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Aliens- do they exist?? Poll section  

77 members have voted

  1. 1. Do you think aliens exist?

    • yes
      57
    • no
      5
    • maybe
      15
  2. 2. If aliens do exist, do you think we should fear them or befriend them?

    • lets all just get along..
      16
    • humans can't handle each other, we sure can't handle aliens.
      24
    • depends on the aliens..
      38
  3. 3. If aliens were to arrive on earth tomorrow, how would you react?

    • Run
      2
    • Panic
      14
    • Fight
      4
    • Ask for an alien telescope (they came from space, maybe they have superscopes)
      58


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1 minute ago, saac said:

Correct, the whole point in fact of the hypothesis; it frames the scope of the investigation. To conflate the hypothesis with concluded science is simply incorrect.

Jim

Indeed, and I plead not guilty to this, m'lud!

:icon_mrgreen:lly

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A theory is just a hypothesis that has survived experimental battering long enough to be called a theory. No theory should be written in stone, all may be amended later. Scientific theories together form a model description of our best understanding of the universe, written down in an unambiguous and testable form (hence the prevalence of mathematics).

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I was going to try and say out of this debate, but a major error is being made.

'What is life' is a philosophical question with no right or wrong answer. Ask 'what is a straight line?' - the answer depends on the rules you set (i.e. are you talking euclidean space, on the surface of a sphere or what...?) Similarly the question 'is this alive' can only be answered in the context of how you define life.

The 'seven requirements' are one attempt at a definition of life based on observing lots of living things and deciding what they have in common. They are not not some absolute property of the universe. There may well be complex 'things' that rely on other 'things' to reproduce, and it the 'seven' excludes worker bees from the definition of living beings... unless you treat the entire bee colony as a superorganism. And if you do that you logically have to give at least some credence to Lovelock's Gaia hypothesis; in which case many things we see as non-living are part of that planet-wide superorganism.

Just as Arthur C. Clarke postulated that any technology is indistinguishable from magic, can we assume that any sufficiently advanced self-reproducing technology is indistinguishable from life?

As for alien life, I personally consider it is probably almost inevitable that given a reasonably stable environment with liquid water present and enough time, some form of 'life' will arise.  My view is that the universe has unlimited capacity for life, but that it may still be very sparsely  distributed because of the scarcity of stable host worlds. I have a hunch suitable moons of gas giants will be more abundant than Earth-a-likes. As for intelligent life we may find evidence of, the 'Drake Equation' is no more than a tool for thinking about what the limiting factors may be than actually calculating meaningful odds. Personally I suspect intelligent life is out there, but like Asimov I have no confidence whatsoever that it would be impractical for any alien civilisation to colonise beyond its own star system.

I can offer no evidence to support the last paragraph; those are just my own 'hunches'.

 

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37 minutes ago, Stub Mandrel said:

I was going to try and say out of this debate, but a major error is being made.

'What is life' is a philosophical question with no right or wrong answer. Ask 'what is a straight line?' - the answer depends on the rules you set (i.e. are you talking euclidean space, on the surface of a sphere or what...?) Similarly the question 'is this alive' can only be answered in the context of how you define life.

The 'seven requirements' are one attempt at a definition of life based on observing lots of living things and deciding what they have in common. They are not not some absolute property of the universe. There may well be complex 'things' that rely on other 'things' to reproduce, and it the 'seven' excludes worker bees from the definition of living beings... unless you treat the entire bee colony as a superorganism. And if you do that you logically have to give at least some credence to Lovelock's Gaia hypothesis; in which case many things we see as non-living are part of that planet-wide superorganism.

Just as Arthur C. Clarke postulated that any technology is indistinguishable from magic, can we assume that any sufficiently advanced self-reproducing technology is indistinguishable from life?

As for alien life, I personally consider it is probably almost inevitable that given a reasonably stable environment with liquid water present and enough time, some form of 'life' will arise.  My view is that the universe has unlimited capacity for life, but that it may still be very sparsely  distributed because of the scarcity of stable host worlds. I have a hunch suitable moons of gas giants will be more abundant than Earth-a-likes. As for intelligent life we may find evidence of, the 'Drake Equation' is no more than a tool for thinking about what the limiting factors may be than actually calculating meaningful odds. Personally I suspect intelligent life is out there, but like Asimov I have no confidence whatsoever that it would be impractical for any alien civilisation to colonise beyond its own star system.

I can offer no evidence to support the last paragraph; those are just my own 'hunches'.

 

Agreed. In asking for a definition of life I meant a definition for the purposes of this discussion. And, as you imply, there might be entirely different beings elsewhere whom we would instinctively want to consider 'alive' without their having to meet the criteria which define life on earth.

It's rather striking that nobody has any difficulty in recognizing life when they see it and yet defining it formally proves tricky. I didn't know about the ambiguity of viruses but there are not many ambiguous cases (are there?) despite the difficulty of defining the word.

Olly

PS What a shame that we no longer have the guidance of our once-resident philosopher, Qualia, on SGL.

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I have a strange feeling that the definition of life might be easier than the definition of intelligence, we do look at it with blinkers on and in our own time frame. I would like to know how super colonies compare  with single organisms or simple life like a forest or the biggest extended life form, fungi.

Alan

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4 hours ago, ollypenrice said:

It's rather striking that nobody has any difficulty in recognizing life when they see it and yet defining it formally proves tricky

Yes, that's a funny one isn't it, I was going to mention that. As humans we have an inherent quality that instintively knows what is life and what isn't. And we can also distinguish what lifeforms are good for us and what aren't. 

The nice ripe red strawberry's are tempting but the green slime on the bottom of the orange is not.

So perhaps if we do happen to come across an alien, we might instintively know if it's friend or foe? Perhaps we already know by instinct, if we delve deep enough, if alien lifeforms exist or not? Sometimes our gut feelings can be quite valuable if we trust them.

 

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A recent fossil find places the beginning of life prior to the late heavy bombardment. Or calls into question whether or not the late heavy bombardment actually happened. I believe it happened.

And life, since the ingredients are everywhere being blown out of supernovas and other nucleogenic behaviors of the universe, is probably common.

I cite the previous evidence.

The earth during much of it's early stages was essentially on the verge of not being in the "Goldilocks zone".

Black smokers, hot springs, and numerous other environments are all examples of regions on our planet that are on the verge of not being in that zone.

http://www.independent.co.uk/news/science/life-on-earth-four-billion-years-old-new-fossil-paleontologists-a7968336.html

My point is, if life was around during the late heavy bombardment, then the Goldilocks zone is larger than we thought, and that means the likelihood, given that the late heavy bombardment did in fact happen (I cite the moon as our evidence it did), then life must at least be one order of magnitude more likely than it was before we found that old fossil.

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9 hours ago, Delasaurus said:

 

So perhaps if we do happen to come across an alien, we might instintively know if it's friend or foe? Perhaps we already know by instinct, if we delve deep enough, if alien lifeforms exist or not? Sometimes our gut feelings can be quite valuable if we trust them.

 

Alas I think the evidence is against this. We seem, collectively at least, to be incapable of recognizing even ourselves as ourselves for the purposes of friendship and are twitching to make enemies on the slightest pretext. My first thought was of racial prejudice but then there's nationalism, regionalism, sexism, homophobia, football club tribalism... This doesn't augur well for an amiable assessment of aliens!

I've just started the book to which I linked earlier. It turns out to very relevant to this thread. The author has laid down his central hypothesis which is that the evolutionary branches leading on one hand to the cephalopods and the other to us constitute two independent experiemnts in the creation of consciousness. This means that the cephalopods are probably the nearest we'll get to intelligent aliens. It's an appealing idea. But I have a question for those, unlike me, who are versed in biology. How sound is this premise? The common ancestor, some kind of small flat worm, possibly light sensitive, must be assumed not to be conscious. While that's probably not too contentious, might there be some way in which this simple creature's makeup predisposed the two subsequent evolutionary branches to develop in particular ways?

Olly

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I wonder if we will, or any life form, will ever be able to travel between systems. With a sample size of 1 it seems that intelligent life develops the capabilities to kill itself before developing the capabilities to travel between the stars. Is all life doomed to limit itself through violence, hence no evidence of aliens?

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46 minutes ago, Filroden said:

I wonder if we will, or any life form, will ever be able to travel between systems. With a sample size of 1 it seems that intelligent life develops the capabilities to kill itself before developing the capabilities to travel between the stars. Is all life doomed to limit itself through violence, hence no evidence of aliens?

This has certainly been suggested, and quite seriously, but it would only apply to us-like aliens with our kind of intelligence and our kind of relationship with their environment. That's to say a relationship in which technology confers advantage.

I wonder if anyone out there has given deep thought to the evolution of technology and its relationship with intelligence. Such a relationship does eist here but I don't see any reason to suppose that this would be universal.

Olly

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1 hour ago, ollypenrice said:

I wonder if anyone out there has given deep thought to the evolution of technology and its relationship with intelligence. Such a relationship does eist here but I don't see any reason to suppose that this would be universal.

Oh my, the evolution of technology (human) is fraught with barriers. It is something I actually studied for part of my theisis. I went back as far as the 1700's and 'technology' was feared in many ways. Napiers bones for an example and the development of the slide rule was heckled because the shipping clerks thought they would be out of a job even in those days. The main barriers, to keep it short, to technology advancing, are social, political, cultural and economic, they each play a part singularly or collectively. You wouldn't believe the amount of technoligically advanced ideas that have been shelved due to peer pressure and other factors. The intelligence link is more probably due to the salvation of jobs or the barrier to income than the advancement of human intellect and wellbeing. We only need to brush the surface of oil products to know that certain folk will not want their income challenged. Despite how good or bad that may be for the goodness of all and the planet.

The main outlet for 'technological advancement' is mainly snapped up by the defense establishments, or large corporations to secure the continuation of their products and services, so maybe that throws some light on our human priority. Hostility and greed?

Until we change our world view from 'will it make me money or will it kill better' then technology has a very weak chance to exploit the larger utilitarian purpose. Wars bring about technological change, starvation and human suffering and world disasters don't I'm affraid...so make what you will of that link to technology and intelligence. As tool makers, we still seem to be stuck on the Planet of the Apes.

So I think the first priority should we encounter any intelligent alien lifeforce would be something along the lines of 'is their weaponary better than ours and how can we make money out of them'.

 

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2 hours ago, ollypenrice said:

The common ancestor, some kind of small flat worm, possibly light sensitive, must be assumed not to be conscious. While that's probably not too contentious, might there be some way in which this simple creature's makeup predisposed the two subsequent evolutionary branches to develop in particular ways?

The evidence suggests that as long as there is a changing environment, that ensures all species are sub-optimal, they will continue to evolve. Whilst this can lead to complexity, and a reduction in entropy this brings the cost of greater energy use. I think it may have been Dawkins (or Stephen Gould) who pointed out that intelligence can be a maladaptation in some circumstances, brains are expensive and are a handicap if you don't need much intelligence to survive.

This is why we still have flatworms and bacteria and they are hugely more successful (in terms of numbers, numbers of generations and bulk of DNA, which may be absolute measures of the success of a replicator).

So intelligence is clearly the exception to the rule,  and flatworms are predisposed to being flatworms, but put flatworms in challenging environments and some will evolve, keep changing those challenges and one possible outcome is intelligence. I would contend, though, that the original potential for intelligence wasn't in the flatworm, it was in the original replicators that pre-existed what we now call life, just as the potential for a bake-off winning cake is in every bag of flour.

The happenstance that intelligence has evolved at least twice does no more than emp0hasise that while it is neither an inevitability, an innate property of life nor a universally optimal solution it is clearly not dependent on a unique set of circumstances or a particular path.

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4 hours ago, Stub Mandrel said:

So intelligence is clearly the exception to the rule,  and flatworms are predisposed to being flatworms, but put flatworms in challenging environments and some will evolve, keep changing those challenges and one possible outcome is intelligence. I would contend, though, that the original potential for intelligence wasn't in the flatworm, it was in the original replicators that pre-existed what we now call life, just as the potential for a bake-off winning cake is in every bag of flour.

So do you think then. that the evolution of intelligence is basically down to the level of survival skills within a certain environment?

It makes sense to me that that is the way intelligence develops.

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18 minutes ago, Delasaurus said:

So do you think then. that the evolution of intelligence is basically down to the level of survival skills within a certain environment?

It makes sense to me that that is the way intelligence develops.

Broadly speaking. If you eat grass the grass might evolve into separate species some of which are less nutritious than others. if you have the brains to spot the better quality grass, you may have more descendants*.

*This is a classic 'evolutionary just-so story' and things are rarely, if ever, as simple as this!

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8 hours ago, Filroden said:

I wonder if we will, or any life form, will ever be able to travel between systems. With a sample size of 1 it seems that intelligent life develops the capabilities to kill itself before developing the capabilities to travel between the stars. Is all life doomed to limit itself through violence, hence no evidence of aliens?

Biology is not my thing but I think I remember that the presence of oxygen is required for most lifeforms except the falculative anaerobia to exist. But I think most of those still need an environment of H20 to live in. For example streptcoccus and salmonella are anaerobic but live in fluids containing oxygen elements. Somebody please correct me if I'm wrong. So the chances of lifeforms, planet hopping are slim due to the lack of O in some form I would think.

I don't think there is much that will live in a vacuum at low temperatures for too long. Flies can survive for a while in low vacuum.

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elements out of equilibrium may reveal life.

It isn't necessarily Oxygen but anything not in chemical equilibrium is a possible signature of life.

as for the notion we have to worry about aliens...

not likely.

the ever and expanding presence of vacuum energy precludes us ever bumping into aliens I believe.

So the meeting of aliens needs to happen sooner rather than later.

Later they will be too far away and instead of needing a warp drive, they'll need a super warp drive harnessing entire actual neutron stars instead of stable micro black holes to reach us.

Probably the best we can hope for is to listen for the attempts to communicate when the universe is older.

Since the universe is relatively young, it is a possibility that we're just very early on the scene and intelligence is just now becoming a thing.



 

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Originally all life on earth was anaerobic.

Then the photosynthesisers came along and started polluting everything with oxygen.

The free iron in the Earth's crust mopped it all up as rust until one day, the iron ran out.

From then on, if you wanted to be truly successful, you needed to be able to cope with oxygen.

I think O2 and photosynthesis will be needed to drive the sort of food chains required to support big-brained and energy inefficient creatures.

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6 hours ago, Stub Mandrel said:

The evidence suggests that as long as there is a changing environment, that ensures all species are sub-optimal, they will continue to evolve. Whilst this can lead to complexity, and a reduction in entropy this brings the cost of greater energy use. I think it may have been Dawkins (or Stephen Gould) who pointed out that intelligence can be a maladaptation in some circumstances, brains are expensive and are a handicap if you don't need much intelligence to survive.

This is why we still have flatworms and bacteria and they are hugely more successful (in terms of numbers, numbers of generations and bulk of DNA, which may be absolute measures of the success of a replicator).

So intelligence is clearly the exception to the rule,  and flatworms are predisposed to being flatworms, but put flatworms in challenging environments and some will evolve, keep changing those challenges and one possible outcome is intelligence. I would contend, though, that the original potential for intelligence wasn't in the flatworm, it was in the original replicators that pre-existed what we now call life, just as the potential for a bake-off winning cake is in every bag of flour.

The happenstance that intelligence has evolved at least twice does no more than emp0hasise that while it is neither an inevitability, an innate property of life nor a universally optimal solution it is clearly not dependent on a unique set of circumstances or a particular path.

I agree with this but I don't think intelligence is different from any other (potentially) evolutionary characteristic. Genetic characters can change and mutations can occur of course that have no impact in evolutionary terms. I.e. they are only really relevant (and evolutionary) if they result in more or less reproduction of your genetic material. This applies as equally to intelligence as it does to all other characters. What remains in the world is basically 'the dregs' I suppose technically!

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38 minutes ago, Delasaurus said:

Biology is not my thing but I think I remember that the presence of oxygen is required for most lifeforms except the falculative anaerobia to exist. But I think most of those still need an environment of H20 to live in. For example streptcoccus and salmonella are anaerobic but live in fluids containing oxygen elements. Somebody please correct me if I'm wrong. So the chances of lifeforms, planet hopping are slim due to the lack of O in some form I would think.

I don't think there is much that will live in a vacuum at low temperatures for too long. Flies can survive for a while in low vacuum.

 

tardigrades not only survive vacuum, they also survive UV radiation at more than 1000 times earth normal and showed no signs of genetic deviations after returning to earth and being rehydrated and having babies.

https://www.sciencedaily.com/releases/2008/09/080908135906.htm

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6 minutes ago, Stub Mandrel said:

Originally all life on earth was anaerobic.

Then the photosynthesisers came along and started polluting everything with oxygen.

The free iron in the Earth's crust mopped it all up as rust until one day, the iron ran out.

From then on, if you wanted to be truly successful, you needed to be able to cope with oxygen.

I think O2 and photosynthesis will be needed to drive the sort of food chains required to support big-brained and energy inefficient creatures.

ah yes, the great mitochondrial invasion.

it forced cells to nucleate or die. Cells that treated it as something they had to kill died, cells that decided to give up a section of their, most of their cellular environs and could create a nucleus lived and prospered. And so multicellular life became possible since the ATP cycle is probably one of the few efficient ways of transferring energy between cells thus allowing symbiosis in the first place really. So the mitochondria, viewed as parasites by the majority, ended up symbiotic.

interestingly, the mitochondria still divide their own genetic material on their own schedule and you get them all from your mother.

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7 hours ago, Delasaurus said:

Oh my, the evolution of technology (human) is fraught with barriers. It is something I actually studied for part of my theisis. I went back as far as the 1700's and 'technology' was feared in many ways. Napiers bones for an example and the development of the slide rule was heckled because the shipping clerks thought they would be out of a job even in those days. The main barriers, to keep it short, to technology advancing, are social, political, cultural and economic, they each play a part singularly or collectively. You wouldn't believe the amount of technoligically advanced ideas that have been shelved due to peer pressure and other factors. The intelligence link is more probably due to the salvation of jobs or the barrier to income than the advancement of human intellect and wellbeing. We only need to brush the surface of oil products to know that certain folk will not want their income challenged. Despite how good or bad that may be for the goodness of all and the planet.

The main outlet for 'technological advancement' is mainly snapped up by the defense establishments, or large corporations to secure the continuation of their products and services, so maybe that throws some light on our human priority. Hostility and greed?

Until we change our world view from 'will it make me money or will it kill better' then technology has a very weak chance to exploit the larger utilitarian purpose. Wars bring about technological change, starvation and human suffering and world disasters don't I'm affraid...so make what you will of that link to technology and intelligence. As tool makers, we still seem to be stuck on the Planet of the Apes.

So I think the first priority should we encounter any intelligent alien lifeforce would be something along the lines of 'is their weaponary better than ours and how can we make money out of them'.

 

this

so in actuality, the likelihood is that any hypothetical aliens stopping by earth would possibly be coming in peace, but earth being the arrogant oil burning apes we are might turn a potentially good situation bad by using what I like to call Intelligance Lite, and boiling everything down to how much money we could make off of it, and how many people we could kill with it and only being able to see the universe through that lens.

Although, Stephen Hawking thinks that we should probably be worried about aliens, which seems to imply that he thinks vacuum energy isn't enough to prevent contact.

But perhaps even Mr. Hawking is projecting our bad ways of "thinking" onto these aliens?

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9 hours ago, Filroden said:

I wonder if we will, or any life form, will ever be able to travel between systems. With a sample size of 1 it seems that intelligent life develops the capabilities to kill itself before developing the capabilities to travel between the stars. Is all life doomed to limit itself through violence, hence no evidence of aliens?

Carl Sagan cites this problem as his reason for wanting SETI in his book The Cosmic Connection. To determine just exactly how often intelligence does lead to self destruction.

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