Extraterrestrials: Hope or Threat

[uk 75]

With all the talk of life on new planets and comets from outside the Solar System I thought it would be fun to debate which of the Hollywood tropes for alien visitors is most likely: ET, Independence Day, The Day the Earth , or Alien.
As a rider is it true that one of the first TV images from our planet heading out into space is Hitler?

 

[steelpillow]

Surprised not to see 2001 or Close Encounters in your list. Here are some more: https://m.imdb.com/poll/tcm4PjcSGNs/

Assuming sublight space travel within the known laws of physics, the aliens will be vulnerable colonists. They would be so accustomed to life in space that they would be put off by the prospect of having to live and work in a badly-matched planetary environment already exhausted by its inhabitants and then climb back out of our planet's gravity well. So they'd settle on Phobos or Deimos as the small moons closest to the sun, mine the odd resource-rich asteroid as well and rebuild their energy supplies. Only when they felt secure or could no longer hide would they make friends, chat with us and swap a few token visits by individuals. Maybe a little low-volume hi-tech trade, but a design data file is a lot easier to send.

Assuming the laws of physics are more amenable, then they have unimaginable technologies, have most probably been around a long time already, and have proved to have more important things on their minds than our scrotty little backwater down the bottom of its well. Only if that super-civilisation is still working its way across the galaxy and gets here tomorrow, might we conceivably need to worry. Macho interference in a bunch of stoneage well-dwellers will not be high on their agenda, most likely they will have engineered their bodies to live robustly in a range of environments, and mobility will be more important to them than settling in one place. But there is a technical possibility they might find Earth, as a "Goldilocks zone" planet, the easiest to terraform their way and create an ideal home from home, in which case we will have no say in what they do to our planet or to us. Maybe leave us a few colonies in biodomes, maybe not. Or we might even be delicious. Think how well that has served the chicken population.

 

[Orionblamblam]

With all the talk of life on new planets and comets from outside the Solar System I thought it would be fun to debate which of the Hollywood tropes for alien visitors is most likely: ET, Independence Day, The Day the Earth , or Alien.

The Andromeda Strain.

.

As a rider is it true that one of the first TV images from our planet heading out into space is Hitler?

Yes. However: the likelihood of ET picking up the '36 Olympics is next to nil. The power of those broadcasts was real low, and the signal would have dropped *far* below the background noise level long before getting even to Proxima Centauri. IIRC, the theoretical limit for detection of even modern TV signals is something like a lightyear, maybe two.

DEW line radars, however, could be picked up meaningful distances away. There's no message in them, however.

 

[Hobbes]

There's no message in them, however.

Yes there is: it's a non-random signal (regular pulses), making it unlikely this signal was of natural origin.

 

[Hood]

Or the trope that Hollywood wouldn't ever film because its the most likely but too boring, alien life that's as advanced as the average bovine creature.
A herd of space cows just sit in a field, munching grass, been munching for 20 million years, likely to go on munching another 20 million years.

No doubt there is intelligent life out there, but we shouldn't get our hopes up they are all budding Marconis or Einsteins. There are millions of species (and millions more than never made it to today) of intelligent lifeforms on earth (which I would define as having powers of communication, capable of social living, dwelling-constructing) and some of them have been around for millions of years but only Homo Sapiens has become intelligent enough to harness nature and physics to a fuller extent. Reptiles and their avian descendants have colonised the earth for 243 million years yet not one of them has evolved intelligence enough to even start metalwork let alone build a spaceship. An alien landing on an Earth without humans would find a lot to see and investigate but they wouldn't have many meaningful conversations.
Even in the human epoch, we've been making radios 120 years, flying for 110, spacefearing for 60, if it comes to that we've only been working metal for 5,000 years out of 350,000.
Mathematically given the billions of stars and countless billions of planets there must several alien lifeforms as intelligent as humans but even that doesn't mean they are Imperial Destroyer driving maniacs. And conversely if life is as diverse as that on earth, there are countless billions of other species of alien life ranging from single-cell organisms to complex lifeforms that are intelligent in their own way but certainly not capable of technological development.

 

[Tony Williams]

My take on where all the aliens are (based on a book review): http://quarryhs.co.uk/Fermi.htm

 

[Foo Fighter]

There is every reason (Considering the number of potential planetary sources) that are are a great many intelligent life forms out there. Why limit them to being AS INTELIGENT AS US, as some think might be possible strikes me as hubris. Why should there not be species much more intelligent than us now? OK, I'm a Trekkie so you can argue "I would say that" but I look at the massive amounts of data we are still getting every day and the number of constellations out there for me, suggests there MUST be much more than just us as a peak of intelligence. TBH, it frightens me that we can be seen as the dwellers of top branch of any developmental tree. There are people on this planet that say ANY other inteligent species must have completely different appearance. <y take is that development of opposable digits makes tool use more likely etc et al, why should there not be more similarities than differences? I just hope that there are many inteligent life forms out there and some of them are amenable cooperation and civilised discourse/trade etc too. I shall get off my soap box now.

 

[steelpillow]

Yes, given a species as far ahead of us as we are of the flatworm, their only interest in us would be zoological and, just as our naturalists have learned not to disturb our natural environment by building hides and developing sophisticated sensors and so on, how much of even the most intensive zoological study would we ever be aware of? Let's just hope they don't slate us for a new hyperspatial bypass.

 

[Fluff]

Firstly, I dont want to follow the chicken, as an evolutionary example. And whilst it worked for Chickens, it didn't work for a chicken.

Back to the aliens, well they may have been brought up correctly, that the only right way to live is to have 3 heads, eat coal and marry your cousin.

As, except for those that did marry their cousin, this means we are all wrong, that they have to genetically manipulate us(for free, as its religion) so I expect their agents will make people disappear, then re-appear with more heads. So we need to look for people with 3 heads, to see how close we are to that point.

 

[galgot]

If there are as advanced life forms (or intelligent, but defining intelligence is difficult) than us , then most likely they can’t travel to us, then they aren’t a threat.

If they are able to reach us, then that means they are very very much more advanced than us anyway, given we are very far from finding a way to reach other worlds.
So in that case , in what way would they be a threat ?
- they would need our resources ? doubtful, if they can travel that far, then they have access the immense resources available in the universe already. I doubt colonizing Earth would give them much more than they could find on other inhabited worlds where they wouldn’t have to deal with us.
- By accident ? possible.

 

[Fluff]

So advanced they only ship their brains, and decide they would like a 'break' of 50 years or so, on a good old fashioned planet, but need a biological transport unit = your body......

 

[galgot]

My body as a transport unit, bad deal for them then

If an advanced and conscious life form manage to travel such distances, its so advanced that I doubt it would need a human body.

 

[bobbymike]

For those who think “Because there might be trillions upon trillions of earth like planets in the entire universe there must be other human type civilizations will ultimately be disappointed by the actual probabilities involved.

There is a computer/statistics professor IIRC (I will try and find the link) who calculated using the most optimistic assessment of possible “liveable” worlds in the universe of something like 10 to the 30th power then took his own work of the probability of chemicals self assembling into “life” even simple reproducing proteins of 10 to the 400th (I may not have the numbers correct but they are as far apart numerically as I’ve illustrated)

He concluded life is so improbable as to be near impossible.

We might be alone in the universe BUT MORE importantly we should act like it and do everything to expand humanity beyond earth cause we might be the most important thing in it.

 

[galgot]

Interesting :
"What I don't know, and I don't know if anybody DOES know, is whether it's possible to have life based on chemicals other than proteins and nucleic acids. Basically, what you need are fairly complex molecules that can combine into more complicated structures, and you need those structures to be able to copy themselves reliably, but still allow for the occasional mistake (i.e., a mutation) so that evolution can happen. Is it possible? That's the sort of question you can't really answer with "no", because there are just about an infinite number of ways of combining various atoms into molecules and compounds, and we can't possible check them all. Now, if you actually found a life form based on something else, then you could definitely say "yes", but you really can't definitely say "no"."

from here :

Life in the Universe

 

[Fluff]

well for some reason the Star Trek crew mostly encountered humanoid species.

The Organian's are made of pure energy, so that's a yes from me.

And.... Tin foil reflects energy, so they will die by their own energy beam weapons....

 

[Orionblamblam]

There is a computer/statistics professor IIRC (I will try and find the link) who calculated using the most optimistic assessment of possible “liveable” worlds in the universe of something like 10 to the 30th power then took his own work of the probability of chemicals self assembling into “life” even simple reproducing proteins of 10 to the 400th (I may not have the numbers correct but they are as far apart numerically as I’ve illustrated)

He concluded life is so improbable as to be near impossible.

NOTE: These "probabilities" of life being vastly improbable to the point of "ten to the power of something very large" are not products of biologists, but creationists, part of their propaganda campaign. Be hesitant to rely on the math of someone who desperately *wants* there to be no other naturally occuring life in a universe with an observable diameter of some ninety billion light years.

Another way to think of it: think of a standard deck of cards. Fifty-two unique cards, each with a "value." For simplicity, assume each card is labeled "1" and "2" and so on up to "52." Imagine an order, any order you like. 1 to 52 in numerical order, say, or 52 to 1 backwards, whatever you like.

Shuffle them good and random, then lay them out one after the other in a line. What are the chances of the cards laying out in the order you pre-selected? About 1 in 8 to the power of 67. This is about as close to "impossible" as you're likely to get. And still... the order that the cards *did* lay out is every bit as "impossible." Shuffle them again, lay them out again... lo and behold, yet another "impossible" string of cards.

The point: the fact that the cards didn't lay out the way *you* wanted doesn't mean that they didn't lay out *at* *all.* The probability that proteins would meet up and doa little dance resulting in *you*? Vanishingly small. But so what. *You,* or Michael Behe, or Jerry Falwell, or Stephen Hawking, or Carl Sagan, or me, or Klaus Starr or Humperdoo... ain't none of us the end-goal of the universe.


Additionally: the creationist math is based on flawed logic, long ago debunked. Behold:

As an analogy, consider the 13-letter sequence “TOBEORNOTTOBE.” A million hypothetical monkeys, each typing out one phrase a second on a keyboard, could take as long as 78,800 years to find it among the 2613 sequences of that length. But in the 1980s Richard Hardison, then at Glendale College, wrote a computer program that generated phrases randomly while preserving the positions of individual letters that happened to be correctly placed (in effect, selecting for phrases more like Hamlet's). On average, the program re-created the phrase in just 336 iterations, less than 90 seconds. Even more amazing, it could reconstruct Shakespeare's entire play in just four and a half days.

When it comes to even as simple a biological process as pre-living protein evolution, natural selection pressures do wonders to speed the process. Each step that actually works is preserved, and the next step builds on that. Just like the evolution of the eye, it doesn't require that the *complete* system fall into place all at once. A partial system is perfectly fine.

 

[edwest4]

Just because supposed aliens have faster than light drives doesn't make them smarter than us. The Wright brothers made their first powerted flight in 1903 and the first atom bomb is detonated in 1945. You can have advanced technology and be relatively stupid at the same time. I view any aliens as not more intelligent, just as having faster than light drives. The "impossible" just takes a little longer.

 

[steelpillow]

What I don't know, and I don't know if anybody DOES know, is whether it's possible to have life based on chemicals other than proteins and nucleic acids.

We need to be clear what we mean by "life". The day is looming closer when an AI wakes up and experiences a stream of consciousness. According to Integrated Information Theory, "consciousness is what information feels like when it reaches a certain level of complexity." Is a conscious robot with a silicon brain "life" in this context or not? Especially if it is able to create evolved clones of itself and they have outlived their creators. Are being manufactured and being alive mutually exclusive? What if such a silicon brain somehow evolved naturally in a rock structure somewhere, would that make it "life"? Or, what if we manufactured it from organic molecules, and android aka simulant?
I have also met serious academics who believe that no artificial machine can ever be conscious, but they have never been able to back that up with any testable scientific argument. Conversely, if a machine passes the most sophisticated series of Turing tests we can devise, science must regard that as how it defines consciousness and say that the machine is conscious.

 

[Fluff]

Just because supposed aliens have faster than light drives doesn't make them smarter than us. The Wright brothers made their first powerted flight in 1903 and the first atom bomb is detonated in 1945. You can have advanced technology and be relatively stupid at the same time. I view any aliens as not more intelligent, just as having faster than light drives. The "impossible" just takes a little longer.

Any sufficiently advanced technology is indistinguishable from magic - Arthur C Clarke

 

[edwest4]

Mr. Clarke is being quoted out of context. It would be magic to primitive people but not magic to those who follow and understand such developments.

 

[Fluff]

Mr. Clarke is being quoted out of context. It would be magic to primitive people but not magic to those who follow and understand such developments.

He didn't say you would call it magic. Easy enough to say there must be a scientific theory that we don't as yet comprehend. He said it will be indistinguishable - not the same as' you will call it magic.'

Lets try this.

We all go to bed tonight, we wake up in a different solar system, with 5 moons around earth.

Option 1 - Magic
Option 2 - scientific theory that we don't as yet comprehend

Whats the difference? Thats what he is saying.

 

[bobbymike]

There is a computer/statistics professor IIRC (I will try and find the link) who calculated using the most optimistic assessment of possible “liveable” worlds in the universe of something like 10 to the 30th power then took his own work of the probability of chemicals self assembling into “life” even simple reproducing proteins of 10 to the 400th (I may not have the numbers correct but they are as far apart numerically as I’ve illustrated)

He concluded life is so improbable as to be near impossible.

NOTE: These "probabilities" of life being vastly improbable to the point of "ten to the power of something very large" are not products of biologists, but creationists, part of their propaganda campaign. Be hesitant to rely on the math of someone who desperately *wants* there to be no other naturally occuring life in a universe with an observable diameter of some ninety billion light years.

Another way to think of it: think of a standard deck of cards. Fifty-two unique cards, each with a "value." For simplicity, assume each card is labeled "1" and "2" and so on up to "52." Imagine an order, any order you like. 1 to 52 in numerical order, say, or 52 to 1 backwards, whatever you like.

Shuffle them good and random, then lay them out one after the other in a line. What are the chances of the cards laying out in the order you pre-selected? About 1 in 8 to the power of 67. This is about as close to "impossible" as you're likely to get. And still... the order that the cards *did* lay out is every bit as "impossible." Shuffle them again, lay them out again... lo and behold, yet another "impossible" string of cards.

The point: the fact that the cards didn't lay out the way *you* wanted doesn't mean that they didn't lay out *at* *all.* The probability that proteins would meet up and doa little dance resulting in *you*? Vanishingly small. But so what. *You,* or Michael Behe, or Jerry Falwell, or Stephen Hawking, or Carl Sagan, or me, or Klaus Starr or Humperdoo... ain't none of us the end-goal of the universe.


Additionally: the creationist math is based on flawed logic, long ago debunked. Behold:

As an analogy, consider the 13-letter sequence “TOBEORNOTTOBE.” A million hypothetical monkeys, each typing out one phrase a second on a keyboard, could take as long as 78,800 years to find it among the 2613 sequences of that length. But in the 1980s Richard Hardison, then at Glendale College, wrote a computer program that generated phrases randomly while preserving the positions of individual letters that happened to be correctly placed (in effect, selecting for phrases more like Hamlet's). On average, the program re-created the phrase in just 336 iterations, less than 90 seconds. Even more amazing, it could reconstruct Shakespeare's entire play in just four and a half days.

When it comes to even as simple a biological process as pre-living protein evolution, natural selection pressures do wonders to speed the process. Each step that actually works is preserved, and the next step builds on that. Just like the evolution of the eye, it doesn't require that the *complete* system fall into place all at once. A partial system is perfectly fine.

You might have just proven my point. The probability is so small yet could happen. Yes it did, us.

But my second point is more relevant. We should act like we are alone and expand to other celestial outposts as soon as possible

 

[Archibald]

Last year I discovered Iain Banks Culture cycle and my mind was blown. I don't say it is perfect, but it is one hell of a refreshing take on the E.T mythos.

A Few Notes on the Culture, by Iain M Banks

If E.T have reached Culture level, then we are barbarians in comparison.

The state of the art > http://library.uniteddiversity.coop.../Iain M. Banks - The State of the Art v1.html

 

[Archibald]

What is very cool those days is that 2/3 of the closest stars less than 10 light years away and with familiar names (Tau Ceti ! Alpha Centauri ! Barnard Star ! Wolf 359 ! Epsilon Eridani !) have been proven to have exoplanets circling them. Pretty cool when one think about it.
What's more, statistics says that a very large percentage of the Milky Way stars (billion of thems) might have exoplanets.

Kepler, how we miss you. Hopefully someday a SpaceX starship will bring it back to Earth - that thing belongs to a museum.

 

[Tony Williams]

There is a computer/statistics professor IIRC (I will try and find the link) who calculated using the most optimistic assessment of possible “liveable” worlds in the universe of something like 10 to the 30th power then took his own work of the probability of chemicals self assembling into “life” even simple reproducing proteins of 10 to the 400th (I may not have the numbers correct but they are as far apart numerically as I’ve illustrated)

He concluded life is so improbable as to be near impossible.

NOTE: These "probabilities" of life being vastly improbable to the point of "ten to the power of something very large" are not products of biologists, but creationists, part of their propaganda campaign. Be hesitant to rely on the math of someone who desperately *wants* there to be no other naturally occuring life in a universe with an observable diameter of some ninety billion light years.

As described in the article I linked to above: Where is Everybody? Fifty solutions to the Fermi Paradox

An extract:

The Fermi paradox is named after the mid-twentieth century physicist who posed a simple question: calculations based on reasonable estimates indicate that this galaxy should host a large number of extraterrestrial civilisations capable of interstellar communication or travel (which Webb shortens to ETCs), yet we have so far been unable to find any evidence for the existence of even one such civilisation. So where are they all?

The astronomer Drake later quantified the calculation like this: the number of ETCs in the galaxy (N) is determined by the rate at which stars form (R), the fraction of stars with planets (fp), the number of those planets with an environment suitable for life (ne), the fraction of those planets on which life actually develops (f1), the fraction of those which produce intelligent life (fi), the fraction of those which develop a civilisation capable of interstellar communications (fc), and finally the number of years that such a culture will devote to communication (L). The "Drake equation" therefore reads N=(R)x(fp)x(ne)x(f1)x(fi)x(fc)x(L). This looks impressively authoritative, but a moment's thought reveals that we have no means of knowing most of the factors, so figures which we enter for them are little better than guesswork. And the calculated number of ETCs will vary greatly depending on the particular guesses we make. Another point is that should any of the factors be zero, then the outcome will also be zero. Despite this, calculations of star formation rates for this galaxy result in N being a very large number even with pessimistic assumptions being made about the other factors. In other words, this galaxy should have been swarming with ETCs for millions of years, which we could hardly have failed to notice.

And my conclusion:

As a result of studying Webb's arguments, I am more pessimistic than I used to be about the chances of other ETCs developing. However, given that there are calculated to be 100 billion stars in our galaxy (that's 100,000,000,000), even if our planet was literally "one in a million" in producing a technological civilisation, that still works out as 100,000 ETCs. So where are they? The answer I favour is "not here now". Two different timescales need to be borne in mind: the age of the galaxy, and the probable lifespan of an ETC. Our own star is around 4.5 billion years old, compared with the average for our galaxy of 6.5 billion years (the oldest star being over 13 billion). So if we assume that it takes 4.5 billion years after star formation to produce a technological civilisation (the only example we've got), that means that other stars average a two billion year advantage over us – lots of time to produce a huge range of ETCs. But how long can these ETCs be expected to last?

Just consider our situation again. We achieved the theoretical capability to communicate with other star systems only within the last century. Only half a century after that, we came dangerously close to wiping out our civilisation in a global thermonuclear war. Many scientists fear that over the next century or two we will have devastated our global environment to such a degree that our civilisation will collapse, giving us only a few centuries of possessing advanced technology. By definition, any civilisation with the technology capable of communicating with ETCs will develop the potential to destroy itself, one way or another. So perhaps ETCs just don't last very long. Suppose that the average is 1,000 years; multiply that by the nominal 100,000 ETCs mentioned above, and you get a total of 100 million "ETC years". Compare that with the 2 billion year average time advantage the galaxy's stars have over our sun, and you will see that an ETC will have been in existence for only about five percent of the last two billion years. So at any given moment there may be only a one-in-twenty chance of a single ETC existing anywhere in this galaxy. And no ETC would have the time to spread very far even if it wanted to; possibly none would ever manage to establish itself on another star system.

This is, of course, speculation built on speculation, but with a grand total to date of just one known example of a life-bearing planet to go on, that is bound to be the case. My vision is this: imagine if a camera could have been sited over our galaxy, filming continuously for the last few billion years, and recording each ETC as a bright flash. Then replay the film in quick time. I think we would see a huge number of ETCs sparkling all over the galaxy, from two billion years ago to the present. But slow the film down, and we may see only one flash at a time, with long pauses between them. Occasionally we might see two or more flashes occurring simultaneously, but on average they would be so far apart that communication between them would be highly improbable.

 

[Fluff]

'He concluded life is so improbable as to be near impossible. ;

But he's wrong...….

 

[bobbymike]

'He concluded life is so improbable as to be near impossible. ;

But he's wrong...….

That’s a powerful counter argument

 

[edwest4]

The question cannot be answered with any level of certainty, including saying the possibility is some fraction above 50%.

 

[galgot]

There is a computer/statistics professor IIRC (I will try and find the link) who calculated using the most optimistic assessment of possible “liveable” worlds in the universe of something like 10 to the 30th power then took his own work of the probability of chemicals self assembling into “life” even simple reproducing proteins of 10 to the 400th (I may not have the numbers correct but they are as far apart numerically as I’ve illustrated)

He concluded life is so improbable as to be near impossible.

NOTE: These "probabilities" of life being vastly improbable to the point of "ten to the power of something very large" are not products of biologists, but creationists, part of their propaganda campaign. Be hesitant to rely on the math of someone who desperately *wants* there to be no other naturally occuring life in a universe with an observable diameter of some ninety billion light years.

As described in the article I linked to above: Where is Everybody? Fifty solutions to the Fermi Paradox

An extract:

The Fermi paradox is named after the mid-twentieth century physicist who posed a simple question: calculations based on reasonable estimates indicate that this galaxy should host a large number of extraterrestrial civilisations capable of interstellar communication or travel (which Webb shortens to ETCs), yet we have so far been unable to find any evidence for the existence of even one such civilisation. So where are they all?

The astronomer Drake later quantified the calculation like this: the number of ETCs in the galaxy (N) is determined by the rate at which stars form (R), the fraction of stars with planets (fp), the number of those planets with an environment suitable for life (ne), the fraction of those planets on which life actually develops (f1), the fraction of those which produce intelligent life (fi), the fraction of those which develop a civilisation capable of interstellar communications (fc), and finally the number of years that such a culture will devote to communication (L). The "Drake equation" therefore reads N=(R)x(fp)x(ne)x(f1)x(fi)x(fc)x(L). This looks impressively authoritative, but a moment's thought reveals that we have no means of knowing most of the factors, so figures which we enter for them are little better than guesswork. And the calculated number of ETCs will vary greatly depending on the particular guesses we make. Another point is that should any of the factors be zero, then the outcome will also be zero. Despite this, calculations of star formation rates for this galaxy result in N being a very large number even with pessimistic assumptions being made about the other factors. In other words, this galaxy should have been swarming with ETCs for millions of years, which we could hardly have failed to notice.

And my conclusion:

As a result of studying Webb's arguments, I am more pessimistic than I used to be about the chances of other ETCs developing. However, given that there are calculated to be 100 billion stars in our galaxy (that's 100,000,000,000), even if our planet was literally "one in a million" in producing a technological civilisation, that still works out as 100,000 ETCs. So where are they? The answer I favour is "not here now". Two different timescales need to be borne in mind: the age of the galaxy, and the probable lifespan of an ETC. Our own star is around 4.5 billion years old, compared with the average for our galaxy of 6.5 billion years (the oldest star being over 13 billion). So if we assume that it takes 4.5 billion years after star formation to produce a technological civilisation (the only example we've got), that means that other stars average a two billion year advantage over us – lots of time to produce a huge range of ETCs. But how long can these ETCs be expected to last?

Just consider our situation again. We achieved the theoretical capability to communicate with other star systems only within the last century. Only half a century after that, we came dangerously close to wiping out our civilisation in a global thermonuclear war. Many scientists fear that over the next century or two we will have devastated our global environment to such a degree that our civilisation will collapse, giving us only a few centuries of possessing advanced technology. By definition, any civilisation with the technology capable of communicating with ETCs will develop the potential to destroy itself, one way or another. So perhaps ETCs just don't last very long. Suppose that the average is 1,000 years; multiply that by the nominal 100,000 ETCs mentioned above, and you get a total of 100 million "ETC years". Compare that with the 2 billion year average time advantage the galaxy's stars have over our sun, and you will see that an ETC will have been in existence for only about five percent of the last two billion years. So at any given moment there may be only a one-in-twenty chance of a single ETC existing anywhere in this galaxy. And no ETC would have the time to spread very far even if it wanted to; possibly none would ever manage to establish itself on another star system.

This is, of course, speculation built on speculation, but with a grand total to date of just one known example of a life-bearing planet to go on, that is bound to be the case. My vision is this: imagine if a camera could have been sited over our galaxy, filming continuously for the last few billion years, and recording each ETC as a bright flash. Then replay the film in quick time. I think we would see a huge number of ETCs sparkling all over the galaxy, from two billion years ago to the present. But slow the film down, and we may see only one flash at a time, with long pauses between them. Occasionally we might see two or more flashes occurring simultaneously, but on average they would be so far apart that communication between them would be highly improbable.

Yes. Also remember reading something like that :
That if we take that a ETC need an earth like planet to exist, the time it takes to reach the tech level to reach to another world , it has already "burned" all his planet energy and life resources.
We are very much on this way...

 

[Fluff]

if we were saying there is and will never be, its a valid argument, the fact that there is, suggests there has been, is or will be.

I don't know who would be saying there will never be, but that's not the discussion point.....

So your in the worlds biggest cinema, its empty, except you and your friend, who is going to meet you there. How do you find them......

 

[Rickshaw]

Personally, I wonder why people worry about the existence of Alien lifeforms which are either inimical or benign. I believe Alien lifeforms will be Alien and incomprehensible to us in their intent. We would be like the Australian Indigenous people who first encountered Europeans in 1776 CE, sailing along the east coast of Australia. Their ships looked amazing and incomprehensible. What they did was incomprehensible. Alien lifeforms will be similar.

 

[TomS]

Personally, I wonder why people worry about the existence of Alien lifeforms which are either inimical or benign. I believe Alien lifeforms will be Alien and incomprehensible to us in their intent. We would be like the Australian Indigenous people who first encountered Europeans in 1776 CE, sailing along the east coast of Australia. Their ships looked amazing and incomprehensible. What they did was incomprehensible. Alien lifeforms will be similar.

From the Indigenous Australian perspective, wouldn't you say the European "aliens" turned out to be pretty inimical and destructive?

I'd guess that an encounter with a technologically superior alien species is likely to have a similarly disruptive effect on human society, even if they aren't intentionally hostile.

 

[edwest4]

There is no way to know. The US government has prepared the best it can for such a possibility, but, for now, it exists only in science fiction stories.

 

[TomS]

There is no way to know. The US government has prepared the best it can for such a possibility, but, for now, it exists only in science fiction stories.

I doubt the US government (or any other government) has seriously thought about such contact, much less prepared for the socio-techno-economic impacts. First contact is pretty much the definition of an "outside of context"* event. It's almost impossible to imagine in advance how society after such an event would unfold.

* A term derived, as you say, from a science fiction story.

 

[Rickshaw]

Personally, I wonder why people worry about the existence of Alien lifeforms which are either inimical or benign. I believe Alien lifeforms will be Alien and incomprehensible to us in their intent. We would be like the Australian Indigenous people who first encountered Europeans in 1776 CE, sailing along the east coast of Australia. Their ships looked amazing and incomprehensible. What they did was incomprehensible. Alien lifeforms will be similar.

From the Indigenous Australian perspective, wouldn't you say the European "aliens" turned out to be pretty inimical and destructive?

Only after the First Fleet arrived in 1788 CE. Until then, the English had arrived, done incomprehensible things and then left. When the First Fleet - second contact in effect - then things became clearer. The First Fleet brought colonists.

I'd guess that an encounter with a technologically superior alien species is likely to have a similarly disruptive effect on human society, even if they aren't intentionally hostile.

No, second or third contact will do that. First contact would be incomprehensible to us in all likelihood.

 

[Arjen]

A computer/statistics education is not the best of starting points to make an educated guess at the likelihood of life emerging anywhere. The boffins at the biochemistry faculty have a better grasp of the processes involved. Even they would turn to astrophysicists for the finesses of world formation. I wonder whether this computer/statistics fellow took into account the consequences of deep time? Billions of years do strange things to the chances of unlikely things happening anyway.

 

[Tony Williams]

If you want to get a view of what an alien might look like, look at an octopus. Completely different structure and morphology from vertebrates, multiple brains, and surprisingly smart, especially considering that they don't live long.

 

[steelpillow]

If you want to get a view of what an alien might look like, look at an octopus. Completely different structure and morphology from vertebrates, multiple brains, and surprisingly smart, especially considering that they don't live long.

Saw a lovely documentary the other week. A scientist and his daughter kept a pet octopus in their living room for a couple of years. When they put the TV on it would plaster itself against that side of the tank and bug its eyes out so it could watch. If it wanted the daughter's attention it would goosh her up the armpit.
The thinking cortex of its brain is structured very similarly to ours despite our last common ancestor being a simple flatworm and the neuron physiology being very different. Brilliant example of where convergent evolution does and does not happen.

 

[Fluff]

Personally, I wonder why people worry about the existence of Alien lifeforms which are either inimical or benign. I believe Alien lifeforms will be Alien and incomprehensible to us in their intent. We would be like the Australian Indigenous people who first encountered Europeans in 1776 CE, sailing along the east coast of Australia. Their ships looked amazing and incomprehensible. What they did was incomprehensible. Alien lifeforms will be similar.

From the Indigenous Australian perspective, wouldn't you say the European "aliens" turned out to be pretty inimical and destructive?

I'd guess that an encounter with a technologically superior alien species is likely to have a similarly disruptive effect on human society, even if they aren't intentionally hostile.

I have no intent when I accidentally stand on an ant hill, but from their perspective its pretty incomprehensible. Accidents happen, we just don't want Earth to be a part of a minor border skirmish....or a Hyperspace bypass...

 

[Orionblamblam]

I'd guess that an encounter with a technologically superior alien species is likely to have a similarly disruptive effect on human society, even if they aren't intentionally hostile.

I have no intent when I accidentally stand on an ant hill, but from their perspective its pretty incomprehensible. Accidents happen, we just don't want Earth to be a part of a minor border skirmish....or a Hyperspace bypass...

As is often the case, the path was blazed in this line of thinking quite a long time ago. In this particualr instance, H.P. Lovecraft's cosmic indifferentism pretty much covers it:

Though cosmicism appears deeply pessimistic, H.P. Lovecraft thought of himself as neither a pessimist nor an optimist but rather a "scientific" or "cosmic" indifferentist,[15] a theme expressed in his fiction. In Lovecraft's work, human beings are often subject to powerful beings and other cosmic forces, but these forces are not so much malevolent as they are indifferent toward humanity.[16] This indifference is an important theme in cosmicism. The noted Lovecraft scholar S. T. Joshi asserts that "Lovecraft constantly engaged in (more or less) genial debates on religion with several colleagues, notably the pious writer and teacher Maurice W. Moe. Lovecraft was a strong and antireligious atheist; he considered religion not merely false but dangerous to social and political progress."[17] As such, Lovecraft's cosmicism is not religious at all, but rather a version of his mechanistic materialism. Lovecraft thus embraced a philosophy of cosmic indifferentism. He believed in a meaningless, mechanical, and uncaring universe that human beings, with their naturally limited faculties, could never fully understand. His viewpoint made no allowance for religious beliefs which could not be supported scientifically. The incomprehensible, cosmic forces of his tales have as little regard for humanity as humans have for insects.[18]

Though personally irreligious, Lovecraft used various "gods" in his stories, particularly the Cthulhu-related tales, to expound cosmicism. However, Lovecraft never conceived of them as supernatural, but extraterrestrials who understand and obey a set of natural laws which to human understanding seem magical. These beings (the Great Old Ones, Outer Gods and others) — though dangerous to humankind — are portrayed as neither good nor evil, and human notions of morality have no significance for these beings. Indeed, they exist in cosmic realms beyond human understanding. As a symbol, this is representative of the kind of universe that Lovecraft believed in.[19] Though some of these beings have - and in some cases create - cults to honor them, to the vast majority of these beings the human race is so insignificant that they aren't given any consideration whatsoever.

It would not take an alien intelligence much developent beyond the merely human to become not just contemptuous of us, but functionally oblivious to our existence.

https://en.wikipedia.org/wiki/Cosmicism