Billions of Possibilities

I ran across a headline a few days ago that stated that scientists now estimate that there may be billions of planets in the galaxy capable of supporting life. What took them so long to arrive at that conclusion?

The Science Fiction writers I grew up reading - Asimov, Clark, Bradbury, Biggles, Haldeman, to name a few - assumed there were plenty of planets that could support life, and that many of them had intelligent occupants. It seemed pretty logical to me.

This is the way I thought about it: solar systems like ours were created by the laws of physics. A star is born surrounded by swirling dust, the dust clumps together to form planets circling that star. Since that's how it happens, why wouldn't it happen around other stars as well? It happens because of physics, so it would.

So, plenty of planets out there.

Capable of supporting life? Some of those planets were certain to be in the 'Goldilocks Zone', where water could exist as liquid and not only as ice. And it didn't make any sense to me that out of all of those planets in the various Goldilocks Zones, ours was the only one that had an atmosphere, the only one that wasn't a gas giant or a small lump of rock. The math - in my mind - just didn't support the idea that out of all the solar systems in this galaxy, there was only one planet that could support life.

Supports an intelligent life? Why not? Whatever circumstances happen to create life, there are billions of possibilities for those circumstances to be replicated on other planets. And it actually only happens once? Again, the math doesn't support that outcome. And if we accept that has happened, then it only seems logical that some of that life would develop intelligence. Because, after all, even on Earth, man is not the only animal that has intelligence.

Perhaps, as scientists, they needed proof of the existence of all those other planets. This also seems strange to me. Why wouldn't they have followed the physics and math to the hypothesis that were many other planets out there that might be interesting? Instead, it seems to me that they went with the theory that we were the only planet with intelligent species, and now they are working to disprove that theory.

I think that's backwards.