[Newfie]

Thanks

[vox_mundi]

The aliens are silent because they're dead

$this->bbcode_second_pass_quote('', 'I')n research aiming to understand how life might develop, the scientists realised new life would commonly die out due to runaway heating or cooling on their fledgling planets.

"The universe is probably filled with habitable planets, so many scientists think it should be teeming with aliens," said Dr Aditya Chopra from the ANU Research School of Earth Sciences and lead author on the paper, which is published in Astrobiology. (The Case for a Gaian Bottleneck: The Biology of Habitability

"Early life is fragile, so we believe it rarely evolves quickly enough to survive."

"Most early planetary environments are unstable. To produce a habitable planet, life forms need to regulate greenhouse gases such as water and carbon dioxide to keep surface temperatures stable."

A plausible solution to Fermi's paradox, say the researchers, is near universal early extinction, which they have named the Gaian Bottleneck.

"One intriguing prediction of the Gaian Bottleneck model is that the vast majority of fossils in the universe will be from extinct microbial life, not from multicellular species such as dinosaurs or humanoids that take billions of years to evolve," said Associate Professor Lineweaver.

[Rod_Cloutier]

SETI, the search for Extraterrestrial intelligence is taking this matter seriously, and are looking for radio or laser transmissions:

$this->bbcode_second_pass_quote('', 'T')o investigate this idea, we have been using the Allen Telescope Array to search for non-natural radio signals from the direction of KIC 8462852. This effort is looking for both narrow-band signals (similar to traditional SETI experiments) as well as somewhat broader transmissions that might be produced, for example, by powerful spacecraft.

But what if ET isn’t signaling at radio frequencies? Our ATA observations are being augmented by a search for brief but powerful laser pulses. These observations are being conducted by the Boquete Optical SETI Observatory in Panama, part of a nascent global network of optical SETI observatories.

[vox_mundi]

The So-Called Alien Megastructure Just Got Even More Mysterious

$this->bbcode_second_pass_quote('', '[')img]http://pop.h-cdn.co/assets/16/31/980x490/landscape-1470507596-starz.png[/img]

Last fall, a little-known star called KIC 8462852 became our planetary obsession when astronomers said that its erratic flickering could be the result of an alien megastructure. Further observation of Tabby’s Star yielded no signs of aliens, but the sudden dips in luminosity continue to defy explanation. Now, things just got a bit weirder.

In an unpublished paper posted today to arXiv, Caltech astronomer Ben Montet and Joshua Simon of the Carnegie Institute describe the results of a new photometric analysis of Tabby’s Star, which was first flagged in the Kepler Space Telescope’s database by citizen science astronomers.

By carefully examining all the full-frame images collected during Kepler’s observational campaign, Montet and Simon discovered something astonishing: Not only did the star’s light output occasionally dip by up to 20 percent, its total stellar flux diminished continuously over the course of four years.

For the first 1000 days of Kepler’s campaign, Tabby’s Star decreased in luminosity by approximately 0.34 percent per year. For the next 200 days, the star dimmed more rapidly, its total stellar flux dropping by 2 percent before leveling off. Overall, Tabby’s Star faded roughly 3 percent during the four years that Kepler stared at it—an absolutely enormous, inexplicable amount. The astronomers looked at 500 other stars in the vicinity, and saw nothing else like it.

“The part that really surprised me was just how rapid and non-linear it was,” Montet told Gizmodo. “We spent a long time trying to convince ourselves this wasn’t real. We just weren’t able to.”

[Plantagenet]

The aliens and their robots building the Alien Megastructure around the star finish one part of the structure, and then they start another part. They get the framework done, and they star installing walls and solar energy collectors.

Of course the effects on the star's apparent intensity are nonlinear. The construction of the megastructure is itself a non-linear process.

[Newfie]

I think you would faint if you were correct.

Except of course it makes perfect sense.

[vox_mundi]

How to Build a RingWorld

$this->bbcode_second_pass_quote('', '[')img]http://pop.h-cdn.co/assets/cm/15/05/640x400/54cb4a7167d5b_-_ringworld-03-0914-de.jpg[/img]

Sci-fi author Larry Niven conjured up such a megastructure for his award-winning 1970 book Ringworld. Niven imagined a ring with a radius of 93 million miles—the sun-Earth distance—with the sun placed at the center. The ring' would reach 600 million miles across and a million miles tall. The vast landscape could comfortably support perhaps trillions of humans (or another similarly ambitious, technologically advanced race).



"The thing is roomy enough: three million times the area of the Earth. It will be some time before anyone complains about the crowding," Niven wrote in a 1974 essay entitled "Bigger Than Worlds."

Niven figured a Ringworld would have a thickness of a few thousand feet, and require raw materials with a mass equal to that of Jupiter. Mountain "walls" a thousand miles high would line each rim, preventing the atmosphere from leaking into space. The inner surface could be sculpted like Earth's surface—full of great (though shallow) oceans, soaring mountains, and prodigious farmland—or whatever its builders desired.

[vox_mundi]

This would be easier ...

Scientists find new Earth-like planet

$this->bbcode_second_pass_quote('', ' ') Scientists are preparing to unveil a new planet in our galactic neighbourhood which is "believed to be Earth-like" and orbits its star at a distance that could favour life, German weekly Der Spiegel reported Friday.

The exoplanet orbits a well-investigated star called Proxima Centauri, part of the Alpha Centauri star system, the magazine said, quoting anonymous sources.

"The still nameless planet is believed to be Earth-like and orbits at a distance to Proxima Centauri that could allow it to have liquid water on its surface—an important requirement for the emergence of life," said the magazine.

"Never before have scientists discovered a second Earth that is so close by," it said, adding that the European Southern Observatory (ESO) will announce the finding at the end of August.

The exoplanet orbiting Proxima Centauri, if confirmed, is just 4.24 light-years away.

This is a mere stepping stone in relation to the scale of the Universe but still too far away for humans to reach in present-generation chemical rockets.

According to NASA's Godard Space Center's website, it lies 39,900,000,000,000 kilometres away, or 271,000 times the distance of Earth to the Sun.

[vox_mundi]

Not a Drill: SETI Is Investigating a Possible Extraterrestrial Signal From Deep Space

$this->bbcode_second_pass_quote('', '[')img]http://www.centauri-dreams.org/wp-content/uploads/2016/08/ratan_2.jpeg[/img]
Strong signal from the direction of HD 164595. “Raw” record of the signal together with expected shape of the signal for point-like source in the position of HD 164595. Credit: Bursov et al.

An international team of scientists from the Search For Extraterrestrial Intelligence (SETI) are investigating mysterious signal spikes emitting from a 6.3 billion year-old star in the constellation Hercules–95 light years away from Earth. The implications are extraordinary and point to the possibility of a civilization far more advanced than our own.

The unusual signal was originally detected on May 15, 2015 by the Russian Academy of Science-operated RATAN-600 radio telescope in Zelenchukskaya, Russia but was kept secret from the international community. Interstellar space reporter Paul Gilster broke the story after the researchers quietly circulated a paper announcing the detection of “a strong signal in the direction of HD164595.”

The mysterious star’s designation is HD164595 and it’s considered to be sun-like in nature with a nearly identical metallic composition to our own star. So far, a single Neptune-like (but warmer) planet has been discovered in its orbit–HD 164595 b. But as Gilster explained, “there could, of course, be other planets still undetected in this system.”

Experts say it is far too early to know what the signal means or where, precisely,it came from.

“The signal is provocative enough that the RATAN-600 researchers are calling for permanent monitoring of this target,” said Gilster. And that’s exactly what is transpiring. As of last night, the SETI institute is diverting its Allen Telescope Array in northern California to investigate while their counterparts at METI International (Messaging Extraterrestrial Intelligence) will utilize Panama’s Boquete Optical Observatory.

“In addition, we need to be alert to the possibility than if we do really find a signal from an advanced civilization, they are also transmitting at other frequencies than the one where we first detected them. That’s why it’s so important to prepare for follow-up SETI observations at both radio and optical frequencies, to be launched as soon as we detect a credible candidate signal at any frequency.”


http://www.geekwire.com/2016/signal-set ... -hd164595/

[Newfie]

Wow....thanks.

If they are a they and they turn out to be more advanced it proves advancement is possible. A small ray of hope!

[onlooker]

Just a wild idea but what if life is getting assistance from advanced ETs(singular or plural ). This would certainly increase the odds of life including intelligent one to survive and prosper

[Newfie]

And who would the first, most advanced, life form be? God?

[Tanada]

$this->bbcode_second_pass_quote('Newfie', 'A')nd who would the first, most advanced, life form be? God?

[onlooker]

Remember you only need just one ET to have sufficiently progressed and then deemed it a worthy calling to do what I said

[vox_mundi]

Possible signal at 11 GHz frequency from sun-like star; Odds not favorable

$this->bbcode_second_pass_quote('', '.').. Could it be a transmission from a technically proficient society? At this point, we can only consider what is known so far. This is a technical story, of course.

First, is the detected signal really coming from the direction of HD 164595? The RATAN-600 is of an unusual design (a ring on the ground of diameter 577 meters), and has an unusual "beam shape" (the patch of sky to which it is sensitive). At the wavelength of the reported signal, 2.7 cm – which is equivalent to a frequency of 11 GHz – the beam is about 20 arcsec by 2 arcmin. In other words, it's a patch that's highly elongated in the north-south direction.

The patch from which the signal seems to be coming agrees in the east-west direction (the narrow part of the beam) with HD 165695's sky coordinates, so that's the basis of the assumption by the discoverers that this is likely to be coming from that star system. But of course, that's not necessarily the case.

Second is the question of the characteristics of the signal itself. The observations were made with a receiver having a bandwidth of 1 GHz. That's a billion times wider than the bandwidths traditionally used for SETI, and is 200 times wider than a television signal. The strength of the signal was 0.75 Janskys, or in common parlance, "weak." But was it weak only because of the distance of HD 164595? Perhaps it was weak because of "dilution" of the signal by the very wide bandwidth of the Russian receiver? Just as a pot pie, incorporating lots of ingredients, can make guessing the individual foodstuffs more difficult, a wide-bandwidth receiver can dilute the strength of relatively strong narrow-band signals.

The chance that this is truly a signal from extraterrestrials is not terribly promising, and the discoverers themselves apparently doubt that they've found ET. Nonetheless, one should check out all reasonable possibilities, given the importance of the subject.

Consequently, the Allen Telescope Array (ATA) was swung in the direction of HD 164595 beginning on the evening of August 28. According to our scientists Jon Richards and Gerry Harp, it has so far not found any signal anywhere in the very large patch of sky covered by the ATA.

However, we have not yet covered the full range of frequencies in which the signal could be located, if it's of far narrower bandwidth than the Russian 1 GHz receiver. We intend to completely cover this big swath of the radio dial in the next day or two. A detection, of course, would immediately spur the SETI and radio astronomy communities to do more follow-up observations.

[vox_mundi]

Either Stars Are Strange, or There Are 234 Aliens Trying To Contact Us

$this->bbcode_second_pass_quote('', '[')img]http://cdn.phys.org/newman/csz/news/800/2016/2-eitherstarsa.png[/img]

... What we're talking about here is a new study from E.F. Borra and E. Trottier, two astronomers at Laval University in Canada. Their study, titled "Discovery of peculiar periodic spectral modulations in a small fraction of solar type stars" was just published at arXiv.org. ArXiv.org is a pre-print website, so the paper itself hasn't been peer reviewed yet. But it is generating interest.

The two astronomers used data from the Sloan Digital Sky Survey, and analyzed the spectra of 2.5 million stars. Of all those stars, they found 234 stars that are producing a puzzling signal. That's only a tiny percentage. And, they say, these signals "have exactly the shape of an ETI signal" that was predicted in a previous study by Borra.

The 234 stars in Borra and Trottier's study aren't random. They're "overwhelmingly in the F2 to K1 spectral range" according to the abstract. That's significant because this is a small range centred around the spectrum of our own Sun. And our own Sun is the only one we know of that has an intelligent species living near it. If ours does, maybe others do too?

The detected signals are pulses of light separated by a constant time interval. These types of signals were predicted by Borra in his 2012 paper, and they are what he and Trottier set out to find in the Sloan data. It may be a bit of a red flag when scientist's find the very thing they predicted they would find. But Trottier and Borra are circumspect about their own results.

[onlooker]

So does this mean "The spectrum of the Sun's solar radiation is close to that of a black body with a temperature of about 5,800 K. "Or "The range of electromagnetic energy emitted by the sun is known as the solar spectrum, and lies mainly in three regions: ultraviolet, visible, and infrared. The solar spectrum extends from about 0.29 µm (or 290 nm) in the longer wavelengths of the ultraviolet region, to over 3.2 µm (3,200 nm) in the far infrared. " Or perhaps that those stars are very similar to the Sun

[vox_mundi]

$this->bbcode_second_pass_quote('onlooker', 'S')o does this mean "The spectrum of the Sun's solar radiation is close to that of a black body with a temperature of about 5,800 K. "Or "The range of electromagnetic energy emitted by the sun is known as the solar spectrum, and lies mainly in three regions: ultraviolet, visible, and infrared. The solar spectrum extends from about 0.29 µm (or 290 nm) in the longer wavelengths of the ultraviolet region, to over 3.2 µm (3,200 nm) in the far infrared. " Or perhaps that those stars are very similar to the Sun

[vox_mundi]

Bizarre Star Dims Again, and Astronomers Scramble to Catch It in the Act

$this->bbcode_second_pass_quote('', '[')img]https://i.kinja-img.com/gawker-media/image/upload/s--PkzRNxFF--/c_scale,fl_progressive,q_80,w_800/xvhna1tgx4hcefmmiab5.jpg[/img]
One theory for the odd behavior exhibited by Tabby star is that two proto-planets smashed into each other (pictured above), producing a massive debris field. A new theory suggests a collision likely occurred—but between a large planet and the star itself.

The star often called the most mysterious in the galaxy has begun darkening again. Scientists are now rushing to watch the event with as many telescopes as they can muster to attempt to understand what is causing its bewildering fluctuations of light.

The star, called KIC 8462852 and nicknamed “Tabby's Star” after Yale University astronomer Tabetha “Tabby” Boyajian, first made news in 2015 when researchers discovered something odd about its light, whose strange brightenings and dimmings have even caused some to speculate it might host alien megastructures around it.

These dimming events are far too substantial to be caused by planets crossing the face of the star, so scientists looked for other explanations. Some have even suggested that it might host signs of intelligent alien life—specifically, a Dyson sphere, a hypothetical megastructure built around a star to capture as much of its energy as possible to power an advanced civilization. It was soon decided that the only way to solve the mystery would be to observe the star in the act of dimming across the electromagnetic spectrum.

... Now scientists have discovered Tabby's Star is dimming again, and are racing to get as many telescopes as they can to watch it in as many wavelengths of light as possible, Wright said. “All week there's been some indication that something might be up,” he said. “Sure enough, at about 4 A.M. this morning [Pacific time], I got a phone call from Tabby [Boyajian] saying that Fairborn Observatory in Arizona had confirmed the star as 3 percent dimmer than it normally is. That's enough to say that it’s absolutely no statistical fluke, and we’ve now confirmed it with multiple observatories.”

Among the telescopes Wright said researchers now hope to use to catch this dimming event in the act:
$this->bbcode_second_pass_quote('', '[')i]—The Green Bank Telescope in West Virginia, the world's largest fully steerable radio telescope
—The Automated Planet Finder at Lick Observatory near San Jose, Calif., a robotic optical telescope
—Both telescopes at the Keck Observatory in Hawaii, which operate in optical and near-infrared wavelengths
—The MMT Observatory in Arizona, an optical telescope
—NASA's Swift Gamma-Ray Burst Mission, which operates in gamma ray, x-ray, ultraviolet and optical wavelengths
‑Las Cumbres Observatory, a worldwide network of robotic optical telescopes
—Fairborn Observatory in Arizona, which operates in optical wavelengths
—The Large Binocular Telescope in Arizona, which operates in optical and near-infrared wavelengths
—The Hobby–Eberly Telescope in Texas, an optical telescope

[GoghGoner]

I would love for this to be an alien mega-structure but something tells me there is going to be a more boring conclusion to this mystery.