I live in San Diego. I have been telling my roommate that I have been hearing these booms the last several months. He thought I was crazy until I pointed them out to him. Now he hears them constantly and is seriously wondering himself.

They happen when there are no planes around, nothing in the sky and nothing huge happening on the ground. I have felt the ground below my feet sink a couple times. Really bizarre.

I have no clue what is hapoening but I can tell you it's very real.