Followup to Aigbusted's question

[Martin]

We had a poll on this question: How many planetary systems in the galaxy have evolved any recognizable life at all, or to be definite, some kind of carbon and water based life analogous to Earth's that we would clearly see as comparable to what we have here, even if still very primitive.

 

and the responses averaged out to 100

 

Let's try the next question. ASSUME that in all the Milkyway there are 100 planets where some recognizable water+carbon life has evolved, even if it is just single celled. Of that 100, perhaps some evolved multicell, central nervous system etc etc, and on up. Perhaps.

 

Of those 100, HOW MANY do you estimate have evolved life sophisticated and curious enough to build radio telescopes and listen for artificial signals?

[iNow]

Zero.

 

I see no reason why another intelligent species would have evolved toward a radio telescope.

 

 

That's just an opinion though, and is potentially subject to serious fault and inaccuracy.

[Martin]

the count includes Earth

so your guess would be ONE (earth being the only instance) I guess.

that makes sense, how about voting in the poll. I would like to have your estimate.

[Reaper]

I think you need to be a little more specific with your question. Are you talking about the present? Or at any time in the galaxy's long history? And do they have to be alive right at this minute?

[Martin]

I think you need to be a little more specific with your question. Are you talking about the present? Or at any time in the galaxy's long history? And do they have to be alive right at this minute?

 

Yeah, I was talking about the present. And being alive and listening (just as we are) right this minute.

 

The premise is that 100 planets evolved some vaguely familiar recognizable life at some point in the past. Of those 100 how many eventually developed radio-astronomy and the curiosity to listen for artificial signals?

 

Maybe it is a dumb question, and maybe you can think of something more inspiring. Given this question, though, I am interested to know what percentages people think likely.

[Mr Skeptic]

Yeah, I was talking about the present. And being alive and listening (just as we are) right this minute.

 

But what do you mean by "this minute"? The galaxy is big, and someone who is alive this minute could die out before we could contact them. So should we count those we could listen to right now as as those we could listen to broadcasts from right now, or those that are currently alive but far away?

[Martin]

But what do you mean by "this minute"?

 

I mean this minute. What don't you understand?

 

The galaxy is big, and someone who is alive this minute could die out before we could contact them. So should we count those we could listen to right now as as those we could listen to broadcasts from right now, or those that are currently alive but far away?

 

So what? I am not asking about could someone receive a message. I didn't ask about that. I am asking a more basic question. How many do you picture are listening---doing radio astronomy prepared to notice artificial signals---at the present time.

 

Tell me what our collective estimate is of that, and maybe I or someone will take it a step further.

[iNow]

the count includes Earth

so your guess would be ONE (earth being the only instance) I guess.

that makes sense, how about voting in the poll. I would like to have your estimate.

 

Indeed. I feel a bit silly having missed this myself.

 

Vote cast.

[Martin]

Thank you iNow!

Civil of you not to leave me dangling. Some of the rest seem reluctant, so let's go with what we have. the average is 2.

 

So we have established what will have to pass for a collective SFN estimate TWO PERCENT of planets which initiate some kind of recognizable life eventually become sensitive to radio signals.

 

Or more exactly (what I asked in O.P.) that percentage have evolved life sophisticated and curious enough to listen for signals (and are doing it now, as clarified with Lockheed's help).

 

So if our collective estimate of 100 is right, and this percentage is right, there are now TWO listening forms of life. So in the whole galaxy there is only ONE OTHER currently listening.

 

that doesn't seem to provide such good odds of ever making contact. they might have died off before they got our message, we reciprocally might have, before we got theirs.

 

the galaxy radius is 50,000 LY. antennas only have so much power and carry only so far.

==================

 

Well hope for the best. Maybe that one other civilization already broadcast a message some tens of 1000s of years ago and it is just about to get here

[Mr Skeptic]

I voted for earth only, but I must say I am just speculating and quite biased. When abiogenesis is understood better I would have a better idea.

 

Even if there were technologically advanced life out there, I doubt that we would find it any time soon if at all. The time delay on messages alone is far greater than we have been a civilized race, then there is signal strength, noise, and the chance that they simply don't want to reply.

[Martin]

OK currently there are 2 votes for ONE and 2 votes for THREE and the average is TWO PERCENT

 

that could be a very optimistic estimate but at least for now it is our halfarzed collective estimate so let's go with it.

 

the idea was that IF you assume the galaxy has 100 planets that so far have initiated our kind of life that TWO would not only have continued on to the level of being curious and capable enough to listen to the radio but also this survived so they or their descendants (if they spread out some) are listening NOW.

 

I think the percentage idea extends to other cases where more planets in the galaxy evolved our kind (carbon-water) life

===================

 

So we can do a what-if. Everybody knows about Gliese 581 which I think is within 20 or 30 LY of here and the outer planet is speculated to be habitable by singlecells, but not really very nice (rather cold much of the time)

 

Let's not count Gliese 581. Imagine something much more optimistic. Suppose that it is discovered using future telescopes that among the TENTHOUSAND NEAREST STARS there is ONE other system which is not only habitable but where recognizable singlecell life has initiated. (Suppose we have some way of telling, like by gas analysis of its planet's atmosphere---not out of the question.)

 

Then the question is, how many in the whole galaxy would you estimate are listening? Using the same two percent rule.

 

==============

this kind of astrobio speculation is not a specialty of mine----if anyone wants to take over and supply a better line of questions or set up a poll along some line they think is clearer, please go ahead.

[Reaper]

I'll go with a more optimistic approach and say that out of the assumed 100, about 3 are actively listening out there right now. Given the extreme lack of data about the nature of extra-terrestrial civilizations its very hard to say; there is a possibility that our guesses are way off.

 

=========================================

 

Perhaps we should also make a poll to try to guess how many aliens out there currently believe they are the center of the universe...

[Realitycheck]

100 sounds really low to start out with. I mean, we start out with 300 billion stars, most of which have planetary systems. The planets are divided 50/50 into gaseous and solid. We'll be conservative and estimate that each star only has 5 planets. .01 percent of the solid planets have sufficient water and suitable atmospheres for life. 5 percent of the planets are positioned adequately in order to support life.

 

We're still looking at 3.75 million planets.

 

I am probably way off on what it takes to provide a suitable atmosphere, but given the scale involved, it shouldn't be too far off.

[Martin]

agentchange, what you are saying would be on topic in the other thread.

http://www.scienceforums.net/forum/showthread.php?t=30422

 

basically here what I'm trying to gauge is our collective idea of a PERCENTAGE.

 

Out of a hundred planets initiating singlecell life---or something earthlike enough we can recognize as carbon+water life---then how many ultimately result in something with the curiosity and capacity to be listening now.

 

You haven't addressed this. So far we have what may be a very optimistic collective estimate of 2.2 percent

 

======================

 

I think what you are talking about is the number of planets in our galaxy which have, at some time, already initiated life.

What you have to say would add to the discussion in that other thread, and I hope you register your best guess in the poll in the other thread. Please respond to the poll here:

http://www.scienceforums.net/forum/showthread.php?t=30422

[Realitycheck]

Sorry, for some reason, I got the impression that the first poll was taken on another forum.

[Martin]

 

...Out of a hundred planets initiating singlecell life---or something earthlike enough we can recognize as carbon+water life---then how many ultimately result in something with the curiosity and capacity to be listening now.

 

... So far we have what may be a very optimistic collective estimate of 2.2 percent

 

 

 

I'm inclined to close down the estimating at this point, having gotten an initial sample and calculated the average.

If we leave the process open ended there's too much chance of the average becoming a football or tug of war between people who want to influence it one way or the other.

[J.C.MacSwell]

I voted 1. 1 out of 100 seems ridiculously high to me (what percentage of Earth's "Amoeba Time" have we been listening?)

 

But I think there are a lot more "Amoeba Planets" than just 100.

[Martin]

I voted 1. 1 out of 100 seems ridiculously high to me (what percentage of Earth's "Amoeba Time" have we been listening?)

 

But I think there are a lot more "Amoeba Planets" than just 100.

 

You sound like you have applied a realistic imagination to this. How about writing down some numbers?

I'd be interested to see what you would estimate---entirely separate from our collective estimate polls.

[Mr Skeptic]

I voted 1. 1 out of 100 seems ridiculously high to me (what percentage of Earth's "Amoeba Time" have we been listening?)

 

But we haven't died out yet. It is entirely possible that our society outlive our own solar system, something amoebas are quite unlikely to do.

[iNow]

But we haven't died out yet. It is entirely possible that our society outlive our own solar system, something amoebas are quite unlikely to do.

 

I think we're lucky if we survive the next century, let alone out survive the solar system.