Many have tried to estimate how far away are aliens. For example, some apply the Drake equation, which is the product of 7 parameters, some of which can vary over quite wide ranges. Resulting estimates tend to be quite uncertain and disputable.
Would you care to speculate on what might occur in a civilization if biological and medical advances paralleled other technologies and essentially offered the possibility of immortality?
Quite aware. Dr. Wright is a leading SETI researcher, and many of my opinions are formed from his work. G Hat was funded by a private donation. Unfortunately his work is often taken to be evidence of absence, instead of what it really is: an important narrowing of parameter/search space.
Mercury is in 3:2 resonance with our Sun.
One key thing about red dwarf tidal locking that I wish I understood is whether planets generally lock 1:1 or get into a resonance that is not 1:1.
In case you're unaware, Jason Wright's G-Hat project is a great source of this search for techno-signatures. https://sites.psu.edu/astro...
Clearly visible implies we've attempted to look for the clearly visible. Luckily NASA has come around and has restored funding to looking for Technosignatures.
Thirty years of dismantling the Hart-Tipler Conjecture in the literature may have something to do with it, but no one said overcoming bias was easy :)
It is evidence of their failure to reach the "clearly visible" step. They may have reached other steps.
Agreed that there are no clearly visible alien civs. I disagree that this is evidence of their absence - especially before we actually look.
Surely if we take "clearly visible" literally, there are no clearly visible alien civs. Yes, there might be civs that are not visible. But if so they can't have expanded very far and changed how their sphere of control looks a lot.
I've been a fan of the Future Humanity Institute for nearly a decade now - and I've enjoyed talks by you, Stuart Armstrong, and Nick Bostrom.
The issue I have with this model is the statement "The fact that we now see no alien civilizations anywhere strongly suggests that any one oasis (e.g., planet) has a very low chance to start from simple dead matter and then give rise to a clearly visible civilization." This seems, for lack of a better word, to be a bias shared by many scholars.
There have been a number of papers that quantify the amount of searching that we have done, and it's very small. Why cannot we use knowledge about the universe as we know it to help us create our best model?
In any population of GC there will be a first and potentially a second. Doesn't this make the question of 'when is the earliest the universe could support a GC?' an important parameter?
The amount of time between the first and second, and the speed at which a GC can do its grabby stuff become the second and third parameter.
Obviously this goes against the assumptions you detail, but I believe exploring these parameters shows a reasonable estimate - that the GC already happened long ago.
Okay, thanks, I’ll look for that recent post before I bother you with more questions.
Flares and tidal locking are less of a problem for water worlds. And they are mainly a problem for multicellular life, so most other steps could take place in an earlier Eden, as per my recent post on that. And whatever steps have to take place around a star like ours could still happen much later in the universe's history.
Robin, the dwarf stars that live substantially longer than our sun have devastating flares, and the habitable zones are so near to the star that the planets in them are tidally locked. They are also more common than Sol-type stars. The fact that we find ourselves orbiting a shorter-lived, less common star does imply poor habitability issues with the dwarf stars. Doesn’t all this interfere with your assumption that if civilizations are super-rare they should find themselves later in the age of the universe?
To be pedantic, in the common parlance "risk of" usually refers to an unfavorable outcome. Favorable outcomes are usually a "chance", "prospect" or "opportunity".
at risk of being awesome, and kicking some alien ass!
This reminds me of the Berezin article, who suggested that the only logical explanation of the Fermi paradox is that we are the first civilization and we will kill all other civilizations (in the nearby region of space). But here you make one step forward and find the size of this nearby region of space.
Also, if the distance between civilizations is around 1Gy and they are agressive, then sending malicious data (SETI-attack) becomes a viable option as it outperforms all other ways of transportation.