Are we Alone in the Universe

Do you believe that there are many other advanced civilizations on planets around other stars in the galaxy?  Carl Sagan said something like this “if we are alone in the universe it would be an amazing waste of space”. I believe otherwise, that it is quite possible that we are the only planet in the galaxy with a technologically advanced civilization. The emergence of life, from unicellular to intelligent, on planets, particularly here on earth. Here are some corroborative facts I’ve been reading from various sources. 

If we suppose that life is easy to start (which I'm not entirely convinced, The RNA world hypothesis has many problems and is difficult to validate), a technological civilization like ours is certainly not easy to come by. There was an amazing consilience of events that occurred in the solar system and on earth that made possible the advent of advanced sentient life on earth. 

Just to name one, when the solar system formed planets there were five rocky planets and four gaseous planets initially. The fifth rocky planet, Theia, was about the size of mars and had an iron core similar to the earth. Fortunately Theia had an orbit very close to that of the earth. At some point, soon after the creation of the solar system, it collided with earth. The effect was that the outer crust of the earth and Theia were blasted into space and formed the moon.

This event was very conducive to creating life on earth including simple unicellular and higher life forms. The main reasons are:

- the formation of a thin crust, and therefore plate tectonics which enabled the formation of land instead of a water world and helped regulate climate

- the formation of a large iron core which created a strong magnetic field thus deflecting the life harmful charged particles (from the sun, etc.)

- because the moon is so large it acts as a stabilizer of the earth's 23 degree inclination. Before the formation of the moon the earth's inclination varied from 0 to 90 degrees which created havoc with climate made the earth not very conducive to create life

- the production of tides highly responsible for life migrating from water to land

There are dozens of effects that the formation of the moon enabled not only life, but intelligent life on earth. In addition to the formation of the moon there were a large number of factors that enabled the formation of our mother planet with just the right combination of elements, orbit, etc. for a technological civilization to emerge.