Will Aliens be Bear Sized?
In a paper titled The Nature of Inhabited Planets and their Inhabitants, author Fergus Simpson argues that the size of aliens in our universe, if aliens even exist, could be predicted. Using Bayes theorem and a variety of different modeling curves to highlight what extraterrestrial life could be like Simpson was able to come to a pretty specific guess of aliens median weight. Simpson hypothesizes that the median weight of an alien would be approximately 692 lbs. This very specific guess has sparked debate among other scientists who argue whether or not his predictions could be valid.
So, how does this odd model work? Simpson used a complicated version of Bayes’ Rule that we learned in class. (The link to the professional paper is below) For example, Simpson used the conditional probability of a civilizations at a fixed time and analyzed how it differs from one sample by an individual using Bayes’ Rule. (page 2 of report) However, the project can be simplified into a more understandable analogy. If you model different species in the universe similar to how different countries and their populations are distributed then you notice some interesting trends.
Say you were to randomly pick a person on Earth. The odds are 1 in 5 that that person will be from China. Similarly the odds are about 1 in 1600 that you’ll get someone from New Zealand. (Live Science) However, there exist significantly more countries that are the size of New Zealand than the size of China. So we would say that China is an extreme group and there exist more populations that are like New Zealand. Similarly, there would exist more civilizations in the universe that are New Zealand sized than China sized. If we assume that countries and their population size are distributed similarly to that of different civilizations in the universe then we can plot a bell curve (not a normal curve) that would predict median civilization size. The weight of an alien was calculated in a similar manner. If you plot the relationship between size and population on a bell curve you find out that the median weight of an alien would be 692 lbs.
http://www.livescience.com/50864-aliens-will-be-bear-size.html
http://arxiv.org/abs/1503.07804
http://themoderatevoice.com/205271/scientist-aliens-will-be-bear-sized/