Evolution is just like some watch that ticks along in a predefined way. The whole meteor wiping out the dinosaurs bit should have made this clear enough. If meteor had hit them 100 million years earlier we wouldn't have birds but might instead have a huge variety of bats.
But that's just the most recent one. What if the Cambrian Explosion had come at a very different time or any number of the other catastrophes followed by random survivors spreading out to fill up the open space?

Even if you had a planet completely identical to Earth but without having the other planets and debris in it's solar system be exactly the same it should get hit by the large rocks at very different times.
But you wouldn't find any planets even that identical anyway. Even with planets humans would do well on there would be variations in size/gravity, the brightness and distance from it's star, composition of it's atmosphere, etc. Again, I'm talking about worlds with air and water and such that would be very friendly to us: even with that they're going to be different.

The number of worlds that are different but livable would greatly greatly outnumber those worlds that were indistinguishable from Earth. There must be some other explanation for why all the aliens we see are human shaped.

Of course they are real, I was abducted by them just 5 days ago... what a party...

I understand what you are saying, and I agree with you about habitable yet uninhabited worlds probably outnumbering inhabited worlds. Basically, I am saying that its all about the mathematics. In an infinite universe it is possible to have a repeating set of variables. The same variables that shaped life here as we know it could repeat at somewhere else or at a different time. Something that complex could repeat with infinite time and space. Mass extinctions and enviromental changes could be replicated in infinite time and space. But I see your point. I suppose it is also possible that humans on other worlds could have somehow came from here. Or perhaps there are aliens who disguise themselves in human form.

Hey Shoku,you're cool. I like the discussion. Of course a lot of this thread is fanciful and psuedo-scientific but it is great to chat with you It is always fun to imagine the possibilities

Even with an infinite universe the planets identical to ours should be so far away that the light from their stars never reaches us (expanding universe makes the distance grow even as the light is moving through it.)

I'm glad you thought that they could be disguising themselves but I can't think of any reason their disguises should be so far off. "Scales? Whoops, I can't tell those apart from skin. Not enough time to do it over" sorts of scenarios would have to happen over and over and over but surely they can at least count to get the number of fingers and toes right!
Getting proportions right is harder for humans and maybe thinking beings in general but they shouldn't ever be so far off as the greys usually are.

There's another way to look at it though- these humanoid aliens might be made genetically to interface with us as well as the original aliens. Trying to have similar ranges of perception as both species and both forms of communication seems like a very appealing explanation for why they should have these forms.

Excellent points. Yes habitable worlds of any kind are probably extremely far away.Possibly even inter-galactically far away Yes, the disguises could be for interface purposes. I totally agree with you on that. You make a lot of great points. However,most of what we are discussing is merely conjecture. A lot of what we know about space and the possiblities of evolution and other life are theories based on theories. So there may be pieces of the puzzle we are missing or information we have not realized yet

Actually after taking an intro to astrology course I've been keeping up with astronomy news so I'm not relying on just conjecture. There should be many many Earth-like planets in our galaxy. The whole drake equation thing pretty much started out as a "here are all of the numbers we need to figure out" staging ground to get the ideas-ball rolling but after we starting working out the first few factors conservative estimates said there should be about 10 civilizations in our galaxy right now and liberal ones were more like 10,000. We're about halfway through the equation right now and so far the values have been more towards the liberal end but still in the middle ground.

Once we check out Europa we will have some very minor non-conjecture estimates for the factor involving the origin of life in general. After that we'll basically have to wait until we've publicly made contact with another civilization or done some seriously exhaustive planet searching in a whole bunch of star systems.

Nonetheless basic chemistry is all you need to be able to tell that there should be lots of Earth-like planets out there. Supernovae throw the heavy elements far and wide and the light ones are all over the place already so basically it comes down to how many stars are there similar to our sun.

For planets a little less habitable for us but still habitable to chemically similar life you could look for planets close to smaller stars or moons around gas giants like Jupiter. There's a pretty simply calculation (well, you wouldn't want to do it by hand but a computer can handle it with less effort than the browser you're looking at this in,) for where you get liquid water and everywhere there's liquid water at least some form of Earth-life can survive.

Bigger stars aren't good places to look because they burn out faster and if there are other big stars forming nearby that's going to mean supernovae that could burn away all the life in nearby systems. So basically you don't want to be to near the center of the galaxy and can sort of limit the search to stars about as far out as we are, which is handy because things similar to where we are are close and that's the first place you'd want to look anyway.

The field I'm actually going into is biology, hence all the certainty about how life works. It's really slow and boring when the environment is stable but when half of the pieces are knocked out making new connections is worth basically doing a retarded ob of it since there's nobody around to do it any better.

So if the dinosaurs had died out early mammals would have had a lousy time because they couldn't take advantage of all the slow connections dinosaurs had laid out. Of course most of those connections went away with the dinosaurs anyway but even so parts of our environment wouldn't have EVER been the way they are without them.

whew....

... just got abducted again tonight... holy crap can these guys PARTY !!!!!

Yes, the odds are "astronomical"

It's all astronomical in astronomy

We're advancing an awful lot for them to be stopping us. What's holding them back?

They are outnumbered on the earth. They are waiting for reinforcements.

They like to work behind the scenes and take over industry and government and currency. This they have already done.

The next step is to disarm the population.

This they are doing.

Don't give up your guns.

They prefer peaceful take over. If this does not work... total annihilation of humans is plan B. If they can't have the earth the word is that they will just destroy it.

I've heard that before. What I'm saying is that I don't get why a race with a 65 million drop on us can't just pacify us with some sort of hypnosis and basically run circles around our politicians. Just a couple hundred years has been enough for us to make tanks that would have been nigh invincible against what we used to use so with millions of years you'd think they could just send in mobile billboard type things we couldn't get rid of and yadda yadda yadda.

Even if they're in some kind of economic slump where everyone is poor they ought to be able to round up enough stuff to make it look like they were rich and then shanghai half of us on transports to go dump us on whatever planet they're not fond of while they started moving in on this planet.

A race that was capable of leaving this planet for another one would have had enough technology at the time to just fake things video of people responding back to their loved ones and it's hard to imagine that they haven't made any further improvement in the millions of years since then.

They are smarter,more advanced,and they have been here (perhaps)longer than us

I think you're absolutely right about a race with a 65 million year head start on us would have technology we could only dream about.

Now consider this “dream”...

Supposing they wanted to imprison people who were political dissidents (or whatever) and supposing they had an advanced "spiritual" technology with which they could brainwash “spirits” into believing they were only bodies and not spirits.

Given that scenario, it is not difficult to imagine this planet as a sort of Devil’s Island prison where bodies are the prison cells. And when the prison cells wear out, the inmate is grabbed and stuffed into another prison cell.

Very interesting Skyhook

Yeah, I got that idea from all the stuff about Xenu. No idea if that's the exact foundation for the story, but given the not-impossible nature of the premises, it makes a whole lot of sense.