5 ms·

That depends on the type of extraterrestrial life discovered. There's a huge difference between us finding extraterrestrial life within our solar system (micro

That depends on the type of extraterrestrial life discovered. There's a huge difference between us finding extraterrestrial life within our solar system (microbes on Mars, for example) and extraterrestrial life from outside the solar system finding us. The latter resolves the Fermi Paradox while the former heightens it. Personally, I'd be really unsettled if scientists found evidence of microbial life on Mars. If life is so common that it can evolve independently twice in the same solar system, the 'Earth is a very rare and special thing' hypothesis is unlikely and there should have been many, many civilizations capable of interstellar travel - and the fact that we haven't encountered any would indicate something deeply weird is going on, most likely extinction events that keep societies like ours from ever reaching other stars. Hell, it's already weird and disturbing that we're discovering so many exoplanets - including earth-sized exoplanets, including exoplanets in the liquid-water belt. Given the continued absence of alien life, that really shouldn't be happening.

pmahoney 12y ago
There was an article in American Scientist a few years back about just how big space is, and how even if there are many intelligent species, they'll just never communicate due to the distances involved (barring exotic new physics). It was a bit sobering. I believe it was this article: http://www.americanscientist.org/my_amsci/restricted.aspx?act=pdf&id=47898461942155 http://www.americanscientist.org/my_amsci/restricted.aspx?ac...
- gyardley 12y ago
  Hey, thanks for the pointer to the article. Unrestricted copy seems to be here: http://physics.ucf.edu/~britt/AST2002/R12-Smith-Alone%20in%20the%20Universe.pdf http://physics.ucf.edu/~britt/AST2002/R12-Smith-Alone%20in%2...
- TheCondor 12y ago
  I think it's unlikely we will find any life on Mars, only the most optimistic folks hold any hope and there is nothing that even suggests it. Whether or not interstellar travel is possible is an interesting question. We are talking about tremendous amounts of energy, time, and incredibly reliable devices. It may simply not be practical or possible. What seems must likely to me is we will sniff out pollution in an exoplanet atmosphere and then there will be lots of discussions and debates about whether or not it could naturally happen. Lack of any radio communication sure is a puzzle though
  - deciplex 12y ago
    Interstellar travel is easy. We have the technology to do it now. The only problem is that humans live really short lives. If humans had lifespans of one million years or so, interstellar travel would be mundane.
  - tiatia 12y ago
    Mate, some people think we already FOUND live on Mars http://en.wikipedia.org/wiki/Life_on_Mars#Viking_lander_biological_experiments http://en.wikipedia.org/wiki/Life_on_Mars#Viking_lander_biol...
skuhn 12y ago
The existence of extinction events seem pretty likely to me, but I also think bad timing can explain a lot. Humanity has had an extremely small window of time in which it could observe non-visual signals from outer space. Radio waves were only discovered in the 1800's. Likewise, it's only after we started broadcasting ourselves that another civilization is likely to be able to detect our existence. We can detect a broad range of signals (but maybe not everything), but the signal types we know about are still bound by the speed of light. Maybe there's a civilization broadcasting towards us right now today, but we won't find out for another 3,000 years. Maybe our signals will reach someone in 10,000 years, and humanity will be extinct.
gojomo 12y ago
Personally I think there are plenty of hints (going back to Viking lander experiments) that there is simple life on Mars. However, there's a cultural reluctance to consense on its existence, unless absolutely positively certain. Fears like yours, about what Martian life could imply about the uniqueness and longevity of our species, are part of the reason for the reluctance. Note that if life is confirmed on Mars, it needn't have independently evolved. Simple life might be more common, even dormant in interplanetary space, than generally believed – seeding both Earth and Mars from earlier sources. (This is the theory of "panspermia".) Or, the same collision processes that brought the Martian-meteor with maybe-fossils to Earth, could have carried live spores between the planets – so a single microbial-evolution inside our solar system could reach multiple planets. Of course then your Fermi fears still apply. ("If microbial life is so common, why are broadcasting/traveling civilizations rare?") But it would mean the 'great filter' applies after, not before, microbial life.

pmahoney 12y ago

There was an article in American Scientist a few years back about just how big space is, and how even if there are many intelligent species, they'll just never communicate due to the distances involved (barring exotic new physics). It was a bit sobering. I believe it was this article: http://www.americanscientist.org/my_amsci/restricted.aspx?act=pdf&id=47898461942155 http://www.americanscientist.org/my_amsci/restricted.aspx?ac...

gyardley 12y ago
Hey, thanks for the pointer to the article. Unrestricted copy seems to be here: http://physics.ucf.edu/~britt/AST2002/R12-Smith-Alone%20in%20the%20Universe.pdf http://physics.ucf.edu/~britt/AST2002/R12-Smith-Alone%20in%2...
TheCondor 12y ago
I think it's unlikely we will find any life on Mars, only the most optimistic folks hold any hope and there is nothing that even suggests it. Whether or not interstellar travel is possible is an interesting question. We are talking about tremendous amounts of energy, time, and incredibly reliable devices. It may simply not be practical or possible. What seems must likely to me is we will sniff out pollution in an exoplanet atmosphere and then there will be lots of discussions and debates about whether or not it could naturally happen. Lack of any radio communication sure is a puzzle though
- deciplex 12y ago
  Interstellar travel is easy. We have the technology to do it now. The only problem is that humans live really short lives. If humans had lifespans of one million years or so, interstellar travel would be mundane.
- tiatia 12y ago
  Mate, some people think we already FOUND live on Mars http://en.wikipedia.org/wiki/Life_on_Mars#Viking_lander_biological_experiments http://en.wikipedia.org/wiki/Life_on_Mars#Viking_lander_biol...

skuhn 12y ago

The existence of extinction events seem pretty likely to me, but I also think bad timing can explain a lot. Humanity has had an extremely small window of time in which it could observe non-visual signals from outer space. Radio waves were only discovered in the 1800's. Likewise, it's only after we started broadcasting ourselves that another civilization is likely to be able to detect our existence. We can detect a broad range of signals (but maybe not everything), but the signal types we know about are still bound by the speed of light. Maybe there's a civilization broadcasting towards us right now today, but we won't find out for another 3,000 years. Maybe our signals will reach someone in 10,000 years, and humanity will be extinct.

gojomo 12y ago

Personally I think there are plenty of hints (going back to Viking lander experiments) that there is simple life on Mars. However, there's a cultural reluctance to consense on its existence, unless absolutely positively certain. Fears like yours, about what Martian life could imply about the uniqueness and longevity of our species, are part of the reason for the reluctance. Note that if life is confirmed on Mars, it needn't have independently evolved. Simple life might be more common, even dormant in interplanetary space, than generally believed – seeding both Earth and Mars from earlier sources. (This is the theory of "panspermia".) Or, the same collision processes that brought the Martian-meteor with maybe-fossils to Earth, could have carried live spores between the planets – so a single microbial-evolution inside our solar system could reach multiple planets. Of course then your Fermi fears still apply. ("If microbial life is so common, why are broadcasting/traveling civilizations rare?") But it would mean the 'great filter' applies after, not before, microbial life.