sadly there are theories that even the strongest signals we send out become indiscernable from white noise/background radiation within 2 light years - the closest other star to the sun (proxima centauri) is 4.2 light years away

Ridley Scott told me this.

JoeTheBro: No not everyone will be having a rubik cube in their hand, and not every planet can sustain life. But there is possiblity if ur having a rubik cube in ur hand then its safe to assume, out of 7 billion people some of them would have rubik cube in their hand at the same time, so there is a possibilty for a life form to exist in our solar system. the closest being Europa one of the jupiters moon.

Intelligent Extraterrestial life form, that is a different question altogether and i believe it is highly unlikely that we would ever be able to find them or contact them, SETI has estimated that if a intellegent life form exist in nearby stars, there is a possibilty we might be able to hear from them by the year 2020, if not then the only hope will be that Intelligent extraterrestrial life form would contact us. 

the problem with this kind of question is, people can only speculate about things which are light years away, based on the data we have collected by our light years inferior technology. So we can only have theories and hypothesis.

Still doesn't mean there's life out there. If you roll a 6 sided dice 31 times in a row, how many possible sequences are there? 1.326x10^24. Do you know how many planets are estimated to be in the universe? Around 10^24. Saying "life must be on other planets because we have it and there are so many planets" is like saying "other sequences must be as prestigious as rolling 31 sixes in a row because there are so many sequences."

I too agree that current radio transmission bands being used are too futile but it does certainly travel long distances. The universal key to communicate is yet to be discovered.

Yes, but I'm saying the stats don't actually predict alien life. You're only looking at the upper layer of the problem without factoring in the rest of the equation.

Given the size and age of the universe, it's incredibly likely that at some point, somewhere, intelligent life existed. Enough time has gone by for civilizations to have evolved, risen, reached their apex and even collapse. So in that sense, I think it's extremely likely that intelligent life, or life of any kind, has existed and exists somewhere in the universe right now.

But those two factors--size and age of the universe--that make it so likely life or intelligent life exists and has existed in the universe, also make it extremely unlikely that two intelligent civilizations will exist in the same span of time, in the same sector of the universe, and have the technological capability to communicate with each other. Life could exist right now on the same level of technological development as us--but what does it matter if they're in a different galaxy? Life far older than us could have colonised an entire galaxy--what does that matter if they are on the other side of the universe to us, and haven't yet mastered the kind of technology or capability that could see them leave their own galaxy? The space between galaxies is often far larger than galaxies themselves, after all.

It's scientifically likely life exists out there. The real challenge, and the real excitement, will come from finding proof of life near us. Thankfully, the range of "near us" will increase as we advance, but those same factors that make life likely to exist also mean that the chances of different forms of life coming into contact are very small.

Out there, on their own planets, yes. Here on earth willingly secreted away in area 51, or Roswell New Mexico, no.

I imagine there are some pretty fundamental sociological principles that are necessary prerequisites to a species becoming technologically advanced. One of them being that over time the societies would tend towards greater cohesion and less violent conflict.

In our infinitesimally meager search of the galaxy so far how many planets have we found in the Goldilocks zone? I think it's about 2 or 3, but they have been gas giants so unlikely to support life as we might recognise it.

Essentially, all that's required for life to potentially develop (or maybe even be likely to develop) is liquid water, we think. As hydrogen and oxygen are pretty common throughout the universe water H2O is likely to be present on many planets. Life probably only needs an abundant liquid, so maybe life can develop in any liquid medium if there's a planet's load of the stuff. Who's to say that some sort of exotic life form couldn't form on a planet that has an abundance of liquid methane.

There's a theory that Jupiter's moon Europa might have liquid water under it's frozen crust. If there's plenty of liquid water under there then it's possible that simple life at least has developed.

Saturn's moon Titan has liquid methane lakes. And space scientists even talk about planets that exist in the "methane habitable zone" implying that liquid methane is a candidate substrate for life to develop. Titan also has water, but it's all ice given it's cold enough to support liquid methane in large quantities.

So my hypothesis is that any planet with large amounts of liquid anything (except maybe mercury) is more likely than not to evolve life.

Methane and Water are being found to be quite abundant substances

So ur saying life on earth came into existence by chance, and that chance cannot be possible anywhere else in the universe. which means there is not even a remote possibility of planet revolving around its sun at a distance which could host an atmosphere and life to thrive on it.