[Bobboau]

not at the genetic level.

[General Battuta]

not at the genetic level.

Cite this comment to make it less wrong. In general saying 'the possibility does not exist' in a flat open universe is an extremely poor idea as all non-zero probability events will recur an infinite number of times across the Hubble volumes.

[Bobboau]

"strong convergence"
that was the phrase you used and the phrase against which I made that post, Strong Convergence. you did not say random chance that it could stumble upon it, but rather you said that there might be strong convergence, implying that given the right conditions things could go the same way and that it would come out the same way. no, the amount of time for a second earth in a second solar system around a second sun all molecularly identical to our own to arise would take longer than the universe will exist and the window of time upon which the concentration of elements exists to allow it may have already passed even given an identical starting point the mere randomness of quantum interactions would still lead the possibilities of what could happen on such a world to be vast to the point of unfathomably unlikely to happen in any one arrangement. the possibility of alien life being genetically compatible in any sense of the word with life on earth is about as likely as a room temperature block of plaster suddenly having all of the heat in it concentrated on the top of it and exploding, now, yes this is possible, but the frequency of it happening would make the combined life expectancy of every proton, neutron and electron in the universe summed up seem infantilecly short. so in any practical sense of the word, no, it's not possible.

[General Battuta]

"strong convergence"
that was the phrase you used and the phrase against which I made that post, Strong Convergence. you did not say random chance that it could stumble upon it, but rather you said that there might be strong convergence, implying that given the right conditions things could go the same way and that it would come out the same way. no, the amount of time for a second earth in a second solar system around a second sun all molecularly identical to our own to arise would take longer than the universe will exist

While these conditions are unnecessary and a misinterpretation of the term strong convergence, your objection is also hilariously wrong; if current cosmological data suggesting a flat, open, infinite universe is correct, an infinite number of precisely identical parallel earths in identical skies exist at this very moment, right down to us having this exact conversation.

and the window of time upon which the concentration of elements exists to allow it may have already passed even given an identical starting point the mere randomness of quantum interactions would still lead the possibilities of what could happen on such a world to be vast to the point of unfathomably unlikely to happen in any one arrangement. the possibility of alien life being genetically compatible in any sense of the word with life on earth is about as likely as a room temperature block of plaster suddenly having all of the heat in it concentrated on the top of it and exploding

Cite. Based on unfounded assumptions. Improbable, I've already agreed many times, but we don't yet know how improbable, especially because current discoveries suggest life is often carried between worlds (to the point where hypothesized life on Mars may be closely related to life on Earth, and said life may in turn originate from compounds that arrived on comets.)

Your response seems kneejerk and ill-founded in current scientific thought, both in terms of your misunderstanding of the enormously parallel scope of the universe across Hubble volumes and in terms of current thought re: shared ancestry biogenesis across worlds and maybe even stars.

And again I've said more than once now that I consider it very unlikely. Why you would possibly want to spend time arguing 'very unlikely' into 'even more very unlikely' escapes me.

[Bobboau]

because your response had an air of contrariety, if you agree don't argue.

also as far as I am aware, a literally spacial infinite universe is not consistent with current scientific theories of the universe and it's development.

[General Battuta]

also as far as I am aware, a literally spacial infinite universe is not consistent with current scientific theories of the universe and it's development.

Your awareness is incorrect. There are three possible topologies for the universe, flat, closed, and saddle-shaped. Current data points to the flat open infinite model.

EDIT - source: http://books.google.com/books?id=KhTJZG-U3ssC&pg=PA161

[Kolgena]

Uh, no.

Surprisingly (I guess), because the Big Bang produced elements that only interact in very specific ways with each other, certain organic structures are make-or-break for life to exist. For one, if it's not carbon based, it won't work. Silicon theoretically could, but it's not abundant enough, and its size is all wrong for it to work that nicely with the other life elements. I think it's less likely that we don't share at least a couple homologous structures or pathways (on a molecular level, of course. Who knows what happens when we get multi-cellular). It's either life doesn't exist anywhere else, or it does and has a pretty high chance that its biochemistry will resemble what we see on Earth.

On a slightly related topic, I think Mass Effect had an interesting take on this, using dextro-DNA turians as part of its lore. It was pretty much a coin flip for life on earth that our molecules are D or L conformation, so it's plausible that there are "mirror image" life forms out there that would be mutually lethal with us.

And Battuta, infinite universe doesn't actually imply infinite Earths. It could be infinite expanses of everything but Earths, or infinite expanses of nothing. It's pure sci-fi to suggest that there's another Earth with a Batutta, Bobboau, and Kolgena duking it out in a GD thread in an alternate HLP. (That aside, your source is almost a decade old. Since we're talking about astrophysics here, I'm not sure if that's reliable anymore)

[General Battuta]

And Battuta, infinite universe doesn't actually imply infinite Earths. It could be infinite expanses of everything but Earths, or infinite expanses of nothing. It's pure sci-fi to suggest that there's another Earth with a Batutta, Bobboau, and Kolgena duking it out in a GD thread in an alternate HLP.

Not so. It is not science fiction at all; it is in fact a mathematical inevitability. Multiply the probability of any non-zero-probability event by infinity and what comes out is an infinite frequency. The probability of the exact configuration of matter that is our entire Hubble volume coming into being is non-zero, because it happened; ergo it must happen an infinite number of times in infinite space assuming homology and isotropy of physical law and matter/energy distribution (neither of which condition we have any reason to believe is violated quite yet.) You will in fact end up with a mathematically predictable average distance between identical Earths, which can be calculated but which is larger than the radius of our Hubble volume.

Max Tegmark, an expert on this type of parallel universe, was a TA for one of my partner Rian's classes at MIT.

(That aside, your source is almost a decade old. Since we're talking about astrophysics here, I'm not sure if that's reliable anymore)

Possible, but it matches up with every other source I have read and I stay current. Obviously no total agreement exists yet, but I've been careful to point to trends in current data, not a total conclusion.

[Kolgena]

1) If the universe is infinite, it doesn't mean that there's infinite stuff in it. Space can be infinite, but the energy in the universe is definitely finite. Therefore, you don't have enough matter/energy to multiply all your probabilities by infinity.

2) Yeah, I'm not well read in modern physics at all, so I was just pointing out that your source is old. I actually have no idea what the current consensus (or lack thereof) is.

[General Battuta]

1) If the universe is infinite, it doesn't mean that there's infinite stuff in it. Space can be infinite, but the energy in the universe is definitely finite. Therefore, you don't have enough matter/energy to multiply all your probabilities by infinity.

I am 80% certain this is incorrect and based on a misconception. What is finite, and what matters to the topology of the universe, is the density of mass-energy. In an infinite isotropic homologous universe the total amount of mass-energy is infinite but it is divided smoothly.

[General Battuta]

Apparently Mr. Tegmark (see above for my intimate relationship with this talented and handsome cosmologist) has calculated the average distance to an identical Hubble volume as 10^10^115 meters.

[Kolgena]

I dunno. I'm having a hard time believing that moments after the big bang, when physics was beginning to materialize/stabilize, that there was a very big (but finite) blob of stuff containing infinite energy density and infinite energy. That **** was supposed to be the singularity.

Then again, there's the 0 energy theory which is nice and elegant, but gives no answer as to the finite/infinite nature of total energy.

Yep, several orders of OHGODMYBRAIN larger than a googleplex is pretty much infinite XD

Hm.. I just had some fun thinking about the aleph orders of infinity that would come into play here when we're talking about plugging in infinities into every term of every equation.

[General Battuta]

I dunno. I'm having a hard time believing that moments after the big bang, when physics was beginning to materialize/stabilize

Physics was already present and stable; it was just well past unification energy. What hadn't happened yet was symmetry breaking.

that there was a very big (but finite) blob of stuff containing infinite energy density and infinite energy. That **** was supposed to be the singularity.

No, there was an infinite blob of stuff containing infinite matter and energy at finite density. Don't fall into the trap of thinking that the universe was once finite and then became infinite; it was infinite the moment t > 0.

This whole issue of the Level I Hubble Volume parallels leads to one of my favorite scientific conclusions ever - all fictional settings that are physically possible have actually occurred. This in turn leads to conclusive proof that Batman is cooler than Superman: Batman exists out there, Superman does not.

[Kolgena]

At the same time, a useless, alcoholic, detained-in-asylum Batman exists as well, in infinite quantity, which is infinitely worse than an idealized but fictional Superman.

That's if I buy this "everything exists RIGHT NOW in INFINITE FREQUENCY" argument at all


Edit: Oh ****. There are infinite 4chans in the universe.

[redsniper]

But there are also infinite HLPs! (not sure if that's much better...)

[watsisname]

It's physically possible that an alternate civilization on some planet somewhere decided it was a good idea to create automated and self-preserving donut factories which ship the donuts to airports where they are then dropped from high altitude out of airplanes so that on their planet it would be constantly raining donuts.  Therefore, in an infinite universe, there are an infinite number of planets where it is constantly raining donuts right now.

**** YEAH.

[Flipside]

On the one hand, I intuitively agree with you. On the other hand, with amino acids similar to those that form the building blocks of life on Earth popping up in comets and distant nebulae, it may be that the fundamental ingredients are universal and that the structures we see are the optimum result.

Very, very doubtful. There's no particular reason that DNA has to be based on that particular set of nucleotides and sugars. Given the number of similar chemicals it's probably simple chance that we've ended up with this particular set rather than any other equally good set. And that's making the assumption that something like RNA is needed as a precursory replicator. If it isn't then it becomes even more doubtful.

Then you have to consider how the **** they're getting to the alien's DNA in the first place. This isn't a matter as simple as just ambling through the cell wall you know. Virii have spent millions of years getting very good at passing through cell walls. With an alien all that adaptation would be useless.

Bacteria are a completely different issue cause they can survive and reproduce quite well outside of the body but virii are parasites. I have a hard time believing that they could infect an alien species. They'd have to be far too similar.

That's my point, no-ones really answered how similar these aliens are going to be, everyone has this set of 'values' inside their head and if someone else's opinion doesn't match those values they must, therefore be wrong. As I pointed out earlier, considering this is a hypothetical conversation, it's not really a question of 'do my aliens match your aliens', the discussion was whether Earth would be worth invading for anything much, to which I still maintain the answer as being 'very, very unlikely'. A decent Space Suit can give you access to a vast number of planetary environments, there's little to be gained from all the effort of dealing with an alien Ecosystem with sentient life, whether those risks are biological, military, chemical etc, they are still a set of risks that simply don't exist if you go to a moon somewhere and mine.

[Bobboau]

it is not beyond reason that some alien race might have some sort of manifest destiny type ideology, a religion of conquest where it is there duty to subjugate all lesser life forms. that would give them a reason to invade, it doesn't have to be logical, it's religion after all.

[Flipside]

It's possible I suppose, but I do have a few problems with the concept that a race which was so violently intent towards its religion would ever successfully unite enough to develop space travel to that level. One of the main motors for development has been conflict, whether that conflict be over politics, land or religion, races that embrace fundamentalism to that level tend to end up being retarded in their development because change is frightening to them, I suspect an advanced race with that level of aggreesiveness would wipe itself out in internal arguments over details of that religion before they got to Space, indeed, even on Earth, fundamentalist countries that launch satellites etc rely heavily on technology developed by other, less fundamentalistic countries to give them a 'leg up', I'm not certain they could have got there by themselves. The most vocal skeptics of these kinds of religion, at least in our own society, tend to be the very people who develop the technologies needed for that kind of endevour.

This is, of course, applying a human viewpoint to alien thinking, and may be completely wrong, since this exact situation is a real threat to our own future, but unless the alien phsychology towards that religion is significantly different to our own (a possibility, as I said) I think the likelyhood of 'Star Crudaders' as it were, to be limited.

[Bobboau]

I could see it as very easy for a species to develop with a belief system that they are the ultimate creation of the universe and all others are made to serve them and this not result in internal conflict if on their home world, before they make contact with another intelligent race, this manifests in the form of domestication of animals, and when they go out into the stars everything they find they view the same as animals.