It's Life, Jim, But Not As We Know It....
I've not done one of these in ages, it seems.
Every so often I like to do a thought provoking, controversial, or just plain out-there post...
I'm not sure if I've done a post on this subject before. If I have, then this may be a repeat.
Anyway, enough pre-amble. Today's question is:
Is there life on other planets?
90% of science fiction would give you the answer "Yes". Actually, there are three separate questions here, which are linked in a progression. 1) Are there other planets out side our solar system? 2) Do any of those planets have life on them, of any sort? 3) Is any of that life intelligent? I want to deal with these questions one at a time, because it makes it easier.
1) Are there planets outside our solar system?
This is important, as we've pretty much established that there is no life as we know it on the other seven and a half planets orbiting the sun. Okay, this is a pretty sweeping statement. There still could be some forms of life on some of the larger moons of Jupiter or Saturn, and there could be life in a form other than we know it within the gas clouds of the four gas giants, but the chances are remote. Even so, the question still remains whether life exists outside the solar system, and life as we know it requires planets like this one.
Astronomers have pretty much established that gas giant planets do exist around other stars. They have done this by detecting the "wobble" in the star caused by the planet's gravitational field. However, for a star to have a significant "wobble" (and yes that is the technical term for it) the planet has to be relatively close to the star, much closer than our gas giants.
All the same that doesn't mean these stars don't have earth-type planets. In fact, the existence of gas giant planets around other stars can be taken as evidence that Earth-type planets do exist. The fact that both exist in our solar system, taken with the theory of how they formed means that, given the unbelievable number of stars in the universe, there MUST be earth-type planets around some of them... The chances of this star being the only one with solid rock planets are so close to zero as to be negligible, especially as we have four and a half of them, plus several moons that would qualify.
So, the answer to question one is pretty much a yes. In this, Science Fiction has it right.
2) Is there life (of any sort) on any of these planets?
Again, Sci-Fi usually says "yes". Even in the few Sci-Fi series that don't have aliens, humans explore the galaxy to find worlds that have native flora and fauna on them, usually looking very similar to our own. Of course, the reason for this is obvious: Just as all "Star Trek" aliens were bipedal humanoids simply because all the actors playing them were bipedal humanoids, if you are filming an alien world, you don't have anywhere to film it except on Earth! Nowadays, with CGI, Sci-Fi movies and TV shows have a lot more scope to depict alien environments, but that requires an interstellar effects budget!
For intelligent life to exist on a world, there has to be unintelligent life. Forget evolution for a moment, and think of practicalities. What is your alien species going to eat? Unless you are surmising a race of intelligent plants that survive by photosynthesis alone, there has to be some sort of food for them.
Now, not all sci-fi has alien flora and fauna. Some require terraforming of other worlds, including the introduction of earth plants and animals. This may be either because the native life is inimical to human life and needs to be replaced, or because there is no life there at all. I would love to write a sci-fi book (or series of books) set in a universe where there is no extra-terrestrial life at all, simply to explore the possibility.
The general consensus, however, is that if there are sufficient Earth-type worlds out there, the chance that ours is the only one with any form of life on it is pretty remote. Only the died-in-the-wool die-hard right-wing Jesus-freak would maintain otherwise, and that is simply because such a person has to believe that we are alone in the universe or his faith takes a serious hit.
Religion aside (And this post is not about religion), the possibility that there is no life at all but what we find on this planet decreases exponentially with the volume of space you include. In the solar system it's pretty high. In the local star cluster it's lower, in the spiral arm of our galaxy it's getting remote, in the whole galaxy, pretty much zero and in the whole universe, forget it!
So, the further we go, the more chance we have of finding some sort of life.
3) Is anybody out there?
Is any of that life intelligent? Well, again, sci-fi is divided. A lot of Space Opera tends towards humanity being the sole occupants of our galaxy. We spread out, we explore, we colonise, we divide, we fight, but it's all humans. Some sci-fi has humanity all ready in the stars, taken there long ago by some unknown entity - or taken there in the future through worm-holes that also took them back in time. Most simply has us expanding out from our home world.
On the other hand, most sci-fi tends towards there being intelligent aliens out there. It gives humanity a natural enemy to unite against, for one. Does the Geneva convention apply to bug-eyed monsters? It gives us the chance to show our species at its best and worst, in our interaction with another species - Sci-fi is often used to highlight the way we've treated our own species in the past. Nichelle Nichols (Lt. Uhura) once commented to Gene Roddenberry, "You're writing morality plays!" To which he replied "shhh! They haven't noticed!"
However, if there are space-faring aliens out there, why haven't they contacted us? The possible answers to this one are many. The most likely would be that they have and we didn't hear about it - Conspiracy theorists love this one, area 51, Roswell and all that. Or they tried and we didn't notice. Unlikely. Or, possibly, they simply haven't noticed us? This is possible if the nearest aliens are more than 50 light years away. (What's a light year? Same as a regular year only with less calories). We've been pumping coherent radiation into the cosmos for nearly a hundred years. It would take that long for any one to notice us and get a signal back if they were up to 50 ly away.
Or, maybe, there is some sort of inter-stellar community that enforces a "prime directive" of no contact with species that do not have interstellar capability yet? This is highly unlikely, but doesn't stop sci-fi writers using it.
Again, the further we go, the more likely we are to find someone with the same or greater level of technology. The chance that every species in the galaxy develops hyper-drives at the same time is pretty far-fetched. If there are others out there, they are probably so far away that it would take millennia - even at super-light speeds, to reach us.
Conclusion: We have no way of knowing, one way or the other. Until we get out there and see for ourselves, or someone from another world finally makes it here, the answer will be a resounding "Don't know".
And even if we do get out into interstellar space and find no living thing, as I've already pointed out, that doesn't mean they aren't there, just that we haven't found them yet. Proving a positive is easy, you only need one example. Proving a negative is next to impossible as you need to explore every possibility and prove that all of them are negative. If we've explored the whole universe except one last planet, and found no life at all, it still doesn't mean there is no life at all on that last planet. It just makes it very very unlikely, that's all.
Every so often I like to do a thought provoking, controversial, or just plain out-there post...
I'm not sure if I've done a post on this subject before. If I have, then this may be a repeat.
Anyway, enough pre-amble. Today's question is:
Is there life on other planets?
90% of science fiction would give you the answer "Yes". Actually, there are three separate questions here, which are linked in a progression. 1) Are there other planets out side our solar system? 2) Do any of those planets have life on them, of any sort? 3) Is any of that life intelligent? I want to deal with these questions one at a time, because it makes it easier.
1) Are there planets outside our solar system?
This is important, as we've pretty much established that there is no life as we know it on the other seven and a half planets orbiting the sun. Okay, this is a pretty sweeping statement. There still could be some forms of life on some of the larger moons of Jupiter or Saturn, and there could be life in a form other than we know it within the gas clouds of the four gas giants, but the chances are remote. Even so, the question still remains whether life exists outside the solar system, and life as we know it requires planets like this one.
Astronomers have pretty much established that gas giant planets do exist around other stars. They have done this by detecting the "wobble" in the star caused by the planet's gravitational field. However, for a star to have a significant "wobble" (and yes that is the technical term for it) the planet has to be relatively close to the star, much closer than our gas giants.
All the same that doesn't mean these stars don't have earth-type planets. In fact, the existence of gas giant planets around other stars can be taken as evidence that Earth-type planets do exist. The fact that both exist in our solar system, taken with the theory of how they formed means that, given the unbelievable number of stars in the universe, there MUST be earth-type planets around some of them... The chances of this star being the only one with solid rock planets are so close to zero as to be negligible, especially as we have four and a half of them, plus several moons that would qualify.
So, the answer to question one is pretty much a yes. In this, Science Fiction has it right.
2) Is there life (of any sort) on any of these planets?
Again, Sci-Fi usually says "yes". Even in the few Sci-Fi series that don't have aliens, humans explore the galaxy to find worlds that have native flora and fauna on them, usually looking very similar to our own. Of course, the reason for this is obvious: Just as all "Star Trek" aliens were bipedal humanoids simply because all the actors playing them were bipedal humanoids, if you are filming an alien world, you don't have anywhere to film it except on Earth! Nowadays, with CGI, Sci-Fi movies and TV shows have a lot more scope to depict alien environments, but that requires an interstellar effects budget!
For intelligent life to exist on a world, there has to be unintelligent life. Forget evolution for a moment, and think of practicalities. What is your alien species going to eat? Unless you are surmising a race of intelligent plants that survive by photosynthesis alone, there has to be some sort of food for them.
Now, not all sci-fi has alien flora and fauna. Some require terraforming of other worlds, including the introduction of earth plants and animals. This may be either because the native life is inimical to human life and needs to be replaced, or because there is no life there at all. I would love to write a sci-fi book (or series of books) set in a universe where there is no extra-terrestrial life at all, simply to explore the possibility.
The general consensus, however, is that if there are sufficient Earth-type worlds out there, the chance that ours is the only one with any form of life on it is pretty remote. Only the died-in-the-wool die-hard right-wing Jesus-freak would maintain otherwise, and that is simply because such a person has to believe that we are alone in the universe or his faith takes a serious hit.
Religion aside (And this post is not about religion), the possibility that there is no life at all but what we find on this planet decreases exponentially with the volume of space you include. In the solar system it's pretty high. In the local star cluster it's lower, in the spiral arm of our galaxy it's getting remote, in the whole galaxy, pretty much zero and in the whole universe, forget it!
So, the further we go, the more chance we have of finding some sort of life.
3) Is anybody out there?
Is any of that life intelligent? Well, again, sci-fi is divided. A lot of Space Opera tends towards humanity being the sole occupants of our galaxy. We spread out, we explore, we colonise, we divide, we fight, but it's all humans. Some sci-fi has humanity all ready in the stars, taken there long ago by some unknown entity - or taken there in the future through worm-holes that also took them back in time. Most simply has us expanding out from our home world.
On the other hand, most sci-fi tends towards there being intelligent aliens out there. It gives humanity a natural enemy to unite against, for one. Does the Geneva convention apply to bug-eyed monsters? It gives us the chance to show our species at its best and worst, in our interaction with another species - Sci-fi is often used to highlight the way we've treated our own species in the past. Nichelle Nichols (Lt. Uhura) once commented to Gene Roddenberry, "You're writing morality plays!" To which he replied "shhh! They haven't noticed!"
However, if there are space-faring aliens out there, why haven't they contacted us? The possible answers to this one are many. The most likely would be that they have and we didn't hear about it - Conspiracy theorists love this one, area 51, Roswell and all that. Or they tried and we didn't notice. Unlikely. Or, possibly, they simply haven't noticed us? This is possible if the nearest aliens are more than 50 light years away. (What's a light year? Same as a regular year only with less calories). We've been pumping coherent radiation into the cosmos for nearly a hundred years. It would take that long for any one to notice us and get a signal back if they were up to 50 ly away.
Or, maybe, there is some sort of inter-stellar community that enforces a "prime directive" of no contact with species that do not have interstellar capability yet? This is highly unlikely, but doesn't stop sci-fi writers using it.
Again, the further we go, the more likely we are to find someone with the same or greater level of technology. The chance that every species in the galaxy develops hyper-drives at the same time is pretty far-fetched. If there are others out there, they are probably so far away that it would take millennia - even at super-light speeds, to reach us.
Conclusion: We have no way of knowing, one way or the other. Until we get out there and see for ourselves, or someone from another world finally makes it here, the answer will be a resounding "Don't know".
And even if we do get out into interstellar space and find no living thing, as I've already pointed out, that doesn't mean they aren't there, just that we haven't found them yet. Proving a positive is easy, you only need one example. Proving a negative is next to impossible as you need to explore every possibility and prove that all of them are negative. If we've explored the whole universe except one last planet, and found no life at all, it still doesn't mean there is no life at all on that last planet. It just makes it very very unlikely, that's all.