That’s the beauty of the Drake equation. It does nothing. 
I suppose the thing that makes me most skeptical about sightings of actual aliens is how human they are. Assuming life evolved on another planet, wouldn’t the odds be overwhelmingly- I’m talking billions-to-one- against their looking like us? Yet the aliens almost invariably are primates with two eyes, a mouth, something like a nose, two legs/two arms. They’re even our size (shorter than average obviously, but certainly bigger than Verne Troyer who’s fully human).
Dolphins and some species of octopae are believed to be extremely intelligent creatures that evolved right here on Earth but look a lot less like us than the “aliens” in most accounts, while the “inhaled by a small dog” size or humanoid aliens the size of Blue Whales wouldn’t seem any more unlikely than humanoid aliens our own size, at least if I understand any aspects of science correctly (i.e. there shouldn’t be a “too small or too big” size for intelligent life since stars and planets come in near infinite variety of sizes).
This.
I’m pretty firmly agnostic on the subject of whether aliens have ever been around the neighborhood. I don’t buy the garden-variety UFOs-as-aliens, though, mostly because those scenarios tend to be so unimaginative.
Here’s why I think we can’t know for sure, one way or the other:
-
Human beings – even smart ones – have a demonstrated capacity to believe complete bullshit, even when we *should *know better and/or derive no obvious benefit from self-delusion. We make up pictures in our heads and believe they’re real. We see things happen and misnarrate the stories we see, and we remember what we tell ourselves better than we remember the patterns of light that hit our eyeballs. We’re also massive anthropomorphizers and see faces in toast and intentions in copy machines. So I can believe that we might have made up all the aliens ever reported (particularly the ones that mostly look like us, but weirder).
-
Human beings – especially smart ones – have a demonstrated capacity to overestimate the accuracy and completeness of our knowledge, science, etc. Over and over and over again, history shows that our predecessors were, like, totally wrong about stuff (flat earth? all useful inventions already invented by the 1800s? Arthur Conan Doyle and the Cottingley Fairies? etc.), and yet we rarely suspect our modern selves of being potentially wrong in any substantial way. So it seems possible that all our theories of why aliens would have a hard time getting here (what with the speed of light and all) could be superseded by some perfectly natural something that we haven’t figured out yet.
These are the same two points that make me agnostic WRT higher power(s).
eyes narrow in suspicion
Really? Cite? While I fully accept the possibility of alien life, given the amount of stars in the galaxy (~100Bn) let alone the universe, I have grave doubts about the existence of intelligent species. We have not picked up a single recognizable confirmed signal despite many decades spent listening. Plus the amount of coincidences that were necessary for our evolution are unlikely to be repeated on other planets even if they are habitable.
That’s the Fermi Paradox in a nutshell.
If they exist then they ought to be here by now. Assuming it’s possible to build sufficiently advanced technology it ought to be possible to cross the galaxy in half a million years without exceeding the speed of light.
As a sci fi reader I’d like to believe in the possibility of alien life, but as a scientist I feel that there is no reliable evidence of their existence.
Isn’t this leading us into circular logic? Aliens don’t exist because they ought to be here by now. And they can’t be here (UFO reports are false) because aliens don’t exist.
Moving thread from IMHO to Great Debates.
Sometimes reading these boards I’m more inclined to go along with the Hitchhiker’s Guide formulation, which “proves” there is NO intelligent life in the universe.
I have no certainty at all that intelligent species exist elsewhere, but…
Radio signals decay with the cube of distance. How far away could *our * signals be detected? The universe is a big place.
Well, a lot of conditions had to come together to allow Earth’s brand of life, but there are a lot of stars out there and we are just beginning to understand that there are probably a lot of planets, too. I don’t think we know enough to speculate reliably as to the probability that these conditions exist somewhere else.
I am doubtful that we could develop such technology ourselves before we become extinct, either by fouling our own nest or by the next big asteroid that crashes into the Earth.
I agree there is no reliable evidence of their existence. I think we need to decide what discussion we are having, though:
a) Discuss the probability of the existence of highly advanced alien life
b) Discuss evidence that alien life has visited Earth
From the moment I opened the thread, I’ve had this going through my mind:
(But for some reason I’ve heard it in Holly’s voice)
I’m in the definitely scads of life out there camp, but finding us? Heck, I moved only an hour outside the city and lots of friends have a hard time finding our place. Space is big.
As has been pointed out, the timing of finding, arriving, and probing all while we’re cognizant of our own navels is preposterous. Space is old.
I can shut my eyes real tight and get over the FtL problem – not so much violating the law but as yet unimagined ways around it: Didn’t someone just publish a speculative paper on riding on a warp wave or something? Maybe no one’s just thrown a seagull at a brick walls hard enough. Anyway, exotic travel vouchers aside, space is still big.
On the other hand, I’ve seen many posts here by Morbo.
On the other other hand, how many of us skeptics also consider exogenesis/panspermia plausible?
Lastly, (I’m out of hands), here’s a little known fact. When you’re being probed (by the gov’t) for a security clearance (Q or otherwise), they don’t generally pause and ask if you believe any cockamamie theories. It just doesn’t come up. In my stint as a gov contractor, I worked and was acquaintances with a slew of high ranking, uber-intelligent, very cleared persons in the Department of Energy. People who not only had intimate knowledge of our nuclear program (e.g., Y12), but were decision makers regarding the program. Some of them, some with the highest clearances possible, believed in some crazy shit. Not all of them, but some. And not just crazy shit like belief in conspiracy theories, but some basic, low-grade racist crap that makes the world a sadder place. So, just because some high-ranking, government employee with hellava-secret clearance says they’ve actually seen the IPU, that doesn’t mean shit.
“Time converts the improbable into the possible.”
As long as the possibility exists, no matter how small, then given a VERY long time and a VERY large number of stars/galaxies/planets, the probablity of unusual coincidences approaches certainty.
Sorry, perhaps I wasn’t clear in my previous post. I accept the existence of some form of alien life given the amount of stars in the galaxy. But the fact that there is no evidence of us being visited leaves several possibilities:
-
They don’t exist
-
They existed but died out before they left home, or never got here or stayed at home.
-
They exist and are still here
-
They existed and died out leaving remains which we may or may not find.
I accept that with our current knowledge there’s no way to tell for sure, but my money is currently on 1 or 2, but like I said I hope I’m wrong.
I thought it was an inverse square relationship, although I’m not certain. As for how far away signals could be detected, not sure, we need an astronomer.
True, given the billions of stars it may happen again somewhere, but possible not in our galaxy. Part of the problem with estimating these probabilities is that we have only 1 case study of how/where life arose, so it’s very difficult to estimate with reasonable certainty any of the last few terms of the Drake equation.
I seem to recall hearing something in the news recently casting doubt on the Drake equation anyway. Will try to track down a cite.
I agree, the likelihood of us surviving long enough is pretty slim IMHO. Although there may be species that evolve that don’t have our self destructive nature.
Can’t we do both? They are interrelated after all. Although it makes sense to discuss 1 first, I think.
Cardasians, The Borg, Tribbles…
Cardasians, Borg and Klingons fair enough, but not the cute furry things.
Besides you’d need to be a good shot to hit one from a distance.
a) I believe in the likelihood that extraterrestrial life exists. I have no reason at this time to believe any of it has come into contact wtih the terrestrial variety.
b) I am skeptical about interstellar travel. There’s that whole lightspeed problem and the distances out there are … well, you know how one would use the word “astronomical” as a hyperbolic adjective in this kind of sentence in reference to anything else that’s freaking huge? Well…
c) The whole cover-up / conspiracy thing is laughable. Our government isn’t organized or unified enough to cover up shit. Those folks can’t collude their way to a budget agreement, c’mon! I don’t see much evidence that many other governments would do any better, btw.
d) Most of the UFO stuff seems to have damn little to do with the possibility of life on other worlds, and instead is a sort of psuedo-science-based alternative religion. Huge batches of stuff you’re supposed to just believe, on zero evidence and for no argued reason aside from buying into the whole worldview shared by the folks who do believe this stuff.
I’m with the general consensus: There is almost certainly intelligent alien life somewhere out there in the cosmos; said life is almost certainly not visiting our planet, or even within reasonable hailing distance. Reasoning is as already given: The gaps of distance and, just as importantly, time are just too friggin’ huge; the technological barriers seem nearly insurmountable; there’s no reasonable basis why they would be coming here to poke things in our butts; and so forth. The arguments have already been stated, ad nauseum, so there’s no point in revisiting them in anything more than summary form.
However, I do want to add two things:
First, on the subject of their appearance, I have always found it strangely telling that the commonly accepted look of the alien visitor, the smallish big-headed “grey,” is extremely reminiscent of not just a bipedal human but a human fetus — and that this image is highly coincidental with a wider awareness of fetal development as a result of inside-the-womb photography. When this photograph exploded into the common consciousness in 1965, many people found it moving and beautiful, but just as many were shocked and horrified. This and similar work constitutes an enormously potent visual corpus. I’m fairly convinced, subjectively, that the typical Alien Gray is a manifestation of a sort of “ontogeny fantasizes phylogeny” phenomenon, and that this represents a kind of collective agreement about the wrongness of a superintelligent ambulatory fetus.
Also:
Despite my skepticism about alien visitation, I must confess to a bright spark of hope deep inside myself, a yearning that, despite the total lack of evidence to support the proposition, I really, really wish it were true. Carl Sagan’s famous quote, saying that no matter how much we may dream, “there is no hint that help will come from elsewhere to save us from ourselves,” strikes directly at the heart of my fantasies. The thing is, though, I recognize very clearly that the power of these fantasies creates a dangerous temptation to compromise critical thinking and surrender to the dreams — and it’s that recognition, more than anything else, really, that energizes my skepticism and makes me such a forceful doubter. In short: It is precisely because I want so badly for this to be true that I must not allow myself to be convinced by anything less than undeniably concrete evidence. It makes me sort of sad that more people aren’t more introspective and responsibly rigorous when evaluating stuff like this.
The arguments are good until C. The Tuskagee experiment was kept under cover for more than 40 years with many people involved. Things can and have been covered up a long time. Like the Gulf of Tonkin.
A couple of comments:
1.) The now-universal “Greys” as UFO pilots is a surprisingly recent development. If you showed that picture in the 1950s or the 1960s people would not think “UFO occupant”. The image hadn’t developed yet. UFO people were “little green men” or very human-looking, or weird, but otherly shaped (like the Flatwoods Monster). It’s been argued that the current image of "Greys’ got its start from the 1975 TV movie The UFO Incident, which adapted John Fuller’s book “The Interrupted Journey” about the Betty and Barney Hill “Abduction”. Betty drawings of the aliens had them human-sized and with pupils in their eyes, but otherwise Greey-like, and the movie popularized this more than the book, and altered them more towards out current imagery. Afterwords, aliens started looking more and more Grey-like.
2.) Although the pictures of fetuses did get more publicity with the 1960s (and especially the Life magazine publication of “The Miracle of Life Before Birth”), the image of the fetus as Creepy Being has been well-known and around longer than that. Aubrey Beardsley used the image a lot for creepy characters.
I like to look at it the other way around - let’s say that human civilization advances to the point where we’re ready to branch out and look for other life in our galaxy (not the whole universe, just our galaxy). Let’s say we build a warp drive that lets us investigate one star every three days - I don’t think this is possible, even at relativistic speeds, but let’s go with three days. And further, let’s say that we expect to find something after having searched only 10% of the stars in our galaxy.
How long should this search take? The answer - a couple hundred million years. In the reference frame of the spaceship travelers, which would be a much longer time for those left at home.
Space is just too vast. If you take a more realistic time of a few years per star, we could search in vain for billions of years.