(TMU) – A new paper claims that black holes retain a kind of photon-based record of space-time history that could yield some of the secrets of the universe.
Astronomers and physicists studying the M87 black hole, recently renamed Pōwehi (which means “embellished dark source of unending creation”), made history earlier this year when they released the first photographic image of a black hole. In their new paper, they argue that the ghostly ring of fire we see could harbor historical records – which some have called “movies” – of the cosmos.
The argument is based on an interferometric study of the vast swirling wreaths of light that are trapped in perpetual orbit around the black hole’s event horizon. This light is comprised of photons, which scientists believe may behave like the rings inside a tree trunk, concentric sequences of information that betray overall age and development.
In the paper, entitled “Universal Interferometric Signatures Of A Black Hole’s Photon Ring,” they write:
“Together, the set of subrings are akin to the frames of a movie, capturing the history of the visible universe as seen from the black hole.”
Studying these rings of photons could help scientists learn more about theories like Einstein’s general relativity.
They could also crack more of the mysteries of black holes, which continue to be one of the most puzzling and monstrous objects predicted by physics. For example, do black holes defy the mandates of quantum mechanics and destroy all information? Do they contain dark matter? Do they curve space-time so severely that matter is sent to the future? Can black holes break the laws of physics by existing in five-dimensional space?
The list goes on and on. Many of the world’s most prominent physicists, including Stephen Hawking and Einstein himself, have spent careers and lifetimes trying to unravel the enigmatic existence of black holes. This has led some thinkers to some very strange theories. For example, mathematical physicist Sir Roger Penrose has suggested that we may actually be able to see the imprints of black holes from alternate universes.
Because of the many related puzzles, the opportunity to study historical records left behind by rings photons inside black holes is tantalizing to scientists.
However, the rings do not exist in perpetuity. Each one is only six days older than its predecessor and is eventually obliterated inside the black hole singularity. So while they cannot be used to peer into the entire history of the universe, “measuring the size, shape, and thickness of the subrings would provide new and powerful probes of a black hole spacetime.”
Scientists have described the discovery as approaching a “cosmic hall of mirrors, where the black hole’s gravity takes light from all directions, warps it and beams it to us as an infinitely recast image of the hole’s surroundings. The result is an epic movie of the history of the universe, as witnessed by a black hole, playing on a dramatically curved screen tens of billions of kilometres across.”
As we continue to learn more about black holes, what will they whisper to us about the nature of reality and the secrets of the cosmos?
European Southern Observatory (ESO) astronomers are astonished to find the closest black hole from Earth. The researchers are saying if you are in the Southern Hemisphere, you can observe this black hole with the naked eye at night. The reason one can so easily view it is that it is only a thousand light-years away from us!
Petr Hadrava is the co-author of the paper published in Astronomy & Astrophysics, which discusses this black hole. He is a scientist at the Academy of Sciences of the Czech Republic, Prague. He explains how the team was surprised to realize that they had found the first stellar system with a black hole that can be observed from Earth unaided.
This relatively dark black hole was rather difficult to spot for the scientists. Black holes are known to flare up when they feed on their companion stars’ matter, which reveals their location to the astronomers. But this particular one did not exhibit such behavior. So it had to be spotted only by tracking its gravitational effect on 2 nearby stars. ESO’s La Silla Observatory in Chile found this black hole with its 2.2-meter telescope.
The researchers were initially observing this HR 6819 system for its 2 very closely spaced stars. One of those stars was orbiting a black every 40 Earth days. So the researchers studied its trajectory to conclude that the black hole was quite big.
“An invisible object with a mass at least 4 times that of the Sun can only be a black hole,” Thomas Rivinius, lead author and ESO scientist, said in the statement.
The handful of black holes discovered in our Milky Way were all discovered with the help of the bright flashes of X-rays they gave away when they were interacting with their environment. But the way our closest black hole was discovered, by studying its gravitational effects, means there are many more such black holes we can now find with this method.
Astronomers are trailing another system LB-1 which they believe also has 3 bodies like the HR 6819. LB-1 is further from Earth than HR 6819 but still relatively close, said another co-author of the paper, Marianne Heida.
(TMU) — Using the combined power of multiple astronomical observatories across the world, astronomers have discovered a stunning set of 39 massive galaxies that had previously been invisible.
The multiple discovery is the first of its kind, according to a study published on Wednesday in Nature, and is set to forever change the way in which scientists look at how galaxies are formed.
The galaxies, which are located billions of light-years away, are intimately connected with supermassive black holes and the distribution of dark matter.
In a press release, lead researcher Tao Wang at the University of Tokyo said:
“This is the first time that such a large population of massive galaxies was confirmed during the first 2 billion years of the 13.7-billion-year life of the universe. These were previously invisible to us … This finding contravenes current models for that period of cosmic evolution and will help to add some details, which have been missing until now.”
And while the Hubble Space Telescope has allowed astronomers to gain major insights into previously unknown parts of the universe, the research team from the University of Tokyo relied on the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile to uncover this latest massive find.
And it appears that the huge galaxies would overwhelm our humble view of the heavens if they were actually visible to us humans. Given the age and distance of the huge galaxies, they have always been hidden from our view thanks to the weak and stretched light emanating from them. As a result of such distance, the visible light becomes infrared.
Kotaro Kohno, the study’s author and a professor at the University of Tokyo, explained:
“The light from these galaxies is very faint with long wavelengths invisible to our eyes and undetectable by Hubble.
So we turned to the Atacama Large Millimeter/submillimeter Array (ALMA), which is ideal for viewing these kinds of things. I have a long history with that facility and so knew it would deliver good results.”
The infrared light from the distant galaxies was originally revealed by the NASA Spitzer Space Telescope before ALMA’s “sharp eyes” detected them, cutting through the thick dust that obscured them from our sight, Wang explained.
“It took further data from the imaginatively named Very Large Telescope in Chile to really prove we were seeing ancient massive galaxies where none had been seen before.”
The new discovery will also shed light on the existence of supermassive black holes. Professor Kohno explained:
“The more massive a galaxy, the more massive the supermassive black hole at its heart. So the study of these galaxies and their evolution will tell us more about the evolution of supermassive black holes, too.
Massive galaxies are also intimately connected with the distribution of invisible dark matter. This plays a role in shaping the structure and distribution of galaxies. Theoretical researchers will need to update their theories now.”
So what would the sky look like if we happened to live in one of these ancient, massive galaxies? Wang explained:
“For one thing, the night sky would appear far more majestic. The greater density of stars means there would be many more stars close by appearing larger and brighter … But conversely, the large amount of dust means farther-away stars would be far less visible, so the background to these bright close stars might be a vast dark void.”
Wang is sure that in the future, new space-based telescopic technology will be able to reveal the chemicals, number of stars and basic composition of the dozens of galaxies that have been revealed. He explained:
“Previous studies have found extremely active star-forming galaxies in the early Universe, but their population is quite limited.
Star formation in the dark galaxies we identified is less intense, but they are 100 times more abundant than the extreme starbursts. It is important to study such a major component of the history of the Universe to comprehend galaxy formation.”
Large Hadron Collider Could Detect Extra Dimensions
March 19, 2015 | by Stephen Luntz
Photo credit: Mopic via Shutterstock. If gravity is draining out of tiny black holes into other dimensions, the LHC may find it
A paper in Physics Letters B has raised the possibility that the Large Hadron Collider (LHC) could make a discovery that would put its previous triumph with the Higgs Boson in the shade. The authors suggest it could detect mini black holes. Such a finding would be a matter of huge significance on its own, but might be an indication of even more important things.
Few ideas from theoretical physics capture the public imagination as much as the “many-worlds hypothesis,” which proposes an infinite number of universes that differ from our own in ways large and small. The idea has provided great fodder for science fiction writers and comedians.
However, according to Professor Mir Faizal from the University of Waterloo, “Normally, when people think of the multiverse, they think of the many-worlds interpretation of quantum mechanics, where every possibility is actualized,” he said to Phys.org. “This cannot be tested and so it is philosophy and not science.” Nonetheless, Faizal considers the test for a different sort of parallel universes almost within our grasp.
“What we mean is real universes in extra dimensions,” says Faizal. “As gravity can flow out of our universe into the extra dimensions, such a model can be tested by the detection of mini black holes at the LHC.”
The idea that the universe may be filled with minute black holes has been proposed to explain puzzles such as the nature of dark matter. However, the energy required to create such objects depends on the number of dimensions the universe has. In a conventional four-dimensional universe, these holes would require 1016 TeV, 15 orders of magnitude beyond the capacity of the LHC to produce.
String theory, on the other hand, proposes 10 dimensions, six of which have been wrapped up so we can’t experience them. Attempts to model such a universe suggest that the energy required to make these tiny black holes would be a great deal smaller, so much so that some scientists believe they should have been detected in experiments the LHC has already run.
So if no detection, no string theory? Not according to Faizal and his co-authors. They argue that the models used to predict the energy of the black holes in a 10-dimensional universe have left out quantum deformation of spacetime that changes gravity slightly.
Whether this deformation is real is a rapidly developing question, but if it is, the paper argues that the black holes will have energy levels much smaller than in a four-dimensional universe, but about twice as large as that detectable for any test run so far. The LHC is designed to reach 14 TeV, but so far has only gone to 5.3 TeV, while the paper thinks the holes might be lurking at 11.9 TeV. In this case, once the LHC reaches its full capacity, we should find them.
Such a discovery would demonstrate the microscale deformation of spacetime, the existence of extra dimensions, parallel universes within them and string theory. If found at the right energy levels, the holes would confirm the team’s interpretation of a new theory on black hole behavior named gravity’s rainbow, after the influential novel. Such an astonishing quadruple revelation would transform physics, although the researchers are already considering the most likely flaws in their work if the holes prove elusive.
This annotated image labels several features in the simulation, including the event horizon of the black hole.
Credit: NASA’s Goddard Space Flight Center/J. Schnittman, J. Krolik (JHU) and S. Noble (RIT)
Professor Stephen Hawking speaks about “Why We Should Go into Space” for the NASA Lecture Series, April 21, 2008.
Credit: NASA/Paul Alers
Keep in mind that Hawking’s bedrock theory of evaporating black holes revolutionized our understanding that the gravitational behemoths are not immortal; through a quantum quirk they leak particles (and therefore mass) via “Hawking radiation” over time. What’s more, astronomers are finding new and exciting ways to detect black holes — they are even working on an interferometer network that may, soon, be able to directly image a black hole’s event horizon!
Black holes are strange regions where gravity is strong enough to bend light, warp space and distort time.
Credit: Karl Tate, SPACE.com contributor
Has Hawking changed his mind? Are black holes merely a figment of our collective imaginations? Are all those crank theories about “alternative” theories of the Cosmos true?!
Fortunately not.
Stephen Hawking hasn’t changed his mind about the whole black hole thing, but he has thrown a complex physics paradox into the limelight, one that has been gnawing at the heart of theoretical physics for the last 18 months.
Black Hole Fight Club
It all boils down to a conflict between two fundamental ideas in physics that control the very fabric of our Universe; the clash of Einstein’s general relativity and quantum dynamics. And it just so happens that the extreme environment in and around a black hole makes for the perfect “fight club” for the two theories to duke it out. But what’s the first rule of the black hole fight club? Don’t talk about the firewall, lest you get sucked into an argument with a theoretical physicist.
At a California Institute of Technology (Caltech) lecture in April 2013, Hawking and other prominent theoretical physicists had an opportunity to describe the problem at hand. Caltech’s Kip Thorne, for example, described the firewall paradox as “a burning issue in theoretical physics.”
The very basis of this burning issue is the thing that makes black holes black — the event horizon. In its most basic form, the event horizon of a black hole is the point at which even light cannot escape the gravitational clutches of the massive black hole singularity. If light cannot escape, it stands to reason that it will appear as a black sphere in space. It is a cosmic one-way street: everything goes in, nothing comes out.
An Unlucky Astronaut
In the general relativity universe, for an astronaut who had the misfortune to fall toward a black hole, he or she wouldn’t notice anything untoward as they passed across the event horizon. It would be a fairly peaceful event, no drama. “Although later on you’re doomed and you’ll encounter very strong gravitational forces that will pull you apart,” noted Caltech physicist John Preskill at the 2013 Caltech event.
However, the quantum universe contradicts this “no drama” event horizon idea as predicted by general relativity.
In 2012, a group of physicists headed by Joseph Polchinski of the University of California in Santa Barbara revealed their finding that if black holes truly do not destroy information — a standpoint that Hawking himself reluctantly advocates — and that information can escape from the black hole through Hawking radiation, there must be a raging inferno just inside the event horizon they dub the “firewall.”
In this case, rather than falling into a “no drama” event horizon, our unlucky astronaut gets burnt to a crisp before getting ripped apart by tidal shear. This is the very antithesis of “no drama” and, therefore, a paradox.
This apparent conflict between what general relativity predicts and what quantum dynamics predicts — two very established fields in physics — is precisely what theoretical physicists are trying to understand. This appears to be yet another situation where gravity and quantum dynamics don’t play nice, the solution of which may transform the way we view the Universe.
Apparent Horizons
So, when Hawking, one of the key players in the great firewall debate, writes a short paper on the topic (regardless of whether or not it has been published) the world takes note.
Hawking’s solution to the paradox removes the black hole’s event horizon, thereby removing the paradox; no event horizon, no firewall. But we’re told all black holes have event horizons — the line you cannot cross or be forever lost inside the black hole — what gives?
Hawking thinks that the idea behind the event horizon needs to be reworked. Rather than the event horizon being a definite line beyond which even light cannot escape, Hawking invokes an “apparent horizon” that changes shape according to quantum fluctuations inside the black hole — it’s almost like a “grey area” for extreme physics. An apparent horizon wouldn’t violate either general relativity or quantum dynamics if the region just beyond the apparent horizon is a tangled, chaotic mess of information.
“Thus, like weather forecasting on Earth, information will effectively be lost, although there would be no loss of unitarity,” writes Hawking. This basically means that although the information can escape from the black hole, its chaotic nature ensures it cannot be interpreted, sidestepping the firewall paradox all together.
Needless to say, this paper has done little to convince Polchinski. “It almost sounds like (Hawking) is replacing the firewall with a chaos-wall, which could be the same thing,” he told New Scientist.
Much of the theoretical debate is hard to fathom and the result of calculations of physical events that we cannot possibly experience in our day to day lives. But don’t mistake this particular debate as solely a high-brow argument in the theoretical physics community. Its foundations are rooted in the growing discomfort we are feeling with the mismatch of general relativity and quantum dynamics (particularly what role gravity plays in the quantum world), a problem that cannot be solved with our current understanding of the universe.
It is, after all, these science problems that we build multi-billion dollar particle accelerators for.
In recent years, cosmologists have begun to think seriously about processes that occurred before the Big Bang. Alan Coley from Canada’s Dalhousie University and Bernard Carr from Queen Mary University in London, published a paper in 2011, where they theorized that some so-called primordial black holes might have been created in the Big Crunch that came before the Big Bang, which supports the theory that the Big Bang was not a single event, but one that occurs over and over again as the Universe crunches down to a single point, then blows up again.
In some circumstances, they say, black holes of a certain mass could avoid this fate and survive the crunch as separate entities. The masses for which this is possible range from a few hundred million kilograms to about the mass of our Sun.
The theory is based on the fact that the Earth, and the rest of the known Universe is occasionally bombarded with unexplained bursts of gamma rays — something that could, according to Coley and Carr, be the result of primordial black holes running out of energy and disintegrating. These small black holes ought to evaporate away in relatively short period of time, finally disappearing in a violent explosion of gamma rays. Some cosmologists say this thinking might explain the gamma ray bursts that we already see from time to time.
Primordial black holes are thought to be of a different type than the regular kind that are formed when a supernova occurs but rather formed in the first “moments” after the Big Bang. Primordial black holes would be smaller and created by the energy of the Big Bang itself and would then have been widely dispersed as the Universe expanded.
In their theory, however, Coley and Carr suggest that some of these black holes, if they actually exist, might have been created by the collapsing Universe as part of the Big Crunch, and then somehow escaped being pulled into the pinpoint singularity comprised of everything else. And then, after the Big Bang, they simply assimilated with the newly formed Universe.
A key problem they agree on is that it would likely be impossible to tell the difference between pre- and post Big Bang primordial black holes.
The theory raises major questions for cosmologists: if the Universe contracts, then blows up, over and over, has this gone on forever? Or is it possible that our view of the Universe is so limited that we’re only seeing one tiny fraction of it, and thus, any theories or explanations we offer, are little more than guesses.
Image at the top of page shows co-orbiting supermassive black holes powering the giant radio source 3C 75. Surrounded by multimillion degree x-ray emitting gas, and blasting out jets of relativistic particles the supermassive black holes are separated by 25,000 light-years. At the cores of two merging galaxies in the Abell 400 galaxy cluster they are some 300 million light-years away.
Such spectacular cosmic mergers are thought to be common in crowded galaxy cluster environments in the distant Universe. In their final stages the mergers are expected to be intense sources of gravitational waves.
More information: Persistence of black holes through a cosmological bounce, B. J. Carr, A.A. Coley, arXiv:1104.3796v1 [astro-ph.CO] http://arxiv.org/abs/1104.3796
ScienceDaily (July 22, 2011) — Water really is everywhere. A team of astronomers have found the largest and farthest reservoir of water ever detected in the universe — discovered in the central regions of a distant quasar. Quasars contain massive black holes that are steadily consuming a surrounding disk of gas and dust; as it eats, the quasar spews out huge amounts of energy. The energy from this particular quasar was released some 12 billion years ago, only 1.6 billion years after the Big Bang and long before most of the stars in the disk of our Milky Way galaxy began forming.
The research team includes Carnegie’s Eric Murphy, as well as scientists from the Jet Propulsion Laboratory, the California Institute of Technology, University of Maryland, University of Colorado, University of Pennsylvania, and the Institute for Space and Astronautical Science in Japan. Their research will be published in Astrophysical Journal Letters.
The quasar’s newly discovered mass of water exists in gas, or vapor, form. It is estimated to be at least 100,000 times the mass of the Sun, equivalent to 34 billion times the mass of Earth or 140 trillion times the mass of water in all of Earth’s oceans put together.
Since astronomers expected water vapor to be present even in the early universe, the discovery of water is not itself a surprise. There is water vapor in the Milky Way, although the amount is 4,000 times less massive than in the quasar. There is other water in the Milky Way, but it is frozen and not vaporous.
