If the universe does not contain 'earth like' life

[Kilgore Trout]

You gather wrong. I believe that Myer is arguing, in part, that the evolution of sentience was a remarkable, unpredictable, and far from inevitable happenstance. Or, to quote Stephen Jay Gould:

Of course, the problem with attempting to gauge the probability of something in such a way is that one is assuming (in the case of 17 trillion combinations of 10 out of 100) that only 1 one of those 17 trillion combinations would result in the formation of sentient life. In fact, we have no idea how many different paths and combinations could lead to sentience. In the end, all we have are speculations, so one can only form an opnion on a broad approach and methodology.

For myself, if I'm going to speculate on the question, I prefer to approach it from the basis of observed emergent processes which arise out of our universe. Being that the universe is composed of the same fundamental building blocks and forces, and that we can observe mass repetition of the same physical things arising in the universe, it seems a reasonable conclusion that if we have observed something emerge once in our universe, that there is little reason to think that given enough time and space, that a similar thing would not emerge repeatedly.

Other speculations may have merit, yet they often seem more narrowly defined, and I've yet to encounter any argument which provides a counter to my own speculative view.

 

[Alceste]

You gather wrong. I believe that Myer is arguing, in part, that the evolution of sentience was a remarkable, unpredictable, and far from inevitable happenstance. Or, to quote Stephen Jay Gould:

​

It seems you are debating a point I have not tried to make. I completely agree with Gould, and I'm also quite certain that life is not unique to our planet. Do you imagine there is a conflict between these positions?

 

[Jayhawker Soule]

For myself, if I'm going to speculate on the question, I prefer to approach it from the basis of observed emergent processes which arise out of our universe. Being that the universe is composed of the same fundamental building blocks and forces, and that we can observe mass repetition of the same physical things arising in the universe, it seems a reasonable conclusion that if we have observed something emerge once in our universe, that there is little reason to think that given enough time and space, that a similar thing would not emerge repeatedly.

Agreed. I'm just not at all sure what constitutes "enough time and space."

 

[Jayhawker Soule]

It seems you are debating a point I have not tried to make. I completely agree with Gould, and I'm also quite certain that life is not unique to our planet. Do you imagine there is a conflict between these positions?

None at all.

 

[Alceste]

Agreed. I'm just not at all sure what constitutes "enough time and space."

All the time and space there is. That is surely enough.

 

[Kilgore Trout]

Agreed. I'm just not at all sure what constitutes "enough time and space."

Me neither. However, 13 billion years and 10^22 stars provides scales of time and space beyond our ability to remotely comprehend.

 

[Jayhawker Soule]

All the time and space there is. That is surely enough.

If you say so.

 

[Alceste]

Of course, the problem with attempting to gauge the probability of something in such a way is that one is assuming (in the case of 17 trillion combinations of 10 out of 100) that only 1 one of those 17 trillion combinations would result in the formation of sentient life. In fact, we have no idea how many different paths and combinations could lead to sentience. In the end, all we have are speculations, so one can only form an opnion on a broad approach and methodology.

For myself, if I'm going to speculate on the question, I prefer to approach it from the basis of observed emergent processes which arise out of our universe. Being that the universe is composed of the same fundamental building blocks and forces, and that we can observe mass repetition of the same physical things arising in the universe, it seems a reasonable conclusion that if we have observed something emerge once in our universe, that there is little reason to think that given enough time and space, that a similar thing would not emerge repeatedly.

Other speculations may have merit, yet they often seem more narrowly defined, and I've yet to encounter any argument which provides a counter to my own speculative view.

Nor me. It is a very reasonable view. I rarely see an opposing view that doesn't base it's argument on an unfounded assumption that the phrase "sentient life" implies a diversity of specifically humanoid features and interests.

 

[Sir Doom]

Are you calling me repetitive?

I wouldn't do that twice.

 

[Musty]

How do you feel about the idea that the universe may not contain earth like life?
Universe may not contain

I always just sort of presumed that there is other life out there.

My understanding is that carbon is a particularly good basis for complex chemistry so it seems reasonable that if life does exist in the wider universe carbon based life will be well represented.

In regards to complex life I imagine that for this to evolve there has to be specific set of conditions arising at a particular time for this to happen. This alone is enough to place a limit on how often the evolution of complex life occurs.

 

[WyattDerp]

You gather wrong. I believe that Myer is arguing, in part, that the evolution of sentience was a remarkable, unpredictable, and far from inevitable happenstance. Or, to quote Stephen Jay Gould:

He said that life didn't necessarily have to lead to exactly us and the other species that "made it so far", but nothing about sentience. Most of the ones who didn't get drawn in the lottery were sentient (as Wikipedia says, "Not to be confused with Sapience."...) as well. And even sapience strikes me as rather circular anyway.. We can only "accept" processes of reasoning as such we can follow, but that doesn't mean a fungus doesn't reason "in their own way". Anyway, we know great apes, dolphins and octopodes are rather bright, I'm sure there's many more, and who is to say there weren't sapient species among those who didn't make it in the lottery?

That a lottery is random in itself doesn't make it "remarkable" that the dice came up the exact way they came up. Getting the same result on two consecutive tries, sure. But one try? We have nothing to compare to, and since nobody made a prediction before the dice were rolled, there is nothing exciting here I can see. Is it "remarkable" that "Homo sapiens sapiens" made it, but "Homo sapiens neanderthalensis" did not? Of course Homo sapiens sapiens would say so, but nah..

 

[LegionOnomaMoi]

What I gather from that argument is that biologists feel physicists are not taking account of the time involved.

A key issue with respect to time is the number of ways in which a planet capable of supporting life can be devastated by things like asteroid collisions. Complex life on this planet has been almost entirely wiped out before, and we're extremely lucky. Our position relative to the sun (which is of a rather fortunate size and nature) means we have a shield from cosmic rays. Galactic cosmic rays influence everything from atmospheric make-up to climate change. In fact, a number of studies have indicated that solar magnetic fluctuations can have a substantial effect on global climate. Other changes which may be potentially catastrophic occur thanks to the early development of life itself (in our case, the drastic change in the atmosphere which might have wiped out life turned out to enable far more complex life, as it vastly increased oxygen levels).

Time actually works against the development of complex life, at least for the most part. Not only is there more that can go "wrong" than can go right, but there is no general reason to suppose that the highly successful forms of life found everywhere on Earth would evolve into multicellular life forms which would continue to increase in complexity. The longer the span of time, the more chances for catastrophe caused by external forces (supernovae, comets, cosmic rays, etc.), internal (changes brought about by new life forms, surface and/or atmospheric variations, etc.), and then the simple fact that there isn't any good reason to suppose that microbial life would, over time, imitate the trend which happened on Earth.

I assume Sagan would respond that physicists feel biologists are not taking account of the space involved.

The optimisim tends to be more with physicists than biologists, and with individuals like Sagan in particular:

Intestingly enough, an article intitled "Deities for Atheists" states:

"My analysis of SETI pioneers found that most were once religious but became either atheists or agnostics as adults. Radio astronomer Frank Drake—creator of the canonical “Drake Equation” for estimating the number of ETIs inhabiting the galaxy—was raised Baptist and later reflected: “A strong influence on me, and I think on a lot of SETI people, was the extensive exposure to fundamentalist religion”. Drake has suggested that “immortality may be quite common among extraterrestrials”. Carl Sagan—who did more than anyone to conventionalize SETI—was raised Jewish and became agnostic. He wrote of SETI’s importance, “It touches deeply into myth, folklore, religion, mythology; and every human culture in some way or another has wondered about that type of question”. ETIs are secular gods. Deities for atheists."​

​

 

[Jayhawker Soule]

He said that life didn't necessarily have to lead to exactly us and the other species that "made it so far", but nothing about sentience.

The debate was about SETI ...

 

[WyattDerp]

And that magically makes the quote say something it doesn't say? Nope.

 

[Alceste]

A key issue with respect to time is the number of ways in which a planet capable of supporting life can be devastated by things like asteroid collisions. Complex life on this planet has been almost entirely wiped out before, and we're extremely lucky. Our position relative to the sun (which is of a rather fortunate size and nature) means we have a shield from cosmic rays. Galactic cosmic rays influence everything from atmospheric make-up to climate change. In fact, a number of studies have indicated that solar magnetic fluctuations can have a substantial effect on global climate. Other changes which may be potentially catastrophic occur thanks to the early development of life itself (in our case, the drastic change in the atmosphere which might have wiped out life turned out to enable far more complex life, as it vastly increased oxygen levels).

Time actually works against the development of complex life, at least for the most part. Not only is there more that can go "wrong" than can go right, but there is no general reason to suppose that the highly successful forms of life found everywhere on Earth would evolve into multicellular life forms which would continue to increase in complexity. The longer the span of time, the more chances for catastrophe caused by external forces (supernovae, comets, cosmic rays, etc.), internal (changes brought about by new life forms, surface and/or atmospheric variations, etc.), and then the simple fact that there isn't any good reason to suppose that microbial life would, over time, imitate the trend which happened on Earth.



The optimisim tends to be more with physicists than biologists, and with individuals like Sagan in particular:
[/LEFT]

Physicists are in a unique position to understand the magnitude of the available time and space where emergent life would have a chance to take root. They can estimate how many billions of planets are orbiting stars like our sun, and how many at a similar distance as the earth, and they know how many billions of years we're talking about. Biologists are earth-focused and don't actually know (at least in a professional capacity) what the odds are of there being another life-bearing planet in the universe. Therefore I will side with the physicists in this case. I would be happy to side with biologists in anything that falls into their area of expertise. Projecting the likelihood of life elsewhere in the universe is outside their scope.

There are all kinds of fascinating beliefs surrounding "aliens", but they're not relevant here. We're still talking about life in general, not anthropomorphic little green men whizzing around our solar system, shepherding humanity toward some greater good.

 

[LegionOnomaMoi]

Therefore I will side with the physicists in this case.

They are the ones responsible for the skepticism. Astrobiology, the main field related to SETI, uses biologists mostly as consultants of sorts. Even mathematical physicists are more likely to publish on this issue (and do, in e.g., a 2012 study published in PNAS) than are biologists. It is astrophysicists behind articles like "Alone in the Universe: Despite the growing catalog of extrasolar planets, data so far do not alter estimates that we are effectively on our own"

The above is more for the general reader, but the same author (a Harvard astrophysicist) wrote/presented much the same at the 2011 AAAS conference (AAAS is one of the most respected scientific associations in the world, and they publish, among other things, the journal Science). There, Smith's contribution concluded "The indication from the past decade of research and discovery is this: we are most probably alone B at least there is probably no other intelligent life within one hundred generations reach to talk to. No wonder there are no signals, nor even faint traces, despite decades of looking. As Enrico Fermi argued, they are not there"

I would be happy to side with biologists in anything that falls into their area of expertise. Projecting the likelihood of life elsewhere in the universe is outside their scope.

Astrobiology, what SETI has pretty much become, is dominated by various physicists and cosmologists. It is they who have changed the view, as biologists aren't typically concerned with life anywhere else, and have been used mainly to consult.

Not that the consensus among physicists is that complex life doesn't exist. Simply that the view guys like Drake and Sagan had and promoted have been replaced by new research and the establishment of an interdisciplinary field devoted to habitable zones, the origins of life, life in the universe, etc. And the view within that field (astrobiology) is considerably less confident than the original SETI guys were. A fair number echo the sentiments quoted above.

 

[Jayhawker Soule]

And that magically makes the quote say something it doesn't say? Nope.

Sometimes - in fact, often - context informs content.
Have a great day ...

 

[WyattDerp]

Sometimes - in fact, often - context informs content.

Yeah, sometimes. If you would like to claim that is the case in this instance, feel free to actually point that out, instead of just stating it's theoretically possible. Cheers.

 

[paarsurrey]

If the universe does not contain 'earth like' life ; I think life here will continue as usual.

 

[Alceste]

They are the ones responsible for the skepticism. Astrobiology, the main field related to SETI, uses biologists mostly as consultants of sorts. Even mathematical physicists are more likely to publish on this issue (and do, in e.g., a 2012 study published in PNAS) than are biologists. It is astrophysicists behind articles like "Alone in the Universe: Despite the growing catalog of extrasolar planets, data so far do not alter estimates that we are effectively on our own"

The above is more for the general reader, but the same author (a Harvard astrophysicist) wrote/presented much the same at the 2011 AAAS conference (AAAS is one of the most respected scientific associations in the world, and they publish, among other things, the journal Science). There, Smith's contribution concluded "The indication from the past decade of research and discovery is this: we are most probably alone B at least there is probably no other intelligent life within one hundred generations reach to talk to. No wonder there are no signals, nor even faint traces, despite decades of looking. As Enrico Fermi argued, they are not there"

Astrobiology, what SETI has pretty much become, is dominated by various physicists and cosmologists. It is they who have changed the view, as biologists aren't typically concerned with life anywhere else, and have been used mainly to consult.

Not that the consensus among physicists is that complex life doesn't exist. Simply that the view guys like Drake and Sagan had and promoted have been replaced by new research and the establishment of an interdisciplinary field devoted to habitable zones, the origins of life, life in the universe, etc. And the view within that field (astrobiology) is considerably less confident than the original SETI guys were. A fair number echo the sentiments quoted above.

Once again, we're simply talking about complex life, somewhere other than here. Not green men whizzing through our own troposphere in fancy ships and wanting a chat.

I always thought SETI was a doomed project, but that has never caused me to waver in my certainty that the universe is teeming with life.