> The big argument against intelligent life being common (and us not being unique) is the existence of stars. No civilization more advanced than us is going to

> The big argument against intelligent life being common (and us not being unique) is the existence of stars. No civilization more advanced than us is going to let stupendous amounts of energy go to waste in the form of star light. If you assume von Neumann probes and Dyson spheres are possible, then star light is incompatible with the existence of advanced technology. What about undetected energy aka dark energy. > Just one factor contributing to this stability is the need for a very large moon to keep the axis of rotation stable over billion of years. If the Earth didn't have its moon the Earth's axis would tip over creating massive climatic change. The more we look at the universe the more unlikely the stability of Earth's climate looks. I have heard this argument but I don't buy it compared to the need for asteroid protection. Things can get various like climate living underground/water. One of the critical things about our solar system that made life happen with out having a mega earth planet with crushing gravity is the presence of Jupiter and Saturn. Jupiter and Saturn were in our solar system at the right place and right time. This theory is called the "Grand Tack" [1] and was recently covered in Scientific America. Needless to say Jupiter continuously protects us from asteroids and various other objects from colliding with us on a continuous basis and not our axis. [2] Continuous asteroid collisions vaporize oceans and destroy atmospheres along with other various debilitating things. [1]: https://en.wikipedia.org/wiki/Grand_tack_hypothesis https://en.wikipedia.org/wiki/Grand_tack_hypothesis [2]: http://imgur.com/gallery/DCLp8yc http://imgur.com/gallery/DCLp8yc