On Earth, these odds were beat even with massive climate changes occurring from time to time.

Add to that the problem of finding the right gravity range for varied enough life forms to compete in varied enough ways… a likely pre-requisite for intelligent life to evolve.

Then figure that no catastrophic stellar events could have occured within a few dozen light years of the planet in question.

Then avoid the problems of self-defeat discussed above.

All things considered, it’s no wonder we’ve found no sign of extra-terrestrial intelligence.

Good show, Tom!

Take Earth’s case:

Things are getting so bad with regard to day to day survival that spending a huge amount of resources and money on interplanetary exploits may prove prohibitive.
Even if we survive and at some point in the future pool international resources to attempt an interplanetary excursion, a simple accident or unluckky mishap could derail any further attempt from happenning ever again.

Think about it:

Say a trillion dollars or more (or the equivalent in today’s wealth)were spent on an attempt to colonize Mars. With all of the problems on Earth, it would take a lot of effort to convince the public that such a project is worth the expense. None-the-less, the project is tried, the colony gets a foothold, and then a massive dust storm dooms the project.
From that point forward, the expensive failure is forever used as an example of why a second attempt is not worth the expense.

Each year that passes makes such projects more prohibitively expensive, and meanwhile more and more problems need to be addressed right here on Earth. Any civ anywhere might face the same sort of problem.
I don’t think we’ll ever leave this little planet for just this reason. We had better just find a way to take care of what we have, and that’s not looking likely either.

Clearly, Seth and Alan haven’t or won’t considered investigating the continuing phenomenon known as UFOs.
Somebody get Dr Rudy Schilds at Harvard Astrophysics Center on the phone to share his opinion about the years of accumulated UFO evidence Just look at these years of reports http://www.nicap.org/chrono.htm

Here comes the little green men jokes

Great discussion on extraterrestrials. The uses for Pink Floyd’s music are endless!
No one has yet mentioned the hostile alien scenario. I just watched Speilberg’s new “War of the Worlds.” It was colored in many ways by the stark rationality of life that is truly alien -unconcerned for us. Do we have notions of how to identify hostility from a safe distance? This line of thinking leads to conservative social views such as isolationism so I doubt it hinders the exploratory nature of science -but what if we found alien moss or goo? What kind of apparatus would we have to build to safely examine it?

-Dave

And the question of whether Newtonian physicals laws apply everywhere.

And since there is no evidence of an intelligence life dominating the universe, what that tells us about the limits of our ability to harness power and control matter.

When talking with Emily you mentioned an event over Tunguska, Siberia saying it was an asteroid impact.
As far as I’m aware, the “the jury is still out” on what exactly exploded there… Could have been a comet.
http://en.wikipedia.org/wiki/Tunguska_event

Good show, however…. Remembering Dr. Carl Sagan and our ‘Pale Blue Dot’

Concern over space junk over our heads, but what about the failed CO2 rocket dumped into our ocean. Will NASA clean it up? Does NASA and other nations simply continue to use the ocean as a dumping ground, unwilling or unable to pick up after themselves?