Users Online Now: 1,891 (Who's On?) Visitors Today: 620,000 Pageviews Today: 795,937 Threads Today: 158 Posts Today: 3,035 06:00 AM

 Back to Forum Back to Thread
Message Subject How could there be any aliens
Poster Handle 071676
Post Content
If there aren't any planets
Quoting: Anonymous Coward 1600864

Well, about every thousand years we seem to have some (plague, nuclear weapons, etc.) that could have eliminated humanity.

Between the ability of an advanced civilization to shoot itself in the foot and those ever present space rocks, survival as an advanced civilization is a little precarious.

We have searched almost 800 solar systems. We haven't found a single rocky planet with water in the sweet spot like earth.
Gliese 581g is the closest we have come:
* Three times larger.
* Three times closer than Mercury (about 1/9 the distance of the earth from the sun).
* Surface temperatures from 160 to -26 (planet is almost tidally locked).

Since it does rotate - but very slowly - the surface gets periodically sterilized.

The odds of finding a planet like earth are 0.12% and getting smaller all the time.

There are 300 billion stars. Lets assume the average civilized time on a planet is 200,000 years. Lets assume the average period a planet is habitable is 3 billion years. The Galaxy is about 13B years old
* 300 billion * .12 = 380 million planets.
* 380 * 3/13 = 88 million
* 88 million * 200,000/3 billion = 5,800 civilizations that we would consider civilized.

If ET is out there there aren't many of them.
Quoting: Poriwoggu

All you would need is one other life form elsewhere to prove you wrong. Even 5800 is still a lot more than 0.