How much intelligent life is there?

[choxorn]

I'm a little doubtful on the bacteria front too...

Why? Bacteria exist in places on Earth that are less habitable than Mars and some of Jupiter and Saturn's Moons.

Why does the universe need to have a reason to exist?

It doesn't, but it seems almost impossible for life to have only evolved intelligence at only one place in the entire universe. The universe is ******* big, Perfy.

 

[Imperialmajesty]

Why? Bacteria exist in places on Earth that are less habitable than Mars and some of Jupiter and Saturn's Moons.



It doesn't, but it seems almost impossible for life to have only evolved intelligence at only one place in the entire universe. The universe is ******* big, Perfy.

We don't have enough information on the rest of the galaxy to make a judgment on the existence of extraterrestrial life. My gut instinct is that it does exist, but if I had to think of it scientifically, I simply have to say "Not enough information".

 

[Perfection]

Why? Bacteria exist in places on Earth that are less habitable than Mars and some of Jupiter and Saturn's Moons.

Well questions about habitability aside (being able to support life is a complicated thing), you have the problem of where did the bacteria come from? On Earth all life seems descended from a single strain, if this initial spark didn't occur on Mars or Enceladus or wherever then we wouldn't see life on it (barring interplanetary transport via meteors or some other form of panspermia). The question of what is needed for this spark, and that could be extremely rare!

It doesn't, but it seems almost impossible for life to have only evolved intelligence at only one place in the entire universe. The universe is ******* big, Perfy.

The universe certainly is big! But the probability of intelligent life arising in any given galaxy/star/world might well be correspondingly small!

 

[Imperialmajesty]

Well questions about habitability aside (being able to support life is a complicated thing), you have the problem of where did the bacteria come from? On Earth all life seems descended from a single strain, if this initial spark didn't occur on Mars or Enceladus or wherever then we wouldn't see life on it (barring interplanetary transport via meteors or some other form of panspermia). The question of what is needed for this spark, and that could be extremely rare!


The universe certainly is big! But the probability of intelligent life arising in any given galaxy/star/world might well be correspondingly small!

Perhaps there were multiple "sparks" on Earth, and the spark all life is descended from on this planet is the one that "won". After all, what type of fossil record would be left from something so small?

 

[warpus]

Bobble head production is a completely natural process. And if you're going to suddenly lump out, "no intelligently created stuff", then I get to rule out, "no millions of years of evolutionary chaos stuff".

My point is that life most likely arose independently of any outside intelligent agent. I mean, even if we were created by aliens, those aliens would have had to be created without any outside intelligent agent.. or by other aliens, etc.

I think my original point was this:

1. Life arising from non-life is a natural process
2. So far all the natural processes happening in this universe that we've observed are a pretty frequent occurrence. I mean, even the rare stuff happens a LOT, simply because the Universe is so huge and contains so much stuff.
3. The probability of a natural event only happening once must be near zero.
4. The probability of a natural event only happening twice, ever, must be near zero.
5. The probability of a natural event only happening three times, ever, must be near zero.
...
38268326832. The probability of a natural event only happening 38268326832. times, ever, must be near zero.

If you look at this data as a curve, you are going to get into realistic and "yeah, this is gonna happen somewhere, for sure" type numbers. But looking at each individual point you end up with a probability so close to zero that it happening would be pretty unlikely.

I mean, what's the probability that exactly 58,888 x 10^5 (number I pulled out of my ass) black holes are going to occur in this universe? Some probability close to zero, right? What about looking at a range, instead 1 single value? The probability goes up, significantly, to realistic values. What's the probability that under 58,888 x 10^5 black holes will occur in this universe? I'm no cosmologist, but this number is going to be far far bigger, MAGNITUDES bigger, an incomprehensible factor bigger than the probability that exactly that many black holes are going to occur.

Taking this concept to the natural event of life occuring from non-life, you'll get similar numbers. Take one discreet value (be it life occuring once, twice, 65,000 times, or 50 x 10^8 times.), and the probability of life occuring exactly that many times will be near zero.

If you look at a range, though, the probabilities are going to be much much higher.

What's the probability that life arose less then 583 x 10^11 times, in this Universe? It will be a much larger number than the probability that it arose less than 583 x 10^4 times, and insane amounts larger than the probability that it arose exactly 583 x 10^2 times, or just once.

That was my previous argument, and I think we're just going to have to agree to disagree. I mean, I'm looking at this from a statistical point of view, whereas you're likely going to disagree with this analysis on principle alone.

 

[GoodGame]

The Drake equation states that:

N = R* x fp x ne x fl x fi x fc x L

where:


ne is the average number of planets that can potentially support life per star that has planets
fℓ is the fraction of the above that actually go on to develop life at some point

Thanks for posting.

I think we have to work on understanding the ne -> fℓ transition before we try to advance this discussion too much further.

 

[Perfection]

Perhaps there were multiple "sparks" on Earth, and the spark all life is descended from on this planet is the one that "won". After all, what type of fossil record would be left from something so small?

That certainly is a possibility! It's also possible that multiple sparks merged to form the single entity that we know call life. The science behind the origin of life is field with many questions, many intriguing theories, but few definite answers.

 

[Perfection]

I think my original point was this:

1. Life arising from non-life is a natural process
2. So far all the natural processes happening in this universe that we've observed are a pretty frequent occurrence. I mean, even the rare stuff happens a LOT, simply because the Universe is so huge and contains so much stuff.

Well, simply no! I am currently playing with a rock. I can pick out 100 features on it that could be visually different in 10 different ways. Presuming these differences are reasonably independent, I can be all but completely assured that there's no rock in the entire universe that looks so much like mine that I could not tell them apart! Certianly there are plenty of other rocks around the universe, some of which bear striking similarity to mine, but none of which are mine.

The proto-life that gave rise to us might be like my rock. It might be that there might be numerous chemical systems that bear an astounding amount of similarity to that proto-life, but it may not in fact function as proto-life (just like there are many rocks that are quite similar to the one I am holding, but are still visually distinguishable from mine). Proto-life may be in fact so rare that in the universe, our strain is probably unique.

It is this possibility that gives one an edge over your ranges and why you can't simply dismiss it as infinitesimally small.

 

[Imperialmajesty]

That certainly is a possibility! It's also possible that multiple sparks merged to form the single entity that we know call life. The science behind the origin of life is field with many questions, many intriguing theories, but few definite answers.

I figured as much, I can't imagine that much is left from those early days, besides its eventual progeny. I would think that that is the place to look, inside ourselves, and no I don't mean some half-assed new aged hippie junk, but I mean actually looking into the genetics of life on earth. Perhaps we can strip away the mutations from our genetic code until we reach millions of years into the past.

 

[warpus]

Well, simply no! I am currently playing with a rock. I can pick out 100 features on it that could be visually different in 10 different ways. Presuming these differences are reasonably independent, I can be all but completely assured that there's no rock in the entire universe that looks so much like mine that I could not tell them apart! Certianly there are plenty of other rocks around the universe, some of which bear striking similarity to mine, but none of which are mine.

There are probably trillions (and likely a much larger amount) of rocks in this universe that you could not distinguish from your rock by using your unaided senses.

Rocks that have the same density, shape, and size? There are probably a lot of those out there too. The universe is a huge place!

The proto-life that gave rise to us might be like my rock. It might be that there might be numerous chemical systems that bear an astounding amount of similarity to that proto-life, but it may not in fact function as proto-life (just like there are many rocks that are quite similar to the one I am holding, but are still visually distinguishable from mine).

Have such chemical systems been observed? What studies support the existence of such a thing?

Proto-life may be in fact so rare that in the universe, our strain is probably unique.

You're saying that there are potentially trillions^trillions (or however many) of different types of chemical soups out there that are all very similar - and that just one of these soups lead to a soup that turned into life.

1. That's a lot of assumptions right there
2. That is still a natural process and you could use my method to analyze it (Notice that my method doesn't assume anything, but simply analyzes the probability of a natural event occuring, no matter what it is)

 

[Perfection]

There are probably trillions (and likely a much larger amount) of rocks in this universe that you could not distinguish from your rock by using your unaided senses.

And you base this "fact" on what?

I figure, that there are 100 different points I can find on my rock where the features could be different in 10 roughly equiprobable ways independent of one another (in actuality it's probably more like hundreds of millions with subtle interdependencies, but this is a good toy model), for example on one part of it, there's a slight chip, if that chip causer was different it could have been shallower or deeper by maybe 10 noticible graduations all of similar probability. There are many many other points on my rock like this I can find where things could have been different by said similar probability. The end result is I can easily estimate the probability of a similar sized rock to have similarity in shape to mine, to be under 10^-100, which makes it in all likelihood completely unique in the universe.

Rocks that have the same density, shape, and size? There are probably a lot of those out there too. The universe is a huge place!

Yet still not nearly huge enough.

Have such chemical systems been observed? What studies support the existence of such a thing?

Well, we know life came into being, we just don't know how likely it is, I have thus far found no compelling reason to believe it is either over or under ~10^-22 per star. Remember, warpus, I'm not saying we are alone, just saying that you can't say we aren't.

You're saying that there are potentially trillions^trillions (or however many) of different types of chemical soups out there that are all very similar - and that just one of these soups lead to a soup that turned into life.

Not exactly:
Just like rocks sufficiently close to my rock, but not exactly the same rock (like those that could be distinguished with an electron microscope, or those that could be distinguished by cutting in two), proto-life might still have several forms similar enough to work. It's just that all those forms may be collectively so rare that they won't be found at a rate more than one per universe.

We can also think about different proto-life that isn't like our proto-life but my argument still works. We can imagine that instead of searching for just my rock, we're searching for my rock or a member of a big ol' box o' rocks. Each rock would be so rare that even collectively we wouldn't find a double for my rock or any of the box rocks in the entire universe.

1. That's a lot of assumptions right there
2. That is still a natural process and you could use my method to analyze it (Notice that my method doesn't assume anything, but simply analyzes the probability of a natural event occuring, no matter what it is)

Your method is simply doesn't work for sufficiently rare events, of which life might be!

 

[Perfection]

I figured as much, I can't imagine that much is left from those early days, besides its eventual progeny. I would think that that is the place to look, inside ourselves, and no I don't mean some half-assed new aged hippie junk, but I mean actually looking into the genetics of life on earth. Perhaps we can strip away the mutations from our genetic code until we reach millions of years into the past.

Unfortunately, there's only so far back we can go. Life itself has a lot of commonality, and shows signs of tremendous evolution before it diverged into the multitudes of life present today. We can certainly answer some questions regarding how life came into being, but the backwards approach is quite limiting. Of course, the forward approach is limiting too. I have sneaking suspicion that the exact chemical pathways we took won't ever be found.

 

[Imperialmajesty]

Unfortunately, there's only so far back we can go. Life itself has a lot of commonality, and shows signs of tremendous evolution before it diverged into the multitudes of life present today. We can certainly answer some questions regarding how life came into being, but the backwards approach is quite limiting. Of course, the forward approach is limiting too. I have sneaking suspicion that the exact chemical pathways we took won't ever be found.

Hopefully technological advances will come down the pipe that will allow scientists to have a more detailed view of the past.

While I coincide that we might never find out the exact chemical pathways we took, I remain hopeful that in the future we might have a better understanding.

Semi Off Topic, but perhaps an understanding of our evolutionary past can tell us something of the evolutionary future. It seems as if the species on this planet are trending towards lesser and lesser different types animals (not sure of the exact taxonomic name for what I am trying to describe)

The past, to me, seems to be a great "weeding out" of species. I wonder what will be left in 500 million years.

 

[Danielos]

I believe that life will appear spontaneously if the conditions are not that harsh. That is, life would be common in universe. However, I do think that the evolution of intelligence is more uncommon. Dinosaurs were the major players on this planet for hundreds of millions of years, yet they remained "stupid". Other animals, like dolphins, are pretty smart but can´t develop a civilization. So, I think life is common, intelligent life uncommon, and advanced civilizations very rare.

 

[kill fire]

Well, simply no! I am currently playing with a rock. I can pick out 100 features on it that could be visually different in 10 different ways. Presuming these differences are reasonably independent, I can be all but completely assured that there's no rock in the entire universe that looks so much like mine that I could not tell them apart! Certianly there are plenty of other rocks around the universe, some of which bear striking similarity to mine, but none of which are mine.

The proto-life that gave rise to us might be like my rock. It might be that there might be numerous chemical systems that bear an astounding amount of similarity to that proto-life, but it may not in fact function as proto-life (just like there are many rocks that are quite similar to the one I am holding, but are still visually distinguishable from mine). Proto-life may be in fact so rare that in the universe, our strain is probably unique.

It is this possibility that gives one an edge over your ranges and why you can't simply dismiss it as infinitesimally small.

That isn't really true. We don't know how large the universe is, but lets just say for an example that it never ends. If that was true, then not only would there be at least ONE rock that had the exact same features as your rock, there would be an INFINITE number of them. The same would be true of proto-life. Of course that's assuming that the universe IS never ending, but even in the known universe there is probably at LEAST one rock that you couldn't tell apart from yours, probably more. That might not be true of proto-life, although it isn't unlikely that there is some human-like creature out there.

 

[emzie]

For the record, if someone had the answer to the question "Is there life outside of our planet?" in an envelope and I was forced to answer yes or no, I would answer yes.

Scientifically speaking, I remain neutral since the data is lacking and probably will remain lacking well past my death. There is nothing wrong with withholding judgment, and dare I say it's probably the proper course of action.

That isn't really true. We don't know how large the universe is, but lets just say for an example that it never ends. If that was true, then not only would there be at least ONE rock that had the exact same features as your rock, there would be an INFINITE number of them. The same would be true of proto-life. Of course that's assuming that the universe IS never ending, but even in the known universe there is probably at LEAST one rock that you couldn't tell apart from yours, probably more. That might not be true of proto-life, although it isn't unlikely that there is some human-like creature out there.

It does end.

 

[Perfection]

I believe that life will appear spontaneously if the conditions are not that harsh. That is, life would be common in universe.

Why do you believe that?

That isn't really true. We don't know how large the universe is, but lets just say for an example that it never ends. If that was true, then not only would there be at least ONE rock that had the exact same features as your rock, there would be an INFINITE number of them. The same would be true of proto-life.

We do in fact have a good estimate of the size of the observable universe (about 100 billion light years in diameter). While time and space presumably continue beyond that point we cannot ever see or interact with it (barring FTL, which I assume impossible). The entirety of space and time here in the observable universe and beyond the observable universe are sometimes referred to as "the universe" and that might well be infinite [with infinite rocks like mine, extraterrestrial civilizations, and Fiftys]. The observable universe is also often referred to as "the universe", which leads to some ambiguity in meaning one says "the universe". You can generally assume that when I say, "the universe" I mean the observable universe.

Thus my calculations are in regards to the observable universe.

Of course that's assuming that the universe IS never ending, but even in the known universe there is probably at LEAST one rock that you couldn't tell apart from yours, probably more.

My calculation definitely disproves that. I say we can reasonably presume that my rock has a less than 10^-100 chance of coming from any given rock. Given that there's only about 3*10^80 cubic meters of volume in the universe, and that my rock's volume is certainly larger then about 10^-19 cubic meters (you couldn't fit a 10 quadrillion rocks like mine into a cubic meter) then even if the entire universe was completely filled with rocks, it is extremely probable that no rock would look exactly like mine.

That might not be true of proto-life, although it isn't unlikely that there is some human-like creature out there.

How do you know it isn't unlikely?

 

[kill fire]

How do you know it isn't unlikely?

well hell if you look at it from a different point of view, how do you know all of your calculations are correct?

 

[Perfection]

well hell if you look at it from a different point of view, how do you know all of your calculations are correct?

Well, my rock calculations are a toy model that are more meant to illustrate a point then to be absolutely correct.

I do think it's a reasonable argument (which I've outlined in previous posts) that my rock is alone in the universe. I can find thousands of unique features on my rock, if only 100 (actually, ~50 would probably do) of them vary with 10 or more equiprobable gradations and are roughly independent, then my calculations must be true.

But in the end, if my rock calculation is incorrect, that doesn't mean that isn't unlikely that a human-like creatures exist. And if you think it isn't unlikely, you should still have a reason! And since you've indicated to me that you do think it isn't unlikely, I don't think it's unreasonable for me to ask why! So how do you know it isn't unlikely?

 

[exhile]

The question is to vague and broad to answer....