From Origin Post 73 That sounds like you expect life to be extremely rare. Why require life to exist in such places in order to be common in the universe? There are a lot of places more suitable than those two. In our solar system there is good reason to not expect life other than on Earth. BTW: Are you referring to any type of life or life capable of producing a technological culture? There is a vast difference in the likely hood of those two possibilities.
It is not that I expect it to be rare, the point is we only have evidence of life on 1 planet. It is possible we are the only life that exists in the galaxy. We do not know what conditions result in life, it could be that it is so difficult to get those conditions that we are a one off fluke. I do not thinks this is the case but there is no evidence to the contrary. Based on our current technology and our current understanding of physics we will not travel to the stars any time in the foreseeable future, so this solar system is the only opportunity to determine if n > 1. Any life no matter how primitive is what I am referring to. The universe is incredibly hostile to life. The only known place that life can exist is in an exceedingly thin shell on a single planet.
You can analyze the composition of light to detect chemicals that indicate the possible presence of life.
From what I have read, in the future we will be able to infer that there may be life on a planet by spectrographic analysis of the atmosphere.
Probability? 1÷2=0.5 Half! 1÷2÷4=0.125 This is if we are the first, which we are not. However, n÷2n÷4n=2 Not one.
What do these numbers and formulae mean? 1 what? 2 what? Why divide them? 4 what? Your answer here is incorrect. That is an exponential function: For n=0.1, the result is 1.25 (.1÷.2÷.4). For n=1, the result is .125 (1÷2÷4). For n=2, the result is .0625 (2÷4÷8), For n=10, the result is .0125 (10÷20÷40).
The common mistake is that people compare the Universe with stars and planets. Yes, the universal expanse cannot support life, it has no properties that can support free existing life. But a star is a source of energy, warmth and planets have chemical compositions. As Robert Hazen clearly demonstrated any planet that even remotely resembles the earth, most likely will evolve a form of life, eventually.. start watching at 25:10
I don't think that is a common mistake, I don't think I have ever heard of anyone making that mistake . A common mistake people make is going to YouTube and finding silly videos to support there hopes.
Well obviously you are not familiar with Robert Hazen. I would suggest you watch the presentation he gave at the Carnegie Institute for Science, after a long introduction which lists his credentials. That's why I suggested to start the video at 25:10. It's you who looks stupid making silly comments about respected scientists. Count yourself lucky that occasionally YouTube does present some very interesting videos. You can also find trash books in any library. Are libraries silly sources for seeking information?
Oh my God he has a long list of credentials? Well then, I guess we now know that Mars and Venus both developed life.Please Register or Log in to view the hidden image!
Where did anyone say ; "we know that Mars and Venus both developed life". Don't misquote me or try to misdirect a statement I made. It's not honest. And not watching the clip will be your loss of some very interesting aspects of bio-chemistry, as all who have watched it will attest to.
. Then you would not say that the universe is incredibly hostile to life. Again, the Universe (space) is hostile to life, but as soon as there is a source of energy and a planet with somewhat similar chemical makeup as the earth, you know like hydrogen, oxygen, carbon, rocks, stuff like that, yes, it is likely that life exists elsewhere in the universe. In fact we already have completely alien non-photosynthetic, sulfur based alien life forms right here on earth. http://www.pbs.org/wgbh/nova/nature/life-in-the-abyss.html But I'm sure you consider NOVA as just another silly program.
No, this does not follow. We have one example. That is no sufficient to establish a probability. To be clear, they are not alien. True, they do not employ photosynthesis, but they are still related to all other life on Earth. They still use the same ol' DNA. This is a pretty humanocentric scare story. Darkness isn't hostile to many forms of life. In fact, it's an advantage to many. Poison is relative to the particular metabolism. Pressure is only an issue for organisms with heterogeneous components, such as lungs and sinuses. Entirely fluid creatures (such as fish) often have no problem with pressure. etc.