# Number of technological civilizations in our galaxy/universe?

How many technological civilizations do you estimate exist in the Milky Way galaxy? Assume the total includes the Earth.

[Define a “technological civilization” as one which can at least make simple machines a la the lever, wheel and axle, wedge, screw, etc. They do NOT have to have advanced tech, like rockets or radio, but may be presumed to soon have the capability.]

The Drake Equation Calculator is a useful tool, but is NOT required for doing your estimate, if you do not wish to use it.

Wikipedia on the Rare Earth hypothesis, which contains an alternative formula with more factors (long story short they broke down many of the original Drake Equation factors into separate ones), tho I could not find an online calculator for it.

For the N’s which are less than one-you can interpret odds of e.g. 1/10 as representing 1 such civ within the nearest 10 galaxies (inclusive of the Milky Way).
Me, I think there might be one other within the closest 100 galaxies (so 1/100 civs in ours), if we are lucky. There appears to be a huge chain of unbroken causal events which must happen to lead to such a civilization, and I simply think that very few of even the suitable planets will ever develop one before something goes wrong on it.

We’re it in the entire known universe since we are the only ones to know what is known and we only know of us.

If it’s one percent chance per galaxy, that gives us about 2 billion technology-using species in the universe. That’s probably better odds than I’d give, but that’s perfectly fine. Point is, with so many galaxies that each have billions to trillions of individual stars, the chance for something to happen once and only once ever has to be so mind-bogglingly low that it’s practically non-existant.

I had a go with the Drake Equation calculator and got 0.0005. I voted 1/10 but probably should have voted 1/1000.

I assumed a rate of star formation of 1 (as I have no idea what this is), half of all stars having planetary systems, one tenth of those having planets suitable for life, one tenth of those developing life, one per cent of those achieving intelligence, one per cent of those developing interstellar communications (personally I don’t think we’ve reached that point yet), and a thousand year lifespan for such communications.

Latest NASA estimate is 7 per year.

I first made a fairly wild-ass guess of 10 civilizations, went to the on-line calculator and plugged in some numbers that I believed were reasonably sound but were themselves rather wild-ass guesses, then looked up 'rate of star formation 'and upon plugging in NASA’s value of 7, came up with 6.3 civilizations. So my first guess came as close as one could get with the poll choices, assuming the calculated values are realistic. So, er, I guess I’m pretty good at wild-ass guessing. Yay me.

Who would really care? Tech is boring.

According to one theory, gamma ray bursts were too common for meaningful life to evolve until 5 bya. Considering that life on earth is 4.1 billion years old (I believe they recently revised it and found life 4.1 billion years old had been found) maybe the universe is teeming with life, but maybe we are the most advanced right now (at least in this galaxy).

I can vouch for at least one technological civilization in our galaxy. If your question had been whether there is any intelligent life, I’d have had to pass. :o

Doesn’t that beg the question? If there’s another technological civilization out there, they might also know what is known, and they would know of themselves.

My WAG was 10 for absolutely no reason, am surprised with the results so far.

Do you mean milky way Galaxy or known universe? They’re two vastly different things, it’s a bigger difference than asking ‘how many people live in my house vs how many people live on Earth’.

Current evidence points to 1 technological civlization in the Milky Way, and I don’t think enough is known about the development of intelligent life to make a good estimate of how common it is. We don’t have detailed enough observations of anything further away to meaningfully talk about other galaxies. I suspect that intelligent life is not all that rare, but that the kind of technological life assumed in the Fermi Paradox (intelligent life that sets out to deliberately colonize every bit of space) is non-existent or vanishingly rare.

Known universe is large. I’d say more than a million.

“We are the only known one in the universe” is a different statement than “We are the only one in the known universe.”

My gut feeling tells me the number of technological civilisations in the universe is disappointingly low, hence my vote for 1000000.

“Something to happen” being the spontaneous formation of life, and then for that life to evolve to a point of becoming intelligent, is something we have no frame of reference for whatsoever. It could very well be a 1 in 10^100^100^100 chance of happening at all, so for it to have even happened once is way beyond the realm of what’s expected, even in a universe as vast as ours.

I voted we’re the only ones because I just find it really wishful thinking to think otherwise. And if there were lots of technological civilizations, there would be some old enough that we’d be able to pick up radio signals from them. Yet people have been listening for over a hundred years since we discovered radio ourselves, and efforts like the SETI project have discovered nothing but dead silence.

I think it is highly probable that we are alone in the galaxy, and not just because we know that we are the result of a very long series improbable events which made our species possible.

Several years ago, an article in Scientific American dealt with the Fermi Paradox. When discussing the prospect of intelligence life in the galaxy, Enrico Fermi wondered “Where are they?” The authors of the article made some assumptions and concluded that a species which had reached our level of development would colonize the galaxy in ~ five million years, a blink of the cosmic eye. This seems reasonable. We will certainly explore the entire solar system within the next thousand years. How fast we go from there will demand new technology, but there is nothing in the laws of physics to prohibit interstellar travel.

So if this is true, and if intelligent life has evolved elsewhere, we should be able to detect it. There should be a lot of events which point to an artificial origin. When pulsars were first detected, it seemed that they were precise signals of intelligent origin, but alas, it was not to be.

We can be less confident in any conclusions regarding other galaxies, but if ours is typical, it looks pretty lonely out there.

Eh, because the universe is so incalculably large and FTL travel is impossible, we may as well be functionally alone in the universe even if we aren’t actually so.