PSU: No Obvious Advanced Civilizations Beyond Earth

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PSU: No Obvious Advanced Civilizations Beyond Earth

Post by bystander » Thu Apr 16, 2015 1:42 pm

Search for Advanced Civilizations beyond Earth Finds Nothing Obvious in 100,000 Galaxies
Penn State University | Eberly College of Science | 2015 Apr 15
[img3="A false-color image of the mid-infrared nebula surrounding the nearby star 48 Librae. This nebula was discovered in the course of the G-HAT survey using NASA's WISE space telescope. The nebula is invisible in most kinds of light, including visible light. (Credit: Roger Griffth (Penn State) / IPAC (NASA/JPL-Caltech))"]http://sites.psu.edu/astrowright/wp-con ... ne.001.jpg[/img3][hr][/hr]
After searching 100,000 galaxies for signs of highly advanced extraterrestrial life, a team of scientists using observations from NASA's WISE orbiting observatory has found no evidence of advanced civilizations in them. "The idea behind our research is that, if an entire galaxy had been colonized by an advanced spacefaring civilization, the energy produced by that civilization's technologies would be detectable in mid-infrared wavelengths -- exactly the radiation that the WISE satellite was designed to detect for other astronomical purposes," said Jason T. Wright, an assistant professor of astronomy and astrophysics at the Center for Exoplanets and Habitable Worlds at Penn State University, who conceived of and initiated the research. ...

"Whether an advanced spacefaring civilization uses the large amounts of energy from its galaxy's stars to power computers, space flight, communication, or something we can't yet imagine, fundamental thermodynamics tells us that this energy must be radiated away as heat in the mid-infrared wavelengths," Wright said. "This same basic physics causes your computer to radiate heat while it is turned on."

Theoretical physicist Freeman Dyson proposed in the 1960s that advanced alien civilizations beyond Earth could be detected by the telltale evidence of their mid-infrared emissions. It was not until space-based telescopes like the WISE satellite that it became possible to make sensitive measurements of this radiation emitted by objects in space.

Roger Griffith, a postbaccalaureate researcher at Penn State and the lead author of the paper, scoured almost the entire catalog of the WISE satellite's detections -- nearly 100 million entries -- for objects consistent with galaxies emitting too much mid-infrared radiation. He then individually examined and categorized around 100,000 of the most promising galaxy images. Wright reports, "We found about 50 galaxies that have unusually high levels of mid-infrared radiation. Our follow-up studies of those galaxies may reveal if the origin of their radiation results from natural astronomical processes, or if it could indicate the presence of a highly advanced civilization." ...

The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies.
  1. Background and Justification - J.T. Wright, B. Mullan, S. Sigurðsson, M.S. Povich
  2. Framework, Strategy, and First Result - J.T. Wright, R.L. Griffith, S. Sigurðsson, M.S. Povich, B. Mullan
  3. The Reddest Extended Sources in WISE - R.L. Griffith, J.T. Wright, J. Maldonado, M.S. Povich, S. Sigurðsson, B. Mullan
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ASTRON: Advanced Alien Civilizations Rare or Absent

Post by bystander » Tue Sep 15, 2015 5:37 pm

Advanced Alien Civilizations Rare or Absent in the Local Universe
Netherlands Institute for Radio Astronomy (ASTRON) | 2015 Sep 15

Sensitive new telescopes now permit astronomers to detect the waste heat that is expected to be a signature of advanced alien civilisations that can harness enormous energies on the scale of the stellar output of their own galaxy. Professor Michael Garrett (ASTRON General & Scientific Director) has used radio observations of candidate galaxies to show that such advanced civilisations are very rare or entirely absent from the local Universe.
[img3="The figure shows what the activities of a Kardashev Type III civilisation might look like - encapsulating the energy of stars by so called Dyson spheres or swarms is one way to harness enormous energies on truly galactic scales. The resulting waste heat products such a galactic scale enterprise would produce, should be detectable by today's telescopes. (courtesy Danielle Futselaar, copyright ASTRON)"]https://www.astron.nl/sites/astron.nl/f ... %20Res.jpg[/img3][hr][/hr]
Advanced civilisations harnessing energies on galactic scales (so-called Kardashev Type III civilisations) are expected to be detectable in the mid-Infrared part of the spectrum via the emission of significant waste heat products. A team of astronomers led by Dr. Jason Wright (Penn State University, USA) has already drawn up a list of several hundred candidate galaxies (culled from a total population of 100,000 objects) where unusually extreme mid-IR emission is observed. One problem is that although rare, this kind of emission can also be generated by natural astrophysical processes related to thermal emission from warm dust.

Professor Michael Garrett (ASTRON & University of Leiden) has used radio measurements of the very best candidate galaxies and discovered that the vast majority of these systems present emission that is best explained by natural astrophysical processes. In particular, the galaxies as a sample, follow a well-known global relation that holds for almost all galaxies - the so-called "Mid-Infrared Radio correlation". The presence of radio emission at the levels expected from the correlation, suggests that the mid-IR emission is not heat from alien factories but more likely emission from dust - for example, dust generated and heated by regions of massive star formation.

As Professor Garrett explains: "the original research at Penn State has already told us that such systems are very rare but the new analysis suggests that this is probably an understatement, and that advanced Kardashev Type III civilisations basically don't exist in the local Universe. In my view, it means we can all sleep safely in our beds tonight - an alien invasion doesn't seem at all likely!" ...

The application of the Mid-IR radio correlation to the Ĝ sample and the search for advanced extraterrestrial civilisations - Michael Garrett
http://asterisk.apod.com/viewtopic.php?t=34666
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Re: ASTRON: Advanced Alien Civilizations Rare or Absent

Post by neufer » Tue Sep 15, 2015 6:26 pm

https://en.wikipedia.org/wiki/Kardashev_scale wrote:
Click to play embedded YouTube video.
<<The Kardashev scale is a method of measuring a civilization's level of technological advancement, based on the amount of energy a civilization is able to utilize. The scale has three designated categories called Type I, II, and III. A Type I civilization uses all available resources on its home planet (~1016 W), Type II harnesses all the energy of its star (~1026 W), and Type III of its galaxy (~1036 W). The scale is only hypothetical, but it puts energy consumption in a cosmic perspective. It was first proposed in 1964 by the Russian astronomer Nikolai Kardashev.

In 2012, total world energy consumption was equivalent to an average power consumption of 17.54 TW (or 0.724 on [the] Kardashev scale). Michio Kaku suggested that humans may attain Type I status in 100–200 years, Type II status in a few thousand years, and Type III status in 100,000 to a million years.>>
https://en.wikipedia.org/wiki/Kardashian_Index wrote:
<<The Kardashian Index (K-Index), named after Kim Kardashian, is a metric measuring the discrepancy between a scientist's social media profile and publication record. Proposed in 2014, the measure compares the number of followers a research scientist has on Twitter to the number of citations they have for their peer-reviewed work. A high K-index indicates an over-blown scientific fame while a low K-index suggests that a scientist is being undervalued. According to the author, researchers whose K-index > 5 can be considered 'Science Kardashians'.>>
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Re: ASTRON: Advanced Alien Civilizations Rare or Absent

Post by neufer » Tue Sep 15, 2015 9:57 pm

Click to play embedded YouTube video.
Click to play embedded YouTube video.
Click to play embedded YouTube video.
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KIC 8462852: Alien Megastructure?

Post by neufer » Fri Oct 16, 2015 3:42 pm

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Re: ASTRON: Advanced Alien Civilizations Rare or Absent

Post by Ann » Mon Oct 19, 2015 3:57 pm

neufer wrote: <<The Kardashian Index (K-Index), named after Kim Kardashian, is a metric measuring the discrepancy between a scientist's social media profile and publication record. Proposed in 2014, the measure compares the number of followers a research scientist has on Twitter to the number of citations they have for their peer-reviewed work. A high K-index indicates an over-blown scientific fame while a low K-index suggests that a scientist is being undervalued. According to the author, researchers whose K-index > 5 can be considered 'Science Kardashians'.>>
Love the Kardashian index (or K-index), Art!

Can't help wondering what Jason T. Wright's K-index might be?

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Re: ASTRON: Advanced Alien Civilizations Rare or Absent

Post by neufer » Mon Oct 19, 2015 6:00 pm

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ANU: The Aliens Are Silent Because They Are Extinct

Post by bystander » Thu Jan 21, 2016 7:13 pm

The Aliens Are Silent Because They Are All Extinct
Australian National University | 2016 Jan 21

Life on other planets would likely be brief and become extinct very quickly, say astrobiologists from ANU Research School of Earth Sciences.

In 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, lead author on the paper, which is published in Astrobiology.

"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."

About four billion years ago Earth, Venus and Mars may have all been habitable. However, a billion years or so after formation, Venus turned into a hothouse and Mars froze into an icebox. ...

The Case for a Gaian Bottleneck: The Biology of Habitability - Aditya Chopra, Charles H. Lineweaver
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Re: ANU: The Aliens Are Silent Because They Are Extinct

Post by neufer » Thu Jan 21, 2016 7:46 pm

.
  • Intelligent life is probably either far advanced or far behind that of the Earth.

    E.g., Tabby's 'WTF' Star may be an indication of a Dyson swarm... or just a smoke signal:
https://en.wikipedia.org/wiki/KIC_8462852 wrote: <KIC 8462852 – eponymously Tabby's Star (after lead author Tabetha S. Boyajian) or WTF Star (formally for "Where's The Flux?", but also a reference to an expression of disbelief) – is an F-type main-sequence star located in the constellation Cygnus approximately 454 parsecs (1,480 ly) from Earth. Unusual light fluctuations of the star were discovered by citizen scientists as part of the Planet Hunters project, and in September 2015 astronomers and citizen scientists associated with the project posted a preprint of a paper describing the data & possible interpretations. The discovery was made from data collected by the Kepler space telescope, which observes changes in the brightness of distant stars in order to detect exoplanets.

Several hypotheses have been proposed to explain the star's large irregular changes in brightness as measured by its unusual light curve. The leading hypothesis, based on a lack of observed infrared light, is that of a swarm of cold, dusty comet fragments in a highly eccentric orbit. Many small masses in "tight formation" orbiting the star have also been proposed. The changes in brightness could be signs of activity associated with intelligent extraterrestrial life building a Dyson swarm. The SETI Institute's initial radio reconnaissance of KIC 8462852, however, found no evidence of technology-related radio signals from the star.>>
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Re: ANU: The Aliens Are Silent Because They Are Extinct

Post by Chris Peterson » Thu Jan 21, 2016 8:00 pm

neufer wrote:.
Intelligent life is probably either far advanced or far behind that of the Earth.
Depends on what you mean by "intelligent". Technological life can't be far behind us. I'm not sure it can be all that far ahead of us, either, but that's an interesting question.

I do tend to side with the view that technological civilization is unstable, and seldom if ever lasts more than a few centuries.
Chris

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Re: ANU: The Aliens Are Silent Because They Are Extinct

Post by neufer » Thu Jan 21, 2016 10:32 pm

Click to play embedded YouTube video.
Chris Peterson wrote:
neufer wrote:.
Intelligent life is probably either far advanced or far behind that of the Earth.
Depends on what you mean by "intelligent". Technological life can't be far behind us. I'm not sure it can be all that far ahead of us, either, but that's an interesting question.

I do tend to side with the view that technological civilization is unstable, and seldom if ever lasts more than a few centuries.
Art Neuendorffer