Our Galaxy Should Be Teeming With Civilizations, But Where Are They?

Project Phoenix ^ | 25 Oct 01 | Seth Shostak

[Brett66]

The Fermi Paradox is based on the idea that we have actually looked for other civilizations, we haven't. SETI is just a cursory examination of a very limited frequency range in a very limited part of the galaxy using very limited instruments whose technology is based on very limited assumptions. When we start directly imaging planets the size of Mars and greater in other solar systems we'll start getting some very tenuous answers but that's only the beginning of the search. To do a serious search we would have to image Mars plus-sized planets within a 50,000 light year radius of Earth. This gives us about 10 billion solar systems to examine before we even have a significant statistical sampling.

[FormerLib]

Fermi realized that any civilization with a modest amount of rocket technology and an immodest amount of imperial incentive could rapidly colonize the entire Galaxy.

Yeah, whatever. No sane person with even a rudimentary knowledge of physics, much less an expert, could possibly believe something this preposterous.

So you're suggesting that Fermi was either insane or lacked even a rudimentary knowledge of physic? How very interesting!

[Leonine]

"Would Columbus have set sail knowing that it would be his grandchildren that would have arrived?" Any civilization considering interstellar travel would have a Columbus in its history, thus inspiring the dedication.

[Young Werther]

..2nd star on the left and straight on till morning."

[Stefan Stackhouse]

CS Lewis addressed this question both in his Space Trilogy and in an essay. His hypothesis is that God could have created many different sentient beings, but because of the Fall, earth is "quarantined" and thus out of contact.

[js1138]

The Fermi Paradox is based on the idea that we have actually looked for other civilizations...

I think you need to go back and read the original article.

[cynicom]

Whale.... Two probabilities exist, given the time and size factors, either life other than earth, has or is existing, or life has never and does not now exist other than earth.

If life has never existed, then truly we are unique in this universe and whether it be earth or someplace else there had to be or is a first life.

Again given the time and size factors, where are they, the odds are in favor of life being out there.

[Brett66]

Until we get spectral images of several billion extra-solar planets we haven't really looked. All the rest is speculation.

[LibWhacker]

"where is everybody?"

Personally, I've always like the answer, "look in the mirror." "They" may have indeed already colonized the galaxy. Problem is, they had to do it as dormant bacteria hitching rides on asteroids and other celestial debris.

Multiple SETI searches have been going on, what, twenty or thirty years now? That's an impressive statistical sample and I think we can begin to draw some valid statistical inferences from the data; namely, technologically we're IT in the Milky Way (small p, perhaps even p<0.05).

Thank God! I don't think I want us encountering a vastly more advanced civilization.

[Smedley]

Well, we are on the edge of our galaxy -- the stellar boondocks as it were.

[x]

Where are they?

Radical Islam got to them.

Or you can insert your own favorite villain in the blank.

Maybe the Alpha Centaurian Lew Rockwell and the Alpha Centaurian Jonah Goldberg's mother got nuclear weapons and destroyed that flourishing civilization. Maybe television radiation turned all of the Vulcans into vegetables or zombies.

[RightWhale]

Like Bradbury said. Who are the Martians?

We are.

It's possible. But it doesn't solve the problem.

[Physicist]

Actually, contrary to those who think that the speed of light cannot be breached, it can be and has (quite recently in separate lab tests).

Not in any way that's relevant to travelling from point A to point B. No violation of Einstein's relativity has ever been observed. Popular articles about light pulses travelling faster than c stem from a confusion about the difference between group velocity and phase velocity.

[WyldKard]

Considering that we are merely children who haven't even left the cradle yet, I think it's a TOUCH premature to assume we're COMPLETELY alone in the universe....

[Redcloak]

I doubt a galactic empire could exist due to the problems of communication and transport accross such huge distances.

These would be problems to us, but not necessarily to all cultures. All that would be needed for a galactic empire would be one race willing to put up with these difficulties and enough time. As Fermi points out, time isn't a problem. Were there enough spacefaring races, then at least one of them would have had the patience to build an empire by now.

On a side note, sci-fi author Harry Turtledove addressed the issue of patience in his "Worldwar" series. In those books, the Earth is invaded by "The Race" during WWII. The Race has been a spacefaring people for thousands of years. Their plans to invade Earth evolved over centuries. They sent a probe to Earth that arrived 600 years earlier. They were so confident that all races shared their patience for slow development that they expected to find nothing more than mounted knights opposing their invasion force; not modern armies able to fight them to a standstill. One of the major themes of the books is the Race's inability to grasp how impatient we are as a species and how this drives our technological development. The Humans, on the other hand, learn patience from the invaders and have begun to plot a counterattack on the Race's homeworld, Tau Ceti.

[Physicist]

You can quibble about the speed of alien spacecraft, and whether they can move at 1 percent of the speed of light or 10 percent of the speed of light. It doesn't matter.

No, but if they can only move at a hundredth of a percent of the speed of light--a much more reasonable figure--then it does matter. The fact is, going from star to star is just plain hard. I fully expect that corporeal human beings will never make the trip. (Once we learn how to transfer our consciousness to nonliving substrates, however, we just might manage it.)

[LibWhacker]

Right! The speculation doesn't. But I think the statistics is there now, or very close, and the solution to the problem is: We're it. There's no one else technologically close to us.

[sadamico]

"Like the perfectly square tunnels of South America."

Please pass me some info on this. Thanks
Scotty

[biblewonk]

They aren't out there, neither is the truth.

[Physicist]

Multiple SETI searches have been going on, what, twenty or thirty years now? That's an impressive statistical sample and I think we can begin to draw some valid statistical inferences from the data; namely, technologically we're IT in the Milky Way (small p, perhaps even p<0.05).

No way can you draw that inference from the SETI data. It's not a question of statistics, it's a question of sensitivity and of coverage. If there were a carbon copy of Earth out there, you wouldn't have to move it very far away before we're highly unlikely to have seen it. We're not close to having looked at our own galaxy exhaustively.