New study: there could be around 36 alien civilizations in our galaxy

"According to a new study in The Astrophysical Journal, there could be dozens of intelligent alien civilizations hiding in our galaxy, all capable of communicating.

“There should be at least a few dozen active civilizations in our Galaxy under the assumption that it takes 5 billion years for intelligent life to form on other planets, as on Earth,” Christopher Conselice, Professor of Astrophysics at the University of Nottingham and lead author of the study, said in a statement.

“The idea is looking at evolution, but on a cosmic scale,” he added.

The researchers say the numbers suggest there are a number of technological civilizations in the Milky Way galaxy.

“In the strong criteria, whereby a metal content equal to that of the Sun is needed (the Sun is relatively speaking quite metal rich), we calculate that there should be around 36 active civilizations in our Galaxy,” Tom Westby, first author and assistant professor at the University of Nottingham, said in the statement.

Previous estimations have been based on educated guesses and opinions — something that can cause numbers to “vary quite substantially,” according to Westby. But the astronomers say their estimation takes the latest research into account.

“Our new study simplifies these assumptions using new data, giving us a solid estimate of the number of civilizations in our Galaxy,” Westby added.

Hidden in the cool research is a major bummer: the average alien civilization would be 17,000 light-years away. It’s also possible that all other intelligent civilizations already kicked the bucket a long time ago."
https://futurism.com/research-could-be-36-alien-civilizations-galaxy

I think the simplest solution of the Fermi Paradox might be that the galaxy is just too big. Even if some civs do exist and did not get destroyed, they will be so far away from each other, that communication or visits would be astronomically unlikely.

 

I've heard of this before, though with as low as 6 civilizations. Doesn't surprise me.

The scale of the galaxy does come to mind. A civilization may very well just run into species level ennui, go virtual, go extinct, fight itself, before it even meets another. 17k ly for 36 civs at a time is humongous. Normal radio communication basically breaks down at 1, 2 ly right? Even laser radio breaks down after a few LY.

Too far, nothing to do, all alone, shouting in a sort of waterfall situation.

 

I played with the Drake equation a few years ago and came up with an estimate of between 1 and 25 civilisations in the Milky Way - the spread mainly depending on how long a typical civilisation lasts. My own suspicion is that we are the only civilisation in the Milky Way and possibly in the whole observable universe. That we are just one civilisation among many or just one on its own - both are scary prospects - to misquote A C Clarke.

 

The issue with the Drake equation is that we actually don't have enough data to really use it...

You can play with it all day long but, we don't know how many worlds would qualify as habitable. We also don't actually know if there are -other- forms of life that could live on distinctly different worlds (as in, not Earth-like). We don't know for sure how long it takes for life to arise at all, let alone the odds of intelligent life nor, how long it takes for simple life to reach a point where intelligence is even possible etc...etc...etc...

 

That's shortsighted -- assuming that any civilization must remain permanently on its planet of origin. Given enough time, a single civilization could colonize a huge swath of the galaxy. And once it did so, it would be effectively immortal, since any cataclysm that wiped out some of it would not get the whole thing.

It was never meant to be used in any actual calculation. It's just a conceptual tool, a way of talking about the factors that are involved in evaluating the question of the frequency with which technological civilizations might arise. It's more about defining what questions we need to ask than positing any actual answers.

 

True if an alien civilization did reach Type 2 on the Kardashev Scale, it would not get wiped out and could expand and cover quite a bit of space and might even get close enough for us to detect its presence. But our galaxy is still immense. I imagine that a Type 2 civilization on the opposite side of the Milky Way could expand to cover hundreds of star systems and probably still remain hidden from us for a long time.

 

That still sounds like educated guesses. Merely more educated than before.

 

Well yes.

 

Dang, and here I was hoping for... 42.

Sigh.

Cheers,
-CM-

 

Well, mostly going from the 1 example we have.. Earth.. Which is a bit myopic in its scale.. We have near Zero facts on what would be habitable to other forms of life.. Even in the Trek universe for examples is that Vulcan is Way hotter, Andoria is way cooler, and orbits a gas giant.. Sheliak are Silicon based.. Etc. Etc.
But say there are civilizations.. what if said system is surrounded by a thick ort cloud.. they wouldn't be able to see out past there system.. so going out in to space wouldn't be a priority or maybe even a thought.
Or say the intelligent species is water born like a smart squid..
Possibilities are endless.. and as we are right now.. we know a little more than .. Nothing.

 

Indeed. Our exoplanet discoveries have proven that the old assumption that our planetary system was typical was quite wrong. It's unwise to use our own single example as the measure of all things.

Limited, but far from zero. The laws of chemistry and physics are the same everywhere in the universe, so we can use those to extrapolate what kinds of molecules and solvents could potentially sustain life in exotic conditions. There have been informed scientific speculations on that subject for generations, such as Isaac Asimov's classic 1962 nonfiction article "Not As We Know It -- The Chemistry of Life," which can be read in its entirety at: http://www.bigear.org/CSMO/HTML/CS09/cs09all.htm#cs09p05

Also, there are extremophilic microbes right here on Earth that can survive in extremes of temperature, dryness, radiation, etc. that would be fatal to us. So we have direct observation of some environments that are habitable to forms of life other than our own, in one sense.

From an astrobiological standpoint, neither one is significantly different from Earth. Both worlds' average temperatures and climates are within the range of extremes found here on Earth, and there are plenty of human populations who live in desert climates like Vulcan or Arctic climates like Andoria.

There's no way such a dense cometary cloud could exist. Our own Oort cloud is so diffuse that there's maybe one comet for every 5 cubic astronomical units. Even a cometary cloud a million times as dense would be far too sparse to block starlight. On the other hand, a star system engulfed in a dense cloud of cosmic dust could be unable to see the stars until it developed radio or near-infrared astronomy. But such engulfing would be a temporary phenomenon, so it'd be quite a coincidence if it happened to overlap the brief sliver of a star system's existence during which a technological civilization was forming.

 

I've read that before. While my grasp of the chemistry is limited, it goes a long way toward establishing what's plausible and what isn't. The s.f. field has all sorts of references to "silicon-based life", but this is the best explanation I've seen for why specifically silicon-based life is plausible, as opposed to life based on gold, manganese, yttrium, tungsten, or whatever fanciful elements come to mind.

 

Although, as Asimov points out, it would more specifically be silicone-based life (silicon-oxygen compounds) than just silicon. Which means that the Horta's rubbery appearance is actually pretty much spot-on.

 

Just about anything that Asimov says can be taken as very nearly fact...

Being a Chemist, he knew what he was talking about in that article.

 

Let's not publicize that one; it'll just encourage Hollywood to go cheaper and claim it's "realistic".

 

we also know very little about the most common form of matter. Plasma and plasma/dust based life might be more common than liquid/solid life. Assuming, huge assumption, that life could develop into an intelligence capable of civilizations, we have no idea what form that would even take, except that it might be ridiculously hard to detect accidentally, without even knowing what it was.

From a standpoint of infinite cosmological expansion, with infinite hubble volumes there must be repeated civilizations similar or identical to our own. So, while as far as i know it cannot be proven, it is not illogal to say there are infinite civilizations if you only count the infinite copies and variants of our own due to the homogenous placement of time and space over vast scales (distances infinitely larger than that of the viewable universe). But while that's interesting, and perhaps there's an exact version of me at vast distance typing the same thing or something similar right now (I hope he or she has six fingers and is into their version of Star trek) that is really more a philosophical point since there is no way to know or ever to have an effect on.

And yet.

If it were possible for a suitable advanced civilization to develop einstein rosenberg bridges, their best bet might not just be an earnest of sweep of just their nearby galaxy hoping to catch some elusive or long dead civilization, but rather to look for these variants of themselves. The most truly interesting thing in the universe might be some equivalent to extradimensional intelligence. Ok I feel Drysony. I'm going to stop now.

 

You mean an Einstein-Rosen Bridge.

 

Or - it could be that actual Space Travel (and reliable long Stellar distance communication ) is INCREDIBLY difficult - and most species who develop technology use the resources in their home star system; and eventually die out. yes, A LOT of things are 'theoretically possible' but it may be you can never make it reliable/safe/or practically feasible (IE it costs to much in available resources, etc.)

Again, we love to theorize and fantasize that there are other planets SO Earthlike, we could just (assuming we could find a way to reliably and safely traverse that VAST distance between Sol and that other world); we could just migrate there and start a new human branch/colony. I honestly don't think such a compatible world exists -(IE one so Earthlike we could easily survive, grow edible fruits, grains, animals, or safely eat whatever fauna evolved on that world) because I DO think evolution is more complex a mechanism and more'World/Biosphere specific' and what's out there won't be compatible/safe for someone who evolved from Earth. Plus if we did have the technology to Terraform some other world the BE Earthlike - why not repair the Earth itself or Terraform one or more of the planets in our own Sol system first?

 

Or build a "Ringworld" around our sun with the available resources? Or building enclosed colonies inside the large Asteroids roaming around this system or...?

 

up too late and reading about McCarthysm back and forth with this forum. Bad mix. My apologies