The Fermi Paradox. Why No Evidence Of Intelligent Life

[jyl]

The "Fermi Paradox" is the apparent contradiction between
1. It is very likely that many, many intelligent advanced civilizations have developed in the universe, and
2. We have found no signs of any.

https://en.m.wikipedia.org/wiki/Fermi_paradox

#1 is because there are at least 1 x 10^21 stars in the observable universe, thus billions of Sun-like stars with planets in the habitable zone. To put some numbers on it, about 10% of stars are Sun-like, and about 20% of those have planets of Earth-like size and Earth-like orbital radius. So call it 1 x 10^19 planets that in the habitable zone. And of course many times more stars of other types. No matter how improbable the circumstances that lead to Earth-like life, those circumstances must have arisen hundreds of billions of times, if not millions of billions. Add the circumstances that might lead to other, non-Earth-like life, and there must be more intelligent life out there than you can shake a stick at if you shook every stick on Earth.

#2 is thus the puzzle.

Maybe the explanation is simply distance. All the light and electro magnetic waves that humans emit would only be detectable for a short distance, if our most sensitive instruments were out in space. If we knew exactly where to look, the detection range increases, but it's still a very small distance at interstellar scale.

Maybe the explanation is time. Civilizations probably have a finite lifespan, so an advanced civilization that developed a million years ago is likely no longer around to be detected by us, and due to light speed delays, an advanced civilization that exists right now is also undetectable.

Maybe the explanation is technology and efficiency. Once humans communicated by broadcast radio waves from powerful transmitters, but in the not too distant future we'll communicate by much higher frequency radio from much lower power transmitters (think an FM radio station vs a cellphone). Perhaps advanced civilisations quickly move beyond the stage of spraying non-directional EM all over the place.

What do you think?. What is the answer to the paradox?. If you had to bet, how many years will it be before man detects evidence of intelligent life on another planet?. 10, 100, 1000, 10000 years, or longer, or never?. Consider that we only have a finite time to do so, before our own civilization disappears.

[motion]

Jeez, we've only been searching for what, 30-40 years? Give it some time.

[GH85Carrera]

Distance.

The Milky Way is a big place and it is just one very ordinary galaxy in the universe of uncounted many thousands or millions. Trillions of miles separate the closest stars to us. The speed of light is paltry and slow in the size of the universe. Space is just unimaginable in size.

[LEAKYSEALS951]

Time.

The cool guy next store was here, just wiped out years ago (or vice versa).

I would just love it if during our lifetimes, we did discover other life in our solar system. Not only that, but that it is related to our life, and was blown from planet to planet "in the wind" so to speak.

The number of amino acids found in meteorites/comets space just amazes me.

[mreid]

The universe is so vast, it is microscopic.

[Jim Richards]

Hey, what about me?


Oh wait...you said intelligent.

[Jim Richards]

Originally Posted by GH85Carrera

Distance.

The Milky Way is a big place and it is just one very ordinary galaxy in the universe of uncounted many thousands or millions. Trillions of miles separate the closest stars to us. The speed of light is paltry and slow in the size of the universe. Space is just unimaginable in size.

Signals get weaker with distance, so our ability to detect extraterrestrial life is a challenge.

[aigel]

Originally Posted by Jim Richards

Signals get weaker with distance, so our ability to detect extraterrestrial life is a challenge.

The only way to "find them" is probably picking up electromagnetic signal that is from an intelligent source. That is tough because of distance.
Signal strength will go down with 1/distance^2, so it really gets weak quickly.
Also, electromagnetic waves travel at the speed of light, which is slow. Many potential locations of life are so far away, any electromagnetic waves arriving now will be almost as old as the universe. It is not likely that civilizations developed very quickly after stars / planets etc. were established. Maybe in a few billion years, something will make it to Earth. Oh, wait, by then we will be melted down with the sun becoming a red giant ...

G

[Embraer]

[Jeff Higgins]

Maybe they saw us first...

[sketchers356]

I wonder how long a civilization can last with both radios and atomic bombs.

[onewhippedpuppy]

Originally Posted by Jeff Higgins

Maybe they saw us first...

And said, eff that!

[911_Dude]

This guy has a good article on the subject:

The Fermi Paradox - Wait But Why

[aigel]

The earliest signals containing images from our planet will be Nazi TV and the 36 Olympics. Much discussed thought, but apparently no big risk:

Will Hitler Be the First Person That Aliens See? | RealClearScience

G

[jyl]

I don't lose any sleep over a hostile alien species detecting our radio waves and then coming to enslave us. First, unless they have faster than light travel, our species will be gone before they get here. Second, there is likely to be many, many equally tasty and equally defenseless species closer to them.

[flatbutt]

we sent our first signals out into the ether 60/70 years ago. Thats not much time to travel to a civilization, be detected and have an answer be returned that we are able to detect.

[fanaudical]

[tcar]

Originally Posted by aigel

The earliest signals containing images from our planet will be Nazi TV and the 36 Olympics. Much discussed thought, but apparently no big risk:

Will Hitler Be the First Person That Aliens See? | RealClearScience

G

...so you saw the movie "Contact"?

[aigel]

Originally Posted by jyl

I don't lose any sleep over a hostile alien species detecting our radio waves and then coming to enslave us. First, unless they have faster than light travel, our species will be gone before they get here. Second, there is likely to be many, many equally tasty and equally defenseless species closer to them.

I had a neighbor who, after a few beers too many, would fantasize about being abducted by aliens and used for sex experiments. When he started that conversation, it was time to go home and call it a night ...

G

[aigel]

Originally Posted by tcar

...so you saw the movie "Contact"?

Never. I read about it in that article for the first time. I'll have to watch it!

G