrino. The new experiment, whose 30-ton detector was recently lowered into place at Fermi National Accelerator Laboratory in Illinois, will look for traces of this elusive particle transforming into another type of neutrino.

Unlike the Higgs boson, the particle thought to explain why other particles have mass and which most physicists predicted should exist for decades, sterile neutrinos would be in the realm of completely unknown physics that only some physicists believe exist, said Bonnie Fleming, the experiment's spokeswoman and a physicist at Yale University. "It would be completely revolutionary," Fleming said.


Ghostly particles

Neutrinos are miniscule, nearly massless subatomic particles that form during nuclear reactions in the hearts of stars, supernovae and other explosive cosmic events. Though trillions of neutrinos pass through our bodies every second, they almost never interact with other matter, giving them the nickname "ghost particles."

The known neutrinos come in three different types, or flavors — electron, muon and tau — and in the last 15 to 20 years, scientists have learned that those flavors oscillate, or change into one another, with a certain frequency. (During collisions, electron neutrinos can also turn into electrons, muon neutrinos can transform into muons, and tau neutrinos can turn into tau leptons, particles that are similar to electrons.

But a few hints suggest there could be a totally new type of neutrino out there. For instance, experiments in the 1990s to detect neutrinos from the sun found possible evidence that electron neutrinos were disappearing. Another experiment designed to probe neutrino oscillation found extra electron neutrinos appearing. One explanation for these anomalies is that the neutrinos were morphing into an intermediate particle called a sterile neutrino.



The 30-ton argon detector has been under construction for two years.


If such sterile neutrinos exist, they would interact only with matter through the incredible weak force of gravity, making direct detection impossible, Fleming told Live Science.


Hunting sterile neutrinos

So starting late this year or early in 2015, Fleming and her colleagues will look for indirect evidence of sterile neutrinos. The experiment, called MicroBooNE, will shoot a beam of pure muon-flavored neutrinos 0.3 miles (0.5 kilometers) through a 30-ton metal tank filled with argon. Though most of these ghost particles will travel through the argon unchanged, some will occasionally change flavor to an electron neutrino, tau neutrino — or possibly a sterile neutrino.

Some fraction of these neutrinos will then go on to collide with the nuclei of argon atoms in the detector.

"They will shatter that nucleus, and parts of that nucleus will go everywhere," said Matt Strassler, a physicist at Harvard University who was not involved in the study. As part of the collision, electron neutrinos will sometimes morph into electrons, Strassler added.

The detector then identifies where, when and what type of particles were created by analyzing the trail left by ionized, or charged, particles after the collision.

Because the researchers know how often electron neutrinos should convert into electrons during such collisions, any deviation from expectations could be a sign that a muon neutrino morphed into an intermediate sterile neutrino, then into an electron neutrino, and finally into an electron.


Longshot physics

Though the discovery of a sterile neutrino is a possibility, it's not likely, Strassler said.

MicroBooNE is working to clarify tantalizing hints in data from a precursor experiment called MiniBooNE, but there's a good chance that MiniBooNE's "dirty measurement" is picking up other processes instead, Strassler said.

Even if the new experiment uncovers something strange, there's no guarantee sterile neutrinos caused the signal, rather than some other completely different interaction, he said.

"There's a very small — not zero — chance that they're actually going to uncover one of the great secrets of the universe," Strassler told Live Science.

http://news.yahoo.com/revolutionary-physics-sterile-neutrinos-lurk-universe-152137211.html

[gwillybj]

The New York Times | Science
The Upshot | Debate That Divides
When Beliefs and Facts Collide
Brendan Nyham | July 5, 2014

Do Americans understand the scientific consensus about issues like climate change and evolution?

At least for a substantial portion of the public, it seems like the answer is no. The Pew Research Center, for instance, found that 33 percent of the public believes “Humans and other living things have existed in their present form since the beginning of time” and 26 percent think there is not “solid evidence that the average temperature on Earth has been getting warmer over the past few decades.” Unsurprisingly, beliefs on both topics are divided along religious and partisan lines. For instance, 46 percent of Republicans said there is not solid evidence of global warming, compared with 11 percent of Democrats.

As a result of surveys like these, scientists and advocates have concluded that many people are not aware of the evidence on these issues and need to be provided with correct information. That’s the impulse behind efforts like the campaign to publicize the fact that 97 percent of climate scientists believe human activities are causing global warming.

In a new study, a Yale Law School professor, Dan Kahan, finds that the divide over belief in evolution between more and less religious people is wider among people who otherwise show familiarity with math and science, which suggests that the problem isn’t a lack of information. When he instead tested whether respondents knew the theory of evolution, omitting mention of belief, there was virtually no difference between more and less religious people with high scientific familiarity. In other words, religious people knew the science; they just weren’t willing to say that they believed in it.

Mr. Kahan’s study suggests that more people know what scientists think about high-profile scientific controversies than polls suggest; they just aren’t willing to endorse the consensus when it contradicts their political or religious views. This finding helps us understand why my colleagues and I have found that factual and scientific evidence is often ineffective at reducing misperceptions and can even backfire on issues like weapons of mass destruction, health care reform and vaccines. With science as with politics, identity often trumps the facts.

So what should we do? One implication of Mr. Kahan’s study and other research in this field is that we need to try to break the association between identity and factual beliefs on high-profile issues – for instance, by making clear that you can believe in human-induced climate change and still be a conservative Republican like former Representative Bob Inglis or an evangelical Christian like the climate scientist Katharine Hayhoe.

But we also need to reduce the incentives for elites to spread misinformation to their followers in the first place. Once people’s cultural and political views get tied up in their factual beliefs, it’s very difficult to undo regardless of the messaging that is used.

It may be possible for institutions to help people set aside their political identities and engage with science more dispassionately under certain circumstances, especially at the local level. Mr. Kahan points, for instance, to the relatively inclusive and constructive deliberations that were conducted among citizens in Southeast Florida about responding to climate change. However, this experience may be hard to replicate – on the Outer Banks of North Carolina, another threatened coastal area, the debate over projected sea level rises has already become highly polarized.

The deeper problem is that citizens participate in public life precisely because they believe the issues at stake relate to their values and ideals, especially when political parties and other identity-based groups get involved – an outcome that is inevitable on high-profile issues. Those groups can help to mobilize the public and represent their interests, but they also help to produce the factual divisions that are one of the most toxic byproducts of our polarized era. Unfortunately, knowing what scientists think is ultimately no substitute for actually believing it.

The Upshot provides news, analysis and graphics about politics, policy and everyday life.

Eiko Ojala

http://www.nytimes.com/2014/07/06/upshot/when-beliefs-and-facts-collide.html

[Buster's Uncle]

Big Dipper Hotspot May Help Solve 100-Year-Old Cosmic Ray Mystery
SPACE.com
by Nola Taylor Redd, SPACE.com Contributor  3 hours ago



A map of the northern sky shows the concentration of ultrahigh-energy cosmic rays stemming from the constellation of Ursa Major.



A hotspot of powerful, ultrahigh-energy particles streams toward Earth from beneath the handle of the Big Dipper constellation. This collection of cosmic rays may help scientists nail down the origin point of the powerful particles, a century-old mystery.

"This puts us closer to finding out the sources — but no cigar yet," Gordon Thomson, of the University of Utah, said in a statement. Thomson is the co-principle investigator for the Telescope Array cosmic ray observatory in southern Utah, which discovered the hotspot, and one of the 125 researchers on the project.

"All we see is a blob in the sky, and inside this blob there is all sorts of stuff — various types of objects — that could be the source," he added. "Now we know where to look."


A hundred-year-old mystery

Gordon worked with an international team of scientists to capture 72 ultarhigh-energy cosmic rays with the Telescope Array over a period of five years. If powerful cosmic ray sources spread evenly across the sky, the resulting waves should also be evenly distributed. Instead, 19 of the detected signals came from a 40-degree circle that makes up only six percent of the sky. The hot spot lies in the constellation Ursa Major, home of the Big Dipper.

"We have a quarter of our events in that circle instead of 6 percent," collaborator Charlie Jui, also from the University of Utah, said in the same statement.

Jui describes the hotspot's location as "a couple of hand widths below the Big Dipper's handle." The region would appear like any other region of the sky to regular optical telescopes.



solar-powered detector at the Telescope Array cosmic ray observatory measures the strength and direction of cosmic rays after they travel through Earth's atmosphere.


According to the researchers, the odds that the hotspot is a statistical fluke rather than real are only 1.4 in 10,000.

The hotspot region of the sky lies near the supergalactic plane, which contains local galaxy clusters such as the Ursa Major cluster, the Coma cluster and the Virgo cluster.

The research, which is an international collaboration of over 100 scientists, was recently accepted for publication in the Astrophysical Journal Letters.

Discovered in 1912, cosmic rays are thought to consist of the bare protons of hydrogen nuclei, or the centers of heavier elements. The powerful particles stream in from various regions of the sky, with energies reaching as high as 300 billion billion electron volts. Cosmic rays are classified as "ultrahigh-energy" if they carry the energy of 1 billion billion electron volts, comparable to a fast-pitch baseball.

While low-energy cosmic rays come from stars like the sun over the course of their life or explosive deaths, the origins of more energetic rays remain a mystery.

Suggested progenitors for the more powerful cosmic rays include Active Galactic Nuclei (AGN), where material is sucked into supermassive black holes at the center of galaxies, or gamma-ray bursts from the explosive supernova death of massive stars. Other potential causes include shockwaves from noisy radio galaxies and colliding galaxies. More exotic possibilities include the decay of "cosmic strings," hypothetical one-dimensional defects proposed by string theory.

Ultrahigh-energy cosmic rays stem from outside the Milky Way, but are weakened by interactions with the cosmic microwave background radiation — the leftover fingerprint from the Big Bang that kicked off the universe. As a result, 90 percent of the detected ultrahigh-energy cosmic rays originate within 300 million light-years of Earth.

According to Jui, a separate study currently in progress suggests that the distribution of ultrahigh-energy cosmic rays in the northern sky is related to concentrations of large-scale structures like clusters and superclusters of galaxies.

"It tells us there is at least a good chance these are coming from matter we can see, as opposed to a different class of mechanisms where you are producing these particles with exotic processes," Jui said.

The Telescope Array houses 523 detectors spread over 300 square miles of desert. Physicists hope to make the observatory more sensitive by doubling the number of detectors and quadrupling the area they cover, which should capture more cosmic rays.

"With more events, we are more likely to see structure in that hotspot blob, and that may point us toward the real sources," Jui said.

A preprint of the article may be found online at arXiv.org

http://news.yahoo.com/big-dipper-hotspot-may-help-solve-100-old-135703814.html

[Buster's Uncle]

First Glimpse of Higgs Bosons at Work Revealed
LiveScience.com
By Tia Ghose, Staff Writer  7 hours ago



An extremely rare collision of massive subatomic particles could reveal the nuts and bolts of how the subatomic particles called Higgs bosons impart mass to other particles.

The Higgs boson particle, which was detected for the first time in 2012, is essentially tossed around like a ball between two force-carrying particles known as W-bosons when they scatter, or bounce off of one another, a new data analysis revealed.

The data comes from the ATLAS experiment, the same proton-collision experiment that revealed the Higgs boson, at the Large Hadron Collider (LHC), a 17-mille-long (27 kilometers) underground atom smasher on the border of Switzerland and France.

By studying how much the Higgs sticks to the W-bosons during this scattering process, the team could learn new details about how strongly the elusive Higgs boson interacts with the field that gives all particles their mass.

"We are basically observing the Higgs boson at work to see whether it does its job the way we expect it to," said study co-author Marc-André Pleier, a physicist with the ATLAS project, and a researcher at Brookhaven National Laboratory in Upton, New York.


Higgs Field

For decades, the Standard Model, the reigning physics theory that describes the menagerie of subatomic particles, was both astonishingly predictive and obviously incomplete.

The long-sought missing piece of the Standard Model was the Higgs boson, a particle proposed by English physicist Peter Higgs and others in 1964 to explain how certain particles get their mass. The theory held that particles like W-bosons pick up mass as they travel through a field, now known as the Higgs field. The more particles "drag" through the field, the more massive they are. If the Higgs field did exist, then by extension another particle, the now-famous Higgs boson (dubbed "the God Particle," a nickname scientists dislike), should also exist as a vibration of that field when other subatomic particles interact with the field.

In 2012, scientists announced they had found the Higgs boson. In the years since, physicists have been busy analyzing data from collisions at the LHC to figure out exactly how the Higgs boson does its job of giving particles mass.


Impossible physics

Other parts of the Standard Model didn't add up without the Higgs boson. For instance, in theory proton collisions could produce pairs of W-bosons that would then scatter, or bounce off of, one another. (W-bosons mediate the weak nuclear force, which governs radioactive decay and fuels the chemical reactions at the hearts of stars, Pleier said.)

At high-enough collision energies, however, the theory predicted that W-boson scattering would occur more than 100 percent of the time, which is physically impossible, Pleier said.

So physicists proposed a subatomic game of catch, where a Higgs boson could bounce off one W-boson in a colliding pair, and be absorbed by the other member of the pair, Pleier said.

The extra Higgs, in essence, fixed the mathematical glitch in the theory.

But W-boson scattering was incredibly rare: It occurs only once in 100 trillion proton-proton collisions, so scientists never had a chance to test their theory, Pleier said.

"It's even rarer to observe than the Higgs boson," Pleier told Live Science.


Higgs at work

While poring over data from the ATLAS experiment, researchers saw, for the first time, glimpses of elusive W-boson scattering, Pleier said.

So far, the team has seen hints of just 34 W-boson scattering events, which showed that the Higgs boson does play some role in this scattering process.

But there is still too little data to say exactly how "sticky" the Higgs boson is to these W-bosons, which would reveal how sticky the Higgs field is. That, in turn, could help reveal more details about how the Higgs field gives other particles their mass, Pleier said.

If follow-up data reveals that the Higgs Boson doesn't seem to be sticky enough, that's an indication that other subatomic particles may be involved in W-boson scattering, he said.

When the LHC ramps up again in 2015 at higher energies, the team should be able to produce 150 times more data than they were collecting when the atom smasher shut down in 2013, which could help flesh out the now-shadowy picture of the Higgs boson in action.

The findings have been accepted for publication in the journal Physical Review Letters and were published in the preprint journal arXiv.

http://news.yahoo.com/first-glimpse-higgs-bosons-revealed-122000650.html

[Buster's Uncle]

Milky Weigh: scientists take weight of the galaxy
AFP
4 hours ago



This image obtained from NASA on January 24, 2013 shows the Large Magellanic Cloud, a satellite galaxy of the Milky Way (AFP Photo/)



London (AFP) - The Milky Way galaxy is lighter than previously thought, according to new research published by British-based scientists on Wednesday.

The study led by the University of Edinburgh is the first time that scientists have been able to measure accurately the mass of the galaxy that contains our solar system, the researchers said.

The Milky Way was found to contain only half the mass of its neighbour Andromeda, which has a similar spiral structure to our own.

"We always suspected that Andromeda is more massive than the Milky Way, but weighting both galaxies simultaneously proved to be extremely challenging," said Doctor Jorge Penarrubia, who led the study.

The research concluded that the extra mass of the Andromeda galaxy was down to dark matter, a little-understood invisible substance that accounts for most of the outer regions of galaxies.

The scientists estimate that the Milky Way contains approximately half as much dark matter as its neighbouring galaxy, though the two are of similar dimensions.

The Milky Way and Andromeda are the two largest in a region of galaxies known to astronomers as the Local Group.

Ninety percent of the matter in both galaxies is invisible, and until now scientists have been unable to prove which is larger.

Previous research has only measured the mass of a galaxy's inner region, but the new study was able to calculate how much invisible matter is contained in outer regions.

Researchers say the findings will help them to understand how the outer regions of galaxies are structured.

"Our study combined recent measurements of the relative motion between our galaxy and Andromeda with the largest catalogue of nearby galaxies ever compiled to make this possible," said Penarrubia.

The findings of the study are supported by research at the University of Cambridge, which used a different set of data to reach very similar results.

The study was published in the Monthly Notices of the Royal Astronomical Society journal.

http://news.yahoo.com/milky-weigh-scientists-weight-galaxy-144138703.html

[Buster's Uncle]

Supernovas Might Create Weird 'Zombie Stars'
SPACE.com
by Charles Q. Choi, SPACE.com Contributor  3 hours ago



These observations from the Hubble Space Telescope show before and after views for the supernova SN 2012Z in the outskirts of the galaxy NGC 1309, 108 million light-years from Earth. Inset: SN 2012Z is seen in 2013, while data from 2005-2006 show its perceived progenitor star pair. Image released Aug. 6, 2014.  Credit: NASA and ESA, Curtis McCully and Saurabh W Jha (Rutgers), Ryan J Foley (Illinois)



The most powerful stellar blasts in the universe may not always destroy stars in explosive supernovas as scientists had thought, but instead leave behind a remnant "zombie star," astronomers say.

These new findings may shed light on the origins of a mysterious kind of star explosion known as a Type Iax supernova, the researchers added.

Supernovas are the most powerful star explosions in the universe. They are bright enough to momentarily outshine their entire galaxies.

Scientists think a kind of stellar blast, known as a Type Ia supernova, occurs when one star pours enough fuel onto a dying companion star, known as a white dwarf, to trigger an extraordinary nuclear explosion. However, researchers have never actually seen what stars actually give rise to these outbursts, thus making their origins uncertain.

"Astronomers have been searching for decades for the progenitors of type Ia's," study co-author Saurabh Jha, an astronomer at Rutgers University in Piscataway, N.J., said in a statement. "Type Ia's are important because they're used to measure vast cosmic distances and the expansion of the universe."


Supernova sleuths

To learn more about white-dwarfsupernovas, astronomers looked at an explosion dubbed SN 2012Z, discovered by the Lick Observatory Supernova Search in 2012. NASA's Hubble Space Telescope also took images of the supernova's host galaxy — NGC 1309, located 110 million light-years away — in 2005, 2006 and 2010 before the explosion took place.

This past data helped researchers discover the apparent progenitor of the supernova. The likelihood the star they detected is related to the supernova is more than 99 percent, they said.

"We were tremendously excited to see a progenitor system for this supernova," lead study author Curtis McCully, an astronomer at Rutgers, told Space.com. "No one had ever seen a progenitor system for a white-dwarf supernova in pre-explosion data, so our expectation was that we wouldn't see anything. Nature surprised us, which is always exciting."

The researchers had expected that the supernova's progenitor system would be too faint to see, as was the case with previous searches for type Ia supernova progenitors.

"I was very surprised to see anything at the location of the supernova," McCully recalled.


Strange supernova science

SN 2012Z was actually a mysterious kind of exploding star known as a Type Iax supernova. First recognized 12 years ago, Type Iax supernovas were originally thought to be fainter cousins of the more common Type Ia supernova, but they now seem to be a related but distinct class. So far, astronomers have identified more than 30 of these unusual Type Iax supernovas, which occur at a rate of about one-fifth that of Type Ia supernovae, but release only between 1 and 50 percent of the energy.

The astronomers found that the progenitor system of SN 2012Z apparently consisted of a white dwarf and a bright-blue companion star. The researchers suggested the companion is a "helium star" whose outer shells of hydrogen have been stripped away, leaving only its helium core.

"Our results show that at least some white-dwarf supernova explosions arise from a white dwarf that accretes material from a luminous companion star," Jha told Space.com.

Instead of destroying the exploding star — as supernovas are often thought to do — SN 2012Z may have left behind a battered and bruised white dwarf, which the researchers called a "zombie star."

"There are indications that the white dwarf may not have been completely disrupted," study co-author Ryan Foley, an astronomer at the University of Illinois at Urbana-Champaign, told Space.com.

These findings suggest that Type Ia supernovas may have different origins than Type Iax supernovas. For instance, before and after images of Type Ia supernovas like SN 2014J and SN 2011fe would have been capable of revealing any blue progenitor system if one existed.However, none was seen.

"It certainly seems like most normal Type Ia supernovae cannot have a luminous blue companion star like in the case for this Type Iax supernova," Jha told Space.com.

Instead, this Type Iax supernova resembles a nova star explosion — a much-less-powerful stellar blast — called V445 Puppis, an explosion in the Milky Way that astronomers detected in 2000. Novas are like Type Ia supernovas in that they occur when white dwarfs accumulate fuel from a companion star, but novas do not completely destroy their stars like supernovas are thought to do. The researchers added that the progenitor system V445 Puppis nova is thought to consist of a white dwarf and a companion helium star, maybe just like SN 2012Z.

One possible scenario for this system the researchers modeled is that it originally consisted of two stars — one weighing four times the mass of the sun, and the other seven times the mass of the sun. The stars began exchanging hydrogen and helium fuel back and forth, with the larger star eventually dwindling to become a white dwarf about the mass of the sun, the researchers suggested.

The blue companion star, in turn, swelled in size and shed its outer layers, until it became a helium star about twice the mass of the sun. The white dwarf then siphoned matter from its blue companion until the extra fuel made it explode as a Type Iax supernova and blow off about half its mass, instead of completely dying, the researchers explained.

However, the researchers acknowledged that they cannot yet rule out other possibilities for the identity of the blue star they saw. For instance, it could have been a massive star 30 to 40 times the mass of the sun that destroyed itself when it detonated.

To settle the question once and for all, the researchers "will get future observations of the system in late 2015 with the Hubble Space Telescope after the supernova light has faded," Jha said. There are two possibilities: Either researchers will see no star at all, as would be the case if the supernova's progenitor was a massive star, or a helium star will be there "but it will have changed due to the explosion," Jha said. "We also hope to see the remnant zombie star," Jha added.

The research is detailed in the Aug. 7 edition of the journal Nature.

http://news.yahoo.com/supernovas-might-create-weird-zombie-stars-193726668.html

[Buster's Uncle]

What?! The Universe Appears to Be Missing Some Light
SPACE.com
by Charles Q. Choi, SPACE.com Contributor  3 hours ago



New data from the Hubble Space Telescope and computer simulations have revealed that the universe has much less ultraviolet light than previously thought.



An extraordinary amount of ultraviolet light appears to be missing from the universe, scientists have found.

One potential source of this missing light might be the mysterious dark matter that makes up most of the mass in the cosmos. But a simpler explanation could be that ultra violet light escapes from galaxies more easily than is currently thought, according to the new research.

This puzzle begins with hydrogen, the most common element in the universe, which makes up about 75 percent of known matter. High-energy ultraviolet light can convert electrically neutral hydrogen atoms into electrically charged ions. The two known sources for such ionizing rays are hot young stars and quasars, which are supermassive black holes more than a million times the mass of the sun that release extraordinarily large amounts of light as they rip apart stars and gobble matter.

Astronomers previously found that ionizing rays from hot young stars are nearly always absorbed by gas in their home galaxies. As such, they virtually never escape to affect intergalactic hydrogen.

However, when scientists performed supercomputer simulations of the amount of intergalactic hydrogen that should exist and compared their results with observations from the Hubble Space Telescope's Cosmic Origins Spectrograph, they found the amount of light from known quasars is five times lower than what is needed to explain the amount of electrically neutral intergalactic hydrogen observed.

"It's as if you're in a big, brightly-lit room, but you look around and see only a few 40-watt lightbulbs," lead study author Juna Kollmeier, a theoretical astrophysicist at the Observatories of the Carnegie Institution of Washington in Pasadena, Calif., said in a statement. "Where is all that light coming from? It's missing."

The researchers are calling this giant deficit of ultraviolet light "the photon underproduction crisis."

"In modern astrophysics, you very rarely find large mismatches like the one we are talking about here," Kollmeier told Space.com. "When you see one, you know that there is an opportunity to learn something new about the universe, and that's amazing."

"The great thing about a 400 percent discrepancy is that you know something is really wrong," study co-author David Weinberg at Ohio State University said in a statement. "We still don't know for sure what it is, but at least one thing we thought we knew about the present day universe isn't true."

Strangely, this missing light only appears in the nearby, relatively well-studied cosmos. When telescopes focus on light from galaxies billions of light years away — and therefore from billions of years in the past — no problem is seen. In other words, the amount of ultraviolet light in the early universe makes sense, but the amount of ultraviolet light in the nearby universe does not.

"The authors have performed a careful and thorough analysis of the problem," said theoretical astrophysicist Abraham Loeb, chairman of the astronomy department at Harvard University, who did not take part in this research.

The most exciting possibility these findings raise is that the missing photons are coming from some exotic new source, not galaxies or quasars at all, Kollmeier said. For example, dark matter, the invisible and intangible substance thought to make up five-sixths of all matter in the universe, might be capable of decay and generating this extra light.

"You know it's a crisis when you start seriously talking about decaying dark matter," study co-author Neal Katz at the University of Massachusetts at Amherst said in a statement.

There still may be a simpler explanation for this missing light, however. Astronomers could be underestimating the fraction of ultraviolet light that escapes from galaxies in the nearby universe. "All that one needs is an average escape probability on the order of 15 percent to relieve the discrepancy," Loeb told Space.com.

Nearby, recent "low-redshift" galaxies have less gas to absorb ultraviolet rays that more distant, early "high-redshift" galaxies, Loeb noted.

"The more I think about it, the more plausible it appears that the escape fraction of ultraviolet photons is higher in local galaxies than in high-redshift galaxies," Loeb said.

On the other hand, "the biggest problem with this possible solution is that there are measurements of local galaxies that indicate the average escape fraction is significantly lower than 15 percent — more like 5 percent," Kollmeier said."In principle, it is possible that these galaxies are not representative and therefore we need to do more such measurements, but we cannot just dismiss the data."

Another potential explanation is ionization of intergalactic hydrogen by x-rays and cosmic rays, Loeb said. Although he noted this radiation does not play a major role in ionizing intergalactic hydrogen in the most distant corners and earliest times in the universe, astronomers may want to see how much of a role x-rays and cosmic rays play in the nearby universe, "where they are produced more vigorously," he said.

The scientists detailed their findings in the July 10 issue of the Astrophysical Journal Letters.

http://news.yahoo.com/universe-appears-missing-light-125115861.html

[Buster's Uncle]

3D Galactic Map May Solve Interstellar Puzzle
SPACE.com
By Nola Taylor Redd, SPACE.com Contributor  44 minutes ago



Maps of the measured DIB absorption in respect to the area they cover in our galaxy.



Scientists have created the first 3D map of a type of astronomical interference that has puzzled astronomers for nearly a century.

The new map could help scientists finally nail down the identity of the material that creates "diffuse interstellar bands" (DIBs) in observations of stars, the study authors said.

The researchers focused on the single DIB 8620, one of over 400 absorption lines, with the goal of narrowing down its source.

"DIB 8620 does not seem special compared to other DIBs," lead author Janez Kos, of the University of Ljubljana in Slovenia, told Space.com by email.

However, as a spectral feature often used to measure stellar motion, it is "the most observed DIB."

The result was the first large-scale map of DIB interference, and the first three-dimensional study of the DIB-bearing clouds in the interstellar medium.



These maps show the amount of light absorbed by the DIB (left) and the dust between stars (right). Red indicates that more light was absorbed than blue. The top maps show the northern galactic hemisphere, while the bottom row shows the southern


Astronomers break the light streaming from distant stars into prismlike lines called spectra, separated by wavelength, in order to determine what stars are made of. Some of the light is absorbed by the material it passes through along the way, creating absorption bands in the data.

While some of the bands are caused by cool gases in the stars' atmospheres, diffuse interstellar bands have remained a mystery since their identification in 1922. These bands are spread across visible, infrared, and ultraviolet wavelengths, and correspond to no known atom or molecule.

Some of the first proposed sources were molecules on dust grainsbetween stars, according to Kos. It has also been suggested that the strange absorption bands are caused by carbon-based molecules that are either simple or in long chains.

"None of these were ever proved to be the carriers," Kos said.

In order to investigate DIB 8620, Kos and his international team of astronomers turned to the Radial Velocity Experiment (RAVE) survey of stars in the Milky Way created by the Australian Astronomical Observatory’s Schmidt telescope. RAVE contained the spectra of almost half a million stars across the galaxy, all located in the southern sky.

Using the measurements of DIB 8620 in the spectra of the stars, Kos and his team created a map of the interference source across the galaxy, measuring the density of the material by how strong its absorption line is in the stars detected by RAVE. The data taken from the survey revealed the distance of each star, allowing for the 3D mapping of the material in the interstellar medium.

The scientists then compared the DIB map with an independently constructed map of the interstellar dustalong the plane of the galaxy.

While the results are similar, the two maps don’t match up precisely, suggesting that there is a "strong correspondence between the two," according to the research paper. Rising above the plane of the galaxy, the density of the source for DIB 8620 drops more slowly than the density of the dust — a surprising find since the two sources otherwise align fairly well.

"Even though the correlation between the DIB and dust is good, the two components do not share the same distribution in the interstellar medium," Kos said.

The implication is that "DIBs experience a mechanism of their own during their creation and migration through the galaxy," Kos said.

The team cautions that these implications should not be extended to all DIBs, as different bands demonstrate different behavior. However, the techniques used to study DIB 8620, combined with other surveys of the Milky Way, should allow for similar maps to be made, narrowing down the source of a century-old mystery. RAVE limited the team to studying only a single band, but different surveys should allow for the study of some of the other 400-plus measurements.

The research was published online today (Aug 14) in the journal Science.

http://news.yahoo.com/3d-galactic-map-may-solve-interstellar-puzzle-181959255.html

[Buster's Uncle]

Stephen Hawking Says 'God Particle' Could Wipe Out the Universe
LiveScience.com
By Kelly Dickerson, Staff Writer  1 hour ago



Simulated data from the Large Hadron Collider particle detector shows the Higgs boson produced after two protons collide.



Stephen Hawking bet Gordon Kane $100 that physicists would not discover the Higgs boson. After losing that bet when physicists detected the particle in 2012, Hawking lamented the discovery, saying it made physics less interesting. Now, in the preface to a new collection of essays and lectures called "Starmus," the famous theoretical physicist is warning that the particle could one day be responsible for the destruction of the known universe.

Hawking is not the only scientist who thinks so. The theory of a Higgs boson doomsday, where a quantum fluctuation creates a vacuum "bubble" that expands through space and wipes out the universe, has existed for a while. However, scientists don't think it could happen anytime soon.

"Most likely it will take 10 to the 100 years [a 1 followed by 100 zeroes] for this to happen, so probably you shouldn't sell your house and you should continue to pay your taxes," Joseph Lykken, a theoretical physicist at the Fermi National Accelerator Laboratory in Batavia, Illinois, said during his lecture at the SETI Institute on Sept. 2. "On the other hand it may already happened, and the bubble might be on its way here now. And you won't know because it's going at the speed of light so there's not going to be any warning."

The Higgs boson, sometimes referred to as the 'god particle,' much to the chagrin of scientists who prefer the official name, is a tiny particle that researchers long suspected existed. Its discovery lends strong support to the Standard Model of particle physics, or the known rules of particle physics that scientists believe govern the basic building blocks of matter. The Higgs boson particle is so important to the Standard Model because it signals the existence of the Higgs field, an invisible energy field present throughout the universe that imbues other particles with mass. Since its discovery two years ago, the particle has been making waves in the physics community.

Now that scientists measured the particle's mass last year, they can make many other calculations, including one that seems to spell out the end of the universe.


Universe doomsday

The Higgs boson is about 126 billion electron volts, or about the 126 times the mass of a proton. This turns out to be the precise mass needed to keep the universe on the brink of instability, but physicists say the delicate state will eventually collapse and the universe will become unstable. That conclusion involves the Higgs field.

The Higgs field emerged at the birth of the universe and has acted as its own source of energy since then, Lykken said. Physicists believe the Higgs field may be slowly changing as it tries to find an optimal balance of field strength and energy required to maintain that strength.

"Just like matter can exist as liquid or solid, so the Higgs field, the substance that fills all space-time, could exist in two states," Gian Giudice, a theoretical physicist at the CERN lab, where the Higgs boson was discovered, explained during a TED talk in October 2013.

Right now the Higgs field is in a minimum potential energy state — like a valley in a field of hills and valleys. The huge amount of energy required to change into another state is like chugging up a hill. If the Higgs field makes it over that energy hill, some physicists think the destruction of the universe is waiting on the other side.

But an unlucky quantum fluctuation, or a change in energy, could trigger a process called "quantum tunneling." Instead of having to climb the energy hill, quantum tunneling would make it possible for the Higgs field to "tunnel" through the hill into the next, even lower-energy valley. This quantum fluctuation will happen somewhere out in the empty vacuum of space between galaxies, and will create a "bubble," Lykken said.

Here's how Hawking describes this Higgs doomsday scenario in the new book: "The Higgs potential has the worrisome feature that it might become metastable at energies above 100 [billion] gigaelectronvolts (GeV). … This could mean that the universe could undergo catastrophic vacuum decay, with a bubble of the true vacuum expanding at the speed of light. This could happen at any time and we wouldn't see it coming."

The Higgs field inside that bubble will be stronger and have a lower energy level than its surroundings. Even if the Higgs field inside the bubble were slightly stronger than it is now, it could shrink atoms, disintegrate atomic nuclei, and make it so that hydrogen would be the only element that could exist in the universe, Giudice explained in his TED talk.

But using a calculation that involves the currently known mass of the Higgs boson, researchers predict this bubble would contain an ultra-strong Higgs field that would expand at the speed of light through space-time. The expansion would be unstoppable and would wipe out everything in the existing universe, Lykken said.

"More interesting to us as physicists is when you do this calculation using the standard physics we know about, it turns out we're right on the edge between a stable universe and an unstable universe," Lykken said. "We're sort of right on the edge where the universe can last for a long time, but eventually it should go 'boom.' There's no principle that we know of that would put us right on the edge."


Not all doom and gloom

Either all of space-time exists on this razor's edge between a stable and unstable universe, or the calculation is wrong, Lykken said.

If the calculation is wrong, it must come from a fundamental part of physics that scientists have not discovered yet. Lykken said one possibility is the existence of invisible dark matter that physicists believe makes up about 27 percent of the universe. Discovering how dark matter interacts with the rest of the universe could reveal properties and rules physicists don't know about yet.

The other is the idea of "supersymmetry." In the Standard Model, every particle has a partner, or its own anti-particle. But supersymmetry is a theory that suggests every particle also has a supersymmetric partner particle. The existence of these other particles would help stabilize the universe, Lykken said.

"We found the Higgs boson, which was a big deal, but we're still trying to understand what it means and we're also trying to understand all the other things that go along with it

"This is very much the beginning of the story and I've shown you some directions that story could go in, but I think there could be surprises that no one has even thought of," Lykken concludes in his lecture.

http://news.yahoo.com/stephen-hawking-says-god-particle-could-wipe-universe-193636349.html

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