It&#x27;s an uninformative prior (<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Prior_probability#Uninformative_priors" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Prior_probability#Uninformativ...</a>). Meaning it&#x27;s the best estimate you can make, if you don&#x27;t have any additional information about the problem. Obviously we have a lot of additional information on human lifespans, which allows us to build a more accurate probability distribution.<p>Also see my comment above.