Tagged: Extraterrestrials Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 8:40 am on May 15, 2016 Permalink | Reply
    Tags: , , Extraterrestrials, , WOW signal 1977   

    From livescience: “Alien ‘Wow!’ Signal Could Soon be Explained” 

    Livescience

    April 19, 2016 [this just appeared in social media]
    Ian O’Neill

    1
    A color scan of the original computer printout of the “Wow!” signal as detected by the Big Ear Radio Observatory in 1977.
    Credit: Big Ear Radio Observatory and North American Astrophysical Observatory (NAAPO)

    The story behind the famous “Wow!” signal has an eerie quality that has inspired countless science fiction alien encounters and is often lauded as one of the strongest pieces of evidence that we are, in fact, not alone in the universe.

    However, its “alien intelligence” authenticity has been questioned since that fabled night on Aug. 15, 1977 at 10:16 p.m. ET when astronomer Jerry Ehman used the Ohio State University’s Big Ear radio telescope to sweep the skies for signals that may have originated from an extraterrestrial civilization.

    Ohio State Big Ear Radio Telescope

    On that night, Ehman found something. And since that night, astronomers have been trying to figure out what it means.

    While pointed in the direction of 3 star systems named Chi Sagittarii, in the constellation of Sagittarius, Big Ear detected a 72 second radio wave burst, a signal far stronger than background noise. On the observatory’s computer printout, Ehman circled the burst with the infamous annotation “Wow!”

    This excitement wasn’t an overstatement, it was this kind of signal he was looking for, the kind of signal astronomers thought a technologically-capable alien civilization would produce.

    The Big Ear printout contains a bunch of apparently random numbers and letters, but Ehman’s red pen circles a cluster of digits “6EQUJ5” with other circles around a “6” and “7” on separate columns. This particular code first uses the numbers 1-9 and then the alphabet A-Z to denote signal strength. As the burst suggests, the signal strength hit “6” and then blasted through the letters reaching a peak of “U” before subsiding back into the numerical scale at “5.” There was then a slight wave trailing the main signal (hence the circled “6″ and “7”). The wave profile of the “Wow!” signal is graphically envisaged here.

    However, since that day in 1977, a detection of a signal of that strength has not been replicated. Even after the SETI Institute was founded in 1984, and countless efforts have been made to find another radio burst like the “Wow!” signal, astronomers have been faced with silence in the cosmos; a problem that has only served to intensify the Fermi Paradox unease.

    SETI Institute

    Now, Antonio Paris of St Petersburg College, Fla., an ex-analyst of the US Department of Defense, hopes to solve the mystery and he suspects that an entirely different cosmic phenomenon is to blame.

    In an interview with The Guardian.com, Paris says that his investigative background sent him on a mission to find another possible explanation for the “Wow!” signal and he tracked down two “suspicious” comets that may have been in the vicinity of Chi Sagittarii on Aug. 15, 1977. Interestingly, these comets, called 266P/Christensen and 335P/Gibbs, were only discovered in 2006 and 2008, so weren’t considered as possible reasons for the signal in 1977 as no one knew of their existence.

    But what have comets got to do with errant radio bursts?

    The “Wow!” signal was recorded in the 1420MHz radio frequency band. It just so happens that cosmic neutral hydrogen naturally radiates at this frequency — it is therefore an abundant signal that is commonly used in astronomy. This is no coincidence; through alien-hunting logic, should there be an extraterrestrial species wanting to make contact, what frequency would they use? Firstly, as we only have ourselves to use as an alien template, we have to assume that hypothetical aliens will likely use radio waves. Secondly, if they are using radio waves to communicate with us, they would likely use a frequency that other intelligent aliens would be naturally tuned into. 1420MHz is the “universal water cooler,” where intelligent life could check into and potentially chat.

    The bummer is, however, that comets contain copious amounts of hydrogen in their atmospheres. Say if the “Wow!” signal was actually caused by the chance passage of a comet through the radio telescope’s field of view, packing a powerful radio surge?

    In 2017, Comet 266P will once again orbit in front of Chi Sagittarii and Comet 335P will do so the following year and Paris wants to test this hypothesis. Unfortunately, existing radio telescopes are already booked, so he has to buy or build his own radio antennae in time for the cosmic encounters. He has a crowdfunding campaign set up to raise the $20,000 he needs and is most of the way there.

    It may be a long shot, but as is the way with many astronomical studies, all possible phenomena need to be ruled out before a discovery is made and, should Paris’ experiment prove the “Wow!” signal was in fact caused by interference by an undiscovered comet, the universe will get quieter once again, making the Fermi Paradox even more bewildering.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 3:48 pm on March 1, 2016 Permalink | Reply
    Tags: , , ET Search: Look for the Aliens Looking for Earth, Extraterrestrials, ,   

    From SA- “ET Search: Look for the Aliens Looking for Earth” 

    Scientific American

    Scientific American

    March 1, 2016
    Alexandra Witze

    Planet transit
    Light Curve of a Planet Transiting Its Star. NASA/Kepler

    By watching how the light dims as a planet orbits in front of its parent star, NASA’s Kepler spacecraft has discovered more than 1,000 worlds since its launch in 2009.

    NASA Kepler Telescope
    NASA/Kepler

    Now, astronomers are flipping that idea on its head in the hope of finding and talking to alien civilizations.

    Scientists searching for extraterrestrial intelligence should target exoplanets from which Earth can be seen passing in front of the Sun, says René Heller, an astronomer at the Max Planck Institute for Solar System Research in Göttingen, Germany. By studying these eclipses, known as transits, civilizations on those planets could see that Earth has an atmosphere that has been chemically altered by life. “They have a higher motivation to contact us, because they have a better means to identify us as an inhabited planet,” Heller says.

    About 10,000 stars that could harbour such planets should exist within about 1,000 parsecs (3,260 light years) of Earth, Heller and Ralph Pudritz, an astronomer at McMaster University in Hamilton, Canada, report in the April issue of Astrobiology. They argue that future searches for signals from aliens, such as the US$100-million Breakthrough Listen project, should focus on these stars, which fall in a band of space formed by projecting the plane of the Solar System out into the cosmos.

    Breakthough Listen
    Breakthrough Listen Project

    Breakthrough Listen currently has no plans to search this region; it is targeting both the centre and the plane of our galaxy, which is not the same as the plane of the Solar System, as well as stars and galaxies across other parts of the sky.

    The idea of searching for worlds whose inhabitants could see Earth transits dates back to at least the 1980s. But astronomers can now update and revise their ideas thanks to what they have learned from Kepler, Heller says.

    In the zone

    The zone of space in which Earth transits would be visible is a relatively narrow strip. It gets even narrower if restricted to geometries in which the Earth passes less than half a solar radius from the Sun’s centre—which gives a transit that should be easily visible, if aliens have a tool similar to Kepler.

    Heller and Pudritz went through a catalogue of stars compiled using data from the Hipparcos satellite and found 82 Sun-like stars in this zone that are within 1,000 parsecs of Earth. Because not all of the stars in this region of space have been discovered, Heller and Pudritz extrapolated the number of known stars to the number that probably exists and came up with roughly 10,000 candidate stars. If these stars have planets, and if the planets have intelligent life forms, they could have long ago spotted the blink of an Earth transit and begun beaming signals towards us, Heller says.

    One of the closest known stars in the zone is Van Maanen’s Star, only 4 parsecs away. It is a white dwarf star, the remains of a stellar explosion, and may or may not have planets orbiting it. But if they did exist, they would provide a ringside seat for watching Earth. “If any civilization survived the death of their star, they could see us transiting our own Sun,” says Heller.

    For four days in 2010, the Allen Telescope Array in northern California looked for signals coming from the region of space directly opposite the Sun, says Seth Shostak, an astronomer at the SETI (search for extraterrestrial intelligence) Institute in Mountain View, California.

    Allen Telescope Array
    Allen Telescope Array

    The goal was to test whether extraterrestrials might be timing any transmissions to reach Earth just as they see it transiting the Sun. No signs of aliens were found, and no follow-up is planned.

    “Unfortunately, there are more good ideas for SETI experiments than there are SETI experimenters to act on them,” says Andrew Siemion, an astronomer at the University of California, Berkeley.

    In the next five or so years, the European Space Agency’s Gaia satellite is likely to discover most of the nearby stars in the Earth transit zone, Heller says.

    ESA Gaia satellite
    ESA/Gaia

    Until then, he and Pudritz plan to use data from K2, the Kepler follow-on mission, to hunt directly for planets in the zone—and to look for aliens who might be looking for us.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Scientific American, the oldest continuously published magazine in the U.S., has been bringing its readers unique insights about developments in science and technology for more than 160 years.

     
  • richardmitnick 1:59 pm on September 19, 2015 Permalink | Reply
    Tags: , , , Extraterrestrials,   

    From SETI Institute: “Could We Really Find E.T?” 


    SETI Institute

    9.19.15

    By Seth Shostak, Director of the Center for SETI Research, and Nathalie Cabrol, Director of the Carl Sagan Center

    1
    Seth Shostak

    2
    Nathalie Cabrol

    Some recent articles in the press convey the impression that our current efforts to find intelligent life beyond Earth are unlikely to succeed simply because our technology is not advanced enough to sense alien signals.

    Of course, that’s not true. Consider the Allen Telescope Array[ATA], currently being used every day by the SETI Institute in its hunt for signals from other star systems.

    Allen Telescope Array
    ATA

    This instrument is exquisitely sensitive – it could find some of the powerful radars that we have here on Earth at a distance of dozens of light-years. Any society that is even slightly more technically advanced than our own could easily manage a deliberate radio transmission that the Array could pick up. For SETI researchers, it’s a matter of aiming our antennas in the right direction, and tuning to the correct spot on the dial.

    But could it be that our incomplete understanding of physics is keeping us from finding the extraterrestrials? Perhaps they don’t use radio, but have moved on to some hypothetical new communication mode. Of course that’s possible, but it’s at least as probable that radio and light are – and always will be – the most efficient method of sending bits of information from one star system to another.

    In any case, the possibility of “new physics” invalidating today’s SETI experiments is an indefensible reason to abandon the search. One might have pointed out to Columbus that wooden ships were a poor way to traverse an ocean, and he should just wait for aviation. But the wooden ships were good enough.

    Our SETI technology will, of course, improve with time. Nonetheless, the discovery of a signal betraying extraterrestrial intelligence could still happen today, tomorrow, or next week. But only if we search.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    SETI Institute – 189 Bernardo Ave., Suite 100
    Mountain View, CA 94043
    Phone 650.961.6633 – Fax 650-961-7099
    Privacy PolicyQuestions and Comments

     
  • richardmitnick 3:54 pm on September 17, 2015 Permalink | Reply
    Tags: , , Extraterrestrials, ,   

    From SETI Institute: “Jill Tarter Elected President of California Academy of Sciences” 


    SETI Institute

    9.17.15
    No Writer Credit

    1
    Jill Tarter

    She’s a renowned SETI researcher, and member of the SETI Institute’s Board of Trustees. And now Jill Tarter has been selected to be the new president of San Francisco’s prestigious California Academy of Sciences.

    Jill was pivotal to the creation of the SETI Institute in 1984; The NASA SETI program of which she was a part became the Institute’s first project. In 1998, she was appointed to the Bernard M. Oliver Chair for SETI Research, and more recently Tarter became officially affiliated with the California Academy’s Board of Trustees.

    “In the eight years that I’ve been a Scientist Trustee at the Academy, I’ve found a number of different ways that that organization and the SETI Institute could help each other on projects,” Tarter says. “After all, we have overlapping interests regarding life, both here on Earth and beyond. And both organizations have a passion for sharing what they know with the world.”

    Tarter’s efforts in the SETI enterprise are legendary, and include the initiative for constructing the Allen Telescope Array [ATA], the only radio telescope deliberately designed for searching for signals due to extraterrestrial transmitters.

    Allen Telescope Array
    ATA

    An informed and energetic champion of the search for company in the cosmos, she can be frequently seen explaining the science behind this enterprise on television and in print. She has also been identified as the prototype for the Ellie Arroway character in the Carl Sagan novel, Contact.

    A winner of many awards, including a Lifetime Achievement Award from Women in Aerospace, Tarter has a long-standing interest in education and in promoting a better understanding of science by the public. She gives several dozen talks each year.

    “As I assume the role of President of the Academy and continue my service on the SETI Institute Board of Trustees, I look forward to finding or creating many more ways we can work together,” Tarter notes.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    SETI Institute – 189 Bernardo Ave., Suite 100
    Mountain View, CA 94043
    Phone 650.961.6633 – Fax 650-961-7099
    Privacy PolicyQuestions and Comments

     
  • richardmitnick 3:22 pm on August 25, 2015 Permalink | Reply
    Tags: , Extraterrestrials,   

    From io9 via SETI: “How SETI Will Understand Messages Broadcast by an Alien Intelligence” 


    SETI Institute

    1

    8/24/15
    George Dvorsky

    NRAO VLA
    Karl V. Jansky Very Large Array

    Imagine the day when we finally receive a signal from an extraterrestrial intelligence, only to find that there’s a message embedded within. Given that we don’t speak the same language, how could we ever hope to make sense of it? We spoke to the experts to find out.

    Communication with Extraterrestrial Intelligence, aka “CETI”, is the branch of SETI concerned with both the transmission and reception of messages between ourselves and an alien civilization. Scientists have been trying to detect signals from an extraterrestrial intelligence (ETI) since the 1960s, but haven’t found anything.

    Allen Telescope Array
    SETI Institute’s Allen Telescope Array

    3
    SETI@home, a public distributed computing project running on BOINC software and using data from the Arecibo Observatory
    Arecibo Observatory
    Arecibo Observatory

    SETI@home
    BOINC

    At least not yet. If and when we do receive a signal, whether it be an intercepted transmission or a deliberate attempt to get our attention, we’ll be tasked with deciphering an alien message. It could prove to be a monumental task, but it’s a problem with no shortage of solutions.

    Natural or Unnatural Signals?

    The first challenge will be to recognize an incoming alien signal. This may prove easier said than done.

    When pulsars were first discovered, for example, their eerily precise spectral flashes convinced some scientists that we were actually looking at some sort of alien beacon. And in 1977, the 72-second-long Wow! signal was likewise interpreted as extraterrestrial in nature. More plausibly, it was just a natural, continuous signal, or some human-instigated artifact.

    2

    These episodes aside, most SETI researchers agree that an alien signal will be unambiguous.

    “Due to the random motions of the particles that are ultimately at the source of natural electromagnetic emission, these emissions tend to get spread out in frequency or in time,” says Andrew Siemion, a PhD candidate in astronomy at SETI-Berkeley. “Technology, on the other hand, is capable of producing very fine time and frequency structure. We can use this fine structure to distinguish between natural and ‘unnatural’ sources.”

    Siemion says it’s important to keep in mind that our knowledge of physics and the cosmos isn’t complete, and it’s conceivable that there are some natural processes that could mimic the types of signals we look for in SETI experiments.

    “But discovering these would be great as well,” he told io9.

    According to Douglas Vakoch, Director of Interstellar Message Composition at the SETI Institute, we should actively look for signals that stand out from the cosmic static as distinctly artificial.

    “The radio signals created by nature are spread out on the radio dial,” he says. “We’re looking for narrowband signals at one place on the radio dial.”

    Overcoming the Language Barrier

    Given that an ETI would most assuredly “speak” a different language than any found on Earth, it’s fair to ask how we could ever hope to overcome such a barrier.

    How SETI Will Understand Messages Broadcast by an Alien Intelligence

    2
    Linear A tablets. (Credit: University of Houston/CC BY 3.0)

    And indeed, linguists are already struggling with this issue as it pertains to Linear A—an undeciphered writing system used in ancient Greece. It’s not immediately obvious if we’ll ever crack the code of this ancient language. Likewise, if we ever intercept an unintentional alien message, say something akin to a radio or television transmission, we may never be able to decipher the message, save for any visual or acoustic information gleaned from the broadcast.

    But it would likely be a different story if the message was intentional.

    “If an advanced civilization did want to communicate with us, they would probably choose to base their communication on something we have in common, such as the fact that we live in the same physical universe,” says Siemion. “They might use the properties of astrophysical objects, like pulsars, quasars or the shape of our galaxy, as a first step at teaching us their language.”

    Siemion says that an advanced ETI, if they were fairly close to us, say within 40-50 light-years, might actually know quite a lot about us. They may have already taken it upon themselves to decipher parts of our early radio and television transmissions. If this is the case, Siemion says it may be very easy for them to communicate with us in a way we understand.

    Speaking in Math

    Alternately, we can forgo arbitrary symbolic communication altogether and use the logic of math as a communication medium. As Vakoch says, the ability to communicate mathematics will allow aliens to communicate virtually anything that can be quantified.

    “One of the most basic parts of mathematics is counting,” Vakoch told io9. “When we think of counting, we usually imagine counting 1, 2, 3, and so on. But there are other ways to count as well.”

    For example, Vakoch says we could tell an ETI about the Fibonacci series by starting with the simplest numbers, zero and one, and then add them together, and then repeat the process over and over, adding the last two numbers in the series. Zero plus one is one, one plus two is two, and so on until the Fibonacci series is obvious.

    Spencer Greenberg from Ask a Mathematician says it shouldn’t be too hard for an ETI to develop a signal that, if we received it, could tell us it was created by another intelligent life.

    To understand why, Greenberg considers how we ourselves might construct a signal if we wanted aliens to notice that we’re intelligent. To that end, he devised a (somewhat oversimplified) approach that assumes an ETI would have developed the notions of binary encodings of integers (which is by no means an overreaching assumption).

    3
    Talking in code: Greenberg says we could pulse our signal by emitting a relatively high frequency, and at other times emitting a relatively low frequency. Each high section of our signal could represent the digit 1, and each low section, the digit 0. “With this mechanism in place, it’s easy to transmit in binary,” says Greenberg.

    By sending out pulses in binary, Greenberg says we could let the receiver know how many bits we’re using to represent a single number. After settling on the number of bits per group (e.g. 16), we could communicate our system by simply starting the message off with counting.

    So for instance, if we wanted to signal that we are treating groups of 16 bits as a single number, we could transmit all the binary numbers from 0 to 65,535 in order, each of which would be represented by 16 binary digits. Therefore, our transmission would start 0, 1, 2, 3, 4, and so on, which in binary, with 16 bits per number, would be:

    0000000000000000, 0000000000000001, 0000000000000010, 0000000000000011, 0000000000000100, etc.

    Greenberg says that instead of sending each of these numbers a single time through, we might actually want to send each sequence of 16 bits a fixed number of times in a row (say, 100 times each) to provide for redundancy. That way if our signal gets corrupted in transit, it’s still easy to correct any mistakes that are introduced.

    It should be obvious to an alien receiver that we are sending digits in groups of 16, with each 16 digit block representing a number. That would allow us to transmit any number we please (so long as it’s between 0 and 65,535) by representing it in the next 16 digits of our binary code.

    At that point there would be plenty of options for what to send to prove that we’re reasonably intelligent. We could transmit all the prime numbers from 2 up to 65,521. We could also send triplets of numbers where the third number in the triplet is equal to the first two multiplied together, or we could send pairs of numbers that are twin primes. We could even convey mathematical formulas by creating special symbols like an equal sign.

    Other ways to Communicate

    6

    In 1974, scientists transmitted a message into space consisting of 1,679 bits, arranged into 73 lines of 23 characters per line. Called the Arecibo Message, it consisted of the Arecibo telescope itself, our Solar System, DNA, a stick figure of a human, the biochemicals of terrestrial life, and other things.

    Such messages aren’t perfect or overly sophisticated, but they can convey simple concepts, like our location relative to our Sun, and our physical appearance. Clearly, an ETI could send or transmit a similar pictorial message.

    6
    The Pioneer message: So simple even an alien could understand it. (Credit: NASA)

    Mathematics could also be used to send algorithmic messages. These systems, such as CosmicOS and logic gate matrices, use a small set of math and logic symbols to form the basis of a simple programming language that an alien receiver could conceivably run on a virtual machine. Algorithmic messages, if complex enough, could actually be used to convey advanced concepts—and even signs of intelligence—if run on a sufficiently advanced computer system.

    7
    Binary logarithms represent a microarray of expression data for 8,700 mouse genes. (Credit: Louis M. Staudt/National Cancer Institute/Public domain)

    As for natural language processing, we’re still a long ways off from having the ability to make sense of arbitrary symbols. But Laurance Doyle, a member of the SETI institute, is using math to do just that. Doyle is trying to use information theory—a branch of math that looks at the structure and relationships of information—to separate binary code from random 0’s and 1’s. The idea is to find linguistic substance within undefined symbols, whether they be written or oral, and an associated grammar and syntax. Fascinatingly, Doyle’s work is being applied by marine biologists in an effort to crack the dolphin language code.
    Hmm, What to Talk About…

    Assuming that an alien civilization wants to reach out to us and say “hello”, it’s reasonable to wonder what else they might want to say to us.

    Vakoch says the most important thing an alien civilization could communicate to another is their intention to make contact.

    Siemion says ETIs might offer tips on existential dangers to humanity, both intrinsic threats, like biological weapons or artificial superintelligence, and extrinsic threats, such as asteroid impacts or a looming nearby supernova.

    “Some people believe that technological progression and increased altruistic tendency go hand-in-hand—that is, that the more advanced a civilization becomes, the friendlier they get,” says Siemion. “Personally, I don’t think we have any evidence of that. In fact, I think we have evidence that the contrary may be the case.”

    The Risk Factor

    Indeed, this could be a rather dangerous exercise. We run the risk of receiving and translating a malign message, such as a trojan horse that contains a kind of computer virus, or the seeds of our own destruction.

    And as we’ve written before at io9, the effort to deliberately transmit messages to aliens—an endeavor known as METI—needs to be seriously re-considered. Our efforts to reach ETIs could alert an evil force to our presence.

    8
    Alien Outpost

    “Sending messages of our own creation to try to make any possible aliens aware that we exist, is an incredibly risky proposition,” says Greenberg. “Sure, they might be friendly, but then again, they might not—and that’s a big risk to take,” says Greenberg. “Attempting to wake up a force more powerful than ourselves that we do not understand is simply not a good plan.”

    Vakoch says that concerns of alerting an ETI to our presence are too late.

    “Any civilization with the ability to travel between the stars would already know we’re here from our accidental leakage radiation,” he says. “So a sufficiently advanced extraterrestrial might already have picked up ‘I Love Lucy.’ But they still don’t know that we’re attempting to communicate with them. That’s the most important reason for us to transmit powerful, intelligible signals to other stars—to let any intelligence out there know we’re ready to make contact.”

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    SETI Institute – 189 Bernardo Ave., Suite 100
    Mountain View, CA 94043
    Phone 650.961.6633 – Fax 650-961-7099
    Privacy PolicyQuestions and Comments

     
  • richardmitnick 2:08 pm on March 31, 2015 Permalink | Reply
    Tags: , , Extraterrestrials,   

    From New Scientist: “Is this ET? Mystery of strange radio bursts from space” 

    NewScientist

    New Scientist

    31 March 2015
    Sarah Scoles

    Mysterious radio wave flashes from far outside the galaxy are proving tough for astronomers to explain. Is it pulsars? A spy satellite? Or an alien message?

    CSIRO Parkes Observatory
    CSIRO/Parkes Radio telescope

    BURSTS of radio waves flashing across the sky seem to follow a mathematical pattern. If the pattern is real, either some strange celestial physics is going on, or the bursts are artificial, produced by human – or alien – technology.

    Telescopes have been picking up so-called fast radio bursts (FRBs) since 2001. They last just a few milliseconds and erupt with about as much energy as the sun releases in a month. Ten have been detected so far, most recently in 2014, when the Parkes Telescope in New South Wales, Australia, caught a burst in action for the first time. The others were found by sifting through data after the bursts had arrived at Earth. No one knows what causes them, but the brevity of the bursts means their source has to be small – hundreds of kilometres across at most – so they can’t be from ordinary stars. And they seem to come from far outside the galaxy.

    The weird part is that they all fit a pattern that doesn’t match what we know about cosmic physics.

    2

    To calculate how far the bursts have come, astronomers use a concept called the dispersion measure. Each burst covers a range of radio frequencies, as if the whole FM band were playing the same song. But electrons in space scatter and delay the radiation, so that higher frequency waves make it across space faster than lower frequency waves. The more space the signal crosses, the bigger the difference, or dispersion measure, between the arrival time of high and low frequencies – and the further the signal has travelled.

    Michael Hippke of the Institute for Data Analysis in Neukirchen-Vluyn, Germany, and John Learned at the University of Hawaii in Manoa found that all 10 bursts’ dispersion measures are multiples of a single number: 187.5 (see chart). This neat line-up, if taken at face value, would imply five sources for the bursts all at regularly spaced distances from Earth, billions of light-years away. A more likely explanation, Hippke and Lerned say, is that the FRBs all come from somewhere much closer to home, from a group of objects within the Milky Way that naturally emit shorter-frequency radio waves after higher-frequency ones, with a delay that is a multiple of 187.5 (arxiv.org/abs/1503.05245).

    They claim there is a 5 in 10,000 probability that the line-up is coincidence. “If the pattern is real,” says Learned, “it is very, very hard to explain.”

    Cosmic objects might, by some natural but unknown process, produce dispersions in regular steps. Small, dense remnant stars called pulsars are known to emit bursts of radio waves, though not in regular arrangements or with as much power as FRBs. But maybe superdense stars are mathematical oddities because of underlying physics we don’t understand.

    It’s also possible that the telescopes are picking up evidence of human technology, like an unmapped spy satellite, masquerading as signals from deep space.

    The most tantalising possibility is that the source of the bursts might be a who, not a what. If none of the natural explanations pan out, their paper concludes, “An artificial source (human or non-human) must be considered.”

    “Beacon from extraterrestrials” has always been on the list of weird possible origins for these bursts. “These have been intriguing as an engineered signal, or evidence of extraterrestrial technology, since the first was discovered,” says Jill Tarter, former director of the SETI Institute in California. “I’m intrigued. Stay tuned.”

    Astronomers have long speculated that a mathematically clever message – broadcasts encoded with pi, or flashes that count out prime numbers, as sent by aliens in the film Contact –could give away aliens’ existence. Perhaps extraterrestrial civilisations are flagging us down with basic multiplication.

    Power source

    But a fast radio burst is definitely not the easiest message aliens could send. As Maura McLaughlin of West Virginia University, who was part of the first FRB discovery points out, it takes a lot of energy to make a signal that spreads across lots of frequencies, instead of just a narrow one like a radio station. And if the bursts come from outside the galaxy, they would have to be incredibly energetic to get this far.

    If the bursts actually come from inside the Milky Way, they need not be so energetic (just like a nearby flashlight can light up the ground but a distant light does not). Either way, though, it would require a lot of power. In fact, the aliens would have to be from what SETI scientists call a Kardashev Type II civilisation (see “Keeping up with the Kardashevs”).

    But maybe there’s no pattern at all, let alone one that aliens embedded. There are only 10 bursts, and they fit into just five groups. “It’s very easy to find patterns when you have small-number statistics,” says McLaughlin. “On the other hand, I don’t think you can argue with the statistics, so it is odd.”

    The pattern might disappear as more FRBs are detected. Hippke and Learned plan to check their finding against new discoveries, and perhaps learn something about the universe. “Science is the best game around,” says Learned. “You don’t know what the rules are, or if you can win. This is science in action.”

    If the result holds up, says Hippke, “there is something really interesting we need to understand. This will either be new physics, like a new kind of pulsar, or, in the end, if we can exclude everything else, an ET.”

    Hippke is cautious, but notes that remote possibilities are still possibilities. “When you set out to search for something new,” he says, “you might find something unexpected.”

    THE first search for extraterrestrial intelligence, Frank Drake’s Project Ozma, looked for radio broadcasts from hypothetical aliens in the 1960s.

    Around the same time, cosmologist Nikolai Kardashev began to wonder what a truly advanced civilisation’s radio messages might be like. His main conclusion: more powerful than ours. In a 1963 paper called Transmission of Information by Extraterrestrial Civilizations, he grouped ETs into three categories according to how big their broadcasts could be. The labels stuck, and SETI scientists still use them today.

    A signal from a Kardashev Type I society uses a planet’s worth of energy, pulling from all its resources – solar, thermal, volcanic, tectonic, hydrodynamic, oceanic, and so on.

    A Type II civilisation has a star’s worth of output at its disposal. It would have to capture all its sun’s radiation, throw material into a black hole and suck up the radiation, or travel to many planets and strip them of resources.

    A Kardashev Type III civilisation controls the power output of a galaxy like the Milky Way. If a galaxy was home to just one Type III society, it would be completely dark except for the waste infrared radiation (heat) blowing from their massive engineering projects.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 8:42 am on March 28, 2015 Permalink | Reply
    Tags: , , Extraterrestrials, , , ,   

    From SETI’s Seth Shostak at NYT: “Messaging the Stars” 

    New York Times

    The New York Times

    MARCH 27, 2015

    SETI Seth Shostak
    Seth Shostak

    SETI Institute

    1

    For more than a half-century, a small group of astronomers has sought intelligent company among the stars. They’ve done so by turning large radio antennas skyward, hoping to eavesdrop on signals from an advanced society. It’s a program known as SETI, the Search for Extraterrestrial Intelligence.

    But now some researchers propose that we should do more than simply don headphones and await E.T.’s call: We should make serious efforts to encourage a response from putative aliens by deliberately transmitting our own messages. It’s a simple idea, akin to tossing a bottle into the cosmic ocean. But recent arguments for what’s termed active SETI have loosed a storm of controversy, one that has even washed into the halls of academe.

    Why is this? Why has the sending of dispatches to worlds many trillions of miles distant suddenly become a hot-button issue? The simple answer is that there’s now a perception that advertising our existence could be a mortal threat to the planet.

    The reasoning is this: While no one has yet offered decisive proof for life beyond Earth, in the past two years astronomers have learned that tens of billions of habitable planets suffuse our galaxy. Consequently, to believe that only Earth has spawned intelligence is to insist that our world is the site of a miracle. That point of view rarely appeals to scientists.

    The aliens could very well be out there. And that realization has spurred a call by some for broadcasts intended to elicit a communication from at least the nearest other star systems. But we know nothing of the aliens’ possible motives or behavior. Therefore, it’s conceivable that betraying our existence might prompt aggressive action from space.

    Broadcasting is likened to “shouting in the jungle” — not a good idea when you don’t know what’s out there. The British physicist Stephen Hawking alluded to this danger by noting that on Earth, when less advanced societies drew the attention of those more advanced, the consequences for the former were seldom agreeable.

    It’s a worry we never used to have. Victorian-era scientists toyed with plans to use lanterns and burning pools of oil to contact postulated Martians. In the 1970s, NASA bolted greeting cards onto spacecraft that will leave our solar system and wander the vast reaches between the stars. The Pioneer and Voyager probes carry plaques and records with information about what humans look like and where Earth is, as well as a small sampling of our culture.

    NASA Pioneer 10
    NASA/Pioneer 10

    NASA Voyager 1
    NASA/Voyager 1

    Those messages move at the speed of rockets. But in 1974, a three-minute encoded pictogram was transmitted using the large radio antenna at Arecibo, Puerto Rico.

    Arecibo
    Arecibo Radio Observatory

    It moves at the speed of light, 20,000 times faster. More recent radio transmissions include a Beatles song beamed by NASA to the North Star, a Doritos advertisement launched to a planetary system in the Big Dipper, and a series of broadcasts sent to nearby stars using an antenna in Crimea.

    When most people believed that aliens were no more than easy black hats for Hollywood, the idiosyncratic nature of these messages could be easily dismissed. But if cosmic company is a legitimate possibility, shouldn’t we offer up something more edifying than pop music and snack food? A deliberate transmission should represent all of humanity — not short-circuit the important question of who will speak for Earth.

    Consequently, recent conferences on the merits of active SETI have sought the advice of social scientists. Among their worries is whether to be up front about humanity’s seamy side: Should we tell the extraterrestrials about war and injustice?

    Personally, I think this concern is overwrought. Any society that can pick up our radio messages will be at a level of development at least centuries beyond our own. They would be no more incensed by our bad behavior than historians who learned that Babylonians attacked one another with spears. It seems naïve to imagine that, by shielding aliens from the less flattering aspects of humanity, we would somehow lessen any incentive to do us harm. If there’s a danger, mincing words is unlikely to eliminate it.

    A better approach is to note that the nearest intelligent extraterrestrials are likely to be at least dozens of light-years away. Even assuming that active SETI provokes a reply, it won’t be breezy conversation. Simple back-and-forth exchanges would take decades. This suggests that we should abandon the “greeting card” format of previous signaling schemes, and offer the aliens Big Data.

    For example, we could transmit the contents of the Internet. Such a large corpus — with its text, pictures, videos and sounds — would allow clever extraterrestrials to decipher much about our society, and even formulate questions that could be answered with the material in hand. Sending the web on its way would take months if a radio transmitter were used. A powerful laser, conveying bits much like an optical fiber, could launch these data in a few days.

    Sending messages — even big ones — is technically feasible. However, there’s still the highly controversial matter of whether to broadcast at all. Who decides? One could simply let the public weigh in, but doing so wouldn’t address the security issue. Even if a majority is comfortable with a transmission, how does that mitigate the possible danger?

    The inability to gauge this peril prompts some critics to argue that, given the possibly existential threat posed by active SETI, we should choose the side of caution. We should simply forbid powerful transmissions to the skies. Indeed, a small consortium of academics in California has drafted a petition urging this.

    It’s a wary approach. It’s also poor insurance. Any extraterrestrials with technology advanced enough to threaten us will surely have antennas larger than our own, instruments that can pick up the television and radio signals broadcast willy-nilly since World War II. We are already shouting into the jungle, albeit with less volume than a deliberate signal. But the dangerous creatures may have good hearing.

    Additionally, if we forbid high-powered transmitters aimed at the sky, we shut out such obvious future technologies as better radars for aviation and tracking dangerous asteroids. Do we really want to hamstring our descendants this way?

    A decision to engage in active SETI has not been made. The benefit — learning our place in the cosmos — is only hypothetical, and so is the danger. But I, for one, would hesitate to let a paranoia based on nothing more than conjecture shackle the activities of our children and our children’s children. The universe beckons, and we can do better than to declare that future generations should endlessly tremble at the sight of the stars.

    Seth Shostak is the director of the Center for SETI Research at the SETI Institute, and a host of the radio program Big Picture Science.

    See the full article here.

    SETI Institute promoted the Allen Telescope Array for signal collection.

    Allen Telescope Array

    The Arecibo Radio Telescope is the prime source for data for SET@home a Citizen Science project that runs on personal computers with BOINC software from UC Berkeley.

    SETI@home screensaver

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 7:33 pm on March 3, 2015 Permalink | Reply
    Tags: , , Extraterrestrials, , ,   

    From Space.com: “The Father of SETI: Q&A with Astronomer Frank Drake” 

    space-dot-com logo

    SPACE.com

    February 26, 2015
    Leonard David

    Arecibo Observatory

    Detecting signals from intelligent aliens is a lifelong quest of noted astronomer Frank Drake. He conducted the first modern search for extraterrestrial intelligence (SETI) experiment in 1960. More than five decades later, the hunt remains front-and-center for the scientist.

    5
    Frank Drake

    Drake also devised a thought experiment in 1961 to identify specific factors believed to play a role in the development of civilizations in our galaxy. This experiment took the form of an equation that researchers have used to estimate the possible number of alien civilizations — the famous Drake Equation.

    The Drake equation is:

    N = R*. fp. ne. fl. fi. fc. L

    where:

    N = the number of civilizations in our galaxy with which radio-communication might be possible (i.e. which are on our current past light cone);

    and

    R* = the average rate of star formation in our galaxy
    fp = the fraction of those stars that have planets
    ne = the average number of planets that can potentially support life per star that has planets
    fl = the fraction of planets that could support life that actually develop life at some point
    fi = the fraction of planets with life that actually go on to develop intelligent life (civilizations)
    fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
    L = the length of time for which such civilizations release detectable signals into space

    Drake constructed the “Arecibo Message” of 1974 — the first interstellar message transmitted via radio waves from Earth for the benefit of any extraterrestrial civilization that may be listening.

    The message consists of seven parts that encode the following (from the top down):[4]

    The numbers one (1) to ten (10)
    The atomic numbers of the elements hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up deoxyribonucleic acid (DNA)
    The formulas for the sugars and bases in the nucleotides of DNA
    The number of nucleotides in DNA, and a graphic of the double helix structure of DNA
    A graphic figure of a human, the dimension (physical height) of an average man, and the human population of Earth
    A graphic of the Solar System indicating which of the planets the message is coming from
    A graphic of the Arecibo radio telescope and the dimension (the physical diameter) of the transmitting antenna dish

    3
    This is the message with color added to highlight its separate parts. The actual binary transmission carried no color information.

    Space.com caught up with Drake to discuss the current state of SETI during an exclusive interview at the NASA Innovative Advanced Concepts (NIAC) 2015 symposium, which was held here from Jan. 27 to Jan. 29.

    Drake serves on the NASA NIAC External Council and is chairman emeritus of the SETI Institute in Mountain View, Calif. and director of the Carl Sagan Center for the Study of Life in the Universe.

    Space.com: What’s your view today concerning the status of SETI?

    Frank Drake: The situation with SETI is not good. The enterprise is falling apart for lack of funding. While NASA talks about “Are we alone?” as a number one question, they are putting zero money into searching for intelligent life. There’s a big disconnect there.

    We’re on the precipice. The other thing is that there are actually negative events on the horizon that are being considered.

    Space.com: And those are?

    Drake: There are two instruments, really the powerful ones for answering the “are we alone” question … the Arecibo telescope[above] and the Green Bank Telescope [GBT].

    NRAO GBT
    GBT

    They are the world’s two largest radio telescopes, and both of them are in jeopardy. There are movements afoot to close them down … dismantle them. They are both under the National Science Foundation and they are desperate to cut down the amount of money they are putting into them. And their choice is to just shut them down or to find some arrangement where somebody else steps in and provides funding.

    So this is the worst moment for SETI. And if they really pull the rug out from under the Green Bank Telescope and Arecibo … it’s suicide.

    Space.com: What happens if they close those down?

    Drake: We’re all then sitting in our living rooms and watching science fiction movies.

    Space.com: How about the international scene?

    Drake: The international scene has gone down too because all the relevant countries are cash-strapped also.

    There is a major effort in China, a 500-meter [1,640 feet] aperture spherical radio telescope. The entire reflector is under computer control with actuators. They change the shape of the reflector depending on what direction they are trying to look. The technology is very complicated and challenging. The Russians tried it and it never worked right. But … there are serious resources there.

    Space.com: Why isn’t SETI lively and bouncing along fine given all the detections?

    Drake: You would think. All those planetary detections are the greatest motivator to do SETI that we ever had. But it hasn’t had any impact, at least yet.

    Space.com: How do you reconcile the fact that exoplanet discoveries are on the upswing, yet mum’s the word from ET?

    Drake: People say that all the time … saying that you’ve been searching for years and now you’ve searched thousands of stars and found nothing. Why don’t you just give up … isn’t that the sensible thing?

    There’s a good answer to all that. Use the well-know equation and put in the parameters as we know them. A reasonable lifetime of civilizations is like 10,000 years, which is actually much more than we can justify with our own experience. It works out one in every 10 million stars will have a detectable signal. That’s the actual number. That means, to have a good chance to succeed, you have to look at a million stars at least — and not for 10 minutes — for at least days because the signal may vary in intensity. We haven’t come close to doing that. We just haven’t searched enough.

    Space.com: What are we learning about habitable zones?

    Drake: Actually the case is very much stronger for a huge abundance of life. The story seems to be that almost every star has a planetary system … and also the definition of “habitable zone” has expanded. In our system, it used to be that only Mars and Earth were potentially habitable. Now we’ve got an ocean on Europa … Titan.

    The habitable zone goes out. A habitable zone is not governed just by how far you are from the star, but what your atmosphere is. If you’ve got a lot of atmosphere, you’ve got a greenhouse effect. And that means the planet can be much farther out and be habitable.

    6
    “Radio waving” to extraterrestrials. Outward bound broadcasting from Earth has announced humanity’s technological status to other starfolk, if they are out there listening.
    Credit: Abstruse Goose

    Space.com: What is your view on the debate regarding active SETI — purposely broadcasting signals to extraterrestrials?

    Drake: There is controversy. I’m very against sending, by the way. I think it’s crazy because we’re sending all the time. We have a huge leak rate. It has been going on for years. There is benefit in eavesdropping, and you would have learned everything you can learn through successful SETI searches. There’s all kinds of reasons why sending makes no sense.

    7
    Frank Drake, center, with his colleagues, Optical SETI (OSETI) Principal Investigator Shelley Wright and Rem Stone with the 40-inch Nickel telescope at Lick Observatory in California. Outfitted with the OSETI instrument, the silver rectangular instrument package protrudes from the bottom of the telescope, plus computers, etc.
    Credit: Laurie Hatch Photography

    That reminds me of something else. We have learned, in fact, that gravitational lensing works. If they [aliens] use their star as a gravitational lens, they get this free, gigantic, super-Arecibo free of charge. They are not only picking up our radio signals, but they have been seeing the bonfires of the ancient Egyptians. They can probably tell us more about ourselves than we know … they’ve been watching all these years.

    Space.com: Can you discuss the new optical SETI efforts that you are involved with? You want to search for very brief bursts of optical light possibly sent our way by an extraterrestrial civilization to indicate their presence to us.

    Drake: It’s alive and well. We’ve gotten a couple of people who are actually giving major gifts. There’s no funding problem. There is a new instrument that has been built, and it’s going to be installed at the Lick Observatory [in California] in early March.

    The whole thing is designed to look for laser flashes. The assumption is — and this is where it gets to be tenuous — the extraterrestrials are doing us a favor. It does depend on extraterrestrials helping you by targeting you. These stellar beams are so narrow that you’ve got to know the geometry of the solar system that you’re pointing it at. They want to communicate. They have to be intent on an intentional signal specifically aimed at us. That’s a big order. So there are required actions on the part of the extraterrestrials for this to work. The big plus is that it’s cheap and relatively easy to do.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 9:01 am on February 8, 2015 Permalink | Reply
    Tags: , Extraterrestrials, ,   

    From Space.com: “How Would the World Change If We Found Alien Life?” 

    space-dot-com logo

    SPACE.com

    February 06, 2015
    Elizabeth Howell

    1
    If contact with extraterrestrial life is made through radio telescopes, a decipherment process may have to take place to understand the message.
    Credit: NASA

    In 1938, Orson Welles narrated a radio broadcast of “War of the Worlds” as a series of simulated radio bulletins of what was happening in real time as Martians arrived on our home planet. The broadcast is widely remembered for creating public panic, although to what extent is hotly debated today.

    Still, the incident serves as an illustration of what could happen when the first life beyond Earth is discovered. While scientists might be excited by the prospect, introducing the public, politicians and interest groups to the idea could take some time.

    How extraterrestrial life would change our world view is a research interest of Steven Dick, who just completed a term as the Baruch S. Blumberg NASA/Library of Congress Chair of Astrobiology. The chair is jointly sponsored by the NASA Astrobiology Program and the John W. Kluge Center, at the Library of Congress.

    Dick is a former astronomer and historian at the United States Naval Observatory, a past chief historian for NASA, and has published several books concerning the discovery of life beyond Earth. To Dick, even the discovery of microbes would be a profound shift for science.

    “If we found microbes, it would have an effect on science, especially biology, by universalizing biology,” he said. “We only have one case of biology on Earth. It’s all related. It’s all DNA-based. If we found an independent example on Mars or Europa, we have a chance of forming a universal biology.”

    Dick points out that even the possibilities of extraterrestrial fossils could change our viewpoints, such as the ongoing discussion of ALH84001, a Martian meteorite found in Antarctica that erupted into public consciousness in 1996 after a Science article said structures inside of it could be linked to biological activity. The conclusion, which is still debated today, led to congressional hearings.

    2
    Photo of the martian meteorite ALH84001. Dull, dark fusion crust covers about 80% of the sample

    “I’ve done a book about discovery in astronomy, and it’s an extended process,” Dick pointed out. “It’s not like you point your telescope and say, ‘Oh, I made a discovery.’ It’s always an extended process: You have to detect something, you have to interpret it, and it takes a long time to understand it. As for extraterrestrial life, the Mars rock showed it could take an extended period of years to understand it.”

    Mayan decipherments

    In his year at the Library of Congress, Dick spent time searching for historical examples (as well as historical analogies) of how humanity might deal with first contact with an extraterrestrial civilization. History shows that contact with new cultures can go in vastly different directions.

    Hernan Cortes’ treatment of the Aztecs is often cited as an example of how wrong first contact can go. But there were other efforts that were a little more mutually beneficial, although the outcomes were never perfect. Fur traders in Canada in the 1800s worked closely with Native Americans, for example, and the Chinese treasure fleet of the 15th Century successfully brought its home culture far beyond its borders, perhaps even to East Africa.

    Even when both sides were trying hard to make communication work, there were barriers, noted Dick.

    “The Jesuits had contact with Native Americans,” he pointed out. “Certain concepts were difficult, like when they tried to get across the ideas of the soul and immortality.”

    Indirect contact by way of radio communications through the Search for Extraterrestrial Intelligence (SETI), also illustrates the challenges of transmitting information across cultures. There is historical precedence for this, such as when Greek knowledge passed west through Arab translators in the 12th Century. This shows that it is possible for ideas to be revived, even from dead cultures, he said.

    Allen Telescope Array
    SETI’s Institute’s Allen Telescope Array

    SETI@home screensaver
    SETI@home project

    Arecibo Observatory
    Arecibo Observatory. used by SETI@home

    “There will be a decipherment process. It might be more like the Mayan decipherments,” Dick said.

    The ethics of contact

    As Dick came to a greater understanding about the potential cultural impact of extraterrestrial intelligence, he invited other scholars to present their findings along with him. Dick chaired a two-day NASA/Library of Congress Astrobiology Symposium called “Preparing for Discovery,” which was intended to address the impact of finding any kind of life beyond Earth, whether microbial or some kind of intelligent, multicellular life form.

    The symposium participants discussed how to move beyond human-centered views of defining life, how to understand the philosophical and theological problems a discovery would bring, and how to help the public understand the implications of a discovery.

    “There is also the question of what I call astro-ethics,” Dick said. “How do you treat alien life? How do you treat it differently, ranging from microbes to intelligence? So we had a philosopher at our symposium talking about the moral status of non-human organisms, talking in relation to animals on Earth and what their status is in relation to us.”

    Dick plans to collect the lectures in a book for publication next year, but he also spent his time at the library gathering materials for a second book about how discovering life beyond Earth will revolutionize our thinking.

    “It’s very farsighted for NASA to fund a position like this,” Dick added. “They have all their programs in astrobiology, they fund the scientists, but here they fund somebody to think about what the implications might be. It’s a good idea to do this, to foresee what might happen before it occurs.”

    It’s also quite possible that the language we receive across these indirect communications would be foreign to us. Even though mathematics is often cited as a universal language, Dick said there are actually two schools of thought. One theory is that there is, indeed, one kind of mathematics that is based on a Platonic idea, and the other theory is that mathematics is a construction of the culture that you are in.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 3:34 pm on December 30, 2014 Permalink | Reply
    Tags: , , , Extraterrestrials   

    From AAAS: “Detecting extraterrestrial life through motion” 

    AAAS

    AAAS

    Ecole Polytechnique Fédérale de Lausanne

    Looking for life on other planets is not straightforward. It usually relies on chemical detection, which might be limited or even completely irrelevant to alien biology. On the other hand, motion is a trait of all life, and can be used to identify microorganisms without any need of chemical foreknowledge. EPFL scientists have now developed an extremely sensitive yet simple motion detector that can be built easily by adapting already-existent technology. The system has proven accurate with detecting bacteria, yeast, and even cancer cells, and is considered for the rapid testing of drugs and even the detection of extraterrestrial life. The work is published in the Proceedings of the National Academy of Sciences (PNAS).

    Giovanni Dietler, Sandor Kasas and Giovanni Longo at EPFL have developed a motion detector that uses a nano-sized cantilever to detect motion. A cantilever is essentially a beam that is anchored only at one end, with the other end bearing a load. The cantilever design is often used with bridges and buildings, but here it is implemented on the micrometer scale, and about 500 bacteria can be deposited on it.

    c
    Example of a cantilever

    The idea comes from the technology behind an existing microscope, the atomic force microscope. This powerful microscope uses a cantilever to produce pictures of the very atoms on a surface. The cantilever scans the surface like the needle of a record player and its up-and-down movement is read by a laser to produce an image.

    a
    An atomic force microscope on the left with controlling computer on the right.

    The motion sensor the Dietler and Kasas developed works the same way, but here the sample is attached on the cantilever itself. For example, a bacterium attaches to the cantilever. If the bacterium is alive, it will inevitably move in some way, e.g. move its flagellum or simply carry out normal biological functions. That motion also moves the much smaller and sensitive cantilever and it is captured by the readout laser as series of vibrations. The signal is taken as a sign of life.

    The EPFL scientists successfully tested their novel system with isolated bacteria, yeast, mouse and human cells. They even tested soil from the fields around the EPFL campus and water from the nearby Sorge river. In each case, they were able to accurately detect and isolate vibration signatures from living cells. When they used drugs to kill anything alive, the motion signals stopped.

    “The system has the benefit of being completely chemistry-free,” says Dietler. “That means that it can be used anywhere – in drug testing or even in the search for extraterrestrial life.” The scientists envision a large array of cantilever sensors used in future space exploration probes like the Mars rover. As it relies on motion rather than chemistry, the cantilever sensor would be able to detect life forms in mediums that are native to other planets, such as the methane in the lakes of Titan.

    However, the more immediate applications of the cantilever system are in drug development. Used in a larger array, the cantilevers could be covered with bacteria or cancer cells and incubated with various drug compounds. If the drugs are effective against the attached cells, the motion signals would decrease or stop altogether as the cells die off. This approach would be considerably quicker than current high-throughput systems used in by pharmaceutical companies when looking for candidate antibiotics or anticancer drugs.

    “This is really the next step,” says Dietler. “But we’re still calling ESA and NASA to see if they’re interested.”

    ###

    This work represents a collaboration of EPFL’s Laboratory of Physics of Living Matter with the University of Lausanne and the Vlaams Institute for Biotechnology.

    Reference

    Reference

    Kasas S, Simone Ruggeri FS, Benadiba C, Maillard C, Stupar P, Tournuc H, Dietler G, Longo G. Detecting nanoscale vibrations as signature of life. PNAS 29 December 2014. doi: 10.1073/pnas.1415348112

    See the full article here.

    The American Association for the Advancement of Science is an international non-profit organization dedicated to advancing science for the benefit of all people.

    Please help promote STEM in your local schools.
    STEM Icon
    Stem Education Coalition

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: