News Article | May 10, 2017
Flash Physics is our daily pick of the latest need-to-know developments from the global physics community selected by Physics World's team of editors and reporters The first practical source of a randomly polarized stream of single photons has been created by physicists in Japan. The source is based on a negatively charged defect in diamond in which two adjacent carbon atoms are replaced by a nitrogen atom and a vacant lattice site. These "NV centres" have several properties that could make them useful for creating quantum-information systems – including the ability to emit single photons on demand. To date, work on single-photon sources has focused on supplying photons that are in specific polarization states. This is because quantum information can be encoded and transmitted in such polarization states. There are certain applications, however, that would benefit from a stream of photons in which the polarizations of successive photons are truly random and uncorrelated. Now, Keiichi Edamatsu, Naofumi Abe and colleagues at Tohoko University have shown that NV centres with a certain orientation with respect to the diamond lattice will emit randomly polarized photons. Writing in Scientific Reports, the team says that its source could find use as a random-number generator and also for performing tests on fundamental aspects of quantum mechanics. The production of J/ψ mesons in proton collisions in the Large Hadron Collider (LHC) at CERN does not agree with predictions made by a widely used computer simulation. That is the conclusion of physicists working on CERN's LHCb experiment who have studied the jets of hadrons that are created when protons collide at 13 TeV. These jets contain large numbers of J/ψ mesons, which comprise a charm quark and a charm anti-quark. The LHCb team was able to measure the ratio of the momentum carried by the J/ψ mesons to the momentum carried by the entire jet. It was also able to discriminate between J/ψ mesons that were created promptly by the collision and J/ψ mesons that were created after the collision by the decay of other particles. Analysis of the data reveals that PYTHIA – a Monte Carlo simulation used to model high-energy particle collisions – does a poor job at predicting the momentum carried by prompt J/ψ mesons. The possibility of such a discrepancy had already been identified in theoretical work and has now been confirmed experimentally. The apparent shortcomings of PYTHIA could have a significant effect on how particle physics is done because the simulation is used both in the design of collider detectors and also to determine which measurements are most likely to reveal information about physics beyond the Standard Model of particle physics. The measurement is described in Physical Review Letters. The Search for Extraterrestial Intelligence (SETI) Institute has named its first fellows. Seth Shostak, Mark Showalter and Edna DeVore were honoured at SETI's first annual gala fundraiser for their contributions to scientific research and outreach. Shostak has been with SETI for 26 years as its senior astronomer, overseeing the radio-observing programmes. He also hosts SETI's radio show and podcast, and is the editor for the institute's magazine Explorer. Senior scientist Showalter specializes in planetary rings and moons. Over the course of his 12 years at SETI, he has discovered three planetary rings and six moons, including Saturn's Pan and Pluto's Kereros and Styx. DeVore is the institute's director of education and during her 25 years at SETI she also served as acting chief executive for two years. She has led outreach and education projects for NASA missions, including SOFIA and Kepler, and oversees the Research Experience for Undergraduates programme, funded by the National Science Foundation. "Mark, Edna and Seth have distinguished themselves throughout their careers through groundbreaking work and an uncompromising commitment to excellence and innovation," says William Diamond, who heads the SETI Institute.
News Article | May 20, 2017
In 2015, astronomers discovered what's become known as one of the strangest stars seen so far in the universe. Weird things are happening around KIC 8462852 (aka Tabby's Star or Boyajian's Star) once again, sending scientists into a panic to get as many big telescopes trained on it as possible. What's weird about the star is that it goes through dramatic and somewhat random periods of getting dimmer from our viewing perspective here on Earth. Stars tend to get dim when things like planets or even huge clouds of dust pass in front of them, but that kind of thing usually happens on a regular schedule, and only accounts for slight amounts of dimming. But the dimming observed at KIC 8462852 doesn't fit the usual patterns of planets or a companion star (which it does have, but it's very distant and can't explain what astronomers are seeing). To make things weirder, the star has also shown a 15 percent decrease in brightness over the past century. This week, observations of the star located some 1,400 light-years away showed a potentially major dimming event was beginning to happen again. This sent astronomers like Tabetha Boyajian, who is credited with discovering the star and its odd nature, scrambling on social media and elsewhere to get "eyes" on the system, both human and technological. Astronomer Jason Wright put out a similar call and took questions via a livestream Friday afternoon about the event. When the star first made headlines, Wright threw out the admittedly far-fetched hypothesis that giant alien megastructures like a partially constructed Dyson sphere could explain the odd patterns of dimming, including the slow dimming over the last century. (It's slow to humans, but actually quite significant and fast on cosmic time scales.) Wright said that as of early Friday, the star had dimmed very suddenly by 3 percent in just a few days. "And so we are officially on alert and we are asking astronomers on telescopes ... to please take spectra (light measurements) of the star," Wright said. Most scientists, including Wright and Boyajian, don't think it's very likely that there is an alien civilization building planet-size structures around one of their stars. They think that something like a swarm of colliding comets around the star could make the most sense. But the star's behavior continues to be very unusual to the point that most potential explanations can't really be ruled out, including some very industrious aliens. There have already been some efforts to check KIC 8462852 for alien signals that could come from an intelligent civilization, and that search has returned nothing so far. Perhaps that will change this weekend though. Wright and colleague Andrew Siemion from the Berkeley SETI Research Center said Friday that they're hoping to using telescopes at UC Berkeley and the huge National Radio Astronomy Observatory radio telescope in Green Bank, West Virginia, to check out the weirdest star in the galaxy while it's doing its very weird thing. Technically Literate: Original works of short fiction with unique perspectives on tech, exclusively on CNET.
News Article | May 25, 2017
Inauguration with Essay on Exoplanets by SETI Scientist The newly launched science platform Capeia not only seeks to stimulate discussion but is also committed to spreading the information and ideas that are expressed on this website into the depths of the World Wide Web. So much so that it provides an extra crowdfunding scheme to collect funds with which to provide a reward on a monthly basis for the scientist whose contribution attracts the most attention. For accurately determining an article’s attention, Capeia has conceived an algorithm that not only covers conventional parameters such as views and shares but also measures whether an article is read entirely or dropped halfway through. Furthermore, significant weight is put onto whether visitors’ comments or inquiries are addressed by the author in due time. Capeia, therefore, does not define impact merely through the response an article draws by the community but explicitly observes the attention it gets by its author following publication. Rüdiger Schweigreiter, Editor: “Capeia does not support a ‘Fire and Forget’ publishing policy. Impact is not a one-way street. We do not limit the definition of impact to the attention an article receives from the audience but extend it to the post-publication attention it gets from its author. Taking into account both the audience and the author for metric analysis lives up to Capeia’s mission to strengthening the relationship between scientists and the interested public.” Capeia is proud to put this scoring algorithm into use with an article on exoplanets by SETI scientist Franck Marchis. In this essay, Dr. Marchis expounds the state of the art of exoplanet detection and outlines future technological possibilities. A simulation, which is shown here for the first time, illustrates what exoplanets might look like when viewed through the next generation of telescopes that are currently under construction.
News Article | May 24, 2017
The discovery of these and other extra-solar planets (and their potential to host life) was an overarching theme at this year's Breakthrough Discuss conference. Taking place between April 20th and 21st, the conference was hosted by Stanford University's Department of Physics and sponsored by the Harvard-Smithsonian Center for Astrophysics and Breakthrough Initiatives. Founded in 2015 by Yuri Milner and his wife Julia, Breakthrough Initiatives was created to encourage the exploration of other star systems and the search for extra-terrestrial intelligence (SETI). In addition to prepping what could very well be the first mission to another star system (Breakthrough Starshot), they are also developing what will be the world's most advanced search for extra-terrestrial civilizations (Breakthrough Listen). The first day of the conference featured presentations that addressed recent exoplanet discoveries around M-type (aka. red dwarf) stars and what possible strategies will be used to study them. In addition to addressing the plethora of terrestrial planets that have been discovered around these types of stars in recent years, the presentations also focused on how and when life might be confirmed on these planets. One such presentation was titled "SETI Observations of Proxima b and Nearby Stars", which was hosted by Dr. Svetlana Berdyugina. In addition to being a professor of astrophysics with the University of Freiburg and a member of the Kiepenheuer Institute for Solar Physics, Dr. Berdyugina is also one of the founding members of the Planets Foundation – an international team of professors, astrophysicists, engineers, entrepreneurs and scientists dedicated to the development of advanced telescopes. As she indicated during the course of the presentation, the same instruments and methods used to study and characterize distant stars could be used to confirm the presence of continents and vegetation on the surface of distant exoplanets. The key here – as as been demonstrated by decades of Earth observation – is to observe the reflected light (or "light curve") coming from their surfaces. Measurements of a star's light curve are used to to determine what type of class a star is and what processes are at work within it. Light curves are also routinely used to discern the presence of planets around stars – aka. the Transit Method, where a planet transiting in front of a star causes a measurable dip in its brightness – as well as determining the size and orbital period of the planet. When used for the sake of planetary astronomy, measuring the light curve of worlds like Proxima b could not only allow astronomers to be able to tell the difference between land masses and oceans, but also to discern the presence of meteorological phenomena. These would include clouds, periodic variations in albedo (i.e. seasonal change), and even the presence of photosynthetic life forms (aka. plants). For example, and illustrated by the diagram above, green vegetation absorbs almost all the red, green and blue (RGB) parts of the spectrum, but reflects infrared light. This sort of process has been used for decades by Earth observation satellites to track meteorological phenomena, measure the extent of forests and vegetation, track the expansion of population centers, and monitor the growth of deserts. In addition, the presence of biopigments caused by chlorophyll means that the reflected RGB light would be highly-polarized while UR light would be weakly polarized. This will allow astronomers to tell the difference between vegetation and something that is simply green in color. To gather this information, she stated, will require the work of off-axis telescopes that are both large and high-contrast. These are expected to include the Colossus Telescope, a project for a massive telescope that is being spearheaded by the Planets Foundation – and for which Dr. Berdyugina is the project lead. Once completed, Colossus will be the largest optical and infrared telescope in the world, not to mention the largest telescope optimized for detecting extrasolar life and extraterrestrial civilizations. It consists of 58 independent off-axis 8-meter telescopes, which effectively merge their telescope-interferometry to offer an effective resolution of 74-meters. Beyond Colossus, the Planets Foundation is also responsible for the ExoLife Finder (ELF). This 40-m telescope uses many of the same technologies that will go into Colossus, and is expected to be the first telescope to create surface maps of nearby exoplanets. And then there's the Polarized Light from Atmospheres of Nearby Extra-Terrestrial Planets (PLANETS) telescope, which is currently being constructed in Haleakala, Hawaii (expected to be completed by January 2018). Here too, this telescope is a technology demonstrator for what will eventually go into making Colossus a reality. Beyond the Planets Foundation, other next-generation telescopes are also expected to conduct high-quality spectroscopic studies of distant exoplanets. The most famous of these is arguably NASA's James Webb Telescope, which is scheduled to launch next year.
News Article | May 26, 2017
A strange star that has baffled astronomers for more than two years has started displaying highly unusual behavior again, leaving astronomers excited at the prospect of finally finding out what exactly is going on. KIC 8462852 is star with a mass about 1.5 times the size of the sun, and it’s almost five times brighter. In 2015, astronomers led by Tabetha Boyajian of Louisiana State University announced something very odd was happening to the star’s luminosity, or brightness. Astronomers normally track a star’s luminosity in order to find out about the planets orbiting it. When a planet passes in front of a star, some of the light is blocked out, and the luminosity drops. Trending: Rex Tillerson Declines to Host Ramadan Event at State Department, Breaking 18 Years of Tradition After analyzing data from the Kepler Space Telescope, scientists discovered huge dips in KIC 8462852’s brightness that lasted between five and 80 days, with the star sometimes losing as much as 20 percent of its luminosity. A dip of 20 percent means something absolutely ginormous must be passing in front of it. To put it into perspective, if we were observing Jupiter (the biggest planet in our solar system) passing in front of the sun from a distant galaxy, it would block out around 2 percent of the light. The dimming was also irregular—a planet passing a star would take place at regular intervals, with the same dip in brightness each time—and it varied in intensity. Often there were just small dips of a few percent. That meant whatever was causing those dips was a mystery. Ever since KIC 8462852’s weird behaviour was discovered, scientists have proposed several hypotheses: a huge family of comets swarming the star; another massive and as-of-yet undiscovered star; KIC 8462852 consuming a planet. But none have been able to fully explain the dimming. A more headline-grabbing proposal was that the dips were the result of an “alien megastructure.” Theoretical physicist Freeman Dyson had popularized the idea of such a structure back in the 1960s. He said that an advanced alien civilization would eventually develop the technology to harness energy from its star. One way to do this would be to build a huge structure around said star, that could generate power from it. While scientists generally agree that this is a very remote possibility, it cannot be completely ruled out. Researchers with the Search for Extraterrestrial Intelligence (SETI) looked for radio signals coming from the star’s galaxy (which could be a sign of alien life) but failed to find any. Over the last two years, astronomers have continued to monitor the star for further signs of activity. Being able to watch the dips as they are happening with a variety of telescopes and instruments will allow them to take more accurate measurements—potentially allowing them to find out what is going on. On May 19, Boyajian announced that KIC 8462852 had started dipping again, causing a flurry of excitement. Jason Wright, associate professor of astronomy and astrophysics at Pennsylvania State University, who initially proposed the possibility of an alien megastructure, tweeted: “ @tsboyajian's star is dipping. This is not a drill. Astro tweeps on telescopes in the next 48 hours: spectra please!” In a YouTube discussion about the dimming on May 19, Wright said they had been “on alert” for around a week before the dimming fully began. “Just in the last two days it got suddenly dimmer,” he said, adding that they had confirmed the light from the star had dipped by 3 percent. “That was enough to say this was no statistical fluke.” Most popular: Jared Kushner and the Kremlin: Trump Son-in-law and Adviser Had Undisclosed Contacts With Russian Ambassador Following the announcement, astronomers around the globe took time from their own scientific research and turned their telescopes to KIC 8462852. The data from their recordings is now being filtered back to the teams involved. Wright said they do not expect to solve the mystery of KIC 8462852 anytime soon; they are currently analyzing a huge amount of data collected. “We have data we haven’t even had a chance to look at yet,” Wright tells Newsweek. “We are literally just trying to figure out how to put it all in one place so everyone can see it organized in a way that people know how to use it. “We want to let anyone who wants to work on this help. This is the first clear dip we’ve seen since the Kepler mission [where the dips were initially noticed].” Wright says the periods of dimming are “unpredictable,” though previous data indicates they occur in bunches. “So we’re hopeful this is just the first of many, and hopefully even deeper, dips to come in the near future. But even if not, even if it’s another year, we have so much data I’m sure we’ll be able to exclude some possibilities.” At the moment, it looks like the current dip is coming to an end. “Of course we don’t know, and we don’t know if another is about to start,” Wright adds. Since the latest dip began, two new proposals for the cause have been put forward. Both appear on arxiv.org, an online server where scientists can share their research before it is formally published. The first proposal suggests an object in the outer solar system, while the other points to a massive planet with two trails of “Trojan asteroids.” The second, Wright says, is a “very creative proposal.” The study suggests there is a large planet orbiting KIC 8462852. This planet is preceded and followed by a huge cloud of Trojan asteroids. The orbital period is 12 years, so we should see a full cycle of dimming again in 2021. “It’s a neat proposal,” says Wright. “It addresses some but not all of the weirdnesses of the star. It’s a very clever way to explain why there were quite a few dips at the beginning of the Kepler mission, then not very many except for one very extraordinary dip that occurred about halfway through. And then a very large number of dips at the end. “I should say there are still some big difficulties with this model. At the moment it’s just a proposal, it’s not a fully fleshed-out model. It’s very clever but it doesn’t explain a long-term dimming we see, or the lack of infrared. It also proposes some phenomena that are at least as extraordinary as anything else that’s been proposed.” However, if correct, scientists would be able to confirm it within the next decade. “It has to be a 12-year period. So it has to come back,” Wright says. “I hope we will have figured it out by then—but if this is right, then we might see a repeat performance of the asteroids in 2021, and eventually the planet itself.” NASA's Trappist-1 Planets Could Be Seeding Each Other with Alien Life How Science Might Be Able to Explain UFO Sightings and Alien Abductions
News Article | April 21, 2017
A few years ago, the search for extraterrestrial intelligence was in the doldrums. Short of cash, astronomers were forced to beg for scarce time on tiny telescopes, relying on volunteers to donate their spare computing power for analysis. Then, in 2015, Russian entrepreneur Yuri Milner came along, donating a vast sum of money to the cause. The result was the Breakthrough Initiatives, a 10-year program to search more than a million stars for artificial radio and laser signals. The first results in that search are already in. For 692 stars, the Breakthrough Initiative team looked for signals that appeared unnatural or unusual in some way, and last night the details of the 11 events ranked highest for significance. In a press release, the team wrote: "The pipeline produced millions of hits for the sample as a whole, of which the vast majority are almost certainly radio frequency interference from human technology." Don't get too excited though, because the team doesn't reckon that any of them are aliens yet. "Eleven events rose above the pipeline threshold for significance, but further detailed analysis indicates that it is unlikely that any of these signals originate from artificial extraterrestrial sources," they said. But the hunt continues. Every six months, they've promised to , complete with the software used for analysis, so that enthusiasts around the world can help develop increasingly sophisticated algorithms to comb through it. “With the submission of this paper, the first scientific results from Breakthrough Listen are now available for the world to review,” said Andrew Siemion, director of the University of California, Berkeley’s SETI Research Center. “Although the search has not yet detected a convincing signal from extraterrestrial intelligence, these are early days. The work that has been completed so far provides a launch pad for deeper and more comprehensive analysis to come.” Meanwhile, the European Southern Observatory has details of a newly-discovered exoplanet which it claims is the best candidate yet in the search for life. The planet, which bears the catchy name LHS 1140b, is a little larger but much more massive than Earth and orbits in the habitable zone of the faint star LHS 1140. Most excitingly, though, the observatory believes that it has retained most of its atmosphere. “This is the most exciting exoplanet I’ve seen in the past decade,” said Jason Dittmann of the , lead author of a paper describing the discovery. “We could hardly hope for a better target to perform one of the biggest quests in science — searching for evidence of life beyond Earth.” Xavier Delfosse and Xavier Bonfils, who both contributed to the discovery, added: “The LHS 1140 system might prove to be an even more important target for the future characterisation of planets in the habitable zone than Proxima b or TRAPPIST-1. This has been a remarkable year for exoplanet discoveries!”
News Article | April 25, 2017
(Phys.org)—The team of researchers working on the Breakthrough Listen project (based at the University of California, Berkeley SETI Research Center) has released preliminary findings after sifting through several petabytes of data obtained from three telescopes involved in the research project. The findings have been made available on the project's website as the team awaits publication of a paper in the Astrophysical Journal.
News Article | April 26, 2017
THE most ambitious search so far for extraterrestrial intelligence has released its first data – and there are no aliens yet. The lack of success could be explained by the result of a new approach to calculating the likelihood of detecting alien signals. This calculation suggests we might never make contact, even if extraterrestrial life is common. The search for extraterrestrial intelligence (SETI) has been active for decades. Breakthrough Listen aims to be the largest, most comprehensive search ever. The $100 million initiative uses three of the world’s most sensitive telescopes to look for alien signals from the 1 million closest stars to Earth and the 100 closest galaxies. “It’s like finding a needle in a haystack,” says Seth Shostak at the SETI Institute in California. “But we don’t know how many needles are there.” Breakthrough Listen team members have analysed the light from 692 stars so far. They have found 11 potential alien signals, none of which remained promising after further analysis. “It’s the beginning of a very exciting time,” says Avi Loeb at Harvard University. “But while it’s exciting, it’s still very risky. We could find nothing.” That’s exactly what an assessment by Claudio Grimaldi at the Swiss Federal Institute of Technology in Lausanne predicts. Most methods for calculating the likelihood of detecting alien signals start with an expected number of sources. Instead, Grimaldi started with what volume of the galaxy could be reached by alien signals, a value that requires fewer assumptions about the nature and abundance of extraterrestrial life. “It’s the beginning of a very exciting time. But while it’s exciting, it’s still very risky. We could find nothing” Grimaldi assumed that signals from an extraterrestrial emitter might get weaker or be blocked as they travel, so they would only cover a certain volume of space. It’s relatively simple to calculate the probability that Earth is within that space and so able to detect the signal. “Not all signals can be visible at the same time – only those that intersect with the Earth,” says Grimaldi. He found that even if half of our galaxy was full of alien noise, the average number of signals that we would be able to detect from Earth is less than one (Scientific Reports, doi.org/b562). This implies that, even if there are lots of aliens out there, we might never be able to hear from them. But some researchers take umbrage: Grimaldi’s method still requires you to plug in numbers for how far alien signals could be detectable and how long they last – neither of which is known. “You have to make some assumptions about what the aliens are doing in all these calculations, unfortunately, and the data set that we have with alien activity is fairly sparse,” says Shostak. Our only example of intelligent life is on Earth, and there’s little reason to expect that ET resembles us. But, says Loeb, extraterrestrial signals should be no harder to find than other astronomical events. “The question of whether you can detect a signal has nothing to do with whether it’s artificial or natural, and astronomers routinely detect lots of kinds of signals,” he says. “In SETI, theory is great, but observation is the gold standard,” says Douglas Vakoch, president of METI International, which aims to send messages to extraterrestrial intelligence. It’s not difficult to think up a different signal that we would be able to detect, he says. For example, if there were alien life at the TRAPPIST-1 planets, just 40 light years away, they wouldn’t need particularly advanced technology to contact us. It seems implausible that we would miss their call. This article appeared in print under the headline “Why we might never detect alien signals”
News Article | March 20, 2017
Adding a page to the book of regenerative medicine that is all about treating body parts and repair of tissues with engineered alternatives, scientists at the University of Ottawa have demonstrated that human tissues can be grown on apples. In technical terms, this type of tissue development is known as biohacking. Andrew Pelling, who is heading the Pelling Laboratory at Ottawa University's Laboratory for Biophysical Manipulation, has been spearheading research to go beyond the possibilities of genetic and chemical manipulation of cells. Pelling's objective was to study the behavior of cells when physical surroundings change. The method was successfully tested on lab mice by injecting the cellulose scaffolding under its skin. Currently, it is in the developmental stage, and the method is yet to be used in human beings. The study has been published in PLOS One. The new strides in biohacking are demonstrated at Pelling's lab, where an ear enclosed in a dish on a sheet-metal is on display. It could be mistaken for a human ear, but in reality, it is an apple carved in the shape of an ear. Good preparation goes into making the apple grow human tissues. Removing cellulose is the first part to populate the human tissues. To extricate the cellular material, apple is bathed in boiling water and liquid dish soap to break open the apple's cells. When the apple's cellular material is gorged out, rigid cellulose scaffolding remains, to which the mammalian cells are appropriately packed. "Biohacking is the new gardening," notes Pelling. The new method is inspiring scientists to grow human tissues not only on apples but in other plant products as well. More options will mean regenerative medicine getting a fresh leg up with more scaffolds to graft skin and bone. This open-source approach is cost effective because no proprietary host is sought, and a biomaterial such as an apple is quite cheap and readily available. That makes a cost difference of shelling out $1,000 versus a few pennies for a scaffold. In creating alternatives for body tissues, the traditional focus has been on animals. There was obvious reluctance to leverage the plant kingdom despite its flexibility to offer a wide variety of architectures that can handle the requirements of human physiology. For doctors, the challenge has been creating organs using the right materials that can grow new cells in the desired shape and structure. In open-source biohacking, collagen structures are prepared to colonize the proprietary cells of a patient by scrapping the dependence on polymer molds. That takes away the big cost burden induced by organic biomaterials that are manmade and commercially produced by companies. "This kind of exploratory work is important, because it expands the toolkit," commented Jeffery Karp, a biomaterials expert at Harvard Medical School. He said fundamental discoveries like this would provide better options for practitioners of translational medicine. The experiments at Pelling Lab are also buoyed by the support of Canada's somewhat-liberal regulatory regime in health care. The regulatory climate is a bit different from the scene in Europe and the United States, where resistance is high against genetically modified organisms. Canada encourages biohacking for possible applications in medicine. Pelling, on his part, is trying to broad base the methods for involving the general public in the experiments. His vision is that by merely tweeting the experiments to the lab and working on do-it-yourself projects from home, the public should contribute to biohacking by working on their own equipment and biomaterials around them. "Imagine people set up cell cultures the same way they donate computer power to SETI," adds Pelling. Meanwhile, Japan's Hitachi Chemical will acquire PCT, a leading American company in regenerative medicine. The Asian company will expand its equity base from the existing 19.9 percent to take the remaining 80.1 percent from Caladrius Biosciences to make the U.S. company a wholly owned subsidiary. Hitachi Chemical plans to produce cells used in treatments for cancer and other diseases at a new Yokohama facility for rapid international expansion. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.
News Article | April 17, 2017
In the last decade, the Keck Observatory in Hawaii, one of the world’s most powerful telescopes, has spent hours staring at the night sky in search of exoplanets and accumulating huge amounts of data about potential new worlds elsewhere in the Milky Way. But maybe, Nate Tellis wondered, Keck might have picked up something else along the way. Somewhere in all that data, could there be a signal from an intelligent civilization trying to reach Earth? Tellis is a scientist at the University of California at Berkeley, where, as his LinkedIn biography puts it, he spends his days “trawling” astronomy datasets for statistical deviations, trying to figure out whether they’re actually extraterrestrial pings. He searches particularly for laser light, powerful pulses of photons that could be as short as a nanosecond. Tellis, along with astronomer Geoff Marcy, recently dug into the Keck archives for data from 5,600 stars, observed between 2004 and 2016. Tellis and Marcy built a laser-detecting computer algorithm to comb through all that recorded starlight—and the result, detailed in a recent study in the Astronomical Journal, is the largest survey of its kind in the field of optical-based searches for extraterrestrial life. Recommended: America Can’t Do Much About North Korea It didn’t find anything. So far, this has been par for the course when it comes to the search for extraterrestrial life, better known by the shorthand SETI. Astronomers first began using telescopes to look for potential alien communication in 1960, and they have been met with silence ever since. “I think when you’re doing a SETI project, it’s very important not to get discouraged by a null detection,” Tellis said. “SETI has been in process for about 60 years, and it’s been non-detection after non-detection after non-detection.” Astronomers and engineers have spent that time developing more powerful technology to conduct SETI surveys. The majority of SETI searches have relied on radio telescopes, which scour the skies for signals in the radio and microwave parts of the light spectrum. In the 1960s, “lasers were new, tricky, low-power devices; by contrast, radio technology had been developing for decades and was relatively mature,” according to a history from the SETI group at Harvard. These days, lasers can outshine the sun, albeit in tiny pulses. But a tiny pulse—preferably more than one, to prove it’s not a fluke—is all it would take for a distant, advanced civilization to tell Earth “hey, we’re here!” If humans can get really good at sending radio and laser signals, the reasoning goes, maybe intelligent civilizations beyond Earth can, too—and then send them our way. Unlike radio SETI, optical SETI looks for signals in the visible portion of the light spectrum. Lasers travel well over galactic distances. The light, concentrated into a narrow beam that can be 10 times as bright as the sun, would experience less interference from interstellar dust and gas than radio waves might. Laser emissions are also capable of carrying massive amounts of information. The network of cables at the bottom of the ocean is a collection of pulses of light, firing at high frequencies to transmit digital data and bring us the internet. The dataset Tellis used for his study contained thousands of observations of stars as young as 200 million years and stars as old as nearly 10 billion years. Keck’s instruments collected millions of photons of light from these stars. What Tellis and his algorithm looked for were brief surges in photons. The first run of the data reported 5,000 potential candidates for mysterious laser beams, but they were eventually ruled out, explained away as emissions from stars’ outer layers, cosmic rays from our sun, or internal reflections from telescope instruments. Tellis got some firsthand Keck time to observe at least one target, KIC 8462852, a star about 1,500 light-years from Earth. In 2015, astronomers announced the Kepler space telescope had observed an unusual dimming of its light, which some believe could be caused by structures built by an advanced civilization around the star. The light emission observed from KIC 8462852 was the best candidate for an alien laser beam in the survey before it was ruled out. The results may not have been surprising, but the method is noteworthy, says Jason Wright, an astronomer at Penn State University who contributed to some of the software code Tellis and Marcy used in the study. Recycling astronomical datasets that were produced for another purpose is pretty unusual, but it makes sense. There is strong competition among astronomers for observation time on the world’s best telescopes, and SETI proposals are usually low on the priority list. “If you proposed to do a laser SETI study on Keck with thousands of hours, there’s nobody that will let you do it,” Wright said. Meanwhile, there’s plenty of astronomical datasets sitting around, waiting for a second look. One man’s trash is another man’s treasure, even in the search for life in the universe. Tellis, Wright said, “was digging through all the trash in case someone threw out a diamond.” Tellis’s survey, like all SETI surveys, has its limitations. The data examined only some types of stars, in a specific wavelength range, and in Earth’s cosmic neighborhood. The telescope may not have been able to detect signals that were too faint or too bright, and too far away. Optical SETI also depends on something beyond our control: a laser beam must first be aimed at Earth for it to be detected. Imagine another life-form on a distant world conducting the same kind of search, Tellis said. “If we had pointed our telescope at Earth at sort of the distance that we’ve been doing here, we wouldn’t have seen us,” he said, because Earth is not firing a laser beam into the universe as a beacon of its existence. Other worlds may not be, either. “Every single one of those stars could have a New York City, a Paris, a London, and we would have no idea,” Tellis said. Read more from The Atlantic: The Easter Egg Roll and the Bygone Era of White House Openness Will Tesla Do to Cars What Apple Did to Smartphones? This article was originally published on The Atlantic.