Post by Andrei Tchentchik on Jan 31, 2020 10:43:06 GMT 2
(.#378).- Do ET's exist? The researchers' answer will not please Ufologists.
Do extraterrestrials exist? The response of these researchers will not please ufologists.
October 5, 2016.
Grégory Rozières
Le HuffPost
chandra.harvard.edu/photo/2009/ngc6872/ Image credit: X-ray: NASA/CXC/SAO/M.Machacek; Optical: ESO/VLT; Infrared: NASA/JPL/Caltech Caption credit: Harvard-Smithsonian Center for Astrophysics Read more about Chandra: www.nasa.gov/chandra p.s. You can see all of our Chandra photos in the Chandra Group in Flickr at: www.flickr.com/groups/chandranasa/ We'd love to have you as a member!" data-caption="This composite image of data from three different telescopes shows an ongoing collision between two galaxies, NGC 6872 and IC 4970. X-ray data from NASA's Chandra X-ray Observatory is shown in purple, while Spitzer Space Telescope's infrared data is red and optical data from ESO's Very Large Telescope (VLT) is colored red, green and blue. Astronomers think that supermassive black holes exist at the center of most galaxies. Not only do the galaxies and black holes seem to co-exist, they are apparently inextricably linked in their evolution. To better understand this symbiotic relationship, scientists have turned to rapidly growing black holes -- so-called active galactic nucleus (AGN) -- to study how they are affected by their galactic environments. The latest data from Chandra and Spitzer show that IC 4970, the small galaxy at the top of the image, contains an AGN, but one that is heavily cocooned in gas and dust. This means in optical light telescopes, like the VLT, there is little to see. X-rays and infrared light, however, can penetrate this veil of material and reveal the light show that is generated as material heats up before falling onto the black hole (seen as a bright point-like source). Despite this obscuring gas and dust around IC 4970, the Chandra data suggest that there is not enough hot gas in IC 4970 to fuel the growth of the AGN. Where, then, does the food supply for this black hole come from? The answer lies with its partner galaxy, NGC 6872. These two galaxies are in the process of undergoing a collision, and the gravitational attraction from IC 4970 has likely pulled over some of NGC 6872's deep reservoir of cold gas (seen prominently in the Spitzer data), providing a new fuel supply to power the giant black hole. Read entire caption/view more images: chandra.harvard.edu/photo/2009/ngc6872/ Image credit: X-ray: NASA/CXC/SAO/M.Machacek; Optical: ESO/VLT; Infrared: NASA/JPL/Caltech Caption credit: Harvard-Smithsonian Center for Astrophysics Read more about Chandra: www.nasa.gov/chandra p.s. You can see all of our Chandra photos in the Chandra Group in Flickr at: www.flickr.com/groups/chandranasa/ We'd love to have you as a member!" data-credit="NASA's Marshall Space Flight Center/Flickr">
SPACE - "The truth is elsewhere". Really, Mulder? If like the hero of X-Files, you believe in extraterrestrials, this American study will displease you. After analyzing nearly 100,000 galaxies, researchers at the University of Pennsylvania have come to the conclusion that there are no aliens in this immensity. Finally ... no aliens evolved enough to have colonized their entire galaxy.
In a study published April 15 by the Astrophysical Journal, researchers at the "Study Center on Exoplanets and Living Worlds" have unveiled their results. They explain that they have used the Nasa Space Telescope (Wyse), which specializes in the analysis of infrared wave emissions.
Why these waves in particular? For, according to the researchers, a civilization sufficiently developed to have spread throughout a galaxy would need a lot of energy to support itself.
However, "the fundamental principles of thermodynamics tell us that all this energy must radiate in the form of heat", and that this heat must be seen in the form of infrared, says Jason T. Wright Phys, one of the authors of the study. "In the same way that your computer expels heat when it works".
And the result is disappointing: out of the 100,000 most promising galaxies, those emitting the most infrared, none emitted enough to validate an intelligent extraterrestrial life.
Are we alone? A problem that fascinates researchers
However, the authors of the study will study 50 galaxies that have shown high levels of infrared. Not enough to prove a presence of extraterrestrials in a galaxy, but enough to dig the subject. "We will investigate whether these levels of radiation come from a natural astronomical process or may indicate the presence of an alien civilization".
The Center for Exoplanets and Living Worlds in Pennsylvania is not the only one to wonder about a possible extraterrestrial life. Far from there.
The Seti is an American program specifically dedicated to the search for aliens. Founded in 1960, its primary goal is to detect extraterrestrial signals, seeking, for example, to contact other civilizations. Many universities participate in the program, such as the prestigious Cornell and Harvard.
If the US federal government had cut the project (which required 2.5 million budget per year) in April 2011, new funding was found a few months later, thanks to donations from the private sector and the US Air Force.
Paradox and equation
At the origin of Seti, there is an American astronomer, Frank Drake, who has imagined an equation to estimate the number of civilizations in our galaxy. Basically, the goal is to calculate the number of stars created every year in our galaxy, then among them, how many have a planet that can shelter life and finally it is the chance that intelligent life there developed. All weighted by the average lifespan of a civilization.
In short, an equation with very, very many unknowns that allow all astronomers interested in the issue to make their own hypothesis.
But for 50 years, the Seti has still not heard anything. So, should we doubt? After all, if there was an extraterrestrial civilization that had colonized several planets with millions of years of existence, why have not we found them yet? The Milky Way is 50,000 light-years in radius. Even traveling at 1% of the speed of light, an extraterrestrial civilization would have colonized a galaxy in a few million years. A dust on the scale of the universe.
This is called the Fermi paradox, the name of the physicist who first stated it. Not especially focused on astrology (he is one of the creators of the atomic bomb), he would have asked the question during a debate between friends in 1950.
But the counter discussion (if we can call it a debate between different scientists who are members of the Manhattan project) has taken an impressive scale over time. You only have to see the wikipedia page dedicated to it. Hundreds of sources, many of them from scientific work could not be more serious.
Contact and do not wait to be contacted
For some, any society reaching a certain technological level ends up self-destructing. For others, it is a problem of distance: the universe is gigantic, and all the data that arrives to us are actually millions of years old. As for travel in space, it would be so long to cross such areas that there would be no interest for a civilization to lend itself to it. Some also believe that other civilizations could live by respecting the resources of their planet, without trying to expand.
It could also be a simple time problem, for Bill Nye, the famous American popularizer. We have only really listened to space for 50 years. It is little, considering the size of our galaxy. Some scientists even believe that it is time to try to contact an extraterrestrial life through our radio transmitters. A debate that is still raging, as Slate reports, especially since it is not said that an extraterrestrial society, if it exists, will be benevolent.
Meanwhile, the absence of a sign of a galactic-scale civilization in the known universe is not very good news for Mulder. Is the truth elsewhere? In the meantime, only emptiness answers this question.
F I N .
Do extraterrestrials exist? The response of these researchers will not please ufologists.
October 5, 2016.
Grégory Rozières
Le HuffPost
chandra.harvard.edu/photo/2009/ngc6872/ Image credit: X-ray: NASA/CXC/SAO/M.Machacek; Optical: ESO/VLT; Infrared: NASA/JPL/Caltech Caption credit: Harvard-Smithsonian Center for Astrophysics Read more about Chandra: www.nasa.gov/chandra p.s. You can see all of our Chandra photos in the Chandra Group in Flickr at: www.flickr.com/groups/chandranasa/ We'd love to have you as a member!" data-caption="This composite image of data from three different telescopes shows an ongoing collision between two galaxies, NGC 6872 and IC 4970. X-ray data from NASA's Chandra X-ray Observatory is shown in purple, while Spitzer Space Telescope's infrared data is red and optical data from ESO's Very Large Telescope (VLT) is colored red, green and blue. Astronomers think that supermassive black holes exist at the center of most galaxies. Not only do the galaxies and black holes seem to co-exist, they are apparently inextricably linked in their evolution. To better understand this symbiotic relationship, scientists have turned to rapidly growing black holes -- so-called active galactic nucleus (AGN) -- to study how they are affected by their galactic environments. The latest data from Chandra and Spitzer show that IC 4970, the small galaxy at the top of the image, contains an AGN, but one that is heavily cocooned in gas and dust. This means in optical light telescopes, like the VLT, there is little to see. X-rays and infrared light, however, can penetrate this veil of material and reveal the light show that is generated as material heats up before falling onto the black hole (seen as a bright point-like source). Despite this obscuring gas and dust around IC 4970, the Chandra data suggest that there is not enough hot gas in IC 4970 to fuel the growth of the AGN. Where, then, does the food supply for this black hole come from? The answer lies with its partner galaxy, NGC 6872. These two galaxies are in the process of undergoing a collision, and the gravitational attraction from IC 4970 has likely pulled over some of NGC 6872's deep reservoir of cold gas (seen prominently in the Spitzer data), providing a new fuel supply to power the giant black hole. Read entire caption/view more images: chandra.harvard.edu/photo/2009/ngc6872/ Image credit: X-ray: NASA/CXC/SAO/M.Machacek; Optical: ESO/VLT; Infrared: NASA/JPL/Caltech Caption credit: Harvard-Smithsonian Center for Astrophysics Read more about Chandra: www.nasa.gov/chandra p.s. You can see all of our Chandra photos in the Chandra Group in Flickr at: www.flickr.com/groups/chandranasa/ We'd love to have you as a member!" data-credit="NASA's Marshall Space Flight Center/Flickr">
SPACE - "The truth is elsewhere". Really, Mulder? If like the hero of X-Files, you believe in extraterrestrials, this American study will displease you. After analyzing nearly 100,000 galaxies, researchers at the University of Pennsylvania have come to the conclusion that there are no aliens in this immensity. Finally ... no aliens evolved enough to have colonized their entire galaxy.
In a study published April 15 by the Astrophysical Journal, researchers at the "Study Center on Exoplanets and Living Worlds" have unveiled their results. They explain that they have used the Nasa Space Telescope (Wyse), which specializes in the analysis of infrared wave emissions.
Why these waves in particular? For, according to the researchers, a civilization sufficiently developed to have spread throughout a galaxy would need a lot of energy to support itself.
However, "the fundamental principles of thermodynamics tell us that all this energy must radiate in the form of heat", and that this heat must be seen in the form of infrared, says Jason T. Wright Phys, one of the authors of the study. "In the same way that your computer expels heat when it works".
And the result is disappointing: out of the 100,000 most promising galaxies, those emitting the most infrared, none emitted enough to validate an intelligent extraterrestrial life.
Are we alone? A problem that fascinates researchers
However, the authors of the study will study 50 galaxies that have shown high levels of infrared. Not enough to prove a presence of extraterrestrials in a galaxy, but enough to dig the subject. "We will investigate whether these levels of radiation come from a natural astronomical process or may indicate the presence of an alien civilization".
The Center for Exoplanets and Living Worlds in Pennsylvania is not the only one to wonder about a possible extraterrestrial life. Far from there.
The Seti is an American program specifically dedicated to the search for aliens. Founded in 1960, its primary goal is to detect extraterrestrial signals, seeking, for example, to contact other civilizations. Many universities participate in the program, such as the prestigious Cornell and Harvard.
If the US federal government had cut the project (which required 2.5 million budget per year) in April 2011, new funding was found a few months later, thanks to donations from the private sector and the US Air Force.
Paradox and equation
At the origin of Seti, there is an American astronomer, Frank Drake, who has imagined an equation to estimate the number of civilizations in our galaxy. Basically, the goal is to calculate the number of stars created every year in our galaxy, then among them, how many have a planet that can shelter life and finally it is the chance that intelligent life there developed. All weighted by the average lifespan of a civilization.
In short, an equation with very, very many unknowns that allow all astronomers interested in the issue to make their own hypothesis.
But for 50 years, the Seti has still not heard anything. So, should we doubt? After all, if there was an extraterrestrial civilization that had colonized several planets with millions of years of existence, why have not we found them yet? The Milky Way is 50,000 light-years in radius. Even traveling at 1% of the speed of light, an extraterrestrial civilization would have colonized a galaxy in a few million years. A dust on the scale of the universe.
This is called the Fermi paradox, the name of the physicist who first stated it. Not especially focused on astrology (he is one of the creators of the atomic bomb), he would have asked the question during a debate between friends in 1950.
But the counter discussion (if we can call it a debate between different scientists who are members of the Manhattan project) has taken an impressive scale over time. You only have to see the wikipedia page dedicated to it. Hundreds of sources, many of them from scientific work could not be more serious.
Contact and do not wait to be contacted
For some, any society reaching a certain technological level ends up self-destructing. For others, it is a problem of distance: the universe is gigantic, and all the data that arrives to us are actually millions of years old. As for travel in space, it would be so long to cross such areas that there would be no interest for a civilization to lend itself to it. Some also believe that other civilizations could live by respecting the resources of their planet, without trying to expand.
It could also be a simple time problem, for Bill Nye, the famous American popularizer. We have only really listened to space for 50 years. It is little, considering the size of our galaxy. Some scientists even believe that it is time to try to contact an extraterrestrial life through our radio transmitters. A debate that is still raging, as Slate reports, especially since it is not said that an extraterrestrial society, if it exists, will be benevolent.
Meanwhile, the absence of a sign of a galactic-scale civilization in the known universe is not very good news for Mulder. Is the truth elsewhere? In the meantime, only emptiness answers this question.
F I N .
