On Monday, October 16, the National Science Foundation (NSF) will host an event at the National Press Club in Washington, DC featuring researchers from the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo collaborations, along with scientists from approximately 70
observatories from around the world. Journalists are also invited to attend the event, which is intended to be the global reveal for new findings on gravitational waves.
First the scientists will discuss the new findings, which are from LIGO, Virgo, and various other observatories from all over the world. Next, telescope teams studying extreme cosmic events in partnership with the LIGO and Virgo collaborations will discuss their recent findings. The event will begin for the press and public at 10:00 a.m., EDT.
On September 14, 2015 the LIGO team first detected gravitational waves, a discovery that they announced in February of 2016. Gravitational waves are created (among other things) by the compacting and releasing of the fabric of spacetime as two black holes orbit each other in a dance of death. The first observed event confirmed Einstein’s general theory of relativity, via which he posited spacetime as a singular and unitary phenomenon, and was a milestone in astronomy and physics that would usher in a new field of gravitational-wave astronomy. Three more detections were confirmed since then, the most recent of which was the first joint LIGO and Virgo detection.
Solving Time-Old Mysteries
Physicists from the LIGO project were recently awarded the Nobel for their work with gravitational waves. Their work detecting gravitational waves has permanently changed astronomy and physics, and not simply because it confirms Einstein’s theory of relativity. The detection of the waves will also offer insight into how the universe is expanding — insight that could never have been accessed without otherwise appealing to dark matter, a term that is ultimately a placeholder for a massive force of we-know-not-what that has long eluded the scientific community. Gravitational wave research is also likely to reveal the nature of dark matter.
Event organizers are asking journalists who wish to attend the event to RSVP as soon as possible to firstname.lastname@example.org, and no later than noon EDT Friday, October 13. The National Press Club is located in Holeman Lounge at 529 14th St. NW, 13th Floor, in Washington, DC.
Based on a new study, the same equipment that was integral to the work of this year’s winners of the Nobel Prize for Physics — gravitational wave detectors — might be able to provide valuable insight into another enigmatic field of research: dark matter.
“The nature of dark matter is one the greatest mysteries in physics,” the study’s co-author Emanuele Berti noted in a University of Mississippi news release. “It is remarkable that we can now do particle physics – investigate the ‘very small’ – by looking at gravitational-wave emission from black holes, the largest and simplest objects in the universe.”
Berti and an international team of researchers produced calculations that suggest that some kinds of dark matter could form clouds around black holes. The going theory is that these clouds emit gravitational waves that could be detected by certain advanced equipment. “Surprisingly, gravitational waves from sources that are too weak to be individually detectable can produce a strong stochastic background,” explained co-author Richard Brito.
Dark matter is estimated to be five times as abundant as ordinary matter, and yet, no one has been able to directly detect it. It has the potential to unlock all kinds of secrets about the universe, so the great amount of interest in this topic by scientists and astrophysicists isn’t surprising.
If Berti and the rest of his team are correct in their belief that gravitational wave detectors will allow us to finally “see” dark matter, the implications would be tremendous. As Brito noted, “This is a new, exciting frontier in astroparticle physics that could shed light on our understanding of the microscopic universe.”
Indeed, gravitational waves shake the world both literally and figuratively. The “ripples” in spacetime detected by LIGO were the result of a collision between two black holes some 1.3 billion years ago in a rather distant galaxy.
By the time they reach Earth, gravitational waves are already very weak, and detecting them requires the use of extremely specialized instruments called laser interferometers. Although observed for the first time in September 2015, LIGO didn’t officially confirm their detection of gravitational waves until February 2016 as the researchers wanted to be certain of their discovery.
Pushing the Boundaries of Physics
The detection of gravitational waves has changed astrophysics forever, not just because it confirms Einstein’s general theory of relativity, but also because it illustrates our ability to observe the universe in a way that we’ve never done before. Thanks to LIGO, we’re now able to “hear” the universe in a completely unique way. Gravitational waves give us a fresh appreciation and understanding of how the universe expanded and continues to expand.
While the three new Nobel laureates were the pioneers of this work, making invaluable contributions to the LIGO project, this discovery was the product of decades of work by teams of researchers, and Thorne doesn’t want to take all the credit.
“It should go to all the people who built the detector or to the members of the LIGO-Virgo Collaboration who pulled off the end game,” he told The New York Times.
Thorne also expressed his astonishment at how the research followed the path he predicted decades ago. “For me, an amazing thing is that this has worked out just as I expected when we were starting out back in the ’80s,” he noted. “It blows me away that it all come out as I expected.”
Now that the technology is in place, Thorne expects to detect more gravitational waves in the coming years. “An enormous amount of rich science is coming out of this,” he said, and in fact, just last month, LIGO and Virgo astronomers detected their fourth spacetime ripple. Additionally, they now have the ability to accurately pinpoint the source of gravitational waves, adding to the precision with which we can observe this remarkable, world-shaking phenomenon.
Scientists announced this week that they have once again recorded gravitational waves, ripples in space-time, from a pair of black holes colliding 1.8 billion light years away. They recorded the event on August 14, the fourth time in the past two years that astronomers have detected and recorded such ripples from collisions of black holes. The scientists made the announcement in a Physical Review Letters paper, as well as at a G7 meeting of science ministers in Turin, Italy.
The August collision involved a black hole with a mass of about 31 times that of the Sun, and another with 25 solar masses. Once the two crashed, they created a black hole with a mass of 53 solar masses. In line with earlier gravitational wave detections, the remaining three solar masses transformed into the gravitational waves the scientists detected. The August observations were the result of Virgo’s August 1 debut, a new gravitational wave detector in Italy built by the European Gravitational Observatory.
Earlier detections of gravitational waves were made by LIGO, a pair of L-shaped antennas in Louisiana and Washington. Since LIGO first detected the waves in February 2016 — confirming Albert Einstein’s prediction and verifying the nature of black holes — the scientists working with LIGO have been searching for more insights into the universe. Although the newer Virgo antenna is only one-fourth as sensitive as the LIGO antennas, the network can now triangulate the sources of gravitational waves, allowing optical telescopes to search for any accompanying visible effects sparking in the night sky.
The astronomers will continue working to improve their instruments until fall of 2018 when their next observation run will begin. LIGO Scientific Collaboration spokesman David Shoemaker told the New York Times: “This is just the beginning of observations with the network enabled by Virgo and LIGO working together. With the next observing run planned for Fall 2018, we can expect such detections weekly or even more often.”
According to a new study by a team of astronomers from the Center of Cosmology at the University of California Irvine, such mergers are far more common than we thought. After conducting a survey of the cosmos intended to calculate and categorize black holes, the UCI team determined that there could be as many as 100 million black holes in the galaxy, a finding which has significant implications for the study of gravitational waves.
Their study began roughly a year and a half ago, shortly after LIGO announced the first detection of gravitational waves. These waves were created by the merger of two distant black holes, each of which was equivalent in mass to about 30 Suns. As James Bullock, a professor of physics and astronomy at UC Irvine and a co-author on the paper, explained in a UCI press release:
“Fundamentally, the detection of gravitational waves was a huge deal, as it was a confirmation of a key prediction of Einstein’s general theory of relativity. But then we looked closer at the astrophysics of the actual result, a merger of two 30-solar-mass black holes. That was simply astounding and had us asking, ‘How common are black holes of this size, and how often do they merge?’”
Traditionally, astronomers have been of the opinion that black holes would typically be about the same mass as our Sun. As such, they sought to interpret the multiple gravitational wave detections made by LIGO in terms of what is known about galaxy formation. Beyond this, they also sought to create a framework for predicting future black hole mergers.
From this, they concluded that the Milky Way Galaxy would be home to up to 100 million black holes, 10 millions of which would have an estimated mass of about 30 Solar masses – i.e. similar to those that merged and created the first gravitational waves detected by LIGO in 2016. Meanwhile, dwarf galaxies – like the Draco Dwarf, which orbits at a distance of about 250,000 ly from the center of our galaxy – would host about 100 black holes.
They further determined that today, most low-mass black holes (~10 Solar masses) reside within galaxies of 1 trillion Solar masses (massive galaxies) while massive black holes (~50 Solar masses) reside within galaxies that have about 10 billion Solar masses (i.e. dwarf galaxies). After considering the relationship between galaxy mass and stellar metallicity, they interpreted a galaxy’s black hole count as a function of its stellar mass.
A Common Occurrence?
In addition, they also sought to determine how often black holes occur in pairs, how often they merge and how long this would take. Their analysis indicated that only a tiny fraction of black holes would need to be involved in mergers to accommodate what LIGO observed. It also offered predictions that showed how even larger black holes could be merging within the next decade.
As Manoj Kaplinghat, also a UCI professor of physics and astronomy and the second co-author on the study, explained:
“We show that only 0.1 to 1 percent of the black holes formed have to merge to explain what LIGO saw. Of course, the black holes have to get close enough to merge in a reasonable time, which is an open problem… If the current ideas about stellar evolution are right, then our calculations indicate that mergers of even 50-solar-mass black holes will be detected in a few years.”
In other words, our galaxy could be teeming with black holes, and mergers could be happening in a regular basis (relative to cosmological timescales). As such, we can expect that many more gravity wave detections will be possible in the coming years. This should come as no surprise, seeing as how LIGO has made twoadditional detections since the winter of 2016.
With many more expected to come, astronomers will have many opportunities to study black holes mergers, not to mention the physics that drive them!
Over the years, astronomers have readily detected stellar black holes, which are relatively small and equal in mass to a few Suns or less, and supermassive black holes, which are equal in mass to millions of Suns. However, black holes of intermediate mass have notably eluded detection, prompting scientists to theorize why. New research suggests that intermediate-mass black holes might not have been discovered because they may not exist in our modern-day Universe for a very simple reason: the growth rate of black holes.
Scientists believe that stellar-mass black holes form when huge stars die and collapse inward. These are the “standard” black holes you might envision when you think of stars dying, or when you imagine the millions of black holes that dot our Universe. Supermassive black holes are those that form the hearts of large galaxies like our own Milky Way. To date, the oldest supermassive black holes found include a discovery from 2015 — a throwback to a much younger version of our Universe, when it was only about 875 million years old. The overall picture presented by our findings on supermassive black holes so far indicates that those early days of the Universe were friendlier for the formation of supermassive black holes, since matter was more concentrated in the much smaller Universe.
The ESA’s Science Program Committee met on June 20, and at the top of their agenda was addressing planning for the agency’s missions to come over the next 20 years — one of which will be a three satellite Laser Interferometer Space Antenna mission (LISA). The space antenna was designed to detect gravitational waves. The LISA mission has been selected to move forward and is set to launch in 2034.
The project uses the satellite trio to create a huge triangle in space. The satellites form the corners and lasers bouncing across the 2.5 million kilometers (1.55 million miles) between them form its sides. The triangle itself will follow Earth as it orbits the Sun. Meanwhile, the satellites will be sorting through an impressive array of cosmic noise to determine which signals are the most promising signs of supermassive black holes, and which are just false leads.
Starting Where LIGO Stops
The Laser Interferometer Gravitational-wave Observatory (LIGO) first detected gravitational waves in September 2015, confirming its initial findings when the waves were detected again in June of 2016. By February of 2017, scientists learned that LIGO also produces the waves. Earlier this year, LIGO detected the waves for the third time. They appear to be from a supermassive black hole that’s 49 times larger than our sun.
LISA is taking the detection of gravitational waves to the next level by searching for supermassive black holes millions of times larger than those found by LIGO. LISA should also be able to give scientists enough lead time to observe the black holes with telescopes, enabling us to discover more about how these collisions work.
“We’ll be able to see signals for months, so we’ll have time to point all these other telescopes at that point in the sky to see if there’s any other signals coming from that area when the merger happens,” ESA’s senior advisor for science & exploration Mark McCaughrean told New Scientist.
The Laser Interferometer Gravitational-wave Observatory (LIGO) just detected gravitational waves, ripples in time and space, for the third time. Two black holes collided, forming a huge black hole 49 times more massive than our sun, and this generated the waves. This kind of collision was also the cause of the waves detected previously by LIGO, although the masses of the black holes varied. This repetition of the discovery confirms that a new area of astronomy now exists.
“We have further confirmation of the existence of stellar-mass black holes that are larger than 20 solar masses — these are objects we didn’t know existed before LIGO detected them,” MIT’s David Shoemaker, a LIGO spokesperson, said in a press release. “It is remarkable that humans can put together a story, and test it, for such strange and extreme events that took place billions of years ago and billions of light-years distant from us. The entire LIGO and Virgo scientific collaborations worked to put all these pieces together.”
In September 2015, LIGO first directly observed these gravitational waves during its first run since receiving Advanced LIGO upgrades. The second detection followed in December 2015, and this latest detection, called GW170104, followed in January of this year. In each case, both of LIGO’s twin detectors perceived gravitational waves from the collisions of the black holes, but this latest observation does offer a few new pieces of information.
For example, it suggests which directions the black holes might be spinning in, and indicates that at least one of the black holes in the pair may not be aligned with the overall orbital motion. Scientists are hoping that they can learn more about how binary black holes form by making more LIGO observations.
This work is testing, and thus far providing proof for, the theories proposed by Albert Einstein. For example, the theory of relativity says that dispersion, the effect that happens as light waves in a physical medium travel at different speeds, cannot happen in gravitational waves. LIGO has not found any evidence of dispersion in gravitational waves, as predicted by relativity.
“It looks like Einstein was right — even for this new event, which is about two times farther away than our first detection,” Georgia Tech’s Laura Cadonati, the Deputy Spokesperson of the LIGO Scientific Collaboration (LSC), said in the press release. “We can see no deviation from the predictions of general relativity, and this greater distance helps us to make that statement with more confidence.”
Moving forward, the LIGO-Virgo team will keep searching LIGO data for any hint of gravitational waves emanating from the far corners of the Universe. The sensitivity of the detector will improve during the next run starting in late 2018 after researchers apply technical upgrades, hoping to see even more. Caltech’s David Reitze, the LIGO Laboratory’s executive director, said in the press release, “While LIGO is uniquely suited to observing these types of events, we hope to see other types of astrophysical events soon, such as the violent collision of two neutron stars.”
As much as our understanding of the universe has grown over the past decade, we are still a few missing of the threads that make up the interstellar tapestry. Among other things, we’ve yet to understand what accounts for more than 25 to 27 percent of the mass and energy and 80 percent of the gravity in our observable universe. This Dark Matter, scientists believe, could be made up of particles that remain undetectable and largely unknowable for us.
However, scientists have recently put forward a new model to help us understand these particles — and possibly to “hear” them as well.
To do this, they combined several of the craziest concepts in physics — such as Black Holes, Gravitational Waves, and dark matter. “The basic idea is that we’re trying to use black holes…the densest, most compact objects in the universe, to search for new kinds of particles,” researcher Masha Baryakhtar told Gizmodo.
Tuning In and Listening
Of course, it helps that gravitational waves — a fundamental part of Einstein’s general theory of relativity — have been discovered and confirmed in 2016, providing a handle to work with. The theory Baryakhtara and colleagues developed, which was published in the journal Physical Review D, puts forward a way to understand black holes and axions by following a “gravity atom” model.
In this model, a black hole works like an Atom with axions as electrons. Atoms and electrons interact via electromagnetism, whereas axions interact with a black hole via gravity. Axions jump around a black hole, gaining and losing energy and releasing gravitational waves. As the black hole rotates, it supercharges the space around it, producing more axions through what’s known as a superradiance effect. This could produce 10^80 axions — as many as the total number of atoms in the entire universe.
Now, with the estimated abundance of axions, the researchers believe it’s possible to actually hear the hum of the gravitational waves produced by this atom-like behavior of the black hole-axion system. “You’d see this at a particular frequency which would be roughly twice the axion mass,” said Baryakhtar said in the Gizmodo interview. To detect these, scientists can rely on the very instrument that detected gravitational waves in the first place, giant detectors called Laser Interferometer Gravitational Wave Observatory (LIGO).
These can be adjusted to tune in on axions. “With the current sensitivity we’re on the edge” of detecting axions, Baryakhtar explained. “But LIGO will continue improving their instruments, and, at design sensitivity, we might be able to see as many as 1000s of these axion signals coming in.”
Of course, this is still just theory, and theoretical physics is a tough field to work in. But instruments like LIGO are helping us understand the vast and largely unknown space outside of our world. Just as it’s helped discover gravitational waves, which previously existed only in theory, the LIGO may soon discover particles like axions. We may be entering a new era in physics.
Now, the most sensitive detector of spacetime ripples in the world turns out to also be the best producer of gravitational waves. “When we optimize LIGO for detection, we also optimize it for emission [of gravitational waves],” said physicist Belinda Pang from the California Institute of Technology (Caltech) in Pasadena according to a report in Science. Pang was speaking at a meeting of the American Physical Society last week, representing her team of physicists.
Gravitational waves are ripples that are produced when massive objects warp spacetime. They essentially stretch out space, and according to Einstein, they can be produced by certain swirling configurations of mass. Using uber-sensitive twin detectors in Hanford, Washington, and Livingston, Louisiana, LIGO is able to detect this stretching of space.
Once they realized they could detect gravitational waves, the physicists posited that the sensitivity of their detectors would enable them to efficiently generate these ripples, too. “The fundamental thing about a detector is that it couples to gravitational waves,” said Fan Zhang, a physicist at Beijing Normal University. “When you have coupling, it’s going to go both ways.” The LIGO team tested their idea using a quantum mathematical model and found that they were right: their detectors did generate tiny, optimally efficient spacetime ripples.
Quantum mechanics says that small objects, such as electrons, can be in two places at once, and some physicists think that it’s possible to coax macroscopic objects into a similar state of quantum motion. According to Pang, LIGO and these waves could be just the things to make it happen.
Though that delicate state couldn’t be sustained for very long periods, any amount of time could give us added insight into quantum mechanics. We could measure how long it takes for decoherence to occur and see what role gravity might play in the existence of quantum states between macroscopic objects. “It’s an interesting idea, but experimentally it’s very challenging,” explained Caltech physicist Yiqui Ma, one of Pang’s colleagues. “It’s unbelievably difficult, but if you want to do it, what we’re saying is that LIGO is the best place to do it.”
Any added insight into quantum activity could not only help us build better quantum computers, it could completely revolutionize our understanding of the physical universe. LIGO is already in the process of receiving upgrades that will help it detect even fainter gravitational waves, and eventually, the plan is to build the Evolved Laser Interferometer Space Antenna (eLISA), a gravitational wave observatory in space. Within the next decade, not only could LIGO be regularly detecting gravitational waves, it could also be finding ever more advanced ways to create them and furthering our understanding of the quantum world in unimaginable ways.
The transition from one year to the next is always a little uncertain – an uneasy blend of anxiety and optimism, it’s also a time of retrospection, introspection, and even a little tentative prognostication. And since the latter is our stock-in-trade at Futurism, we believe now is the perfect time to look ahead at what 2017 has in store for us.
And 2017, we feel pretty confident in predicting, will be even better. So, in that spirit, here’s a sample of what we think will be some of the most exciting headlines in space for the coming year.
LIGO and Virgo Join Forces
Gravitational wave astronomy had a pretty good year in 2016, no doubt about it. In fact, it was Year One for that fledgling science, but now it’s time to begin the systematization of the field and look to refine the instruments and hone their precision. 2017 will be the year that the LIGO telescopes in Washington and Louisiana are joined by the European Virgo interferometer in Italy, which will finally allow astronomers to triangulate the gravitational wave signals they’re detecting.
With luck, sometime in the coming year, we’ll finally pinpoint the location of the colliding black holes whose swan song we’ve been hearing in the ripples of spacetime; and by coordinating with space telescopes, we might even succeed in glimpsing a visual counterpart to the phenomenon.
Private Spaceflight Takes Off
Okay, maybe this one’s a little obvious — especially considering the enormous strides that the billionaire rocket-boys are yearly making. Still, it bears repeating…no, it bears shouting from the rooftops: every new advance in private spaceflight brings us closer to one of those great societal “phase transitions” — a new economy, a new paradigm, a whole new history.
Virgin Galactic is still looking to get back in the game after its SpaceShipTwo fatally broke apart over the Mojave Desert in 2014; and one of its other ventures, a commercial supersonic transporter, is slated to begin prototype testing in late 2017. Meanwhile, Bezos’ Blue Origin is still on track to begin launching test astronauts before the year’s end. And that’s a big deal, folks, because it would mean the private space companies have graduated from launching inert payloads of expensive electronics to finally lofting delicate packages of fragile human flesh — perhaps the most expensive resource we have.
So let’s hope 2017 isn’t just another year of remarkable firsts in private spaceflight. Let’s hope it marks a turning point in human history.
But SpaceX is set to blast into 2017 on Sunday with its first launch since the September disaster. Look for more milestones in the year ahead—from the long-awaited maiden flight of the Falcon Heavy, to test flights of its crew capsule (including a manned mission?—hey, we can dream), to further updates on Musk’s marvelous Martian stratagem.
The Red Planet has never felt closer than it does today; and nowadays it seems the world turns on Elon Musk’s dreams. So a healthy, pioneering SpaceX is something we can all root for.
The End of an Era
It seems that 2017 will also be the year we bid goodbye to the steadfast Cassini, whose Saturnian sojourn will finally come to an end when the probe plummets into the Ringed Planet’s atmosphere — a spectacular farewell salute to its longtime host. That day in the middle of September will be bittersweet — a sad but necessary conclusion to a two-decade mission that provided us with a wealth of discoveries, magnificent images, and forever changed our understanding of the Solar System.
The splendid little spacecraft will continue doing science up to the very end — spending some months swinging between Saturn and its mighty rings, and snapping pictures throughout its suicidal plunge into the great planet’s atmosphere.
Meanwhile, the launch of NASA’s TESS (Transiting Exoplanet Survey Satellite) by year’s end will further expand our understanding of the universe. Like its predecessor, the fruitful Kepler Telescope, TESS will use the transiting method to seek out new worlds, and…well, if we’re lucky, maybe new civilizations too. And don’t forget Juno, whose science mission at mighty Jupiter will really begin in 2017.
We’ve only picked out some of the most exciting potential trends and developments in space in 2017, extrapolating from last year and relying (perhaps overmuch) on the forecasts of private space companies and national space agencies.
But our greatest hopes for the new year lie in the unexpected—those new discoveries we just can’t predict, like the detection of GW150914, or the discovery of Proxima Centauri b, or finding the potentially habitable worlds of TRAPPIST-1.
So stay tuned to Futurism—it’s going to be an exciting year!
Read the rest of our series on the science and tech of 2017:
Physicists studying LIGO’s data on the black hole merger claim it reveals “echoes” of gravitational waves that contradict predictions made by Einstein’s general theory, which has been proven by LIGO on more than one occasion now. Previously, physicists believed that Einstein’s theory broke down in extreme conditions, such as those found at a black hole’s core. However, these recently discovered echoes seem to indicate that relativity fails around a black hole’s edges, far from its center.
As part of the standard model based on Einstein’s theory, nothing should be found at the edge of a black hole (its event horizon). This contradicts other theories such as the one that corresponds to quantum physics, which suggests that an event horizon should have a firewall, a ring of high-energy particles, around it.
Cosmologist Niayesh Afshordi at the University of Waterloo in Canada created models of these black hole mergers that assumed they did have something at their event horizons. The timing of the echoes following the release of gravitational waves in the mergers recorded by LIGO matched up perfectly with those expected by Afshordi’s models. This supports the idea that the edges of black holes do have some structure and not a whole lot of nothingness as suggested by Einstein’s theory.
The Puzzle That Is the Universe
“The LIGO detections, and the prospect of many more, offer an exciting opportunity to investigate a new physical regime,” said black-hole researcher Steve Giddings from the University of California, Santa Barbara (UCSB).
For now, more research is needed to see if these echoes were a fluke or something that will completely reshape our understanding of a black hole’s event horizon. If proven to be permanent fixtures of a merger, we would need a new theory to explain this and similar phenomenon — at least until the elusive theory of everything comes along.
In any case, observation of future black hole mergers can confirm whether these echoes were just flukes or random noise. “The good thing is that new LIGO data with improved sensitivity will be coming in, so we should be able to confirm this or rule it out within the next two years,” said Ashfordi.
It’s no surprise that the universe continues to confirm theories of physics one minute and break them the next. So much of the universe is still a big unknown as far as we’re concerned. Theories come and go, and although Einstein’s has been relatively successful, the emergency of new technologies will continue to allow us to challenge earlier assumptions.