why

[thugfella]

does anyone no or have a theory why earth is the only planet with water and living life and why we are probly the only planet with a temperature that people can live in ...?probly not in the universe but we are probly in our galaxy....any theory is good

 

[alpha_taur1]

I doubt if the Earth is the only planet of its type in the galaxy. It certainly is unique in the solar system.<br /><br />We'll have to wait until we have more sophisticated techniques to determine whether there are other planets similar to ours. Oxygen is one anomaly that we could look for. <br /><br />You might have heard of the Rare Earth Theory by Ward and Brownlee. Their rare Earth hypothesis predicts that while simple, microbial life will be very widespread in the universe, complex animal or plant life will be extremely rare.<br /><br />It is very difficult to predict anything with a sample size of 1. <br /><br />It's a bit like models of planetary condensation. They predicted that we should get a grouping of planets condensing from the Solar nebula similar to those we find in the Solar System(Quinn et al, UW). This may still be true, but so far we haven't found a single extra-solar example of a solar system like ours, and models of solar system formation have had to be revisited since the 1980s. <br />

 

[nevers]

My "theory" is that we are not the only planet with water and living life. We are probably not the only planet with a temperature that people (humans like us) can live in. In our Solar System: yes. In our own Galaxy: no.<br /><br />It's my thought (and probably others too) that we just happen to be in the "sweet" spot relative to our Sun. In my "adventures" I've talked to many people from around the world. Most of them don't realize that all the stars we can see, visually and telescopically (and beyond) are all Suns: like ours more or less. Each of those Stars/Suns have the potential for having a planet the same distance or relative to it that can give it all the same things that require a "life" like ours here on Earth. The odds mathematically of Earth being the only planet in the Universe that can sustain life (of any kind) is highly unlikely. In my book...

 

[lewcos]

I compare our planet to a seed.<br /><br />We have been watered and we get sufficient sunlight so we grow.

 

[yevaud]

Yes, the "Life Zone." We're actually within 5% of the inner limit of it, according to some theories.<br /><br />Mars is actually within the zone too, according to the same theory. If it had been large enough (Earth sized, really), it might also be alive.<br /><br />Pretty fascinating. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>