41–50 of 102 posts
I find the definition of intelligent life, specially as given by astronomers, amusing. Looking for a second carbon-based lifeform, in a planet identical to Earth, beeping out on the radio spectrum, in the same time frame as us? How cute. Meanwhile, we miss a bigger definition of life right under our noses. Unfortunately reductionism is ingrained in science.
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>Where are the macrostructures? We don't see Dyson spheres or other evident macroscale engineering. Everything we can see so far looks natural. This is more troubling than an absence of detectable communications. Assuming a Dyson sphere was nearby, how would we detect it? What would it look like? If it's able to make use of most of a star's radiation output, wouldn't that make it very difficult to see? It wasn't unti…
The black space is at about 3 Kelvin temperature. A Dyson sphere would necessarily (the star inside would heat it) have a much higher temperature than mere 3 K above the absolute zero. Thus it would radiate heat according to whatever its temperature, and be quite distinct compared to the cold back space background.
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The ground assumption in all of this is that we have some comprehension of the technological end-game / plateau. I.e. that a civilization far more advanced than our own will still care about solar energy and EMR communications. Who is going to build a Dyson Sphere for fun? We could be totally wrong about this. We probably are. The other possibility is that there's not much more technology for us. Can we build self-re…
To be clear, "self-replicating probe" includes all technologies that can transport, at a minimum, human genetic material, a record of all human science and technology to date, and creche-building technology to a distant star. So a few grams or kilograms of bootstrap molecular nanotechnology, computing material, shielding, some form of reaction engine, fuel for deceleration, and fired by the hundred from a solar-syste…
The idea that you can seed the universe with civilizations in the manner described is highly dubious. You're assuming someone advanced enough to do this yet primitive enough to want to do it and that "it" works at all. Suppose that the galaxy produces one star system in a thousand with a suitable planet, and the seed has a one in a thousand chance of actually producing a successful replication. (Both of these one in a thousands seem to me to be quite optimistic.) The equations look a lot less deterministic.
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Even a Dyson sphere can't just swallow the star's radiation. It makes use of a potential gradient, which means it would have to radiate away some energy on the outside. This would probably show up as, say, a brown dwarf. Still, if it's not in our direct neighborhood the chances of us discovering it are even lower.
The Wikipedia article defines a Dyson sphere as a system of orbiting solar-power satellites meant to completely encompass a star and capture most or all of its energy output.
The way I view it, by definition someone has to be first. We just don't know enough about all the variables, such as noted by others in this discussion the probability of evolving to sentience, to state with any confidence that we can't be the first in our galaxy or the portion of it that we're looking at.
According to whom? See https://en.wikipedia.org/wiki/Relativity_of_simultaneity
The way I view it, by definition someone has to be first. We just don't know enough about all the variables, such as noted by others in this discussion the probability of evolving to sentience, to state with any confidence that we can't be the first in our galaxy or the portion of it that we're looking at.
>The way I view it, by definition someone has to be first. no :). That is the beauty of this Universe - global full order of things on timeline isn't possible. Specifically space-like separated events don't have a preferred order, i.e. given 2 space-like separated events A and B, both statement - A precedes B and B precedes A - have the same validity, basically it is meaningless to talk about their timeline order.
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>Where are the macrostructures? We don't see Dyson spheres or other evident macroscale engineering. Everything we can see so far looks natural. This is more troubling than an absence of detectable communications. Assuming a Dyson sphere was nearby, how would we detect it? What would it look like? If it's able to make use of most of a star's radiation output, wouldn't that make it very difficult to see? It wasn't unti…
Even a Dyson sphere can't just swallow the star's radiation. It makes use of a potential gradient, which means it would have to radiate away some energy on the outside. This would probably show up as, say, a brown dwarf. Still, if it's not in our direct neighborhood the chances of us discovering it are even lower.
Intelligence may not be adaptive from the gene perspective. One can see a large number of plausible reasons this might be the case by observing human society and humanity as a whole. If it is in fact true, appearances of that trait would likely be rare and short lived across the universe.
The other great apes are quite intelligent and occupy the top spots in their ecological niches. Bottlenose dolphins pass the mirror test for self-awareness and appear to have individual names [1], and are at the top of their ecological niche. Elephants pass the mirror test and are at the top of their ecological niche. Octopuses are surprisingly intelligent for invertebrates, and are among the top predators in their n…
It would suggest cognitive thought or at least, competence is a "mutation" forced upon the life-form by environment(s).
Time would only play a miniscule, but essential part in that process until the life-form figured out time doesn't seem to matter too matter.
Obligatory talking points associated with the Fermi Paradox: - It takes a very short time in comparison to the age of the galaxy for a single self-replicating probe to result in a descendant probe visit to every star. A few million years. This means that you cannot really argue plausibly that all civilizations fail to do this - it would take trivial effort for just one faction within just one advanced civilization to…
Where are the macrostructures? We don't see Dyson spheres or other evident macroscale engineering. This might be a stupid question, but could the Red Square Nebula be considered a candidate? http://en.wikipedia.org/wiki/Red_Square_Nebula
Regards,
There might be billions of rockballs in the galaxy with life and intelligence at some level, maybe even up to the level of say a dolphin or a dog or even a chimpanzee on the high end. This might be the status today, or for the last hundred million years and the next hundred million. But those planets (and other orbs of lifebearing rock) aren't going to be sending spaceships our way anytime soon.
But let's suppose there's a million space capable intelligences spread out equally in the Milky-Way...what's the probability of them giving our particular system any interest whatsoever? The Drake equation is a fine estimate for the number of civilizations, but not for the probability that they'll contact us.