"Humans" elsewhere in the universe?

[A Lone Voice]

With all the billions of stars in our galaxy, and the billions of galaxies in the universe, it seems probable that there is other, (intelligent, maybe "human") forms of life 'out there.' But how many might even come close to resembling us?

Think about it: Earth is something like 4.7 billions of years old (if I'm not exact on this point, please correct); but: how many planets have a moon to stabilize a planet's orbit, as our moon does? Without a moon, placed EXACTLY where it is, would oceans still have tides? With the type of sun we have, how many planets are the same distance away, forming a variance of temperature like Earth? How many planets possibly possess the same 23% tilt that Earth does, making a much larger portion of the surface inhabitable with the presence of seasons?

How many planets have a similar sort of land mass, and plate tectonics, allowing ocean currents to regulate weather, as Earth does? Or the sort of atmosphere that developed on Earth, based on the ability of plants and trees existing on large land masses to convert carbon dioxide into oxygen? At the rate it does to support human life? And the temperature variance (of what, 120 degrees?) to support human life?

And then there is the whole evolution thing (not to irritate those who believe in Creation, but staying with my original thought). Would mammals have developed like they did if a comet had not hit the Yucatan peninsula, changing the Earth from an environment favoring reptiles and dinosaurs to one favoring mammals? And from that, would the condition of fauna allow primates to evolve, as they did on Earth?

And that brings me to Time: What are the chances of all of these conditions being not only met, but being met RIGHT NOW somewhere else? How much has the occasional comet set back life on Earth? Or speeded it up? The point being, what are the odds that another planet has met all of these conditions, and are now in the same 10,000 year span as we are?

There surely must be other life somewhere in the universe, but what are the odds that something looking like us is really out there?

[playmaker88]

With all the billions of stars in our galaxy, and the billions of galaxies in the universe, it seems probable that there is other, (intelligent, maybe "human") forms of life 'out there.'

There surely must be other life somewhere in the universe, but what are the odds that something looking like us is really out there?

Well if the odds are a billion to one chance, there are lots. A billion really is a serious number (difficult to truly imagine on my part), but in fairness the conditions you stipulate (our conditions) are fairly fantastic too, we are really fortunate to be here, of that there is no doubt.

[Trippy Mushroom]

A Lone Voice, did you just finish a Coming Global Superstorm? The information it states is remarkably similar to what you posted.

[stewey]

I would say possible, although more likely those other humans are dead by now, as the universe is quite old and odds are they were created long before us judging by the odds of life being "formed".

[A Lone Voice]

I would say possible, although more likely those other humans are dead by now, as the universe is quite old and odds are they were created long before us judging by the odds of life being "formed".

True. As I said, with the billions upon billions of planets in the universe, many solar systems would have to be approximately the same age. Although with human's short history, a variance of just 100,000 years would cause us to miss each other's development.

But what if, somewhere, a solar system formed which might be almost identical to our Solar System? What if the third planet from the sun didn't have a moon? Would that cause a change, however slight?

I can't see how it would not. With all the variables that caused human life to evolve, I don't see how it could ever be repeated.

Unless we get into a spiritual discussion...

[playmaker88]

http://news.bbc.co.uk/1/hi/sci/tech/3532440.stm

Is our solar system unique? Despite this I still say the odds are that our system is not unique but it lessens the likelihood of similar life-forms certainly.

[Red Shift]

I quote from my nice book " The Encyclopedia of space" ways to calculate civilisations,

Each of the factors can lead to a estimate of 10 million civilisations in the milky way galaxy at any one time!

The main question is, what point of civilisation are they at? as it is believed that all life didn't start at the same time (although we cannot be sure) it is known that there could be huge gaps, a likely reason to why SETI has turned up no results is that all the surrounding civilisations are still around times such as cavemen or the dark ages.

If there are other civilisations in the milky way and we are the oldest by a large gap, it may be our desendants who make contact with a primative civilisation.

Every one sees aliens as beings with mental capacity millions of times better than our own, whereas it is very possible that aliens are green slime, and green slime is not capable of communicating its existance!

(As far as i know)

[lazserus]

To start off, even if another planet in the universe was identical to Earth in its atmospheric chemical make-up, a moon the same size orbiting, and being the same distance from a host star similar to Sol, the chances of other "homosapiens" inhabiting the planet are rather slim. Intelligent life? Of course, but not humans. Evolution is a very strange mechanism, and then when coupled with natural selection your probability gets a bit splashy. There's still a very significant amount of chance/entropy involved in macroevolution, thus the end results on mirrored planets would still be very different.

I would say possible, although more likely those other humans are dead by now, as the universe is quite old and odds are they were created long before us judging by the odds of life being "formed".

To add to this thought, probability shows that Earth and our solar system is still in it's infancy compared to others in the universe. The universe is roughly 12-15 billion years in age and our solar system is a mere 5 billion years old. Some scientists would have you believe that it takes exactly 4-4.5 billion years for intelligent life to spring up on a planet, but that logic is biased and flawed. Mainly because they look at life on Earth and don't take into consideration several other factors. One factor is particular is the new discoveries by paleontologists. More and more discoveries are supporting that life sprang up on Earth as early as 3.9 billion years ago. That's several billion years previous to the original theories. A lot of fossils bring signs of simple organisms living in the seas dating almost the age of the planet itself during the Precambrian Era during the Archean eon. We've also found that there were definite signs of small mammals, even primates during the end of the Cretaceous period in the Mesozoic Era. That's some 30+ million years earlier than previous theories. Away from the rant, this basically shows how quickly life can evolve in any given condition.

Is our solar system unique? Despite this I still say the odds are that our system is not unique but it lessens the likelihood of similar life-forms certainly.

I've read a few articles on well substantiated science sites that say our solar system is, in fact, not unique. There was a discovery just this year of one very very similar to our own. Even with a solar system different from our own, that means nothing when dealing with the evolution of life. Remember, life can survive and flourish in some of the most brutal environments.

[marglarg]

To fully answer this I think we also have to ask the question, 'where did we come from'. From a creationists' perspective, if God created everything, why would he then stop at just one world like our own. It would be an awefull waste of space to just have one inhabited planet with humans amongst the huge expanse of the universe.

From an evolutionists' point of view, we are back to debating along the lines of Laz's reasoning regarding timelines etc for life to evolve to beings like us.

If we are a product of alien intervention then there could be countless worlds out there with humans.

I'm not saying one solution is more possible than the other, I simply don't know. BTW, is there definite proof of our evolutionary past? ie. has it been shown without doubt that we have evolved from primitive apes / man?

I know I could probably look this up but I'm sure there are some savvy people out there who can give us the run down.

[lazserus]

The theory of evolution is just as sound as the theory of gravity. Microevolution has been proved in different environments with different species many many times. There is significant fossil evidence for macroevolution as well. A good source to learn more is http://www.talkorigins.org.

[dutchie]

Always good to see you ride your favourite horse, Laz...

[lazserus]

I've just found it's the best source from credited scientists. A lot of other articles I've read from other sources turn out to be biased laymen information.