The Drake parameter R* = The rate of star formation (new stars / year). It is set to LogUniform(1,100), meant to be representative of the Milky Way. I can easily replace that in the model with 2000*LogUniform(1,100) to explore your question. The other Drake parameter that might need some thought is f_c = The fraction of intelligent civilizations that are detectable / contactable. For now, let’s not alter this one. The other Drake parameters shouldn’t really change, at least assuming they are similar galaxies.
With that change to R*, P(N<1) -- the probability there isn’t another in the Virgo cluster, becomes 81% (for the 2nd model version with the t V λ decomposition for f_l, which had previously been 84%). The 1st model version that used a LogNormal for f_l changes from 48.5% to 38%.
The versions that explored a less extreme model of f_l (the rate of abiogenesis) see a much bigger change. For example, when f_l is set to 100%, it changes from 10% for Milky Way to 0.05% for Virgo. The Beta distribution version of f_l goes from 23% to 1%.
Your intuition might be that the prob. of being alone would drop by a factor of 2000, which obviously isn’t what happens. What you do see is the distribution for N = # of detectable civilizations (which is a probability dist, not a point prob) shifts right by a factor of 2000. But that doesn’t mean the area under N<1 sees that same change.
The Drake parameter R* = The rate of star formation (new stars / year). It is set to LogUniform(1,100), meant to be representative of the Milky Way. I can easily replace that in the model with 2000*LogUniform(1,100) to explore your question. The other Drake parameter that might need some thought is f_c = The fraction of intelligent civilizations that are detectable / contactable. For now, let’s not alter this one. The other Drake parameters shouldn’t really change, at least assuming they are similar galaxies.
With that change to R*, P(N<1) -- the probability there isn’t another in the Virgo cluster, becomes 81% (for the 2nd model version with the t V λ decomposition for f_l, which had previously been 84%). The 1st model version that used a LogNormal for f_l changes from 48.5% to 38%.
The versions that explored a less extreme model of f_l (the rate of abiogenesis) see a much bigger change. For example, when f_l is set to 100%, it changes from 10% for Milky Way to 0.05% for Virgo. The Beta distribution version of f_l goes from 23% to 1%.
Your intuition might be that the prob. of being alone would drop by a factor of 2000, which obviously isn’t what happens. What you do see is the distribution for N = # of detectable civilizations (which is a probability dist, not a point prob) shifts right by a factor of 2000. But that doesn’t mean the area under N<1 sees that same change.