Been pointing this out for years, but am not an astrophysicist and do not play one on TV (and did not stay at a Holiday Inn Express last night.)
Of possible interest
You are not alone.
Settling this question, once-and-for-all:
“We don’t know.”
Then there is always the Fermi Paradox
The Fermi paradox:
the apparent contradiction between the lack of evidence and high probability estimates[1] for the existence of extraterrestrial civilizations.[2] The basic points of the argument, made by physicists Enrico Fermi (1901–1954) are:
There are billions of stars in the galaxy that are similar to the Sun,[3][4] and many of these stars are billions of years older than the Solar system.[5][6]
With high probability, some of these stars have Earth-like planets,[7][8] and if the Earth is typical, some may have developed intelligent life.
Some of these civilizations may have developed interstellar travel, a step the Earth is investigating now.
Even at the slow pace of currently envisioned interstellar travel, the Milky Way galaxy could be completely traversed in a few million years.[9]
According to this line of reasoning, the Earth should have already been visited by extraterrestrial aliens. In an informal conversation, Fermi noted no convincing evidence of this, leading him to ask, “Where is everybody?”[10][11] There have been many attempts to explain the Fermi paradox,[12][13] primarily either suggesting that intelligent extraterrestrial life is extremely rare or proposing reasons that such civilizations have not contacted or visited Earth.
In a country where people actually believe the Globull worming stuff, though, it's no wonder people accept it.
How the Hell people who claim to be all about what science can prove swallow any crap spoon fed to them by the media never ceases to amaze me.
Then there is the Dark Forest theory - the not-friendly aliens, the predators: the lions, the tigers, the crocodiles, the bears. waiting to pounce on prey, on potential threats, on the helpless, om the week, on the naive ...
“Skuld, are you saying that no space aliens ever said ‘Hello’ to us? Not once?”
“Sorry, Keiichi. Sad to say, they never did. The Search for Extra-Terrestrial Intelligence [SETI] had been ongoing for decades by your time. Near the end, they crowed-sourced the signal analysis out to over a million home-based computers, each as powerful as a Cray supercomputer of 30 years prior. They searched practically the whole spectrum for a modulated signal across both hemispheres of the sky. They found nothing.”
“Nothing?”
“Oh, there were a couple odd one-shot signals, like the famous ‘Wow’ signal in 1977, but never anything definite.”
“So what’s the explanation then? Why is the universe so silent?”
“The answer is simple.”
“Well?”
“Everybody is hiding.”
“Hiding from what?” Keiichi chuckled, “The Borg or something?”
Skuld wasn’t laughing. “Basically, yes.”
“You’re serious.”
“I am. Look, it only takes one [bleep]-hole alien race to ruin the whole neighborhood.”
“Wait, the Borg are real?”
“No. It’s much more primitive than that. It only takes one jerk race to decide that they have to be the only ones to exist in the galaxy. Some time long ago, nobody knows when exactly, some long dead and unnamed alien race built and launched a set of self-replicating probes called Von Neumann probes, named after the famous computer scientist who first postulated them.”
“Self-replicating probes.”
“Yeah. It is actually not all that particularly hard for an advanced civilization to create them. The unmanned probes were automated and operated on fairly simple software. They travelled at sublight speed. They searched for coherent signals and home it on them. When they get a lock they then shove an asteroid to set it on a collision course with the signal source. Then they make more probes from raw material in the ejecta and go out again.”
“But that’s awful!”
“I know. We call them Berserkers, named after the SF author Fred Saberhagen who first wrote several stories about them. Berserkers are just another type of predator, one that preys on intelligent life. Remember what I showed you earlier - that predators will always be found anywhere life exists? It is a universal constant.”
“So is that what happened to the Earth?”
“No. But it would have. Sooner or later.”
“Really?”
“Keiichi, the TV signals transmitted from I Love Lucy in the 1950’s were dozens of light-years out in space by your time. Eventually a Berserker would have locked on and it would have all been over. So even if the KBO didn’t hit, Earth was going to be doomed anyway. I’m sorry.”
“But if Earth’s technology had gotten advanced enough, quickly enough, before they got there then perhaps a defense..”
“No. Then Earth would have just succumbed to gray goo or something else.”
“You think so? Why?”
“Because it’s a simple fact that most sentient races don’t reach the level of spaceflight, or if they do, it is not for very long. Such civilizations typically self-destruct. Or they turn inward. Or they turn murderous.”
“You mean like the Scorpio galaxy, the Empire fighting the Rebel Alliance and all that.”
“Yes. It was remarkable how long their space-faring era lasted given how unstable and violent it was. All that destruction. But all that occurred a long time ago, in a galaxy far, far away.”
“What happened to them?”
“Some moved on, but most destroyed themselves. The typical pattern.”
“The typical pattern?”
“Eventually these civilizations self-destruct. They reach a critical turning point. Technology progresses faster, then faster, then even faster still, until the line goes almost straight up. Vernon Vinge called it the ‘singularity’. When this happens every individual possesses incredible power. They become demigods, or they think they are. It’s not unlike how Asgard was.”
“And it takes just one bad apple to wreck the whole barrel. Like Sena.”
“Yes. When every person has the power and technology to destroy the world, sooner or later one of them will. Life is delicate. It takes only one deflected asteroid or one vial of grey goo to wipe out all life overnight. It could even be accidental, a science experiment that goes out of control.”
“It’s unstable.”
“The problem is that Earth’s technology would have rapidly progressed to the point where any idiot could build a world-ending weapon, be it biosphere-eating nanites or whatever, even by mistake.”
“So Earth never got to see a cool Star Trek future.”
“Sadly, no. Life is just too fragile. The Star Trek film Into Darkness showed how just one person could mess up even as advanced a civilization as that one. It’s just too easy to drop stuff from orbit.”
Keiichi’s shoulders slumped. “Great. Now you are just bumming me out.”
“Sorry about that. Didn’t mean to. I’m just trying to explain why God had to cut short the story’s ending in Revelation and rescue the survivors. Otherwise nobody would have survived.”
What are the chances that the first aliens to find us are Episcopalians? Military? Fugitives from justice? Space Vikings? Pirates? Missionaries? Psychopaths? Good guys? Bad guys?
Like the first natives seeing the Spanish galleons approaching over the horizon. Might be good news. Might not.
If there are societies out there they were planted by the same God as we. But you might expect a similar mix of virtue and character flaws among its citizens. The history of our relations with the less-technically-advanced on this earth are any guide, first contact could lead to a rocky relationship.
This is a mere rehash of a Michael Crichton lecture at Caltech in 2003 titled ‘Aliens Cause Global Warming’
https://stephenschneider.stanford.edu/Publications/PDF_Papers/Crichton2003.pdf
That’s where the concept of Drake having no meaning came from.
“This serious-looking equation gave SETI a serious footing as a legitimate intellectual inquiry.
The problem, of course, is that none of the terms can be known, and most cannot even be
estimated. The only way to work the equation is to fill in with guesses. And guesses—just so
we’re clear—are merely expressions of prejudice. Nor can there be “informed guesses.” If you
need to state how many planets with life choose to communicate, there is simply no way to make
an informed guess. It’s simply prejudice.
As a result, the Drake equation can have any value from “billions and billions” to zero. An
expression that can mean anything means nothing. Speaking precisely, the Drake equation is
literally meaningless, and has nothing to do with science. I take the hard view that science
involves the creation of testable hypotheses. The Drake equation cannot be tested and therefore
SETI is not science. SETI is unquestionably a religion”
Michael Crichton
I always found it strange that the Drake Equation is taken so seriously, when not one element of it can be proven or demonstrated at all.
https://www.amazon.com/Out-Dark-David-Weber/dp/076536381X
Here is an alien invasion look that I have to recommend, for those that might be interested in such a thing. Weber is a pretty big sci-fi writer.
but...but...Aliens!
But surely the point is that we don't know exactly just how likely it is that we will find extraterrestrials or that they will find us, except to say that it is very unlikely.
So you can play with the variables to see what makes it more or less likely. If the variables are more or less correct and the relationship between them is more or less correct, faulting the formula for not giving you an exact answer looks like quibbling.
Of course we don't (and can't) know the right answer. It's going to be guesswork for the foreseeable future.
My opinion anyway, as the most unscientific person I know.
Besides the size of the Earth and a habitable distance from the Sun, these features include its elemental composition, a sufficiently large amount of liquid water, the composition and thickness of Earth’s atmosphere, the rate of rotation on its axis, the strength of the magnetic field, the amount of actinide radioisotopes for coredecay heat, the movement of the tectonic plates, the thickness of Earth’s crust, the size, density, orbital distance and tidal action of Earth’s moon, the nearly circular orbit of the Earth around the sun, the tilt of Earth’s axis, the ratio of land-to-ocean surface area, the arrangement of continents relative to the slight eccentricity of the Earth’s orbit and axis, the orbital plane of Earth and the other planets around the sun, the size and relative position of the large gaseous planets, like Jupiter and Saturn relative to that of the Earth and the inner planets, the orbital locations of asteroid and planetoid groups, the lack of large planets inside the Earth’s orbit, the elemental composition of our sun, the age and size of our sun, the heliosphere of the sun, the position of our solar system with respect to the galactic arms, the relative position of our solar system from any supernovas, the location of our solar system relative to the galactic center, and the size and shape of our galaxy. No doubt more could be listed.
These factors and many others suggest that, with all the planets associated with the billions of stars in the Milky Way galaxy, the estimated probable number of planets with Earth-like conditions hospitable to intelligent life is likely very close to the experimentally known value of one.
Yup! It’s hard hard to extrapolate from an example of exactly one.
Freegards
We’re still a primitive species barely out of the Stone Age. SETI would never detect Quantum entanglement communication in a thousand years. As far as speed of light being a barrier, wormholes or some future technology might overcome it. The thought of going faster than the speed of sound was an impossible dream and considered witchcraft a couple of hundred years ago. Who knows what we will discover a thousand years from now? Technology is advancing at an unbelievable pace. Discoveries beyond anyone’s wildest dreams are coming to fruition.
We know almost nothing about chemical evolution (why do we have only L-amino acids? why do we have only D-sugars? it takes proteins to make nucleic acids and nucleic acids to specify the composition of proteins - what came first, functional proteins or functional nucleic acids? etc).
And until we know the mechanism of chemical evolution, we can’t even speculate on the odds of it occurring in a given setting.
And if we don’t know those odds, it doesn’t matter how many stars exist or what fraction have planets, we’re operating completely in the dark: if there are 10^60 stars, and the odds of the chemicals required for life developing in the fashion that occurred on earth are 10^(-61), then we’re probably it (and if those odds are 10^(-50), we may have plenty of company). But we just don’t know, and it doesn’t look like we’re anywhere close to knowing.