This analysis assumes 420 billion civilizations have existed over a 2 billion time period. The distances between galaxies is so great (2.5 MLY to Andromeda - nearest galaxy) that civilizations can probably never travel outside their galaxy. Thus the number of civilizations outside the Milky Way may be interesting but almost irrelevant from a practical standpoint.
This translates to about 6 intelligent civilizations over the life of the Milky Way. Even if one assumes they are off by a factor of 1,000 that still means 6,000 civilizations in the Milky Way over billions of years. If one assumes civilizations only last a million years or less before killing themselves off then the chances of simultaneous civilizations existing in the Milky Way is likely rare if nonexistent.
All of this guess work but the underlying concepts make sense to me.
I call BS.
It’s called the “must be” theory of science.
as long as we just have to sit on this planet twiddling our thumbs, yes, people are going to smoke pipes and come up with all kinds of weird ideas. We just need to get our there.
Pure unadulterated CRAP.
Of the 4.5 million years of earth’s existence, beings on the planet have only been able to transmit a radio signal for around 100 years.
It’s not that advanced civilizations have not existed or will never exist, it is the improbability that they exist at this very moment and could communicate or provide any sign of their existence.
Why is it that sci-fi people are so self loathing? Who is to say we aren’t the first and most advanced carbon based lifeform in the universe?
If you live in California you most certainly live in an (illegal) alien civilization.
Or life on earth could be a unique and singular penomenon.
The only known facts are that there is life here and so far there is no evidence of life anywhere else.
How many civilizations are in existence “ right now”? Does “ right now” have any meaning at all when you factor in relativity?
They wouldn’t want us to know about them. Who would want to risk cultural contamination from a species insane enough to aim nuclear weapons at each other in their own biosphere?
Before we’re we’re married, I told my future wife that I estimated my fortune was $420 billion. After we were wed and she wanted to go shopping, I told her there was no sign of life in my bank account.
I bet there is some form of a galactic notice like a pilots NOTAMs to avoid our solar system. Too immature and stupid.
In 1974, I did a scholarly study of the existing literature on SETI and exobiology. My conclusions then were that there was a mode of 800 alien intelligences in the lifetime of the Milky Way Galaxy, and a 20% chance that we are going to be the only emerging technological species, assuming we get back out there and explore, and don’t blow ourselves up or get whacked by a supernova, etc.
Note that this says nothing about non-technological life in the galaxy, and assumes that the reports of ET are incorrect to date. It also doesn’t take into account Hugh Everett III’s Ph.D. thesis - which postulates an uncountably infinite number of branches to this time line. If one adds on my addendum to Everett, that crossovers must occur, then life is abundant, and we cannot destroy all life.
But intelligent life, technological life, is a different kettle of fish.
What complete horsecrap. Who says any of these planets are “habitable” just because they have water? What about temperature, atmosphere, mineral content, concentrations of toxic material. I realize alien life could be anything right down to silica based instead of carbon based, but this article is still complete 100 percent BS. There is no evidence whatsoever that any of these planets could support life of any kind, but lets just pull something out of our ass and play make believe.
What a load of crap.
Different things make sense to different people. To me, the Universe and the existence of life is non-random. Based on that premise, it makes no sense to me to come up with a guess about the probability of other life in the Universe. That is mixing apples (my non-random premise) with oranges (probability of random events). As for me, I have no problem at all believing that the entire unimaginably vast Universe is just the background or stage for the incredibly important, almost unbelivebaly important, saga of humanity. More specifically, if God cared enough about mankind for the Incarnation etc, why would it be so hard to believe that the Universe is or may be just a background for this greatest story of all. Just my two cents.
Interesting thoughts, but not much pertinent to reality.
The “underlying concepts” are mathematical postulates that pretend that certain individual attributes - liquid water - are, or relative distance from a sun, or size & possession of heavier elements and carbon, are all on their own “evidence” of “possible life”, when we have no empirical evidence even in our own solar system that those attributes have produced life.
It is guessing game being done with even less fact-based-assumptions than the “global warming” models.
Given the state of human understanding of “solar biology” to date - pre-K you’d have to call it, the idea that “astrobiology” can today speak with any authority on the self-named “branch of science” it has taken, is at the height of human intellectual arrogance.
Humans will learn much more about this solar system and finally a long time afterward reach beyond this solar system with some form of exploration of other solar systems (maybe 1,000 years form now) before any humans MIGHT be able to speak with any authority on something such as “astrobiology”. Until then it is all pretense based on assumptions that pretend to know more than we know.
Life - seems more than probable. However, that doesn’t mean civilizations.
Google the Fermi Paradox. If advanced civilizations were that common we could literally watch stars disappear in the night sky.