This topic contains 44 replies, has 37 voices, and was last updated by  Duck 7 months, 2 weeks ago.

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  • #3619

    Niles
    Participant

    I suspect a lot of people now no longer believe that we on Earth are alone in the universe and that there may be other comparable life forms out there. What are your thoughts.. do you believe aliens exist?

  • #3620

    kal
    Participant

    I think there are aliens out there but I’ve no idea what form it might take. There’s bound to be some microbes out there I think, though, if not something more developed.

  • #3621

    ricky
    Participant

    Of course they exist, ask any red necked yank who’s been probed.
    Or is that down to excessive methanol consumption?

  • #3622

    just another Dave
    Participant

    To find out if there are aliens you need to find out if DNA generic throughout the Universe – I suspect that it is.

    Have a google of ‘panspermia’

  • #3624

    Niles
    Participant

    And is DNA generic throughout the Universe – I suspect that it is

    Have a google of ‘panspermia’

    Interesting. Maybe panspermia could be harnessed in some way to permit ultra distant space travel.

  • #3625

    callum
    Participant

    I definitely believe there is something out there.
    These seems to be an infinite number of planets and I find the idea that we are the only planet with life to be exceptionally arrogant.

    There was a 2000AD comic strip that I still remember from being a kid.
    The whole thing was about a space ship that was going to be the first manned thing ever to leave our galaxy but in the last couple of pictures it gets stuck at the edge of the galaxy, the final picture shows a overview of what is going on.
    Our galaxy has been enveloped in a massive bubble with caution bio hazard signs all round it as the rest of the universe carries on flying around, trading and being prosperous.

  • #3626

    sar
    Participant

    I don’t think the we’re alone theory is based on arrogance. More a pessimistic view of statistics

  • #3627

    jack
    Participant

    When we are still discovering new life forms on Earth and finding them in more and more unexpected places the form they take will be myriad. We are discovering more and more planets that have the same conditions as gave life on Earth. The odds just go up every week. We may discover life within our own solar system in the next 5 years and not on Mars. Another exciting mission in progress.

  • #3628

    howard
    Participant

    @jack And who is to say that life needs the same conditions as we have.
    Who knows what kind of life could be out there.

  • #3629

    mo
    Participant

    Surely since to our knowledge life has only ever arisen once on Earth, all other things being equal, the possibility of the rise of life itself might be seen as being pretty unlikely? With a sample size of one positive planet (Earth) and one apparently negative but not yet properly surveyed planet (Mars) out of the presumably billions of potential ‘Goldilocks Zone’ planets in the galaxy, any attempt to measure likelihood one way or the other seems pretty meaningless. What if the likelihood of the rise of life locally itself negatively outstrips (I’m probably not expressing this properly) the number of planets with the potential to house life more or less as we know it? Surely then it’s actually unlikely that there is any other life in the Universe, just that we’re the only one to have the luxury of passing comment on it? Obviously impossible to measure though. Maybe they’ll just turn up and we can put this one to bed

  • #3630

    stew
    Participant

    Surely since to our knowledge life has only ever arisen once on Earth, all other things being equal, the possibility of the rise of life itself might be seen as being pretty unlikely?

    @mo No. Even using very pessimistic (but yes – still guessed at) numbers, the probability is pretty high we’re not alone: https://en.wikipedia.org/wiki/Drake_equation

    (note this equation is apparently just for the Milky Way galaxy – as there are trillions of trillions of galaxies out there… things get a lot more positive looking).

  • #3631

    nobroo
    Participant

    So many galaxies, so many stars, so much distance. Unimaginable numbers. Local intelligent life, maybe not. But intelligent life somewhere surely approaching certainty?

  • #3632

    oldman
    Participant

    I tended to take the view that we were not likely to be alone, the Drake equation was certainly a big factor. Then in mid 2017, I think, I saw Brian cox give a reasoned counter. I recall he argued that we haven’t yet picked up a signal from ET, or come across a Turing machine is strong statically evidence for intelligent civilizations being widespread. This is not the same as there being life of some form, this I consider to be quite likely. I’m not sure why I now think about intelligent, civilizations.

  • #3633

    ben
    Participant

    @mo Life on earth can tolerate a few hundred degrees temp range. In water, air and other gases. Given the number of stars, solar systems etc.. it would be more surprising if we alone in the universe.

  • #3634

    Nerdkid
    Participant

    Surely since to our knowledge life has only ever arisen once on Earth,

    @mo Two reasons why I strongly disagree with your premise:

    (1) We don’t know that life has only arisen once. Perhaps another kind of life arose (before or after what we know) that lost out the evolutionary battle long before the fossil record. Not that the earliest realisation(s) of life leave any fossil record anyhow.

    (2) If the basis of life-as-we-know-it hadn’t arisen, would some other kind have life arisen?

    Another point to your wider post.

    (3) Life arose very early on in the history – and the expected total life – of Earth. It’s dangerous to infer to much from a single data point, but this does rather suggest that it wasn’t a difficult thing to happen.

  • #3635

    mo
    Participant

    @stew That equation doesn’t really deal with the likelihood of life actually arising though does it? The chapter “Fraction of the above that actually go on to develop life, fl” touches on it saying that for one reason and other it appears to be a fairly likely outcome given the right conditions, but then this:

    “From a classical hypothesis testing standpoint, there are zero degrees of freedom, permitting no valid estimates to be made.”

    Does not the whole usefulness of the equation rather hinge on that? That’s not a rhetorical question, I don’t know much about statistics so could do with some clarification.

    @ben But just because it is tolerable, doesn’t mean there’s anything about to tolerate it in the first place, necessarily.

    (1) We don’t know that life has only arisen once. Perhaps another kind of life arose (before or after what we know) that lost out the evolutionary battle long before the fossil record. Not that the earliest realisation(s) of life leave any fossil record anyhow.

    @nerdkid True, but as you say due to the fossil record, unknowable.

    (2) If the basis of life-as-we-know-it hadn’t arisen, would some other kind have life arisen?

    Quite possibly.

    (3) Life arose very early on in the history – and the expected total life – of Earth. It’s dangerous to infer to much from a single data point, but this does rather suggest that it wasn’t a difficult thing to happen.

    Hadn’t thought of that, thanks.

    I’m not arguing that extra terrestrial life is unlikely, rather that it might be unlikely. I’m interested in the way the criteria are interpreted. Whether as Siward nicely put it above “So many galaxies, so many stars, so much distance. Unimaginable numbers.” is itself sufficient to say that it’s actually likely that there is extra-terrestrial life or just that the correct conditions for extra terrestrial life are likely.

    I hope I’m not coming across as having a strong opinion one way or another on this and it’s great to hear from you people who know what you’re talking about. Cosmology, biology, statistics – hell of a problem and fascinating stuff.

    • This reply was modified 7 months, 2 weeks ago by  mo.
  • #3636

    Chris B
    Participant

    I tended to take the view that we were not likley to be alone, the Drake equation was certainly a big factor. Then in mid 2017, I think, I saw Brian cox give a reasoned counter.

    @oldman Brian Cox has been to busy jetting around the world to think about it.

    Detection of ET has been based on looking for “obvious” radio signals.

    We have rarely broadcast an “obvious” signal in to space for that purpose – if a twin SETI program to ours was running a few hundred light years away it would almost certainly have missed our signals.

    The other source of obvious radio signals *was* stray AM and FM radio and analogue TV broadcasts. These have all but ceased and their replacements are broadband speed spectrum signals that are increasingly less obvious unless you know exactly what you’re looking for. More and more data is travelling over optical fibres rather than radio waves. There was perhaps a 50 year golden window where the hypotethical parallel SETI program had a chance of detecting Earth by its stray radio emissions.

    To my mind this resolves the so-called Fermi Paradox. It was a bad paradox as if baked-in massive human centric assumptions that were tied to a very precise time era.

  • #3638

    gregory
    Participant

    Surely since to our knowledge life has only ever arisen once on Earth,

    @mo The different theories for the origin of life on Earth fascinate me. Several viable paths – we’ll likely never ever know which one(s) it was but the work does show how it could arise in different environments.

    But it goes beyond that – there are a number of things about cosmology and particle physics that happen to be just-right for the formation of life. So far most of those things “just are” – we have no scientific explanations for why they are as they are. We just measure them, and marvel that if they were even slightly off, atoms wouldn’t exist, or nuclei wouldn’t undergo fusion in stars, or stable planetary orbits wouldn’t exist (hello extra dimensions), or the universe would have flown apart until every atom was out of contact with every other atom etc.

    Then, once you have amino acids it’s almost like the whole path to multi-cellular life is just there waiting to be found. At no point has there been an unbridgeable gap.

    I like to consider myself a tree of science, and am rabidly anti religion, yet when I stop and think about it, the coincidences really do stack up.

    Beyond the cop-out answer of “anthropic principle” there is some comfort that if things were different, perhaps some unimaginable-to-us form of consciousness would arise and would have similar thoughts.

    I hope to see a lot of answers before I die, and I poke away at a particular part of biological cells in a microcosm of that. I think really understanding the origin and mechanisms of consciousness may be tied up in all this.

  • #3639

    logi
    Participant

    Surely since to our knowledge life has only ever arisen once on Earth

    @mo It only had to once…

    And there are different forms of life, that use different chemical pathways for energy, some of which are mutually incompatible. Early oceanic life was sulphur-‘breathing’. It was mostly eliminated by the evolution of oxygen-based lifeforms; oxygen was toxic to them. The chemistry of the sea changed from one containing metal sulphides, to the one we have now. Vestiges of the sulphur-breathing life remain around the ‘hot smokers’ on the sea bed.

  • #3640

    stew
    Participant

    That equation doesn’t really deal with the likelihood of life actually arising though does it? The chapter “Fraction of the above that actually go on to develop life, fl” touches on it saying that for one reason and other it appears to be a fairly likely outcome given the right conditions, but then this:

    @mo No it doesn’t – but it pretty much shows that even using very modest values, there is a very high chance of there being intelligent life out there (and by extension, non-intelligent life is even more likely than that).

    “From a classical hypothesis testing standpoint, there are zero degrees of freedom, permitting no valid estimates to be made.” Does not the whole usefulness of the equation rather hinge on that? That’s not a rhetorical question, I don’t know much about statistics so could do with some clarification.

    I think it just means you can’t get any concrete answers from the equation. It can only be used to show that given some favourable parameters, there will almost certainly be life out there.

  • #3641

    ben
    Participant

    But just because it is tolerable, doesn’t mean there’s anything about to tolerate it in the first place, necessarily.

    @mo True. But were know the compounds required. We now have a reasonable understanding of star destruction, planet forming, plus the goldilocks distance from a sun. It just comes down to statistics that a planet will form in the required distance from a sun, etc.. whilst mathematically quite possible it does not of course mean it’s guaranteed to happen.

    I guess it comes down to belief or lack of. And that’s before you even consider multi verse theories.

  • #3642

    Luke
    Participant

    So where does the concept of god fit with the concept of aliens?

  • #3643

    Mick
    Participant

    So where does the concept of god fit with the concept of aliens?

    @luke Does it matter, if you’ve got both I’m sure they can be mashed together in a messy but serviceable compromise (just don’t pick at the edges or think too hard). It’s not like individual religions present especially coherent pictures of their gods before you add aliens.

  • #3644

    Jaffa
    Participant

    Does not the whole usefulness of the equation rather hinge on that? That’s not a rhetorical question, I don’t know much about statistics so could do with some clarification.

    @mo The Drake equation is only a concise way of expressing an interesting, and not (to most people) immediately obvious, problem; not a way of generating any answers.

    It multiplies a series of factors that are either imprecisely understood or completely unquantifiable and so any probability it generates is extremely likely to be hopelessly wrong by many orders of magnitude. It’s a classic example of expressing complete guesswork in a mathematical format to produce answers that look a bit like data.

  • #3645

    frog
    Participant

    There’s “nobody” out there. No comparable life forms, “nobody” we can communicate with, “nobody” who can communicate with us, no civilizations, no intelligent “life” whatsoever. Nothing, zilch, zip, nada.
    There’s no harm in looking, it’s what we do, we go out and look around. And the process will probably bring/drive advances in science and technology. But we won’t find “anyone”, and “they” won’t find us.

  • #3646

    Jaffa
    Participant

    @frog Interesting. What makes you so sure?

    The huge distances (times) between us and or neighbours making meaningful communication near impossible should we ever find somewhere to send messages? Our near inability to communicate effectively with comparable lifeforms here on earth, even sometimes with our own species? The improbability of intelligent life surviving the development of the tools for its own destruction? Or do you think we as earth-life and humans are special somehow?

  • #3647

    frog
    Participant

    Interesting. What makes you so sure?

    @jafa It’s an opinion. And I’m willing to be persuaded by evidence to the contrary. I’m less willing to be persuaded by claims that space is really big and if it happened once then it must have happened loads of times.

    The huge distances (times) between us and or neighbours making meaningful communication near impossible should we ever find somewhere to send messages? Our near inability to communicate effectively with comparable lifeforms here on earth, even sometimes with our own species? The improbability of intelligent life surviving the development of the tools for its own destruction? Or do you think we as earth-life and humans are special somehow?

    I don’t know what you mean by special, I think we’re unique – until somebody shows that we’re not. The alternative would be to believe in something that there is no evidence for.

  • #3648

    nutter
    Participant

    The alternative would be to believe in something that there is no evidence for.

    @frog Absence of evidence is not evidence of absence.

    Especially when we know that we are not able to gather that evidence (lack of suitable technology) and when the evidence we are able to gather (exoplanets) is starting to show that our star system is in no way special, unusual or extraordinary.

    The alternative is to remain open minded.

  • #3649

    nutter
    Participant

    There could easily have been other comparable life in the universe already, and after the human race has gone. If you just consider earth and the past 4 billion years, humans have only been able to send or receive signals for around a hundred years. The odds of two independent species arising in the universe at the same time and communicating or even knowing of each other’s presence is low, but that doesn’t reduce the chances of either existing.

    Personally, I think if life evolves through similar means, DNA etc.. then it’s just a matter of time before intelligence comes along due to evolutions very nature.

  • #3650

    Person
    Participant

    All we know is that it has happened here, on this planet. So the most you can say is that if there is an identical planet in an identical position then perhaps intelligent life might arise. But even though it has happened here that doesn’t mean that it would automatically have happened in an identical environment elsewhere, the pansmermia could have drifted past that planet.

  • #3657

    nomad
    Participant

    The preponderance of habitable zone planets in the small fraction of our galaxy surveyed so far. Let alone the number of galaxies out there.

    The rapidity with which life started on this planet, combined with the number of different experiments that have showed biogenesis in young-planet environments. Not to mention the sheer dull commonness of our star – there’s nothing to suggest the environment from which our planet formed or in which it developed life is special.

    The discovery that intelligence has separately evolved many times on earth in many different species – this suggests it’s not an improbable event.

    Like I say, there is copious partial evidence.

    The other way I look at it is to imagine the estimated 1,000,000,000,000,000,000,000,000 planets in the observable universe. Then I imagine the vast array of physical laws and initial conditions that would not permit life to form, and the smaller but still wide range of values that would permit life to swarm all over them. Just how precise and small would those conditions have to be such that intelligent life forms on only one planet that itself is no different to all the others? That would imply the hand of a very particular god in creation.

    What I think you want is *direct evidence*. “I can’t be certain that alien life exists without direct evidence” is a logically sound position, and no reasonable scientist would I think disagre with it (except perhaps those whose funding depends upon dark matter) but they’d all also agree with a statement that they can’t be sure bob geldof isn’t having a dump in the toilet down the hall without taking a direct evidentiary look. Yet I doubt anyone has their autograph book out…

  • #3658

    chris
    Participant

    The preponderance of habitable zone planets in the small fraction of our galaxy surveyed so far. Let alone the number of galaxies out there.

    The rapidity with which life started on this planet, combined with the number of different experiments that have showed biogenesis in young-planet environments. Not to mention the sheer dull commonness of our star – there’s nothing to suggest the environment from which our planet formed or in which it developed life is special.

    The discovery that intelligence has separately evolved many times on earth in many different species – this suggests it’s not an improbable event.

    Like I say, there is copious partial evidence.

    @nomad No, that isn’t evidence (partial or otherwise) for intelligent life elsewhere. What you have produced is a hypothesis suggesting that life could occur elsewhere (because it happened here).

    The other way I look at it is to imagine the estimated 1,000,000,000,000,000,000,000,000 planets in the observable universe. Then I imagine the vast array of physical laws and initial conditions that would not permit life to form, and the smaller but still wide range of values that would permit life to swarm all over them. Just how precise and small would those conditions have to be such that intelligent life forms on only one planet that itself is no different to all the others? That would imply the hand of a very particular god in creation.

    You’re just back to saying that the universe is really big and intelligent life simply can’t only exist in one place.

    What I think you want is *direct evidence*. “I can’t be certain that alien life exists without direct evidence” is a logically sound position, and no reasonable scientist would I think disagre with it (except perhaps those whose funding depends upon dark matter) but they’d all also agree with a statement that they can’t be sure bob geldof isn’t having a dump in the toilet down the hall without taking a direct evidentiary look. Yet I doubt anyone has their autograph book out…

    No, what I’d like to see proper “evidence” and you’re just persuading people that you haven’t got any.
    And your reasoning is weak, Bob’s human, he shits, probably in a toilet, he has various honorary degrees so he does attend places scientists frequent, he could well be having a dump in the toilet down the hall. He could also be sharing the bog with a little green man. But I wouldn’t get your autograph book out.

    • This reply was modified 7 months, 2 weeks ago by  chris.
    • This reply was modified 7 months, 2 weeks ago by  chris.
  • #3661

    nomad
    Participant

    @chris Nonsense and you know it. That is not what I’m saying, and if you genuinely can’t understand my posts then I’m sorry. It’s possible to imagine looking up at a universe and saying “its really big and really hostile to life, we are lucky we are here at all”. That’s not what I thought when I had the opportunity to put my eyeball after a lens at the prime focous of a 4 meter class telescope.

  • #3662

    how
    Participant

    It’s all probabilities.

    However, I lean towards there being life out there. Not because ‘if it happened here, it must have happened elsewhere’ but because I’d need some pretty extraordinary evidence that the odds of it happening once are lower than the odds of it happening multiple times.

    This isn’t provable one way or the other. I highly doubt they’ve visited. But I believe that the evolution of life is both fundamentally and entirely a physical process. As such, we are not special. Believing this is the only planet on which life has evolved seems to me a highly unlikely proposition.

    It’s like the difference in probability between someone sharing our birthday and two people in a group sharing a birthday. Starting your chain of probabilistic reasoning from the privileged position of this planet seems to be missing the point to me.

  • #3663

    jumpingjack
    Participant

    he way I see it is life has ‘happened’ at least once and we know of no logical reason why it can have only happened once therefore it probably could have happened again (perhaps even here on earth) and again and again. Given the apparently very large number of opportunities for life chemically similar to ours to arise and evolve it seems unlikely to me that it hasn’t. There is of course also the possibility of life very different to ours and hard for us to imagine.

  • #3664

    Mr snrub
    Participant

    I think that the chances that there is life out there in another galaxy is very high, the chances of it being comparable to some form of earth life, is moderately high, the chances of it being “intelligent” on a par with human life on
    earth is evens to moderately high. The chances of our ever being able to communicate with intelligent life in another galaxy is moderately low. The chances of our ever being able to meet “intelligent” life on another galaxy ie we travel to them or they travel here is very low to nil.

  • #3665

    sad
    Participant

    It basically doesn’t matter, even if there’s if there’s a 0.001% chance of the genesis of life occurring (on a planet with the right conditions etc), 13,000,000,000 * 4,500,000,000,000 rolls of the dice means that you can be wrong about the chances many orders of magnitude and you’re still looking at life evolving on billions and billions of worlds.

    The basic point is that the universe is so insanely large that it doesn’t matter how incredibly rare the event is; we know it can happen (we’re proof) therefore, it’s happened elsewhere.

    For anything else to be more likely, you either have to believe that scientific laws are not universal, that the genesis of life is a one time event (therefore non physical / so rare an event that us even existing is beyond extremely improbable – this is less likely than the simple explanation that there is other life) or that there is a God.

  • #3666

    troll
    Participant

    Here are my calculations on life developing elsewhere in the universe…

    Some definitions. I use ‘life’ as shorthand for ‘intelligent life’. ‘N’ is the number of potentially habitable planets, and ‘P’ is the probability of intelligent life developing on any one planet. For a given N and P, we can ask what is the probability of life developing on a precise number, n, of planets, for example p(n=0) is the probability of life developing on 0 planets, p(n=1) is for life developing on just one planet and p(n>1) is the probability of every possible combination with life on more than one planet.

    P = 1/N is the probability most likely to yield precisely 1 habitable planet. For P=1/N:
    p(n=0) = 36.7%
    p(n=1) = 36.7%
    p(n>1) = 26.6%

    So we see that even with the optimal probability for life on one planet, that is not the guaranteed outcome. We can discount the n=0 case because we have direct evidence against it (our existence). That leaves the probabilities as follows:
    p(n=1) = 58.0%
    p(n>1) = 42.0%

    So in the absolute best case we can say that if life arises once, there is a 42% probability that intelligent life arrises more than once.

    But, what if we don’t have the optimal probability?

    P = 0.1/N, then p(n=0) = 90% : If p is one tenth the optimal value, there is a 90% chance that no life develops anywhere in the univerise.
    P = 10/N, then p(n>1) = 99.95% : If p is ten times the optimal value, there is a 99.95% chance that life develops more than once in the universe.

    One needs to know the number of potentially habitable planets accurately to within a factor of 10 to come anywhere close to determining the best-case probability of life developing in order for there to be only one planet with life. You have literally no idea what that number of planets is, but your view is that the probability must be precisely one in that number. You are the one implicitly sticking precisely the correct number of zeros on that probability to get the outcome you believe in against all likelihood.

    Beyond the sheer statistical improbability of the probability being precisely that required to give best odds at n=1, there is the absurdity that we can have literally no idea on the *lower* bound of that probability. We see the observable universe but it’s likely to be larger than what we can see, as distant regions are causally disconnected due to cosmic inflation – that pesky zero point energy (oh so important to realizing the Alcubierre metric). So even if you do count all the observable planets and calculate your magic probability, it’ll be to large. Unless something even more magic means we are only the only intelligent life in our currently causally connected part of the universe.

    If we turn out to be alone, I would start to wonder very, very closely about why that is. Alternatively, if someone insists this is almost certainly the case, I would ascribe that to likely theological thinking, as to do so flies in the face of all rational.

  • #3667

    dizzy
    Participant

    Whilst I like to think it’s like the Clangers up there, the fact we’ve picked up nowt on the radio could mean that intelligent and tech producing life is incredibly rare. The fact that life had been on earth for 3.8bn years before anything intelligent and technology producing evolved would be further evidence of this rarity. So call me controversial, but this means we’re incredibly precious and should really try to look after ourselves and the planet…

  • #3668

    Ali
    Participant

    Whilst I like to think it’s like the Clangers up there, the fact we’ve picked up nowt on the radio could mean that intelligent and tech producing life is incredibly rare. The fact that life had been on earth for 3.8bn years before anything intelligent and technology producing evolved would be further evidence of this rarity. So call me controversial, but this means we’re incredibly precious and should really try to look after ourselves and the planet…

    @dizzy Equally it could mean that easily detectable (high power near-omnidirectional broadcast AM/FM, active pulsed search radar) radio communication is a short lived phenomenon (as appears the case on earth) and that for most of the ~100y we’ve been broadcasting anything recognisable we’ve not been seriously looking anywhere in the sky let alone everywhere for traces of other civilisations. Modern radio signals look like noise.

    Looking after our life support system makes sense for a number of reasons that shouldn’t really need expanding past no.1

  • #3669

    evie
    Participant

    @dizzy Why would you expect to be able to pick things up on the radio, imagine the signal strength that would reach earth from even the nearest star, then imagine the signal type and how different it would be from background noise, then imagine we’d be able to decode / recognise it as something special.

    I’m not in the least surprised, Voyager has 23 Watt transmitters, the amount of signal the reaches earth is now 10 exponent -16 watts (1 part in 10 quadrillion). Voyages 1 is 139 AU away from Earth, Proxima Centauri (the next nearest star to us) is 268774.6 AU from Earth. So the nearest star, and there’s plenty more further away , is 1,933 times further away than Voyager 1 is now!

    Admittedly 23 Watts isn’t a massive transmitter power, but you can see what happens to the signal strength with distance, and it’s not as easy as twice the distance = half the signal.

    So I’m not surprised we’ve not picked up any signals from our fellow intelligent life.

  • #3670

    em
    Participant

    I’m no scientist and I can’t take in many of the facts and figures about things like this. What I do know is that, as a kid, when people talked about the enormity if the universe I used to thing in terms of equating the size of the earth to a pin head and the relative “size” of the universe being the size of a house!
    Obviously, as I’ve got older, I’ve come to appreciate that this is a totally ridiculous comparison and, if the truth were known, it must be nigh on impossible to relate in any way the size of the earth to the size of the universe – if you know what I mean ;o|
    My own feeling is, in simple terms, that the universe(not just the “seeable” universe) is so unimaginably huge that the chances of there NOT being somebody else out there must be pretty slim. It’s just that they may be so unimaginably far away that we will never reach them.
    Sorry if that’s ridiculously simplistic but my brain hurts ;o)

  • #3671

    harry
    Participant

    Life evolved rather quickly on the early earth and left fossils 4ish billion years ago – we would find that early world utterly uninhabitable, and those creatures would not be able to survive in normal atmospheric conditions now, so I find this assumption that you require earthlike conditions for a rather similar life form rather limiting, and not very realistic.

    I personally will not be surprised if we were to find primitive life somewhere else in the solar system, somewhere on a moon with some kind of chemical sea and a way ot provide energy, or to find fossil evidence on mars. Life seems very keen to form , develop

  • #3672

    el
    Participant

    @harry I agree Dinosaurs existed, all very alien to what exists now. For me that shows how life can evolve in many ways in a very different atmosphere but in all that time they failed to evolve into anything like a modern human with our abilities to plan and build. In a few billions of years civilisation could rise and fall as could our present epoch before we are discovered or we find similar life forms to us such is the expanse of space/time

  • #3673

    Duck
    Participant

    I think the question of life elsewhere in the Universe is a no brainer, with a very high probability of intelligence somewhere. The numbers are just too overwhelming. I think its far more interested to speculate whether there is ever any likelihood of us ever crossing paths with it (or them with us) – even indirectly through EM waves. Given our understanding of Special Relativity being what it is, its hard to see it happening right now.

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