Do aliens really exist, and if they do, do they visit Earth?

I just watched “Signs” and it started me thinking… do I believe in aliens?..
I think I do. Not in the Star Trek or Star Wars variety, but inhabitants of other planets…YEAH. I mean, Im not so egotistical as to think that Earth is the only planet that has residents. What do you think?

guess no one really cares.

blink If I was a sane person, I would be asleep right now. Be patient for replies, please. And I care, I’m just more of a non-verbal lurker than anything else. oh, and participation in the “a” thread over there is good too.

I don’t know what I believe about aliens. It’s really hard to get life to form. All these little, little things that have to be just right … but if it happened once it can happen again. Sure would make the universe more interesting, from a writer’s perspective!

yes, I think there’s a good chance there are others “out there.” If we ever meet, however, that’s a lot less likely, without better technology on at least one side.

<fumbling around for a :sleep: icon>

Im insane too, because Im not asleep either.
So, Shadez, you believe there are others out there, but Im taking it you dont believe we have ever been “visited”?

I have never seen an alien, nor a UFO. I worked with an individual for over twelve years, and one day he called me aside and asked me if I believed in UFOs. I told him I didn’t know. He proceeded to tell me the neatest story about his family encounter with Aliens. His mother saw one first looking through the kitchen window, and screamed. The whole family ran outside to see some little men running for the woods, they lived out in the country, and after a bit they saw a UFO lift off from the woods.

Their neighbors also saw it lift off from about a mile away. He said they called the Air Force and the Bluebook people came and found a large burned spot in the woods. After investigating the spot and the footprints, etc, they left calling it an unknown.

I looked up the Bluebook story and found it, it was as he said it was. Now I have no reason to disbelieve this guy, he was always honest with me.

So, due to that, yes, I believe that there are UFOs and aliens. I hope they are not anything like the movie “Signs”, I was disappointed in the movie, expected more about crop circles and less horror movie.

There’s no problem at all with the idea of extraterrestrials existing - it may even be that the formation of bilogical life is inevitable given (reasonably)Earth-like conditions.

But there’s a big problem with the idea of aliens coming to visit us; everything we currently understand about the nature of the universe suggests that interstellar travel would be difficult in the extreme (I hesitate to say impossible, we had a thread on that anyway) - appeals to “well, they might have technology far in advance of our own” don’t really work for me - unless their technology has offered them a way to overturn what we consider to be fundamental properties of the universe, then they’re going to have a damn hard time getting here.

Very good point about the technology. But who says conditions have to be “Earth-like”? Maybe life develops around the environmental conditions.

Sure; when I said 'reasonalby Earth-like", I was only thinking about vaguely similar temperature ranges, liquid water, moderate gravity, similar proportions of available chemicals etc.

Much speculation has been made regarding alternate life chemistries (silicon based being one of the more popular), but as far as I understand it there are reasons why this wouldn’t be as likely (based on the limitations of what you can actually do with certain elements) as the kind of chemistries we see here on Earth).

All I really meant by the statement is that given the formation of an Earth-like planet, maybe the formation of biological life is inevitable.

Difficult to tell as we have a very small statistical sample on which to base our speculations

I think that the most eloquent of arguments for the existence of Aliens is that they HAVEN’T visited earth

The earth type chemistries might be the most likely, based on the fact that we are here, but we really need to get a larger sample before we can say anything for definite…
some imaginary chemistries and body shapes here.

the fact that SETI hasn’t turned any civilisations up in our galactic neighbourhood is not surprising, given the unlikely nature of the development of intelligence, and the fact that SETI couldn’t detect the Earth if it was more than a hundred ly away.
but the most advanced civilisations should have been here by now, using the assumptions in the Fermi Paradox…
I find it hard to believe that UFO’s are controlled by anything I would call intelligent, because (if they are not just collective hallucinations) they act in such a bizarre fashion…
but who is to say that a hundred years of subrelativistic flight has not driven them bonkers.

Even if aliens could visit earth, why would they want to? Any civilisation that has developed technology advanced enough to travel between the stars would obviously not need technology or natural resources from us.

The only possible reason i can think of why aliens would be interested in us is just simple curiousity. They might send their equivalent of social anthropologists to study us, and they would not contact us, because then they would have ‘contaminated’ our culture and civilisation. If they’re advanced enough to reach Earth, then i imagine they wouldn’t have any problems avoiding detection by us.

Thats what i believe anyway - i firmly believe intelligent aliens exist, but i doubt very much any have come anywhere near our solar system. Even if they have, i think they would hide from us…

Am I correct that the US Air Force no longer investigates these phenomena ? Surely, the fact that 50+ years of UFO investigations haven’t turned up anything resembling aliens, means that there is mostly hot air here. Plus, most of the people who claim contact with aliens are pretty strange…maybe the whole UFO thing is like the Salem Witch trials…no real evidence, but lots of hype.
Personally, I think it wouldbe nice if some friendly aliens called on us…but the sad fact is, we are probably alone…any other intelligent life isprobably far away, and will never make contact with us.

Why does everyone assume that aliens would be friendly? For all we know, aliens could land on earth with giant space ships, suck up all the drinkable water, ignore us puny humans as if we were ants and be on their way.

They would be coming to the wrong place if they want water- Europa, GanYmede, Callisto, Triton all have hundreds of times the fresh water that we do.

So much restraint required(not with you, hideNseek, with one of the other responders)

I’m convinced that life has evolved on other planets. As to whether or not any life forms have visited Earth, I’m skeptical. I’d certainly like to see that it has happened, if for no other reason because it would give us a clue as to how we might travel out there, but so far I don’t think it’s really happened.

Otherwise known as the Fermi paradox.

Imagine that you are an intelligent alien on a planet 100 ly away- you will have detected the planet earth long ago using interferometry and spectroscopy, the earth type planets are rare and precious-

by now you may have noticed trace elements from fossil fuel combustion creeping into the spectrographic readings of earth’s atmosphere- over the next hundred years you might start to detect artificial radio and microwave transmissions-

you get your ship ready and set off at the amazing speed of 0.1 C, thousands of times faster than any human craft- you will get to Earth in about 3100…
see you then…

LIFE on other planets and INTELLIGENT life on other planets are two very different propositions. Earth’s biosphere has an evolutionary history going back about two billion years. (If you’re a Biblical creationist you’re probably not interested in this thread anyway.) In all that time, encompassing multiple eras and epochs and ages and cataclysms and transformations in the nature of life on Earth, in all that time of randomly experimenting and trying out new life forms, this biosphere has, so far as we know, produced only ONE sentient species: Us. (And maybe some of our extinct hominid cousins, but that’s beside the point.) We have been here much less than a million years – by one account I read, only one hundred thousand – either way, an eyeblink in Earth’s history. Our existence would appear to be HIGHLY improbable.

Now, if we visit another planet, one that has life on it, we will be seeing only a snapshot of the long history of life on that planet – and the advent of an intelligent species there might be millions of years in the future, or the past, or never.

Even if life in the Universe is much more common than we imagine, INTELLIGENT life still could be freakishly rare.

It’s all in the Drake Equation – which we could use to calculate the number of sentient races now alive and sharing the Galaxy with us, except that too many of its variables are not only unknown but imponderable, including the length of time a sentient race lasts before extinction. It’s possible that any sentient race is doomed to destroy itself within a definite period of time after developing a certain level of technology; possible, also, that a sentient race, unlike every other living species, has the potential to ensure its own long-term survival and NEVER go extinct until the heat-death of the Universe. We just don’t know.

If another sentient race did exist, and had the resources and technology to cross light-years to visit us, I don’t believe that once they got here, they would just hide and watch and kidnap the occasional anal-probe subject. Of course, we have only our own psychology to use as a guide to theirs.