[Moved from SearchForIntraTerrestrialIntelligence:]

A long, long time, when the universe was still hot and radiation-dominated, life evolved for the first time. It was very unlike life as we know it: it was life on the scale of subatomic particles. In those days, quarks were still roaming free, and so complex structures at the scale of atoms could exist. Since everything was so extremely hot, processes went much faster than they go nowadays. A second to us is like a thousand years to the creatures that were created during the first few years after the BigBang. Of course, when the universe started to cool down, they were sufficiently advanced to ensure their own survival.

OK, so where are they now? If a second to us is a thousand years to them, and they are 15 billion years old, they should be pretty advanced by now. They probably have complete knowledge of the scientific laws, and even know how to produce quality software in time and within budget. If they really exist, they should rule the universe by now, probably using all the universe's resources to try and recreate as much as possible the conditions during the first years after the Big Bang.

And then I looked out of the window, to the night sky, and saw thousands of small, hot spots called "stars". Looked like an ideal habitat for the FirstOnes to me...

-- StephanHouben

''Yes, now you're getting it. But remember, we're made of StarStuff ourselves. At the very least, if the FirstOnes are technological, with the right microscope - something crossed with a sieve - we should be able to find their artifacts. NanoFossils, if you will. And then we could try to reverse-engineer them ...'' 

''I'd bet they'd be far beyond our ability to comprehend. But it'd sure be fun to try! At the very least we might be able to salvage their designs for basic mechanisms - their levers, gears, pulleys, and so on, and maybe put together a communications device to talk with the inhabitants of the sun ...'' -- PeterMerel

I've always thought this was a joke but this page leaves it unclear and some people seem to be taking it seriously. Since no arguments nor references are provided, let's look at what would be necessary for SiTi to be at all credible.

First, we should consider the conditions necessary for complex structures to emerge at our energy scale. (A different form of complex structure might be based on cellular automata.)

Molecules exist because of complex interactions occurring on two distance scales by two extremely different forces of nature. The strong nuclear force holds many different types of nuclei together. It's what's responsible for the existence of carbon, nitrogen and oxygen nuclei. Then, on a much larger scale, the electromagnetic force is responsible for the complex interactions between these very different nuclei.

How does this scheme translate to different conditions? Not very well at all. You can forget any notion of complex structure before gravity split off from the GUT force because until that point there was only one force. And after that happened, we're talking about objects so massive that gravity is on the same scale as the unified GUT force. These exotic massive particles probably wouldn't survive in a hot star any easier than they would in vacuum. The cold of a 100 billion kelvin medium-sized star would quickly freeze any hypothetical SiTi''''''s to death.

''Just what this tangent has to do with molecular nanotech civilizations is mysterious to me. Of course, like everyone else here except RK, I am a stupid person, but can you explain the connection?''

There is none because this page has nothing to do with nanotech (in the usual sense of "molecular") civilizations to begin with. This page postulated small civilizations based on things ''other'' than molecules.

''It doesn't? What the heck do you think Pete was talking about at the top of the page with "intelligent artifacts on the nanoscale"? Did you think he meant some kind of tiny packing-peanuts?''

What do you think Stephan is talking about above "when the universe was radiation dominated"? And why is Peter agreeing with him? Do they just have absolutely no clue about cosmology? Do they not know that carbon didn't even exist "in the first few years of the universe", never mind molecules nor life-forms made from it? I prefer to infer what they're thinking from something more substantial than a throw-away line.

''You elevate your preference to an axiom? No other interpretation permissible by you? Why?''

Sigh. Really.

If "Intra"-TerrestrialIntelligence were nanotech based and it was here, then it's pretty clear that it would annihilate humans and do so within a few hours. Humans need carbon atoms, and nanomachines need carbon atoms and the competition would be swift and merciless. The idea that humans and hostile nanotech can coexist is absurd. The idea that alien nanotech would be benevolent to humans is nonsense, as even fans of SiTi admit. The idea that alien nanotech is passive to the point of stupidity is also absurd. So dealing with SiTi as a form of nanotech is really very uninteresting.

It's not that no other interpretation is permissible by my godly all-controlling self, it's that no other rational interpretation is ''possible''. None has ever been constructed. Saying nonsense like "alien AI/nanotech civilizations will be completely alien to humans to the point where not one of their members are self interested '''at all''' and they're all stupid and passive" or claiming nonsense like "alien AI/nanotech civilizations will transcend the need for computation and energy" isn't constructing anything like an alternative interpretation.

The closest that people have come to something like a reasoned argument for SiTi is to claim that SiTi doesn't function on atoms at all but is subatomic. Since that's something that at least ''resembles'' an argument, I deal with it seriously below. That's being as charitable as it is possible for any person to be and still care for truth.

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That actually brings up an extremely serious problem for any hypothetical SiTi''''''s. It isn't sufficient that structure be theoretically possible. Something has to actively maintain that structure. If they're life-forms then they must use energy to process information (see DefinitionOfLife) but where did the temperature differential come from for them to feed on? We know that the universe at a very early age was extremely uniform, far more uniform than it is today, so how do you drive a heat engine in a homogeneous soup? 

The temperature of intergalactic space is 3 degrees Kelvin. The temperature of a star can easily be hundreds of millions of degrees. That gives temperature differentials of 8 orders of magnitude.

In contrast, the temperature differentials in the Cosmic Microwave Background are on the order of 20 '''micro''' Kelvins (http://www.astr.ua.edu/keel/galaxies/cmbr.html) and the temperature of the CMB at the time was around 3000 degrees Kelvin (http://www.astro.ucla.edu/~wright/BBhistory.html). That's a temperature differential of '''minus''' 8 orders of magnitude. Even the temperature differential available to animals in Earth's insulating atmosphere is at least a tenth of an order of magnitude (ie, 30 degrees at 300 kelvin).

Now here's another fact about life's relation to temperature. In order to maintain coherent information (ie, live) at a higher temperature you need ''more'' power. And not just 'more' but a ''lot more'' since power consumption rises with the '''square of the temperature'''. At 300 kelvin, the human body uses 100 watts. At 3000 kelvin (temperature at last scattering), an equivalently complex organism would need to consume 10,000 watts. At 20,000 kelvin, they would consume 400,000 watts. Where the hell did all that power come from?

''Well, enthalpy in the photosphere of a star seems vastly more than sufficient ... but if your nanites can encode a whole copy of their civilization on the point of a pin, why would they consume so much energy as a gross human body? Seems they'd be tremendously more efficient than we poor accidental things.''

I don't think you understand the point made above. The idea is that ''evolved life-forms'' could not possibly exist in the environment of the very early universe. Some constructed beings ''might'' exist at very high temperatures and very low heat differentials but even that is extremely doubtful. And how those beings could be constructed without any evolved intelligence to construct them in the first place ....

''I take your point about the EarlyUniverseIntelligence notion. Happily SiTi isn't predicated on EUI. The notion that a SiTi would be competing for carbon atoms, however, seems pretty naff. SiTi wouldn't be very interested in cold little pebbles like the Earth. Lots of more useful environments for a SiTi than here!''