There’s the Fermi Paradox and the Drake equation, which many readers are familiar with. There is also lots of action in the astronomy community currently on discovery of new planets. Potentially habitable ones in the “Goldilocks zone” (not too hot, not too cold, juust right!), are hitting the national news periodically these days. For example Kepler-22b, Gliese 581 d (only 20 light-years away which is really close but, also, really far…), HD 85512 b, and some “KOI” planets are pretty intriguing.
Really, astronomy is just getting started. Now we know there are many billions of planets in our galaxy, so there must be lots that *could* support life. Even Titan (a moon of Saturn) might possibly have life of some sort; at least it has lots of organic molecules and more petroleum than we could ever burn, and we have actually landed there and taken pictures from the surface! (See http://www.astronomy.org/StarWatch/January/1-05-titan-huygens.jpg.) I keep one of those pics framed in my office.
In my view the next major step in habitable planet discovery is to detect oxygen in their atmospheres. That is a sure-fire sign of photosynthesis, i.e., extraterrestrial life.
Hi Jared,
Yes, the Fermi Paradox is one of the reasons I became interested in Lifeboat. It is quiet when we should be hearing others, and the more planets they find, the more likely it becomes that technological civilizations destroy themselves. That is not a conspiracy theory, by the way.
Which is why I believe this site is serious business. Not the place for conspiracy theorists to post their babbling.
When most people ask that question, they are really asking are we alone in the galaxy? Some of the things I have read about infrared galaxies suggest to me that we may be looking at large numbers of Dyson spheres. I do not believe that intelligent life is so common that we are likely to find it in our own galaxy, but I do believe it might just be possible to detect the results of civilizations in other galaxies if the civilization is extremely advanced.
“I do not believe that intelligent life is so common that we are likely to find it in our own galaxy”
Hi Mark.
Well.…why?
I believe it should be common– but since we are not hearing any radio signals, they are not lasting very long. Again, the most probable cause– considering our own very dangerous activities with engineering virus’s and producing chemicals not found in nature– is self-destruction.
I read somewhere that they figured out Dyson spheres will not work. Since Dr. Dyson sometimes reads this blog he might comment on this if we are very lucky.
WIth billions of planets in the Milky Way alone, how could quite a number of planets *not* support life, and even intelligent life? However, without faster-than-light travel and/or communication, meaningful interaction with intelligent aliens seems unlikely.
“without faster-than-light travel and/or communication, meaningful interaction with intelligent aliens seems unlikely.”
I disagree Jared,
Since the power requirements go up in a sharp curve after about a third of the speed of light, consider .3c to be the practical speed limit for, let’s say, most of the next century. Considering acceleration and decelleration, let’s call it 4 years for every light year. “Meaningful” depends upon your own personal interpretation. Both life extension and cryopreservation will most likely redefine what is meaningful for most people– perhaps in the very near future. It might very well become meaninful for both of us.
The most likely form of star travel for the next millenium after a century of technological development is small singularity propulsion– perhaps near the end of the next century. This will boost speeds close to light where time dilation will make trips only a few years long (ship board time).
Though simplistic, my rough prediction is this century spent on colonizing the solar system and building up an infrastructure capable of manufacturing sleeper ships, the next century spent building up an infrastructure capable of manufacturing small singularity starships, and the third century will find us expanding into the galaxy in massive migrations.
We just need to consider longer time scales– and possibly living much longer. At least our children or their grandchildren may find intelligent life out there and interact with them in a meaninful way. But not considering them could mean stagnation– much like the often used example of the Chinese empire.
And of course, the reason for this blog; the possibility we might destroy ourselves or be destroyed.
First impression on our extrasolar planet search — which is just in its infancy, indicates that one should expect an abundance of planets in our own Milky Way in habitibal zones, and one need not consider — and should not really bother to consider — beyond our Milky Way — in discussion on this here.
There are three catagories to consider — those in habitibal zone on which life has not evolved, those in habitibal zones on which life has evolved, and those in habitibal zones on which life has evolved to become at least as technologically advanced as ourselves and can communicate.
All indications thus far from SETI suggest that the last catagory is at best a very rare thing, as even if a civilisation had developed EM broadcast technologies a mere 100,000 years ago — a very recent time in the general scheme of the things in the Universe — the signals from even those on the far side of the Milky Way would have reached us by now, and SETI one would suspect would have latched onto something suspicious by now.
While the first catagory is almost a given based on early results of extrasolar planet search, the real world of wonder is whether that second catagory is that common. Which is more difficult for nature to progress? The initiation of life, or the evolution of advanced inteligent life? I would suggest the former is the case, based on our understandings of how evolution works, meaning that the second catagory is also rather uncommon within our galaxy. However, that is just a very humble opinion. Regardless, this leaves us with the prospect, that while it is unlikely that we are alone in the universe, any chance of direct contact is extremely unlikely — so we may as well be alone.
As for sending a probe to find out more — the possiblity of travel to extrasolar planets in habitibal zones to discover non-advanced life is realistically limited to the very nearest of star systems within our galaxy — and if we look within the nearest 50 light years there could be 100 or so Sun-like systems in this space, so our pool of search is already quite contained. And whilst one could dismay at the requirement of near light speed for a probe to reach these in any time frame that could be considered reasonable, perhaps the OPERA results from last year might have given us an early insight into a method to take short-cuts, bizzare as it may seem. However, THAT is surely a long shot. In short — we may not be alone — but we are quite isolated.
Have one response to short lifetime of intelligent life being the reason we don’t see alien civilizations…if they’re really all that intelligent, they should be smart enough not to destroy themselves.
Maybe we’re stupid enough to destroy our civilization, but don’t you think that if there were a million intelligent civilizations in the galaxy, wouldn’t there be one or two really smart, sane ones that manage to survive? Or maybe humans will barely manage to survive, and one day evolve into something smart enough to survive well for long periods?
I kind of tend more to Karl Sahroeder’s “rewilding” idea that advanced enough civilizations might seem like something indistinguishable from stuff we think of as natural. And how much of what we see as natural is really natural? Would we REALLY recognize a billion year old civilization?