If you follow the "natural" idea of how life came about, it is virtually impossible that the process of life occurring has happened only once. This is atheist Carl Sagan's assertion, not mine.

 

So, what ya got?

 

I use to believe that there are many planets with the "coincidental" phenomena that occur in Earth, so, there are many chances that there are life in those... but if it is right, then they are just like us and don't have reach to us as well as we have not doing the same...

 

In the other hand, I reject the so called "aliens" help to do things like the Pyramids and all that... it really dragging down the mankind capacities of building wonderful dreams and the worst nightmare... I believe we are capable of everything we have made... our thoughts and ideas are unmatchable as mankind and the art of course...

 

as a Catholic, I used to believe that mankind is the center and focus of existence, but I've seen that most Catholic formal points of view in this century agreed that Aliens can exists... that there's nothing wrong about it so... right now I'm confuse and have hungry... jajaja...

 

I actually bet there are many many out there, many younger and some older in advancement.

 

Of course the experiment in advancement that is human intelligence has yet to prove whether it's a dead end, i.e., inevitably outgrows its own blood supply. If so, I would suspect there are other now extinct civilizations out there.

 

That speed of light thing though is a tough nut to crack.

 

But I don't believe they have ever come here, and probably never will. Maybe it's we who are the most advanced species (oh no!...) so it's even more difficult that one day we'll live our solar system let alone our galaxy....

 

of course, when I hear some kinds of music we have here in PA, I'm ready to believe quite the opposite...

I'm almost certain that there is life outside of Earth, and probably Intelligent Life too.  However, I highly doubt that any of them have advanced enough technology in order to visit Earth.

 

It's much less probable that life is intelligent.

 

It's much much less probable that life can visit here.

 

 

No, aliens have not been here.

There's most definitely other life in the Universe. I tend to believe we're the only intelligent life though. We most definitely have not been visited by aliens in the past. 

By using the word Aliens and asking if they have visited Earth you are implying sentient life (Yeah I know bacterialogical non-sentient life could get here on comets and meteors, but all of those objects originate in the Oort cloud and would not have come from another solar system and I cannot see life evolving out in the Oort cloud - it's just not a Goldilocks Zone). I wouldn't call bactieria "Aliens" - I would call it alien life though, but we can't detect that over stellar distances so we cannot say whether it exists or not.

 

The practical impossibilities of Interstellar travel rules out the last two options.

 

The Drake Equation (for all it's worth) is only valid for extraterestrial civilisations who are at a sufficient technological advancement to be able to transmit radio signals - those that fail the test we will never know about and those that don't we could still miss, so whether they exist or not is imaterial. And due to the age of the Universe, the age a planet would have to be to have evolved a technological civilisation and the speed of those radiowaves we are restricted to a very small protion of the Universe in which to look.

 

The Rare Earth hypothesis is okay, I can live with that ... the universe is big enough to support more than one Rare Earth - it's just numbers, but the evidence falls by the same test as those predicted by the Drake Equation - unless we can detect their presence we cannot prove they exist.

 

Are we unique? - possibly ... more importantly - are we the first? - likely.

 

 yup hours of fun - and that's just for our galaxy - when you consider how many galaxies there are in the universe it gets quite sobering - not only are we on an insignificant little ball of rock orbitting an insignificant star in the backwaters of the Milkyway galaxy, our galaxy isn't anything special either.

 

Another sobering thought is just how huge our nearest galactic neighbour the Andomeda Galaxy is - it's difficult to see just how big it is because at 2million light-years away it's actually quite dim in our night sky but this mock-up pic shows how big it looks compared to the moon:

 

 

The articles did actually talk a little bit about some of the pessimism about their being multitudes of civilizations equal to or greater than ours. Mainly, that it seems like we should have some sort of signal, but as of now we've seen none.

 

I'm sure this is all old hat to some, but I'm having fun getting a little more up to date.

I don't think anyone who has any knowledge of physics outside of wikisearches does, but I see lots of kids on forums and some in discussions I've had try to use it to refute any points I make. 

It's become very frustrating for me. I wasn't speaking about its use in this thread though.

Brian Greene has written two very good popular science books dealing  mostly with Cosmology and also modern physics in a more general sense. He focuses too much on String Theories which I'm not a fan of, but they're still very good. 

If you're a bit more serious in learning about this kind of stuff I would recommend them. 

 

Glad to hear you're so sure of that. 

 

If we assume that there is intelligent life on a planet orbitting Proxima Centauri, not only have they got to traverse that distance somehow without breaking the laws of physics, they also need a reason to cross that distance.

 

Especially after watching Jedward on the X-Factor.

 

http://www.youtube.com/watch?v=HNu_d9Um1eM&feature=related - http://www.youtube.com/watch?v=HNu_d9Um1eM&feature=related

 

 

Wormholes are a possibility but there would be no way to stabilize the energy o maintain them. 

Dean pretty much answered for me, but I'll just add that our sphere of contact since we began broadcasting radio waves, which would be the easiest way for an alien civilization to detect us, is something like 62 light years. That is hardly anything.

WIthout that how would an alien civilization have even discovered our planet was worth visiting? Why would they even be jumping through wormholes to get here? The time scales just don't add up. 

When you consider that the universe is expanding faster than the speed of light, in fact even some galaxies we can see right now are moving away from us faster than the speed of light, much of the universe is actually out of our reach. We will never be able to even observe much of the universe until the expansion slows let alone travel to it. 

Just to expand on that for a moment... 62 light years means that anything in a sphere of radius 62 light years can detect us. The Milky Way Galaxy is 100,000 light years in diameter and 1,000 light years thick (in the middle) - assuming it was a perfect cylinder (which it isn't) our radio waves have reached 0.0001152% of the volume of the Galaxy - since we live out in the galactic suburbs on the inner rim of the Orion spiral arm where it's considerably thinner than 1,000 light years that percentage is probably a magnitude or two higher, but still pretty small. However, on the bright-side, the density of stars where we are is roughly 0.000424 stars per cubic light year - which means our radio signals could have reached 380 or so stars  (out of 400,000,000,000 or 0.000000096% of the stars in the Galaxy)

 

Excepting of course that such culture only did so for a short amount of time whose arrival doesn't correspond with now.

 

 

A) how does the universe expand faster than c?

 

B) if it does, how does an signal get to us from that edge since the fast we can get light is at c?

A lot of people have trouble with this because it seems to violate special relativity. However, it doesn not because nothing is moving faster than the speed of light. Space itself is expanding . The usual example is glue a bunch of pennies to a balloon and slowly blow it up. The space itself expands while the pennies remain motionless on their section of space, the balloon. 

Special relativity is not violated because speed refers to a movement through space. Also, no information can be transmitted because of this expansion, so no potential paradoxes arise.

B) I'm not sure what you mean by the edge exactly, but we are not receiving any information from objects very distant in the universe. We do receive information from the early state of the universe via the cosmic microwave background. However this is not reaching us from the distant universe, it's just leftover from the past.

Think of a rubber band. As you stretch the rubber band (an ideal rubber band that cannot break) it beginst o cover more space, but there's less of it in each region because as it stretches it gets thinner. You could stretch this at the speed of light for a long time and the rubber band would be present over a great expand, but would be barely detectable in any particular area. That's a good way to think of the CMB. Not as distant universes communicating to us. 

 

 

Well some galaxies are moving away from us at the the speed of light, others are not. Basically the further two objects are from each other, the faster the relative velocity between them is. Thus very close objects are red shifted due to this expansion, but still visible. 

Hubble found the rate of expansion by measuring red shifts. Read about Hubble's Law if you want to know more about that matter. 

 

If you link together the fact of been believer and hysterical, is just your thought or your believe, it doesn't help to any of the discussion here... you are just evidencing that you can't understand the other point of view and that's it...

 

-and I'm talking about aliens, do not report me... please-

I hope you don't believe in god, because if you do, you're a big contradiction. Try using that great argument you just wrote in reverse....

If aliens did exist why would they want to visit Earth? I've talked to some guys when I was in the air force who had some strange experiences that they weren't supposed to talk about though

If you Saw the Under ground classified photos of the Alien Cadaver they captured, you would crap your pants

Once again you completely miss the point of my post. If you read any of the other like 7 posts I made in this thread, obviously I'm not suggesting any conspiracy type moronic ideas like that.

I was agitating him for his flawed reasoning. Saying direct first hand experience isn't the only way of knowing something exists is not be establishing the lack of first hand observation as a sufficient criterion for existence.

Do you just follow me around so you can respond to my posts and demonstrate that you don't understand basic reasoning?

Answer:  Yes

 

And yes I do follow you around