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your opinion on whether civilization exists on another planet

I think civilization probably does exist on another planet
I think civilization probably does NOT exist on another planet
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Offline twinstar

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your opinion on whether civilization exists on another planet
« on: January 27, 2017, 02:37:24 AM »
your opinion on whether civilization exists on another planet



I think civilization probably does exist on another planet

I think civilization probably does NOT exist on another planet

I don't yet have an opinion on this question



Offline twinstar

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Re: your opinion on whether civilization exists on another planet
« Reply #1 on: January 28, 2017, 05:13:24 AM »
Researchers have pinpointed mysterious radio waves from dwarf galaxy billions of light years from Earth



For about a decade, scientists have been able to detect fast radio bursts (FRBs), elusive and powerful flashes that last only a few milliseconds. In that time, only 18 FRBs have been detected. Now, for the first time ever, researchers have isolated the source of several FRBs. They are coming from a dwarf galaxy that is billions of light years from Earth. The "most perplexing mystery in astronomy" - the source of FRBs - is now coming into focus.

Scientists narrow in on source of radio bursts coming from space

Shami Chatterjee, an astrophysicist at Cornell University, says that by knowing the source of FRBs, scientists may be able to unlock clues as to what is causing them. He doesn't think the cause is aliens, but doesn't rule that out either. Instead, he believes that the FRBs could indicate interactions of a neutron star or an active galactic nucleus.

When the scientists found out that a particular FRB was bursting repeatedly, they ruled out the idea that the radio wave was being caused by two neutron stars colliding. The signal was more than just a radio flash or explosive crash; the repetition of FRB 121102 made them look deeper to find the cause.

The repetition also allowed them to focus their detection equipment at a single patch in the sky.

"If you go fishing in this spot in the sky, you might be more likely to get lucky than in other random spots in the sky," Chatterjee says.

The research team was able to start using an interferometer in New Mexico, which consisted of 27 radio dishes called the Very Large Array. This provided them with greater resolution to detect the bursts.  The equipment captured data at 200 frames per second at the selected spot in the sky.

"It was a pretty intensive observational and computational challenge," Chatterjee commented.

Scientists capture images of radio bursts, narrow in on dwarf galaxy Auriga

After 50 hours of data recording, the research team found nothing of significance. That's when they called on the Arecibo Observatory in Puerto Rico. The scientists there were able to capture nine radio images of the elusive bursts. The research teams all narrowed in on an even tinier patch in the sky. The source was revealing itself.

All signs pointed to the constellation Auriga, a dwarf galaxy that is 2.5 to 3 billion light years away. If their theory is correct, then the event causing the bursts had to have occurred billions of years ago. The scientists hypothesize that the cause could have been a newborn magnetar with a strong magnetic field spinning and emitting giant pulses. They say it could also be a magnetar colliding with a black hole, or it could have been an active galactic nucleus emitting blobs of vaporized plasma.

The study, published in the journal Nature, also questions whether all FRBs pulse repeatedly, or if some are singular bursts.




Offline twinstar

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Re: your opinion on whether civilization exists on another planet
« Reply #2 on: January 28, 2017, 06:02:09 AM »
VIEWING EARTH AS AN EXTRA-SOLAR PLANET



What if another civilization had telescopes and spacecraft better than ours? Would Earth be detectable from another planet a few light-years away? Likewise, what will it take for us to detect life on an Earth-like planet within a similar distance? It's interesting to consider those questions, and now, there is data to help answer them. In December 1990, when the Galileo spacecraft flew by Earth in its circuitous journey to Jupiter, scientists pointed some of the instruments at Earth just to see how the old home planet looked from space. Since we knew life could definitely be found on Earth, this exercise helped create some criteria that if found elsewhere, would point to the existence of life there as well. But what if Earth's climate was different from what it is now? Would that signature still be detectable? And could potential biomarkers from extra solar planets holding climates much colder or warmer than ours be obvious? A group of researchers in France input some various criteria garnered from different epochs in Earth's history to test out this hypothesis. What did they find?

One of the most telling of the criteria from the Galileo flyby revealing life on Earth was what is called the vegetation red edge -a sharp increase in the reflectance of light at a wavelength of around 700 nanometers. This is the result of chlorophyll absorbing visible light but reflecting near infrared strongly. The Galileo probe found strong for this evidence on Earth in 1990.

Luc Arnold and his team at the Saint-Michel-l'Observatoire in France wanted to determine some different parameters where plant life similar to Earth's would still be detectable via the vegetative red edge on an Earth-like planet orbiting a star several light years away.

At that distance the planet would be a non-resolvable (in visible light) point-like dot, so the first question to consider is whether the red edge would be visible at different angles. The planet is likely to be rotating, and for example, on Earth, the continents that have the most vegetation are mainly in the northern hemisphere. If that hemisphere wasn't leading the view, would a bio-signature still be detectable? They also wanted to allow for the different seasons, where a hemisphere in winter would be less likely to have vegetative biomarkers than one in summer, and potential heavy cloud cover.

They also input different climate criteria from the last Quaternary climate extremes, using climate simulations have been made by general circulation models. They used data from the present time and compared that to an ice age, The Last Glacial Maximum (LGM) which occurred about 21,000 years ago. Temperatures globally were on the order of 4 degrees C colder than today, and ice sheets covered most of the northern hemisphere. Then, they used a warmer time, during the Holocene epoch 6,000 years ago, when the Earth's northern hemisphere was about 0.5 degrees C warmer than today. The sea level was rising and the Sahara Desert contained more vegetation.

Surprisingly, the researchers found even during winter in an ice age, the vegetation red signal would not be significantly reduced, compared to today's climate and even the warmer climate.

So if another Earth is out there, the vegetaion red edge should allow us to find that Earth-like planet. But we need better telescopes and spacecraft to find it.

The best hope on the horizon is the Terrestrial Planet Finder. ESA has a similar instrument in the works called Darwin.

The teams behind these instruments say they could spot Earth-like planets orbiting stars at distances of up to 30 light years with an exposure measured in a couple of hours.

Arnold's team says that spotting the signs of life on such a planet would be much harder. The vegetation red edge might only be seen with an exposure of 18 weeks with a telescope like the Terrestrial Planet Finder's. An 18 week exposure of a planet orbiting another star would be an almost impossible task.

So when might we eventually see vegetation on another planet? The Terrestrial Planet Finder (TPF) looks unlikely to be launched before 2025 and even then might not have the power to do the job.

More ambitious telescopes later in the century, such as a formation of 150 3-meter mirrors would collect enough photons in 30 minutes to freeze the rotation of the planet and produce an image with at least 300 pixels of resolution, and up to thousands depending on array geometry. "At this level of spatial resolution, it will be possible to identify clouds, oceans and continents, either barren or perhaps (hopefully) conquered by vegetation," the researchers write.



Offline twinstar

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Re: your opinion on whether civilization exists on another planet
« Reply #3 on: January 28, 2017, 06:19:16 AM »
Is There Life on Other Planets?




Most of us, at some point in life, must have pondered over the eternal query of the existence of life on other planets. Are we the only ones in the depths of this endless ocean called the Universe? Read this Buzzle article to know more about the endless list of possibilities that reside somewhere in the corners of our imagination.

Martian Microbes

The meteorite named ALH84001 impacted the Earth in present-day Antarctica more than 15 million years ago. An extensive study of this specimen reveals that the components contain structures, which appear more or less like bacteria or other similar microscopic organisms. Such potential bacteria-like microbes must have fossilized in the meteorite during its formation. This further strengthens the argument that millions of years ago, life did exist on Mars!

Extraterrestrial life has always been the subject of human expressions in various forms like movies, paintings, or popular stories. This topic has been a subject of intense debate, not only among the common people, but also among the intellectuals around the world. However, one fact clearly stands tall; there is no proof till date that can conclusively state or authenticate the presence of a life form other than that on Earth. Even though there is no evidence, the possibility of a civilization existing somewhere out there may be worth considering. Crop circles, another phenomenon that has benumbed humans, is thought to have been influenced by the aliens.

5 Controversial Theories of Life on Other Planets

Drake Equation Theory

? In 1961, US astronomer Frank Drake had developed an equation that suggested the presence of many more life-bearing planets, and the possibility of an alien life form that can communicate. The equation includes several factors like the age and formation of stars, number of Earth-like planets, probability of communication, etc. Initially, this method garnered much attention, as the statistics produced were quite plausible, but later on, as numerous space systems were studied, the calculation started becoming more complex, ultimately producing results that vary a lot.

? The different components of the equation given above can be explained in a very simple, yet effective format. Out of all the components, the mean rate of star formation R* has been calculated approximately till now, which indicates that about four new stars are born at least in our galaxy, the Milky Way, every year. The other factors can only be assumed or guessed, depending on the level of research.

? In a typical galaxy, only a quarter of all the stars are included in solar systems. These formations have at least two planets that can be potentially inhabitable. The components of development of life, evolution of intelligence, and the ability to be technologically superior might develop at a chance of 50% on such planets. If at all a civilization or a race evolves, it might attempt communication in around 4,000,000 years. Thus, putting all these factors in the formula, the equation becomes:

NT = 4*0.25*2*0.5*0.5*0.5*4,000,000

= 1,000,000

Thus, the number of potential civilizations that are still undiscovered is about a million, which may attempt contact in the near future. But, on a more practical scenario, the existence of different planets that can harbor such a number of forms is very rare and remote.

? The complexity arises from the fact that there are countless factors and parameters that must operate before a life form actually emerges and evolves. If all the variables are summed up, they can stated as: combination of various inorganic molecules that remained in a residual form or a part of the primordial soup (a term that explains the state of matter after the Big Bang), formation of organic molecules that from the inorganic ones, the existence of a star like the Sun that will provide energy for biochemical reactions to take place, change in conditions that are suitable for unicellular life, extreme obstacles that have to be overcome in order that multicellular life becomes successful, etc. As living proof, all the organisms, whether unicellular or multicellullar, primitive or advanced, have passed through these various stages described above.

Panspermia Theory

? The term 'panspermia' has a Greek origin that means 'seeds everywhere'. According to this theory, life was 'seeded' on Earth from outer space, i.e., life was brought to our planet from a foreign space body. Such bodies could have been comets, meteors, or even asteroids that caused an impact on our planet. Mostly, the organisms were in the form of microbes, as multicellular life did not exist millions of years ago. Thus, if life did not first originate on Earth, did it flourish on other planets, before the Earth was even born? If abiogenesis (the process of appearance of life) is possible on Earth, can it take place even on other planets?

? The answers to such questions can be attempted with the help of this theory that was proposed in 1973 in its modern form by two people: a physicist called Francis Crick and a chemist called Leslie Orgel. The theory in its crude form was first mentioned around 450 BCE by a Greek philosopher called Anaxagoras. There are three subtypes of the panspermia concept that explain the origin of life.

Directed Panspermia

According to this concept, highly advanced civilizations that are more developed than us do exist on planets that are close to our world. These civilizations would have intentionally or accidentally spread the biochemical structure to our planet, during its early stages of formation. Though more or less improbable and a bit fictitious, this concept is nevertheless possible.

Ballistic Panspermia

The spreading of life forms from one planetary body to another that are present in the same solar system is called ballistic panspermia. This concept is widely used to explain and debate that life on Earth in fact originated due to seeding from Mars, which was possibly inhabited by alien life forms millions of years ago.

Lithopanspermia

One of the most difficult processes, lithopanspermia refers to the seeding of biochemical forms on another planet that is present in a different solar system, as compared to the system from where the spreading medium belongs to. The DNA molecules have to survive the harsh conditions of outer space before reaching the particular celestial body.

? Although the panspermia concept has garnered much attention in recent years, it does not explain a few points.

A major one is that if life existed on Mars before Earth, where is it now? If it got extinct, then suitable fossil appearances should have been found till now by the three robotic rovers on the red planet.

Also, if a more advanced civilization spread the biomolecules to our planet, why didn't they contact us, i.e., humans, again after our planet underwent significant changes regarding evolution and development of higher life forms?

Such questions might be answered if we ever find aliens on another planet.

Biochemical Evolution Theory

? The most important factor in determining the presence of life is the environment. If we assume that the conditions such as those on planet Earth can be created anywhere in the Universe or already exist in it, then the idea of life on that planet is almost a certainty. Based on the survival mechanism of human beings, we may be able to predict the possibility of a whole new set of beings similar to us.

? Human beings need air to breathe, water to drink, and food for survival. The availability of these factors is a must for each one of us to sustain on Earth. Hence, there is a lot of curiosity among experts with regard to the planet Mars, Mercury, Jupiter, the moons of Jupiter and Saturn like Europa and Titan, respectively, in our solar system. These have been found to have traces of water on their surface. Therefore, there is every chance that life will be able to thrive on these bodies.

? The interaction between inorganic compounds gives rise to organic molecules like proteins, amino acids, carbohydrates, lipids, etc. For such processes to take place, the availability of liquid water is essential. On our planet, the appearance of unicellular forms and the subsequent multicellular organisms too, first took place in the oceans. Moons like Titan, Europa, Enceladus, etc., are being said to consist of oceans underneath their solid surfaces. These bodies particularly might contain methane (CH4), which plays a crucial role in the development of primitive life forms. Thus, the chances of finding extraterrestrial microbes on such moons are quite high, though the occurrence of complex life forms in our own solar system is not detected as of today.

? The 1976 Viking probes sent to planet Mars had detected chemical activity, which was quite similar to the daily activity of living organisms on Earth. NASA had conducted detailed analysis of the samples collected by the probes and closed the speculation, citing lack of concrete results. In 2001, another updated theory based on a complex set of equations suggested the presence of many planets that could sustain life. Jupiter's moon Europa radiates infrared waves, which is typical of an organism such as bacteria. Hence, it is subject to a very intense scrutiny and observation by NASA, but substantial evidence still eludes us. However, all the above incidents have encouraged a lot of interest and a renewed effort by researchers all over the world to settle the claims of life on other planets once and for all.

Theory of Extremophiles

? The organisms (mostly microbes) that can survive the most harsh conditions ever present on our planet, as well as in the outer space are called extremophiles. These life forms are seen on our planet, where extreme conditions are present. Extremophiles are known to exist below the Antarctic ice sheets, near volcanic fumaroles and vents, underwater volcanoes and hot spots, the Earth's exosphere, etc. Some examples of such organisms are: Tardigrades, Chernobyl Fungus, Pompeii Worm, etc. Few multicellular and bioluminescent organisms also exist only at great depths in the ocean, where sunlight cannot penetrate.

? Some planets and even moons also exhibit such harsh conditions, though exact replication is not present. According to expert study and astrobiological research, if the Earth can harbor such organisms under inhospitable parameters, such microbes might also be present on other planets, depending on the intensity of the specific aspect, where the microbes might be found. Such life forms also have to survive against the bombardment of cosmic rays, gamma rays, solar wind, etc. In 2013, a bacterium named Tersicoccus phoenicis was discovered in two regions of the world, one each in South America and the USA. This microbe was only found in the docking chambers of the spacecrafts and nowhere else. Till present, even after a year, extensive studies have been carried out in various regions on our planet, and this organism has not been found in any environment. Thus, it can be assumed that Tersicoccus phoenicis was carried by the spacecraft on entry in our atmosphere from the outer space onto our planet. This microbe may possibly thrive in the exosphere region, or even beyond in the space vacuum.

? Another experiment that is famous for proving this theory is the one where few scientists created surface and subsurface conditions that are similar those assumed to be present on the Europa moon of Jupiter. This moon was particularly chosen as it is the best candidate for the occurrence of marine or oceanic conditions below its surface. In the study, microbes like N. magadii and D. radiodurans were subjected to intense UV radiation. The results showed that most of them died, but few actually survived the onslaught of the UV rays. This indicates that Europa is a prime candidate for the thriving of microorganisms in its oceans, apart from our planet.

? The theory of extremophiles is the least credible one among all, as very little data has been obtained or is available with scientists. This subfield of astrobiology needs sufficient attention, if we continue our search of alien life on other celestial bodies.

Habitable Planet Theory

? Another theory assumes that there is a unique structure (as that of the Earth) that has got the right components to enable life to flourish. The discoveries until now have failed to conclusively prove the existence of conditions exactly similar to those on Earth. If we consider part of the Universe that we know, as a sample of the larger expanse, there might be no life at all. This is again just a probability based on the knowledge, which we have been able to garner till today.

? The Earth is placed in a habitable zone in our solar system, and this zone encompasses the space consisting of at least half of Venus and the whole of Earth and Mars. It extends a bit beyond the Martian orbit. The recently discovered planet called Gliese 581g is a potential example of a planet that exists in the habitable zone of its solar system. There are six planets including 581g that orbit a red star called Gliese 581. This body is more than 20 light years away from the Earth. Other examples of planets that exist within the habitable zones of their system are Kepler-186f and HD 40307g. These exist about 40 and 500 light years away from Earth, respectively. Every exoplanet discovered is first classified on the basis of its surface temperature, presence or absence of atmosphere, size, distance from its sun, composition, etc. Based on these factors, it is categorized to be under a non-habitable or a habitable zone.

? The presence of life beyond the solar system is a very contentious matter. There is a section of people who believe that on account of the expanse of the Universe, there must be a planet like Earth that supports life. The issue is a matter of research and speculation. The argument that there could be a planet like Earth, that exists in the realms of the Universe is a very likely event. Considering the sheer expanse of the Universe, we may be tempted to believe in the theory that there is a parallel civilization flourishing somewhere out in the cosmos. The only constraint facing us and perhaps the aliens is that both sides are unaware of a communication mechanism. We, humans, have come a long way since our evolution on this planet. But our achievements have not yet been able to make us aware of such an extraterrestrial being (if at all it exists). Similarly, if we again assume that a civilization does exist somewhere out there, even they have a long way to go and actually communicate with us.

The SETI (Search for Extraterrestrial Intelligence) Center located in Mountain View, California is dedicated to finding life in the Universe. This organization works in two broad areas: (i) research and development and (ii) projects. The first part includes development of new search techniques and equipment that would facilitate the search?for example, large telescopes and communication devices. The projects are the actual work directed with a well-planned strategy to search for the evidence of life. A lot of people claim to have seen an alien life form. The being is 'immortalized' in our memories by its depiction in various Hollywood movies, which leads us to firmly believe that there is life on other planets.

They say, "reality is more important than dreams", and all our assumptions and theories are still distant dreams created by our mind. The fact remains that so far we have not been able to detect life on other planets, but at the same time, there is no denying the possibility that it might actually exist!





Offline twinstar

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Re: your opinion on whether civilization exists on another planet
« Reply #4 on: January 28, 2017, 08:43:32 AM »
The Universe Has Probably Hosted Many Alien Civilizations




http://www.space.com/32793-intelligent-alien-life-probability-high.html




Many other planets throughout the universe probably hosted intelligent life long before Earth did, a new study suggests.

The probability of a civilization developing on a potentially habitable alien planet would have to be less than one in 10 billion trillion - or one part in 10 to the 22nd power - for humanity to be the first technologically advanced species the cosmos has ever known, according to the study.

"To me, this implies that other intelligent, technology-producing species very likely have evolved before us," said lead author Adam Frank, a professor of physics and astronomy at the University of Rochester in New York. [13 Ways to Hunt Intelligent Alien Life]

Do you believe alien life exists elsewhere in the universe?

 Yes - We may not have found them yet, but they're out there.

 No - Aliens are just part of science fiction.

 I'm not sure

Get Results

"Think of it this way: Before our result, you'd be considered a pessimist if you imagined the probability of evolving a civilization on a habitable planet was, say, one in a trillion," Frank said in a statement. "But even that guess - one chance in a trillion - implies that what has happened here on Earth with humanity has in fact happened about 10 billion other times over cosmic history."

In 1961, astronomer Frank Drake devised a formula to estimate the number of extraterrestrial civilizations that may exist today in the Milky Way.

Adam Frank and co-author Woodruff Sullivan of the University of Washington were interested in the odds that intelligent aliens have ever existed anywhere in the universe. So they tweaked the famous Drake equation, coming up with an "archaeological version" that doesn't take into account how long alien civilizations may last.

Frank and Sullivan also incorporated observations from NASA's Kepler space telescope and other instruments, which suggest that about 20 percent of all stars host planets in the life-friendly, "habitable zone," where liquid water could exist on a world's surface.

The researchers then calculated the probability that Earth was the universe's first-ever abode for intelligent life, after taking into account the number of stars in the observable universe (about 20 billion trillion, according to a recent estimate).

"From a fundamental perspective, the question is, 'Has it ever happened anywhere before?'" Frank said. "Our result is the first time anyone has been able to set any empirical answer for that question, and it is astonishingly likely that we are not the only time and place that an advanced civilization has evolved."

But this doesn't mean that there are lots of intelligent aliens out there, just waiting to be contacted, the researchers stressed.

"The universe is more than 13 billion years old," Sullivan said in the same statement. "That means that even if there have been 1,000 civilizations in our own galaxy, if they live only as long as we have been around - roughly 10,000 years - then all of them are likely already extinct. And others won't evolve until we are long gone. For us to have much chance of success in finding another 'contemporary' active technological civilization, on average they must last much longer than our present lifetime."

(The 10,000-year figure cited by Sullivan refers to humanity's development of agriculture and other "rudimentary" technologies; mankind has been capable of sending radio waves and other electromagnetic signals out into the cosmos for just a century or so.)





Offline twinstar

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Re: your opinion on whether civilization exists on another planet
« Reply #5 on: January 28, 2017, 09:07:59 AM »
Speculations on Communications With Other Planet Civilizations - [Project OZMA 1959-1960]




http://www.ok2kkw.com/eme1960/ozma1960.htm




DURING our lifetime several events have occurred which have had tremendous significance to us all. The first nuclear explosion in 1945 and the Soviet’s Sputnik I are two striking examples. Reception and eventual change of intelligent information with some sort of civilization now in existence on another planet certainly would be an event of tremendous importance to us all. I believe that such an accomplishment appears to be most possible within the next decade. Since this subject should he of utmost interest to all radio amateurs I will attempt in this short article to bring you up to date on the basic premises for such startling speculations and, of more importance, what is being done to bring such an event to reality.

Life on other Planets

Before embarking on the radio communications involved it is necessary to establish that there is a reasonable probability of life existing on other planets capable of generating radio signals. Although such speculations have been going on for years, within the past three months three excellent articles have been published which put the problem clearly in focus. The first was published in the British journal Nature (September 19, 1959, page 844) by Giuseppe Cocconi and Philip Morrison of Cornell University. This paper was quickly followed by an article in the January, 1960, issue of Sky and Telescope, by Frank D. Drake, “How Can We Detect Radio Transmissions from Distant Planetary Systems”, and another in the January 2, 1960, issue of the Saturday Review by John Lear entitled “The Search for Intelligent Life on Other Planets”. This article is a digest of these three with a few “amateur” type speculations of my own.

Concerning life on other planets, the following highly simplified concept is advanced: Stars (such as our sun) are mixtures of hot gases and have been in existence for finite times. It would appear that the formation of planets and eventually “life” is some sort of function of time, temperature, and ingredients. If the proper elements are put in the “pot” and cooked long enough things happen and eventually something like a human could be produced. Billions of years are required to produce intelligent beings from a “potful” of organic molecules.

Astronomers have examined the spectral distribution, temperature, and age of many “seeable” stars and have come up with varying estimates of the probability of planets within the vicinity of these stars having some sort of life that could eventually generate radio transmissions. These estimates range from one star in four to as low as one star in a million with such qualifications. These odds have seemed high enough so that at least one qualified organization is getting ready to try to receive such transmissions.

An Active Program

As far as I can determine the only active program is under the direction of Frank D. Drake of the National Radio Astronomy Observatory at Green Bank, West Virginia. Drake has spent much of his 29 years in radio astronomy. He received his undergraduate training in physics from Cornell and his graduate training, resulting in a Ph.D. in radioastronomy, at Harvard. He states that he has never become a radio amateur because he is “too busy” but he is quite interested in the reaction of the amateur to his program. Drake has proposed a very interesting premise which would indicate that we electronically oriented types are very fortunate to have picked this particular century of centuries to have come into existence since 50 years ago there would have been no place for our talents and 50 years from now electronics as applied to communications will become as pedestrian as a 60 c.p.s. generator. I quote directly from his article.

“What search frequency would be best? Consider what might be called the principle of technical perfection. It is only about 50 years since radio communication was invented, yet we have already very nearly achieved technically perfect instruments, and within 50 more years we should have them. By technical perfection we mean that the limits of communication-system sensitivities are not set by deficiencies in the apparatus, such as receiver noise, but by natural phenomena over which man has no control. This is a state in which further improvements in apparatus will not improve the operational results.

"A century is only about a hundred-millionth of the age of our galaxy. Thus, on the galactic time scale, a civilization passes abruptly from a state of no radio ability to one of perfect radio ability. If we could examine a large number of lifebearing planets, we might expect to find in virtually every case either complete ignorance of radio techniques, or complete mastery. This is the principle of technical perfection. Our civilization may be one of an extremely small minority in transition between the two possible states - this, in fact, may be the only major feature in which man is unique.

“Therefore, it may be logical to assume that the civilizations we might detect possess complete mastery of radio already. The transmissions we seek will obviously be very powerful ones, in which large information transfer over long distances is being attempted. Frequencies will be chosen for which the natural limitations on performance are least. Two of these limitations are important: galactic radio noise emission, and noise from the planetary atmosphere, if reception from beneath the atmosphere is being attempted. “Both these emissions insert noise into the receiver, and have the same effect as though the receiver itself were noisy.

The graph (Fig. 1) shows for the earth the radio-sky temperature produced by each of these sources of noise, and their combined effect. This last would be the excess receiver noise temperature of an otherwise perfect receiver. Obviously, the best frequencies to use for our search are those where this total sky temperature is least. “For instance, from beneath the atmosphere of a planet like the earth, the band from 1000 to 10,000 megacycles per second would be the optimum for reception of long-range transmissions. If, however, reception is being done from above the atmosphere, as the principle of technical perfection and our own success with satellites suggest, frequencies above 10,000 megacycles are also good candidates.”

The almost unanimous recommendation for the choice of a “search” frequency is the region around 1420 Mc. (21 cm.). In 1951 Dr. Harold Ewen, then at Harvard, and now the very active president of the Ewen-Knight Corp. in Natick, Mass., discovered that in the vast, cool regions of space there is considerable radiated energy at approximately 1420 Mc. This radiation comes from the collision of neutral, highly kinetic hydrogen atoms which although they have a density of only 1 per cubic centimeter occasionally collide and one collision in eight is of the type that radiates at 1420 Mc. This radiation is strong enough so that depending on the aperture of the dish of the radio telescope, it can be detected at great ranges. Dr. Drake estimates that as many as 15 radio telescopes throughout the world are observing 1420-Mc. outer space radiation on a 24-hour basis. Astrophysicists such as Cocconi and Morrison of Cornell have postulated that since the interest in the 1420-Mc. radiation of cool, interstellar hydrogen is so strong here on earth, scientists on other planets must also be probing this region to learn more about their galaxy. Hence they have suggested that transmissions very near this frequency might be used to contact our earth. Drake, who is also an astrophysicist, and who probably had no real alternate candidate frequency for such a search, has embarked on a very ambitious program on 1420 Mc. which I will cover in the latter part of this article.

A Couple of Approaches

Before doing so I would like to advance two obvious, but non-astrophysical approaches to the problem. Drake has made the reasonable assumption that some of the most likely civilizations on other planets have long since passed through the critical 100 years of radio development. Is it not logical that a similar critical period exists during which a civilization undergoes the transition from being confined to the ground to baying thorough mastery of the space region within a reasonable distance from his own planet. It would seem to me that some such other planet has long since categorized our earth as a suitable candidate for “civilization brewing” and has been watching us and other suitable planets on a routine, automatic basis from sophisticated radiotelescopes on stable space platforms outside of their own atmosphere.

If such is the case, we can make two further assumptions. First, that like any good radio amateur listening for DX, they will transmit back near the frequency they first heard on a regular basis, and, second, that the millimeter wave region which has advantages which I will shortly describe is available to them both for transmission and reception.

I believe that most of the earlier transmissions from our earth were confined by the ionosphere due to their relatively low frequency. However, sometime around 1936—1938 enough power was radiated routinely on frequencies above 30 Mc. that some of it escaped to outer space where, depending on the sensitivity of the other civilization’s receiving installation, it may have been heard. The first British coastal radar chain and the Yankee network 49.3-Me. 500-kw. e.r.p. f.m. station W43B on top of Mount Asnebumskit are two good examples of stations that might have gotten “through.” Drake, who has almost completely ruled out the possibility of signals coming from other planets within our solar system, has stated that he will concentrate his initial listening to the regions near the two solar-type stars Tau Ceti and Epsilon Eridani which are 11 light years away. If we assume that the round trip then takes 22 years, it is interesting to note that 1938 + 22 = 1960. Since this might be the big year, on a long-shot basis it might he very worthwhile to listen to the region from 30 to 50 Mc. with suitable arrays pointed toward these stars when the m.u.f. is lower than 30. ‘With the present earth state of the art of receiving equipment plus the lugh background noise (see Fig. 1), we must rely on the transmitters on the other planet being most powerful to overcome our deficiencies. Drake believes that the sought-after-signals will of necessity be narrow band and with no spectacular form of modulation. Doppler shift will be evident due to the relative motion of the receiver and transmitter. This shift plus direction may be the distinguishing characteristics of this signal.

Unfortunately, because of previous experience the civilization on the other planet may decide that it is too difficult to try to contact us during our 100 years of transition to radio maturity since during this period they may have to compensate for our lack of an outside-of-atmosphere space platform, plus our inadequate receivers, transmitter, and perhaps unsophisticated correlation detecting schemes.

If he does elect to wait until we mature, the first communication will probably not take place at 30 Mc. or 1420 Mc., but more than likely between two outer atmosphere space platforms operating with very high power in the millimeter wave region above 30 kMc. Here we will have the obvious advantages of no atmospheric absorption plus the capability of generating, with relatively small antennae, very high effective radiated powers over very narrow beam widths. In addition, the vast number of megacycles available in this region would provide bandwidths for very fast rate of intelligence delivery per second. However, unless something really new shows up, we will still be inhibited by what now appears to be the remarkably slow speed of light in exchanging such intelligence.

Project Ozma

Enough of such speculation. Let us return to Drake. With luck in March, 1960, the National Radio Astronomy Observatory in Green Bank, West Virginia, will be listening near 1420 Mc. from an 85-foot telescope such as shown in Fig. 2. The following rule of thumb applies to reception of 1420 Mc. The distance in light years at which strong present-day transmitters can be detected is about equal to the diameter of the parabolic reflector in feet divided by 10. Thus, Drake’s telescope could pick up present-day “earth” style transmitters at a distance of 8.5 light years. The fact that he is concentrating on stars at 11 light years distance implies that he is hopeful that the engineers of the Tau Ceti and Epsilon Eridani planet systems have progressed far beyond our present techniques.

Fig. 2 - A typical radio telescope

"Frank Drake conducted Project Ozma, the world's first modern SETI experiment, from this 85 foot (26m) diameter dish at the National Radio Astronomy Observatory, Green Bank WV. On 8 April 1960, he detected a strong periodic pulsed signal while aimed at the nearby sun-like star Epsilon Eridani. The signal at first seemed to exhibit many of the characteristics we would expect of an extra-terrestrial message. When the signal repeated five days later, Dr. Drake tracked it across the sky with a small waveguide horn antenna, and determined it to be interference from a passing high-altitude aircraft. All subsequent SETI experiments have been similarly plagued by false hits.

SETI League photo." - http://www.setileague.org/photos/hits.htm

Drake’s project is called Ozma after the beautiful princess of imaginary Oz. His system is quite complex and is described by him in his recent article as follows.

“A block diagram (Fig. 3) is given here of the Ozma radiometer, which operates near 1420 megacycles. It is essentially a highly stable narrow-band superheterodyne receiver, which utilizes the principles of both the Dicke radiometer and the d.c.-comparison type (see November 1959, Sky and Telescope).

Fig. 2

“Two horns are placed together at the focus of the parabolic antenna, in order to eliminate terrestrial interference to some extent. These horns give the antenna two beams, one to point at the star under study, the other off into space near the star. As the electronic switch connects first one horn and then the other to the receiver, the telescope will look alternately at the star and at the sky beside it. Any radiation from the star will then enter in pulses whose duration is controlled by the switch. The synchronous detectors near the output end of the circuit will respond only to pulses synchronized with the switch, thus detecting only the desired signal. Receiver noise is eliminated, and also terrestrial disturbances.

“Interference generally enters a radio telescope antenna through the horns directly, without a reflection from the paraboloid. In that case, both horns should receive the interfering signal with the same strength, and when the switch changes from one horn to the other there will be no change of level iii the interference entering the receiver. As a result, the interference signal is not pulsed, and the synchronous detectors ignore it.

“In the present receiver, immediately after the switch there comes a reactance [i.e., parametric] amplifier, to be replaced later with a maser. The amplifier, which gives the radiometer high sensitivity, was built by Ewen-Knight Corp., while the electronic switch was made by H. Hvaturn of NRAO. “The signal then undergoes four frequency conversions, this many being necessary because the final intermediate frequencies are very low, due to the narrow bandwidth requirements. The frequency received by the radiometer is directly dependent on the frequencies of the four oscillators, whose output signals beat with the true signal to produce the intermediate frequencies. In our specifications all four oscillators must hold their frequencies constant to better than one cycle per second on 100 seconds, if the over-all received frequency is also to be that constant.

“This is a most difficult requirement for the first oscillator, because its final frequency is about 1390 megacycles and it therefore must remain constant to one part in a billion. This accuracy is achieved by means of a special quartz crystal oscillator, the crystal being kept at a very constant temperature in an oven within an oven. The output of this oscillator is multiplied in frequency to give the desired final frequency. “A marker-frequency generator is used to provide weak signals from the output of the very stable oscillator at many fixed frequencies. These signals are inserted into the receiver for determining the exact frequency on which the receiver is operating, allowing the detection of Doppler effect.

“After the fourth intermediate-frequency amplification, two filters pick out a broad band of noise, called the comparison band, and a narrow one designated the signal band. The gain of these filters is adjusted so that when very broadband noise enters them their total outputs are equal. When these outputs are passed into the differencing circuit, its output is zero. However, a narrow-hand signal fills only some of the frequencies of the filter for the comparison band, but all of those in the signal-band filter. The output of the narrow-band filter is then greater than that of the broad-band one, and there is a net output from the differencing circuit. This use of the d.c. -comparison circuit makes the radiometer respond only to narrow-band signals. As drawn here, the radiometer is set up for signals for about 40-cycles-per-second bandwidth. In the actual receiver, the electronic filters have variable bandwidths that may be quickly adjusted to desired values.

“The filters placed before the synchronous detectors pass only the frequencies to which the detectors will respond, and reject other frequencies that might cause them to operate improperly. “We see that an output from the final synchronous detector will occur only when receiving a narrow band signal from a direction in which one of the antenna beams is pointing - the desired interstellar signal. The integrator only averages the signal strength over a chosen interval. The other two synchronous detectors and integrators connected directly to the comparison-band and signal-band channels monitor the performance of the radiometer.”

The amateur might well ask what position he could play in such an ambitious project. Such installations as just described don’t lend themselves to back yard installations or amateur pocketbooks. Two suggestions are put forward: If your interests are really strong in the field, perhaps the best approach is to get a job at a radio astronomy observatory. The January issue of Sky and Telescope, for instance, has an advertisement seeking a radio operator for its 85-foot telescope.

Secondly the building of a microwave radio telescope is a good type of club activity. The writer knows of several such projects which will shortly be in operation for amateur moon-bounce communications on 1296 Mc. (One of these is operated by Sam Harris, W1FZJ.) Incidentally, Drake would like to use amateur 1296-Mc. moon-bounce transmissions for calibration signals. Although the previous authors on this subject have demonstrated remarkable restraint on this score, I believe that it would not be appropriate to close this article without some speculation of what might transpire on that eventful day when Drake (a really appropriate name) or some future space-listener actually hears a signal bearing intelligence from another planet.

I am sure that he will have considerable difficulty in verifying its source first to himself, then to his sponsors and eventually his nation. Actually, unscrambling the intelligence will be a job that will need more than the classic Rosetta Stone that linked the Grecian and ancient Egyptian languages.

Drake stated that if the signal is very weak, requiring integration techniques to establish existence, he will agitate for use of a larger dish, such as the big Navy 600-footer which is now under construction. However, if the signals are strong enough, they will obviously be recorded and analyzed by the best cryptographic methods available.

The problem of attracting the attention at the other end over a span of, say, 22 years seems almost insurmountable. I could conjure up many more potential problems of a technical, data handling, and psychological nature. However, the rewards to the nation and total earth population could more than balance the difficulties encountered.

It is dangerous to assume that the inhabitants of other planets are similar to us. However, there must he some important common denominators. A look at such a civilization as ours even 50 years ahead not to mention thousands of years in the future, must provide solutions to medical, social, technical, and many other problems that would greatly benefit mankind . . . perhaps the cure of cancer and a cheaper version of the Beefeater Martini.

I wish to thank the editors of Sky and Telescope and Frank D. Drake for their help in this article and to express my appreciation of the many ideas on this subject provided by Dr. Harold Ewen of Ewen-Knight, Inc., and Messrs. F. S. Harris and H. Cross of Microwave Associates, Inc.





Offline twinstar

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Re: your opinion on whether civilization exists on another planet
« Reply #6 on: January 28, 2017, 09:59:04 AM »
Scientists State: Advanced Alien Civilizations DID Exist Before Us



http://www.ancient-code.com/scientists-state-advanced-alien-civilization-exist-us/




It seems that after all, we may not bee the only intelligent civilization in the known universe.

In 1961, astrophysicist Frank Drake came up with an equation that calculates the number of advanced civilizations likely to exist in the Milky Way galaxy. Today, researchers have remodeled the equation using new data from the Kepler satellite. The results are fascinating.drank-equation

Scientists have concluded that human beings aren't the only intelligent civilization in the universe after a recent revision of the famous Drake Equation of 1961. The equation estimates the number of potential intelligent civilizations in the universe.

Scientists adapted the Drake Equation with data from NASA's Kepler satellite on habitable planets in the cosmos. Researchers modified the Drake Equation from detailing the number of extraterrestrial civilizations that exist now, to about the chance of our civilization being the only one ever existed.

The new research indicates that unless the odds of intelligent lifeforms evolving on habitable planets are extremely low,  life on Earth is not the only one that evolved to an advanced stage.

Scientists explain that the chance of an advanced civilization developing would need to be less tan one in 10 trillion, for our civilization to be the only intelligent one in the known universe.

However, data obtained from Kepler changes everything placing the odds at a much higher percentage, meaning that technologically advanced civilizations are likely to have evolved at a certain point in the life of the universe.

A New Empirical Constraint on the Prevalence of Technological Species in the Universe

Researchers turned to the specific question, ''Has even one other technological species ever existed in the observable Universe?''

Adam Frank, professor of physics and astronomy at the University of Rochester and co-author of the paper stated that: 'The question of whether advanced civilizations exist elsewhere in the universe has always been vexed with three significant uncertainties in the Drake equation.

'We've known for a long time approximately how many stars exist.

'We didn't know how many of those stars had planets that could potentially harbor life, how often life might evolve and lead to intelligent beings, and how long any civilizations might last before becoming extinct.'

'Thanks to Nasa's Kepler satellite and other searches, we now know that roughly one-fifth of stars have planets in 'habitable zones,' where temperatures could support life as we know it.

'So one of the three big uncertainties has now been constrained.'

However, a question that remains a puzzle is how long civilizations might have survived.

'The fact that humans have had rudimentary technology for roughly ten thousand years doesn't really tell us if other societies would last that long or perhaps much longer,' he explained.

However, authors of the study Frank and Woodruff Sullivan of the astronomy department at the University of Washington discovered that they could eliminate that term altogether by simply expanding the question.

"Rather than asking how many civilizations may exist now, we ask 'Are we the only technological species that has ever arisen?" said Sullivan. "This shifted focus eliminates the uncertainty of the civilization lifetime question and allows us to address what we call the 'cosmic archeological question'-how often in the history of the universe has life evolved to an advanced state?" (source)

Frank and Sullivan mixed things up, refreshing the Drake equation. Instead of taking a guess at the odds of intelligent life developing, they calculated the change against it occurring for humanity to be the only known advanced civilization out there. Researchers calculated the chance between a universe where mankind has been the sole experiment in civilization and another one where other advanced civilizations might have developed before the rise of advanced lifeforms on earth.

"Of course, we have no idea how likely it is that an intelligent technological species will evolve on a given habitable planet," says Frank. But using our method we can tell exactly how low that probability would have to be for us to be the ONLY civilization the Universe has produced. We call that the pessimism line. If the actual probability is greater than the pessimism line, then a technological species and civilization have likely happened before." (source)

Sullivan and Frank calculated how unlikely would it be for advanced life to exist if there has never been another one developing somewhere in the ten billion trillion stars in the universe or even among our own galaxy's hundred billion stars. This approach changed the way we look at the Drake equation and the likelihood we are alone in the universe.

"One in 10 billion trillion is incredibly small," says Frank. "To me, this implies that other intelligent, technology producing species very likely have evolved before us. Think of it this way. Before our result, you'd be considered a pessimist if you imagined the probability of evolving a civilization on a habitable planet were, say, one in a trillion. But even that guess, one chance in a trillion, implies that what has happened here on Earth with humanity has in fact happened about a 10 billion other times over cosmic history!" (source)

However, on a smaller scale, the universe are less extreme. Researchers speculate that another technologically advanced species likely evolved on a habitable planet in our galaxy if the odds against it are better than one chance in 60 billion.

"The universe is more than 13 billion years old," said Sullivan. "That means that even if there have been a thousand civilizations in our own galaxy if they live only as long as we have been around-roughly ten thousand years-then all of them are likely already extinct. And others won't evolve until we are long gone. For us to have much chance of success in finding another "contemporary" active technological civilization, on average they must last much longer than our present lifetime."

"Given the vast distances between stars and the fixed speed of light we might never really be able to have a conversation with another civilization anyway," said Frank. "If they were 20,000 light years away, then every exchange would take 40,000 years to go back and forth." (source)

Franck and Sullivan point out in their revolutionary study that even though there aren't other advanced civilizations in the Milky way, the results of the study have a profound scientific and philosophical meaning.





Offline Rudi Jan

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Re: your opinion on whether civilization exists on another planet
« Reply #7 on: January 28, 2017, 10:02:58 AM »
The universe is life itself.

Civilization is another matter.
Suspend all belief. Get the facts ~ Rudi
No one rules if no one obeys ~ Lao Tzu

Offline twinstar

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Re: your opinion on whether civilization exists on another planet
« Reply #8 on: January 28, 2017, 10:12:55 AM »
Scientists Almost Certain Advanced Life On Other Planets Has Existed At Some Point





Are we alone out there? The question of whether or not other advanced civilizations exist somewhere in the vast universe has long been one of the most perplexing uncertainties in science. But new research suggests that the odds of humans being the only intelligent species to have ever existed are next to zero.

In a recent study published in the journal Astrobiology, researchers Adam Frank and Woodruff Sullivan used newly obtained data to reformulate the famous Drake equation, which calculates the probability that intelligent life currently exists in the universe, to measure the probability that intelligent life has ever existed in the universe. Introduced by Dr. Frank Drake in 1961, the original Drake equation identified specific factors thought to play a role in the development of advanced civilizations in order to estimate the number of technological civilizations that may currently exist in our galaxy. Over the past half a century, it has been the most widely accepted tool in the scientific community to predict the current existence of other advanced civilizations.

Yet three large uncertainties plague the original Drake equation. "We've known for a long time approximately how many stars exist," Frank explained in a statement. "We didn't know how many of those stars had planets that could potentially harbor life, how often life might evolve and lead to intelligent beings, and how long any civilizations might last before becoming extinct… Thanks to NASA's Kepler satellite and other searches, we now know that roughly one-fifth of stars have planets in 'habitable zones,' where temperatures could support life as we know it. So one of the three big uncertainties has now been constrained."

Although it is still completely unknown how long other civilizations might survive, a simple change of semantics to the proposed question eliminates this issue altogether. By looking at the probability of how many times in the history of the universe life has evolved to an advanced state, Frank and Sullivan estimate a one in 10 billion trillion chance that humans are the only intelligent species to have ever existed. "One in 10 billion trillion is incredibly small," Frank said. "To me, this implies that other intelligent, technology-producing species very likely have evolved before us."

While the odds are extremely high that we aren't the first intelligent civilization to have ever existed, the original question still remains: Are there any other advanced civilizations that currently exist? "The universe is more than 13 billion years old," explains Sullivan. "That means that even if there have been a thousand civilizations in our own galaxy, if they live only as long as we have been around-roughly ten thousand years-then all of them are likely already extinct. And others won't evolve until we are long gone. For us to have much chance of success in finding another "contemporary" active technological civilization, on average they must last much longer than our present lifetime."




Offline twinstar

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Re: your opinion on whether civilization exists on another planet
« Reply #9 on: January 29, 2017, 03:31:00 AM »
Odds Are Less Than 1 in 10 BILLION TRILLION That We The First Advanced Civilization!


http://sciencevibe.com/2016/06/14/odds-are-less-one-in-10-billion-trillion-that-we-are-not-the-first/



June 14, 2016



A New York Times article, by Adam Frank, published in the Sunday Review points out that "the Odds Are Less One in 10 BILLION TRILLION That We Are Not The First" advanced civilizations, and that the possibility of communicating with extraterrestrials and proving the the existence of an alien society can be viewed with the aid of the "Drake Equation". Here are excerpts from Frank's outstanding article.

"LAST month astronomers from the Kepler spacecraft team announced the discovery of 1,284 new planets, all orbiting stars outside our solar system. The total number of such "exoplanets" confirmed via Kepler and other methods now stands at more than 3,000.

This represents a revolution in planetary knowledge. A decade or so ago the discovery of even a single new exoplanet was big news. Not anymore. Improvements in astronomical observation technology have moved us from retail to wholesale planet discovery. We now know, for example, that every star in the sky likely hosts at least one planet.

But planets are only the beginning of the story. What everyone wants to know is whether any of these worlds has aliens living on it. Does our newfound knowledge of planets bring us any closer to answering that question?

A little bit, actually, yes. In a paper published in the May issue of the journal Astrobiology, the astronomer Woodruff Sullivan and I show that while we do not know if any advanced extraterrestrial civilizations currently exist in our galaxy, we now have enough information to conclude that they almost certainly existed at some point in cosmic history.

Among scientists, the probability of the existence of an alien society with which we might make contact is discussed in terms of something called the Drake equation. In 1961, the National Academy of Sciences asked the astronomer Frank Drake to host a scientific meeting on the possibilities of "interstellar communication." Since the odds of contact with alien life depended on how many advanced extraterrestrial civilizations existed in the galaxy, Drake identified seven factors on which that number would depend, and incorporated them into an equation.

You might assume this probability is low, and thus the chances remain small that another technological civilization arose. But what our calculation revealed is that even if this probability is assumed to be extremely low, the odds that we are not the first technological civilization are actually high. Specifically, unless the probability for evolving a civilization on a habitable-zone planet is less than one in 10 billion trillion, then we are not the first.

To give some context for that figure: In previous discussions of the Drake equation, a probability for civilizations to form of one in 10 billion per planet was considered highly pessimistic. According to our finding, even if you grant that level of pessimism, a trillion civilizations still would have appeared over the course of cosmic history.

In other words, given what we now know about the number and orbital positions of the galaxy's planets, the degree of pessimism required to doubt the existence, at some point in time, of an advanced extraterrestrial civilization borders on the irrational.

In science an important step forward can be finding a question that can be answered with the data at hand. Our paper did just this. As for the big question - whether any other civilizations currently exist - we may have to wait a long while for relevant data. But we should not underestimate how far we have come in a short time."





Offline Dwayne

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Re: your opinion on whether civilization exists on another planet
« Reply #10 on: January 29, 2017, 04:55:52 AM »
Who cares. Tough enough dealing with this planet's "civilization".

Offline twinstar

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Re: your opinion on whether civilization exists on another planet
« Reply #11 on: January 29, 2017, 06:03:08 AM »
A Trillion Alien Civilizations?



http://www.salvomag.com/new/articles/salvo39/zone-9-in-outer-space.php




Another example that had the internet buzzing for many weeks involved several articles and posts claiming that "at least a trillion alien civilizations have almost certainly existed in the universe."3 These claims are founded on four presuppositions:

1. The density and kinds of planets throughout our galaxy and all other galaxies in the universe are roughly the same as what we observe in the vicinity of our solar system.

2. About 20 percent of all planets are habitable.

3. Life inevitably will arise on all habitable planets.

4. The probability of a technologically advanced civilization arising from simple life forms is better than one chance in 10 billion.

Origins of Life (my book coauthored with biochemist Fazale Rana) demonstrates that, from a naturalistic perspective, assumption #3 is certainly incorrect. The probability of life originating naturalistically on a habitable planet is mathematically indistinguishable from zero.4 Since zero times any other factor or set of factors equals zero, then, from a naturalistic perspective, the number of civilizations besides our own that exist in the universe is zero.

The Trouble with the 20 Percent Assumption

There is also much I could say about why assumptions #1 and #4 are deeply flawed, but I will focus on #2 and a new discovery that establishes that far, far less than 20 percent of all planets are habitable.

Assumption #2 only takes into account the "water habitable zone," which is the range of distances from a planet's host star within which-and only within which-it would conceivably be possible for liquid water to exist at some place on the planet's surface at some time during the planet's history. And, indeed, about 20 percent of the more than 3,000 planets discovered so far fall within this water habitable zone.

The percentage drops precipitously, however, if one does not allow the greenhouse effect of the planet's atmosphere to take on a value that perfectly compensates for the host star's brightness. And the percentage takes another steep drop if one desires the planet to retain liquid water on more than 10 percent of its surface for more than a billion years. (Liquid water must be present on a planet's surface for at least 3.5 billion years for there to be even the remotest possibility of the planet sustaining advanced life.)

Eight Habitable Zones

Moreover, in addition to the water habitable zone, there are seven other known habitable zones. I listed and briefly described these zones in "Earth in the Zone," an article I wrote two years ago for Salvo 30 (Fall 2014). For those who missed the article or need a refresher, here again is a list of the eight zones:

1. Water habitable zone

2. Ultraviolet habitable zone

3. Photosynthetic habitable zone

4. Ozone habitable zone

5. Planetary rotation rate habitable zone

6. Planetary obliquity habitable zone

7. Tidal habitable zone

8. Astrosphere habitable zone

In chapter 7 of my just-released book, Improbable Planet, I provide a detailed, thoroughly documented explanation of all eight of these habitable zones.5

Typically, these zones do not overlap. For example, the distance a planet must be from its host star so that it receives enough ultraviolet radiation to enable the synthesis of many life-essential compounds, but not so much as to kill living things, is rarely the same distance that a planet must be from its host star for liquid water to possibly exist on its surface. For 97 percent of all stars, the liquid water habitable zone does not overlap the ultraviolet habitable zone.

A planet is a true candidate for habitability only if it simultaneously resides in all eight habitable zones. So far, the only known planet that dwells in all eight is Earth.

Venus's Desiccating Factor

Now, a ninth habitable zone has been discovered-

9. Electric wind habitable zone.6

This zone was discovered thanks to an electron spectrometer on board the European Space Agency's spacecraft Venus Express. This instrument measured the electric potential in Venus's atmosphere. The result was surprising. At 10 volts, Venus's atmospheric electric field proved to be far stronger than what any astronomer had expected.

The high voltage drives an electric wind in Venus's atmosphere that is powerful enough to drive all heavy ions (atomic nuclei stripped of their electrons) in Venus's ionosphere into interplanetary space. These heavy ions include oxygen ions that once belonged to water molecules.

Previously, astronomers had presumed that the solar wind was responsible for drying out Venus. This new discovery shows that Venus's electric field is the dominant desiccating factor.

But the Sun still plays a role, though less directly. The Venus Express research team determined that Venus's proximity to the Sun explains its strong atmospheric electric field. Venus receives twice as much ultraviolet radiation as does Earth. All this ultraviolet radiation results in a high density of free electrons and ions in Venus's atmosphere, which generates a strong electric field above the planet's surface.7

Confirmation that Venus's proximity to the Sun explains its strong atmospheric electric field comes from failed attempts to detect strong atmospheric electric fields either on Earth or on Mars. Instruments establish that both Earth and Mars possess atmospheric electric fields weaker than 2 volts.8

It's Distance, Not Atmosphere

The discovery of a strong atmospheric electric field on Venus has serious implications for the possible habitability of exoplanets (planets beyond our solar system). The discovery implies that any planet that has an atmosphere thicker than one percent of Earth's and that is closer to its star than about 90 percent of Earth's distance from the Sun will very likely possess an atmospheric electric field strong enough to completely dry out the planet.

It has been known for some time that planets with atmospheres thinner than one percent of Earth's will be unable to prevent deadly radiation, which emanates both from their host stars and from cosmic rays, from penetrating to their surfaces. These planets will also have a water problem. With such thin atmospheres, the boiling point of water will not be greater than the freezing point, implying that liquid water will be absent from their surfaces. For these two reasons, planets with atmospheres thinner than one percent of Earth's cannot be classified as habitable.

What the discovery of a strong electric field on Venus means, with respect to habitability, is that, for planets closer to their host stars than 90 percent of Earth's distance from the Sun, it does not matter how thick their atmospheres are. If the atmospheres are thinner than one percent of Earth's, they will dry out, because they will not be able to hold liquid water. But if the atmospheres are thicker than one percent of Earth's, they also will dry out, because the strong electric field in their atmospheres will desiccate them.

This set of conclusions has enormous implications. The vast majority (over 95 percent) of exoplanets currently classified as "habitable" are closer to their stars than 90 percent of Earth's distance from the Sun. Thus, they no longer can be classified as habitable. To put it another way, for the vast majority of stars, the water habitable zone does not overlap the electric wind habitable zone.

Nine Zones Required

The discovery of the electric wind habitable zone means that for a planet to be a viable candidate for possibly sustaining life, it must simultaneously reside in nine different habitable zones. So far, astronomers have measured the characteristics of 3,484 planets.9 Only one of all these 3,484 planets resides in all nine known habitable zones. That one is Earth.

Given the fine-tuning inherent in each of the nine known habitable zones, and given the extreme improbability that even three of them will overlap, let alone all nine, it seems that nothing less than the supernatural handiwork of a Creator will suffice to explain how a planet could meet all these known conditions for habitability. •




Offline twinstar

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Re: your opinion on whether civilization exists on another planet
« Reply #12 on: January 29, 2017, 06:12:05 AM »
Who cares. Tough enough dealing with this planet's "civilization".



What is civilization?

How is it measured?



Offline twinstar

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Re: your opinion on whether civilization exists on another planet
« Reply #13 on: January 30, 2017, 04:24:43 AM »
AN EARTH-LIKE PLANET ONLY 16 LIGHT YEARS AWAY?



20 April 2016




Earth may have a new neighbour, in the form of an Earth-like planet in a solar system only 16 light years away. The planet orbits a star named Gliese 832, and that solar system already hosts two other known exoplanets: Gliese 832B and Gliese 832C. The findings were reported in a new paper by Suman Satyal at the University of Texas, and colleagues J. Gri?th, and Z. E. Musielak.

Gliese 832B is a gas giant similar to Jupiter, at 0.64 the mass of Jupiter, and it orbits its star at 3.5 AU. G832B probably plays a role similar to Jupiter in our Solar System, by setting gravitational equilibrium. Gliese 832C is a Super-Earth about 5 times as massive as Earth, and it orbits the star at a very close 0.16 AU. G832C is a rocky planet on the inner edge of the habitable zone, but is likely too close to its star for habitability. Gliese 832, the star at the center of it all, is a red dwarf about half the size of our Sun, in both mass and radius.

The newly discovered planet is still hypothetical at this point, and the researchers put its mass at between 1 and 15 Earth masses, and its orbit at between 0.25 to 2.0 AU from Gliese 582, its host star.

The two previously discovered planets in Gliese 832 were discovered using the radial velocity technique. Radial velocity detects planets by looking for wobbles in the host star, as it responds to the gravitational tug exerted on it by planets in orbit. These wobbles are observable through the Doppler effect, as the light of the affected star is red-shifted and blue-shifted as it moves.

The team behind this study re-analyzed the data from the Gliese 832 system, based on the idea that the vast distance between the two already-detected planets would be home to another planet. According to other solar systems studied by Kepler, it would be highly unusual for such a gap to exist.

As they say in their paper, the main thrust of the study is to explore the gravitational effect that the large outer planet has on the smaller inner planet, and also on the hypothetical Super-Earth that may inhabit the system. The team conducted numerical simulations and created models constrained by what's known about the Gliese 832 system to conclude that an Earth-like planet may orbit Gliese 832.

This can all sound like some hocus-pocus in a way, as my non-science-minded friends like to point out. Just punch in some numbers until it shows an Earth-like planet, then publish and get attention. But it's not. This kind of modelling and simulation is very rigorous.

Putting in all the data that's known about the Gliese 832 system, including radial velocity data, orbital inclinations, and gravitational relationships between the planets and the star, and between the planets themselves, yields bands of probability where previously undetected planets might exist. This result tells planet hunters where to start looking for planets.

In the case of this paper, the result indicates that "there is a slim window of about 0.03 AU where an Earth-like planet could be stable as well as remain in the HZ." The authors are quick to point out that the existence of this planet is not proven, only possible.

The other planets were found using the radial velocity method, which is pretty reliable. But radial velocity only provides clues to the existence of planets, it doesn't prove that they're there. Yet. The authors acknowledge that a larger number of radial velocity observations are needed to confirm the existence of this new planet. Barring that, either the transit method employed by the Kepler spacecraft, or direct observation with powerful telescopes, may also provide positive proof.

So far, the Kepler spacecraft has confirmed the existence of 1,041 planets. But Kepler can't look everywhere for planets. Studies like these are crucial in giving Kepler starting points in its search for exoplanets. If an exoplanet can be confirmed in the Gliese 832 system, then it also confirms the accuracy of the simulation that the team behind this paper performed.

If confirmed, G832 C would join a growing list of exoplanets. It wasn't long ago that we knew almost nothing about other solar systems. We only had knowledge of our own. And even though it was always unlikely that our Solar System would for some reason be special, we had no certain knowledge of the population of exoplanets in other solar systems.

Studies like this one point to our growing understanding of the dynamics of other solar systems, and the population of exoplanets in the Milky Way, and most likely throughout the cosmos.





Offline twinstar

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Re: your opinion on whether civilization exists on another planet
« Reply #14 on: January 30, 2017, 04:44:09 AM »
Life on Other Planets?




Given the abundance of life on Earth and the immensity of the known universe, what is the possibility of life on other planets? This question is fun to think about. Consider this possibility just for our Milky Way galaxy, one of an estimated hundred billion galaxies that make up the known universe. Within this galaxy, our Sun is one of one hundred billion-plus stars. That's one hundred billion other suns, each with the potential to have solar systems of its own; but, to the conservative, let's imagine that only one half of those suns in our galaxy actually have planets. This leaves us with roughly ?fty billion suns, each with planets, in the Milky Way galaxy.

However, planets with the characteristics that make them candidates for life-just the right distance from their sun and just the right size for the formation of a life-sustaining atm0sphere-might be relatively rare. Thus, let's be conservative again and grant that only one in every ?ve hundred of those ?fty billion suns in our galaxy has a planet with the basic characteristics required for life as we know it. This still leaves us with roughly a hundred million planets with the potential for life support in just our galaxy.

With the possibility of extraterrestrial life seemingly all around us, perhaps a more appropriate question is: Why haven't we had any visitors? Or if we are having visitations, why aren't they more common? The reason, in large part, may be the extreme size of our galaxy. The average distance between stars, considering all stars, is ?ve hundred light years. And how big is that? Well, one light year is the distance that light, moving at the speed of 186,000 miles per second, travels in one year. And how far is that? Let's do the math: 186,000 miles/second X 60 seconds/minute x 60 minutes/hour X 24 hours/day X 365 days/year = 5,865,696,000,000 miles/year. Yes, one light year is approximately six trillion miles-a colossal distance-and the average distance between stars is not one light year, but ?ve hundred light years! And, of course, the average distance between that particular subset of stars with potentially life-supporting planets would be even greater. In addition to these vast distances in space, we also have "distance" in time-that is, possible civilizations would be scattered in time.

To grasp this concept, consider that our solar system has been around for almost ?ve billion years, but intelligent life (e.g., us), capable of reaching out into space, has been in existence for only a very, very tiny fraction of that time. Thus, at any one time, we may only have a few thousand stars in our galaxy simultaneously supporting a planet with life; and the average distance between these stars, given the size of the Milky Way, would likely be on the order of thousands of light years. None of this rules out the possibility that there could be extraterrestrial beings in our galaxy that are unimaginably more complex, intelligent, and marvelous than we are-beings that perhaps have already checked us out and concluded that we are not very interesting given our primitive state. It is a humbling thought.



Offline twinstar

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Re: your opinion on whether civilization exists on another planet
« Reply #15 on: January 30, 2017, 06:10:55 AM »
The Closest Known Potentially Habitable Planet Is 13 Light-Years Away



http://io9.gizmodo.com/the-closest-known-potentially-habitable-planet-is-13-li-1585896900




Astronomers have discovered two new super-Earths orbiting an ancient 11.5 billion year-old star a "mere" 13 light-years from here. One planet is in the habitable zone, prompting a researcher to wonder what kind of life could have evolved over such a long period.

For comparison, these exoplanets are 2.5 times older than Earth and only two billion years younger than the universe itself, which is about 13.7 billion years-old. If there's life on one of these planets - and that's a big if - it's been there for a potentially very long time.

And amazingly, it's "only" 13 light-years away. That makes it the closest confirmed potentially habitable exoplanet to Earth, not including Tau Ceti e, an unconfirmed planet located 11.9 light-years away. The next best bet after that is Gliese 581-d, which is 20.2 light-years away. It's also worth noting that Alpha Centauri, the closest star to our own - just 4.3 light-years away - hosts a planet, but it's parked way to close to the sun to be habitable (its year is a mere three days long).

Five new planets discovered just 12 light-years away

Astronomers have discovered a habitable planet 20 light years away

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Scientists discover a planet in Alpha Centauri, the star system nearest Earth

This is huge. We've discovered a lot of exoplanets, including rocky Earth-like ones, in…

So, a bit about this discovery. These planets orbit Kapteyn's Star, a halo red dwarf that was discovered at the end of the 19th century by Dutch astronomer Jacobus Kapteyn. It's the second fastest moving star in the sky and the 25th closest star to our solar system. With a magnitude of nine it can be seen through a telescope or with a pair of binoculars. It has a third of the mass of the sun and can be seen in the southern constellation of Pictor.

New data analyzed by astronomers at the Queen Mary School of Physics now shows that Kapteyn is not alone; it's orbited by at least two super-Earths, Kapteyn-b and Kapteyn-c. The astronomers were looking at data collected from the HARPS spectrometer at the ESO's La Silla observatory in Chile. The findings were corroborated by data from HIRES at Keck Observatory and PFS at Magellan/Las Campanas Observatory. The new planets were found using the Doppler Effect, which shifts the star's light spectrum depending on its velocity. This technique allows astronomers to determine several properties of extrasolar planets, including their masses and orbital periods.

A Temperate Super-Earth

Kapteyn-b has a mass that's nearly five times that of Earth's. It may be able to sustain liquid water at its surface; Kapteyn-b orbits every 48 days, which places it in the circumstellar habitable zone. That might sound close - and it is - but keep in mind that red dwarfs are not as powerful as G-type main sequence stars like our own. The astronomers, a team led by Guillem Anglada-Escude, say it's the oldest potentially habitable planet known to date. And by my calculations, it's the closest known and confirmed potentially habitable planet to Earth.

The other planet, Kapteyn-c, is less promising in terms of habitability. It's a massive super-Earth that's seven times heavier than Earth, requiring about 121 days to complete an orbit. Astronomers think it's too cold to support liquid water.

The atmospheric composition of the planets is not known.

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