Re:The Big Alien Theory
by jjk166 on Wednesday June 02, 2021 @10:57AM
(#27369433)
The author goes far beyond just assuming power law distributions.
> We don't yet know the breadth of planet sizes on which intelligent life exists. Some will be larger than others. The larger planets have a greater area, and receive more energy from their star. Therefore they are capable of sustaining larger populations, on average.
It is a major leap to go from planets with larger surfaces sustain larger populations. For starters, increased planet size will increase gravity, which means everything needs to expend more energy and either animals or their food getting larger becomes more difficult. Then what effects will this larger planet have on plate tectonics and continent formation. Further, life does not spread out uniformly over a planet's surface, compare the land area of vietnam to siberia and ask where you would expect to find larger populations.
> A similar connection between area and population is seen among countries on Earth. Those with a larger population also tend to have a larger area.
Compare Canada to Bangladesh. The sizes of nations are an incredibly complex function of conquests and mergers where tiny feudal states tended to get gobbled up by larger polities who in turn became stronger and able to acquire more territory, which was critical to pre-industrial societies where population density was constrained by area and then break apart into smaller polities during industrial times when population densities were not so constrained. Planets have no analogous function - Earth doesn't get the moon's land area because it is more populous, nor does it break into tinier planets as humans gain technology. If instead of countries we looked at continents, we'd see 5 out of 7 do not match the prediction.
On the topic of individual size, the author assumes that if a human is a normal member of a group with the variation in size of the great apes, the average size should be 320kg. Obviously though if you applied the exact same logic to the great apes, you'd be way off. Indeed looking at earth, most species tend to be small. The simple assumption that just because something results in a smaller population size means it should lead to more populations is clearly incorrect in this case, and likewise is questionable in other cases where there isn't a clear causal link.
More generally, the author's logic is a permutation of the doomsday argument, which while being mathematically intriguing is widely critiqued as a method of making predictions about reality.
> We don't yet know the breadth of planet sizes on which intelligent life exists. Some will be larger than others. The larger planets have a greater area, and receive more energy from their star. Therefore they are capable of sustaining larger populations, on average.
It is a major leap to go from planets with larger surfaces sustain larger populations. For starters, increased planet size will increase gravity, which means everything needs to expend more energy and either animals or their food getting larger becomes more difficult. Then what effects will this larger planet have on plate tectonics and continent formation. Further, life does not spread out uniformly over a planet's surface, compare the land area of vietnam to siberia and ask where you would expect to find larger populations.
> A similar connection between area and population is seen among countries on Earth. Those with a larger population also tend to have a larger area.
Compare Canada to Bangladesh. The sizes of nations are an incredibly complex function of conquests and mergers where tiny feudal states tended to get gobbled up by larger polities who in turn became stronger and able to acquire more territory, which was critical to pre-industrial societies where population density was constrained by area and then break apart into smaller polities during industrial times when population densities were not so constrained. Planets have no analogous function - Earth doesn't get the moon's land area because it is more populous, nor does it break into tinier planets as humans gain technology. If instead of countries we looked at continents, we'd see 5 out of 7 do not match the prediction.
On the topic of individual size, the author assumes that if a human is a normal member of a group with the variation in size of the great apes, the average size should be 320kg. Obviously though if you applied the exact same logic to the great apes, you'd be way off. Indeed looking at earth, most species tend to be small. The simple assumption that just because something results in a smaller population size means it should lead to more populations is clearly incorrect in this case, and likewise is questionable in other cases where there isn't a clear causal link.
More generally, the author's logic is a permutation of the doomsday argument, which while being mathematically intriguing is widely critiqued as a method of making predictions about reality.