More on Life In the Universe

"Save the Earth! It's the only one with tacos."

This Hank Green podcast with Dr. Katie Mack picks up on my thoughts about life in the universe. Two new take-aways:

1. Earth is already more than 80% through its habitability window. (That is, before the sun starts to puff out and boils the oceans.*) Over 80% and we're still not an interstellar species.

When life arises, it doesn't have infinite time develop to get to the point where a species is sending out Von Neuman probes. As mentioned before, the vast majority of the history of life on Earth was just single cells. Even after complex life arose, give just the tiniest nudge to the Chicxulub meteor and dinosaurs would still rule the Earth.

2. Even if life sometimes progresses toward intelligent, technological specie(s), it is not inevitable they will want to expand out into the galaxy, no matter how much space nerds want us to.

Some population projections say the number of humans will fall significantly in the next few centuries. Once we get our energy house in order (nuclear) we should be able to increase everyone's quality of life and live incredibly well (far better than on Mars, let alone on an interstellar ship) within the "confines" of this planet. 

* If we needed to, we could already build a solar shield to adjust the amount of sunlight reaching the earth. There should be no problem extending Earth's habitability until the sun gets much bigger / brighter.