Robin Hanson’s writing on Grabby Aliens is interesting to me, since it seems to be one of the more sound attempts to apply mathematical reasoning to the Fermi Paradox. Unfortunately, it still relies on anthropics, so I wouldn’t the slightest bit surprised if it was off by an order of magnitude (or two) in either direction.
What I would like to know (preferably from someone with a strong astronomy background) is: how confident are we that there are no (herein defined) Extremely Obvious Aliens?
Extremely Obvious Aliens
Define Extremely Obvious Aliens in the following way:
They colonize every single star that they encounter by building a Dyson swarm around it that reduces visible radiation by at least 50%
They expand in every direction at a speed of at least 0.5C
They have existed for at least 1 billion years
If such aliens existed, it should be really easy to detect they by just looking for a cluster of galaxies that is 50% dimmer than it should be which is at least 0.5Billion light years across.
How confident are we that there are no Extremely Obvious Aliens?
As with Grabby aliens, it is safe to say there are no Extremely Obvious Aliens in the Solar System. Nor, for that matter are there any Extremely Obvious Aliens within 0.5BLY of the Milky Way Galaxy.
So, for my astronomy friends. What is the biggest radius for which we can confidently say there are 0 Extremely Obvious Aliens? The best answer I can come up with is SLOAN, which was done at a redshift of z=0.1, which I think corresponds to a distance of 1.5BLY.
Is this accurate? Namely, is it safe to say (with high confidence) there are no Extremely Obvious Aliens within 1.5BLY of Earth?
Is there another survey that would let us raise this number even higher?
What is the theoretical limit (using something like JWST)?
Has someone written a good paper answering questions like these already?
[Question] How confident are we that there are no Extremely Obvious Aliens?
Robin Hanson’s writing on Grabby Aliens is interesting to me, since it seems to be one of the more sound attempts to apply mathematical reasoning to the Fermi Paradox. Unfortunately, it still relies on anthropics, so I wouldn’t the slightest bit surprised if it was off by an order of magnitude (or two) in either direction.
What I would like to know (preferably from someone with a strong astronomy background) is: how confident are we that there are no (herein defined) Extremely Obvious Aliens?
Extremely Obvious Aliens
Define Extremely Obvious Aliens in the following way:
They colonize every single star that they encounter by building a Dyson swarm around it that reduces visible radiation by at least 50%
They expand in every direction at a speed of at least 0.5C
They have existed for at least 1 billion years
If such aliens existed, it should be really easy to detect they by just looking for a cluster of galaxies that is 50% dimmer than it should be which is at least 0.5Billion light years across.
How confident are we that there are no Extremely Obvious Aliens?
As with Grabby aliens, it is safe to say there are no Extremely Obvious Aliens in the Solar System. Nor, for that matter are there any Extremely Obvious Aliens within 0.5BLY of the Milky Way Galaxy.
So, for my astronomy friends. What is the biggest radius for which we can confidently say there are 0 Extremely Obvious Aliens? The best answer I can come up with is SLOAN, which was done at a redshift of z=0.1, which I think corresponds to a distance of 1.5BLY.
Is this accurate? Namely, is it safe to say (with high confidence) there are no Extremely Obvious Aliens within 1.5BLY of Earth?
Is there another survey that would let us raise this number even higher?
What is the theoretical limit (using something like JWST)?
Has someone written a good paper answering questions like these already?