h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

We are verry nieve to think they don`t. Space is infantly big and we are the only life. hahahahaha.
we probaly are the lest evolved of intelegent life as well. just becase there is no proof dosent mean they dont exsist.

Just because there is no proof doesn't mean they do.
Just because you believe doesn't mean it's true.
Both of those can be turned round.

The probability that other life exists cannot possibly calculated by us.

¦M¦

Life exists. We are here, well debate if we actually are 'alive', but ayway I'm here and I can sence things.

Other life, well ues I have to say that I believ it does exist elcewheer in the cosmos. I'm really holding out for life on Europa as that would clinch it .

The probabilites for life are tiny however and with things like supernovae and gamma-ray bursters that can sterilise regions of space the locations would be expected to be very few and far between. But we are here and the univers seems to be set up with the right constants to allow life, our kind at least.

On the subject of 's then no I would have to say that they arn't real. It's ludicrous thing that any species will know about us with out our knowing of them, and for said species to travvel vast stella distances just to buzz some random people and leave flattened bits in wheat fields.

will be most likely friendly when they get here and would be rather peleased to find us and probably stay for . Hmm, leaves in hot water.

I'm Yeliab of the h2g2AS by the way.

Let me just say that I don't like aliens.
- they taste funny
- and you don't know where they've been.

Ugh!

Me, I believe wholeheartedly that UFOs exist. I have no doubt that there are things flying around that haven't been identified (UFO, after all, stands for "unidentified flying object"). Whether any of those UFOs are alien spacecraft is quite another matter. I'm inclined to think they aren't.

Suppose they are. Then why are they seen only in remote, isolated areas by people whose credibility is less than impeccable? If the aliens are *trying* to make contact, they're doing an awfully poor job of it, behaving as if they're clueless about how human society works. If they're trying to stay hidden, they're doing an awfully poor job of that, too. Either way, it doesn't say much for the intelligence of these aliens. I think the simpler explanation is that there simply *aren't* alien spacecraft flying around.

What about all those reports? I couldn't say. I don't know enough about them. But considering just how stereotypical the reports seem to be, and how improbably humanoid the "aliens" are, I'm inclined to think it's people convincing themselves that they happened. In particular, considering the weird creatures that are around just on Earth, why expect creatures from another planet to be virtually identical to humans? Why do they never have fur, horns, hooves, ears, tails, wings, interesting coloration, mandibles, or any of the multitude of features that mere Earth creatures have? I've also seen (what appears to me to be reliable) commentary that relates "alien" sightings to similar phenomena in earlier eras, notably the succubus/incubus "sightings" a few centuries back when everyone was worried about what God would do to them if they didn't behave.

This is not to say I think alien life doesn't exist. It probably does. Again, life on earth manages to appear in some downright inhospitable environments (the ultra-hot water vents in the bottom of the ocean, for example). To suppose that it can't appear in equally-inhospitable environments elsewhere in the universe seems foolish. But this is not, as one post had it, "because the universe is so well-tuned for life", but because life is as it is because that's what the laws of physics et al require. (Earth life isn't, say, fluorine-based because fluorine makes a lousy base for life. Period.)

There's also the question of, would we *recognize* aliens if they appeared? The usual assumption is that "they're just like us": they think like us, they use technology like us, they have the same ideals as us. Why should they? Why assume their technology would be recognizable to us *as technology*? What if, say, their "spacecraft" are more like seed pods, or spores (say, from a metal-poor planet which therefore encouraged biological-based technology)? Why assume that they will greet us with open arms, instead of coming to plunder? (Look at human history. If "they're just like us", then perhaps *we* are the inferior natives who are there just to be exploited.)

Enough for now. This ought to stir things up a little.

Almost nothing in the universe happens once. Space is so utterly vast that if it can happen at all then it happens several times. Until recently the existence of planets outside of our solar system was disputed, now a large number have been discovered. If extraterrestrial life didn't exist, then terrestrial life wouldn't either.

I must say that I think man-kind is the only sentient being in the universe. This is because I believe that God created the entire universe in seven days. However I do believe that we'll find life on other planets. Just not anything as intelligent as us.

If the universe is infinitley big there must be an infinate amont of stars, if there is an infinite amount of stars, if there is an infinite amount of stars logically there must be a vast number of planets. The chances that at least one of these planets could sustain life must be relativley high. With that logic, there must be life some where other than on Earth!

There is, however, also a chance that there isn't.

¦M¦

The chance of other life not existing is incredibly small. With several thousand stars for every grain of sand on the planet, the odds that only one star in this would support life (or even intelligent life) is fantastically small.

Yes, theoretically the chance exists, but its comparable to winning the lottery every week for a month.

How do yo know that?

¦M¦

Seen too many space programs

How do they know?

¦M¦

I think they do it with a bit of looking, some multiplying and alot of estimating.

So they don't actually know either?

¦M¦

I've just done a small amount of research from a certain butler-related search engine, and it came up with the number 10^21 stars, or 1000000000000000000000 stars.

No, they don't know exactly how many stars there are, but they can estimate the number of stars in our galaxy (from the number of stars we can see and the density of stars in the galaxy), and estimate the number of galaxies (using a similar method). The number is not exactly correct, but the error is not that huge. Even taking the lower limit there are still a vast number of stars, making the chance that life only exists on a planet surrounding only one of these stars minute.

"making the chance that life only exists on a planet surrounding only one of these stars minute"
How do you know that?

¦M¦

It's by applying Occam's razor (something else from tv ). This states that the most likely answer is probably right. If our star has a planet that can support life, then it is extremly likely that at least one if not many many more have planets that support life as well. It's difficult to imaging that in a thousand trillion trillion stars only one planet from one star actually has the ability to support life.

How do we know that any other planets/satelites/celestial bodies of any kind can actually produce and (or) support life? We don't, so we really can't say how likely or unlikely it is. It seems that it's very likely, but as we have only ever looked for life on one other planet, we really can't know how large or small the probability is.

¦M¦

Technically no. We can only make a good guess. Research is being put into finding rocky planets out of our solar system, and there are plans to search for life of Europa. The guess that scientists make at the moment is by assuming that in 12 billion light years of space some star does have planets similar to earth.

Sorry, I've have to go to bed now.