Why aren't aliens real?

Answer 1

There are aliens out there. See the related link.

That is a very important question.

There are billions of stars in the galaxy (and billions more galaxies) and many of them have planets. Surely we should be seeing aliens everywhere? Why is it that we cannot find any evidence of life on other planets?

There are a number of possible explanations.

1. We are alone.

This seems highly unlikely. Why should the Earth alone produce life? Could life arising be so spectacularly unlikely that only one planet of billions has any?

2. Other civilisations are invisible to our detection

The way we detect alien life is to listen for their radio broadcasts. Currently we produce radiowaves in all directions for our TV and radios and we think aliens will do the same, so we look out for these TV signals from space. However what if they don't use radio waves? Maybe they use something else or nothing at all? Or concentrate their radio waves to where they have to go instead of broadcasting into space?

3. We are the first of many

This is the idea that we are the only beings in the universe capable of civilization for now. The idea is that in the future alien civilisations will arise but at the moment we are the only ones.

This is possible because the universe is still quite young. (About 15 billion years old). Life (we assume) needs a planet to be on, planets form from heavy elements. Heavy elements are very rare in space. Heavy elements are manufacture inside stars, the star has to die before the elements are released. Hence at least one star-generation must occur before planets can form. Perhaps the Earth is the first planet capable of supporting life ever.

(I'm rather like this idea, even though it seems so unlikely)

4. Civilisation is too short-lived.

This is the idea that civilisations only last a few hundred years before blowing themselves up. That means there would only be a small window when the civilization is broadcasting before it ends.

I find this view overly-pessimistic (we don't actually have any evidence of planet-wide civilisations totally destroying themselves)

5. Few and far between,

Say that life only arises once of twice in any galaxy. How could we find it? They would be so far away that their radio signals might not even have reached us yet.

6. Time perception disagreements

This is a long shot: Suppose that an alien's sense of the passing of time is completely different to ours. They might send us a signal which to them is a very distinct pulse of radio waves but to us is confused with the brightening of a star by 1% over a year.

Answer 2

Aliens don't exist because for there to be life on other planets there must be water.

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edited comment

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its true that planets need water for life to exist on it, but keep in mind we know so little about the universe and its been proven that a very very long time ago Mars had large amounts of water on it and could have easily supported life when it had it.

So to say that life on other planets is not possible because they need water, would raise the question is there water on other planets? Keep in mind there is lot more than nine. Something like 3 billion to 3 trillion is range of estimated planets in the universe.

Answer 3

Aliens may or may not exist. No one knows for sure if there are any. People think that because the universe is large, it means that there is definitely life elsewhere. But someone has to be the first form of intelligent life, and there is no indication it isn't us. Whoever the first people are, they would see the huge universe and assume there was plenty of life out there. And they'd be wrong.

I don't see people, at least not scientifically minded people, saying there are no aliens. What I do hear them say is, "No solid proof of aliens is known to exist, so it is not yet time to believe aliens exist". Remember, in science you don't get blamed for not believing in something before the proof comes in. And you don't get credit for being right, if you got that way by sheer guessing.

There are those who pretend that alien proof exists and has been seized and hidden by the US Government. They have no proof of this, only their own imagination to support it. Remember, anecdotes are not evidence! And also remember, the US covers 6% of the Earth's surface... funny how aliens never seem to crash anywhere else, where the government can't hide them.

Answer 4

There could be aliens living among us here on earth. They may change and evolve to appear human to co-exist as a human in a study of life on earth and humanity. No one really knows whether to believe in aliens or other life-forms but it stands to reason that with this big universe we live in, it is unlikely that earth is the only planet inhabited by living creatures. And if there are aliens in existence, their knowledge is far more advanced than the knowledge of those of us here on earth because they've mastered the art of space travel and are able to visit other planets in a more relaxed fashion than we do.

Answer 5

It is kind of hard to prove a negative. Absence of evidence is not the same thing as evidence of absence. So no one can say "aliens aren't real". All that can be said is that "so far, no aliens are known and proven to exist".

aliens may very well be real. personally i think aliens have visited us and that they are peaceful. but some people might say if they are real why haven't they shown themselves to prove they are real. i think that they think if they did, it would cause panic and maybe even a whole war when they don't want one.

Answer 6

There is absolutely no scientific proof of aliens anywhere, let alone among us. It seems likely there may be aliens somewhere out there but that is very different than pretending you have actual proof.

Answer 7

Because aliens have not actually visited Earth, at least not during the modern era. No actual evidence exist because it simply hasn't happened.

Answer 8

No one says they can't, it is just that no one has proven they *do*.

Answer 9

Because they're shy