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Detection of Earth-like Civilizations in Space Now Possible
Mr. McGibby writes "Astronomers have come up with an improved method of looking for extraterrestrial life with an Earth-like civilization. Theorist Avi Loeb proposes to use instruments like the Low Frequency Demonstrator (LFD) of the Mileura Wide-Field Array (MWA), an Australian facility for radio astronomy currently under construction. The array could (theoretically) detect civilizations broadcasting in the same frequencies as our own society. From the article: 'Loeb and Zaldarriaga calculate that by staring at the sky for a month, the MWA-LFD could detect Earth-like radio signals from a distance of up to 30 light-years, which would encompass approximately 1,000 stars. More powerful broadcasts could be detected to even greater distances. Future observatories like the Square Kilometer Array could detect Earth-like broadcasts from 10 times farther away, which would encompass 100 million stars. ' The original paper describes the details."
And to quote Carl Sagan, "Absence of evidence is not evidence of absence."
The flaw with all these searches is that it assumes that any nearby civilizations are exactly at the same level of development as humanity. Isn't high-power broadcast radio actually declining on Earth right now in favor of cable, fiber, and low power systems like the small satellite DBS dishes? If an alien civilization isn't in the same +/- 50 year technological window as we are, we'll probably never hear them even if they are next door. Still, if you don't look you'll never be sure...
"Given the massive distances between stars, astronomical mass extinction theories, and the time evolution takes, aren't the odds of two technically advanced civilizations being around at the same time...umm astronomical? :)"
The true probabilities are not known. We don't know how common life is. We don't know how often a mass extinction of life occurs. We don't know how long evolution takes except for on our one world. We don't have enough data to accurately predict whether or not life is rare or common in the universe. Another perspective could be that it is in fact more likely that advanced civilizations would be around at the same time if the universe has a consistant timeline. If the way that life-harboring star systems form, the way that life itself forms, and the way that intelligent life evolves is analogous across the universe then this may be the Golden Age of intelligent life throughout our galaxy.
There are many tongues to talk, and but few heads to think. -Victor Hugo
That depends on how you are searching. Searching for your keys in a cluttered room with the lights off is going to be difficult, and you may look for quite some time without being able to conclude that the absence of evidence is evidence of the keys' absence.
Thank you, those are some very useful comments. I'm sure that all the astronomers out there, having read your post, are preparing their resignations, and will instead focus their time on solving all of the world's troubles. Thank you again, for bringing these issues to our attention.
One time I threw a brick at a duck.
And to quote Carl Sagan, "Absence of evidence is not evidence of absence."
I'll take your quote and raise: "Extraordinary claims require extraordinary evidence"
You say "you are attempting a negative proof or proof of impossibility" which demonstrates you didn't actually read or understand the parent post which stated, quite clearly, "Absence of evidence is prima facie evidence of absence.", not "Absence of evidence is prima facie proof of absence". Until you sort out the difference between proof and evidence the rest of what you say is moot.
Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.