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entirelyuseless comments on [Link]: KIC 8462852, aka WTF star, "the most mysterious star in our galaxy", ETI candidate, etc. - Less Wrong Discussion
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Comments (43)
The star is 1,480 light years away. Any aliens there will never affect us.
Us personally? That depends on when they started their attack.
If they are a really old and hostile civ, then they already would have found and destroyed us. Since that is not what we observe, they are either not hostile or are relatively young.
Assume for a moment the worst case - they are hostile and young. Due to observation selection effects, most observers detect either no alien civs or alien civs around their same age.
Say it takes 1000 years to go from early space civ (us today), to megastructure civ (them), and say 100 years from early space to get large space telescopes/sensors sufficient to detect most earth size planets within a few 1,000 lyrs. So they are only about 1000 years ahead of us, but 1480 years away.
They would build interstellar sensors around 1100 AD, at which point they would image us from 380 BC. They'd see a biosphere, but hopefully not yet any evidence for civilization, as that shouldn't really be detectable until the industrial era - about 2200 years later.
To detect earth civ circa 380 BC or earlier they'd probably need images from a probe near the planet or at least near the sun, which implies a minimum of ~3000 year round trip time.
In general, I think one can construct an argument that we should expect to have roughly order ~D time until any contact/invasion, where D is the distance in lyrs between us and the alien civ.
Except that a SETI-type attack such as the one described in Hoyle's A for Andromeda (mentioned in the link provided by turchin above) would not necessarily target us specifically; it could be launched by aliens with no knowledge of our existence.
They could send information in form of radiowaves and it could be description of unfriendly AI
What probability do you assign to this happening? How many conjunctions are involved in this scenario?
I estimate total probability of human extinction because of SETI attack in 1 per cent. But much smaller in case of this star. There are several needed conjunctions: 1.ET exist but are very far from each other, so communication is wining over travel. 1 milion light years or more. 2. Strong AI is possible.
So, you see a SETI attack as primarily useful for intergalactic colonization/expansion? It seems to me that a SETI attack would be an efficient way for a civilization to expand within a galaxy as well. Why do you think it would be useful only at such great distances?
Can you explain why you see a SETI attack as so high? If you are civilization doing this not only does it require extremely hostile motivations but also a) making everyone aware of where you are (making you a potential target) and b) being able to make extremely subtle aspects of an AI that apparently looks non-hostile and c) is something which declares your own deep hostility to anyone who notices it.
It results from exponential growth of victims in case of successful SETI-attack. The new victims will send the signal further. It is like virus behaviour. a) we know only location of the previous victim, not the starter. b) not so difficult if sender is more advanced civilization and AI may looks like a helper or gateaway of space Internet. с) the same as a. We don't know who started it. We could see only victims.
Anthropic selection effects make hostile expansive aliens improbable.
Assume that life is plentiful and hostile civs are common. If that was the case then most observers such as ourselves would find themselves on unusually early planets. Instead our planet is somewhate late in the order of all habitable planets to form in our galaxy, and is roughly in the middle for all habitable planets in the universe.
But in fact last research said that our planet is in only first 8 per cent of all habitable planets in the Universe, so probably the opposite is true and future universe is full planet-colonizing alien civilizations.
But if SETI attack is only way of space colonization, no starships, in this case before-radio civilizations will be distributed randomly.
As I pointed out in the other thread, first 8% is not early at all - it is firmly in the middle, statistically speaking. Early would be first 0.000001%. 8% is much closer to the middle than uncertainty in the estimate - well within one std.
Well yeah if there are SETI attacks but no colonization, then sure there could be lots of civs like ours that get snuffed out, and that scenario is still compatible with our observations. I think it's unlikely though for the same reasons any SETI broadcasts are unlikely, as SETI broadcasts don't have much of a purpose, and the scope is narrow. (attack or communication only makes sense between civs at similar development points, and such temporal encounters are unlikely - the number of civs in the galaxy that are within +- 100 years of our dev level is probably < 1, even if the total number of civs in the galaxy is large)
I think that once a civilization fail victim of a SETI atack, it could broadcast for millions or even billions years, spending almost all its resources on it. It will build Dyson sphere and use all it energy to broadcast on maximum possible distance.