Is it possible we are actually alone?

Question

There was this documentary on BBC2 about Earth's geography, and the chances of Earth existing is so amazingly lucky, and us sends it almost impossible just bridging on it.

Answer 1

I am not familiar with the documentary you are referring too, however it given a universe of infinite possibilities, one of those possibilities must be that we are alone.

First we are not even sure how live arose in the first place. Therefore we cannot begin to speculate on how common it is. The extra-solar planets we have discovered so far indicate that our basic ideas about solar system formation is flawed, so we don't even know how common Earth like planets are. In the 4.5 billion years of the Earth's history only one life form have developed intelligence and the ability to use tools, manipulate it's environment and ask the question, are we alone? That's half the life span of the Sun. There are a myriad of variables which make this question incredibly complex. Unfortunately we are dealing with a data point of one (the Earth and our solar system). From this it is difficult do ascertain the answers to many of these questions.

One possibility is something called 'The Fermi Paradox'. It addressed this issue. If there is life in the universe, given the time scales of galactic history, why haven't we been contacted? Maybe we are alone, or maybe we are the first to developed the technology to meaningfully explore the universe.

Answer 2

The first answer sums it up.

Even considering the Drake Equation for determining alien life, we are effectively alone because any aliens who could interact with us would be too far away to do so in any meaningful manner, if at all.

Answer 3

do you mean human civilization?. no , Alien are here for a while..and you dont want see one,,'cause you will pass out. or what else you mean?

Answer 4

I think its "Possible" but I dont think that we are though, it would be wierd if we were alone with all that out there.And also think about it, if the Earth was formed through meteors and all that crashing together stuff, you would think there was some sort of life form on those meteors, we didnt come from nowhere.

Answer 5

All evidence would suggest we're alone

How many examples of alien life do we know of?  zero

How many other earthlike planets do we know of?  zero

The most direct conclusion is that we're alone.  Now, we don't know of anything that would PREVENT life from forming on other planets, we just don't have any evidence of it.

The problem I have with the statistics arguments is that we don't know the likelihood of earthlike planets, or of abiogenesis.  So all the people that are undoubtedly going to answer this question by saying something along the lines of 'the universe is so big there has to be other life out there' are just blowing smoke.  You can't do statistics with a sample size of 1.

Answer 6

No. Given the total number of stars in the entire Universe!

Answer 7

No we cannot possibly be alone. The universe has trillions (probably even more!) galaxies. Living things are out there. They could be the most microscopic things to a million feet tall! You never know. If you think i am crazy, watch this video: http://www.youtube.com/watch?v=uDOOZ_IPb...  

Answer 8

Very, unbelievably unlikely.

Life appeared on Earth very shortly after the conditions for its possibility arose, and all evidence is pointing to life being very easy to create.  In all probability, it forms on any planet that is even remotely Earth-like, which is to say, one that has day after day after day of trillions of lightning discharges from the atmosphere sending massive amounts of electricity through massive primordial seas brimming with complex organic compounds for hundreds of millions of years.

There are likely to be M-class planets all over the universe.  Not, say, 10% per star system likely, but maybe one out of a million likely.  Maybe one out of a hundred thousand.  *Maybe* even one out of a thousand.

That would give us between 400,000 and 400,000,000 M-class planets, and that's just in our one galaxy, which is one of a hundred billion galaxies out there.  And life doesn't even really *need* an M-class planet to form, it just makes it easier.

Is Earth the only inhabited planet in the universe?  Staggeringly, mind-blowingly *unlikely*.  Even assuming only ten billion stars per galaxy, and one M-class planet per million star systems, that comes to 1,000,000,000,000,000 planets in the universe with life on them.  Honestly, I'd guess there are a hundred times that many.

Answer 9

It is possible. There is no proof of life on other planets, so the possibility of us being alone in the whole universe has not been ruled out. But the possibility does not seem likely to me. I suspect life somewhere will be discovered eventually, and then the possibility of us being alone will have been ruled out.

Answer 10

It is certainly possible that we are alone.  The problem is computing the probability of life elsewhere.  Unfortunately, we only have a sample of one planet with confirmed life, our own.  It is not mathematically justified to estimate the probability of any event in the future based on only one known event.  I hope there is life elsewhere, but I would not bet on it being found within this century.

Answer 11

is it possible we are alone?

yes or no.

if you say 'yes', then you are aligning with the religious nuts and the rare Earthers.

if you say 'no' you are being frankly, very unscientific.  Statistics are unreliable when you don't know much about what you are trying to predict.  Not to mention, you align yourself with the tin-foil hat crowd.

take a step back... you ask is it POSSIBLE?  sure, anything's possible.

Someone will mention Drake's Equation, a powerfully persuasive  mathematical argument, that means precisely nothing.  Drake has spent 40 years pretending this eponymously named equation will somehow be accepted as widely and convincing as Enrico Fermi's piano tuners in Chicago.  Never happen... Drake is no Fermi.

Answer 12

I'm not sure what the question is, but there is no way the earth is the only planet in the universe with life on it.  There are probably thousands of other planets filled with beings who are asking the same question as you.  When we find them, we will all sit back and laugh.  Until then all we can do is scratch our heads and wonder.

Answer 13

It kinda like god haven't met him but we know he's there . there are trillions of stars out there and any one could  have a earth type planet around it