They could exist and they could not. "I don't know" should be an answer. I know for a fact that there is alien lifeforms (i.e. bacteria not found on earth). However, I've not seen an indication of intelligent lifeform outside of the planet.

Universe is very big and it's getting bigger. There are a multitude of galaxies (numbers in trillions or more, yet to be found). And there are also theories of parallel universes. Also multiple theories of dimensions, one theory says 10, then another suggests 11, another 26, 5, 10, 8, 7 etc.
Our mother earth is very young. And there are way older grandpas than uncle Sun. Also older great grannies than our Milky Way.
So, I do believe that they exist. A whole lot of them. Maybe they have visited, maybe they are among us or maybe they are yet to arrive, just for others like us.
If they have visited, the oldest epics describes them as they were seen then. Well, whatever! Duh..!!

So, I'm having conflicts between option #2 and #4.
Thus I tossed and arrived at: They exist, but they haven't visited Earth yet.

I only believe in what I can see with my own two eyes.

In other words, we don't know and we can't totally exclude the possibility of a different life form living in the great unexplored part of the universe. But I will only start BELIEVING in "aliens" when we will have definite evidence.

They exist, but they haven't visited Earth yet.

Another ism question... Whether they exist or not, they are irrelevant to my life, so it doesn't matter.

I don't 'believe' in them. I think that there's a possibility that they exist (probability theory and all). But nothing more than that. So there's no option for me

Since it's not only arrogant, but also illogical, to assume that humans are the only intelligent creatures in this entire vast universe, yes, I do think there's a high probability of "aliens" existing. The idea that "with our currently limited ability to explore space we haven't found signs of life, so obviously it doesn't exist," sounds wrong to me.

That being said, I hope that humans never get to interact with them or even know of them. We're talking about a species who can't even respect their own kind or other Earth beings, let alone extraterrestrials. That encounter would not go well. And who knows, maybe the aliens are even more violent than us

Last option for me.

They either haven't visited Earth, or they visited and saw how much a mess we are and left right away.

I strongly believe in other life in the universe, but I'm far more skeptical if it's intelligent. Microbes can live almost everywhere and that's what I would expect to find first.

There's probably life in the universe, but it's also likely that humans will never find out

Aliens exist, and we encounter them on the internet every day. Can't tell if they're on Earth or plugging in from the outside though.

Why do we believe that Aliens have significantly better technology than human mmm...~?
Maybe they're just a lot more primitive than human and doesn't even have the concept of "alien" themselves mmm...

I'm glad to see that a solid majority of the website is being reasonable about this one.

While I'd have liked if there was an honest "I don't know" option, the 4th option is by far the most reasonable.

In our galaxy alone, there have been computed to be approximately 11 billion earth-analog planets orbiting in the safe range of sun-analog stars. When you expand that to other galaxies, there are countless more.

It took 4 billion years for Earth to develop "intelligent" life, 2.4 billion years after it randomly generated protobacterial life in the first place.

Many of the earth-analog planets we've calculated to exist are actually older than earth. The problem is that they're too damn far away for our radio signals (which can only travel at light speed and without enough power will disperse before they can even interpret them) to reach them in our lifetimes.

But there's rogue radiation not emanating from apparent stars that we've detected in space. It seems like noise to us, but it could be the remnants of distant attempts at radio communication from civilizations at our level or even more advanced.

The thing is, it may not even be feasible for inter-system travel to support actual life. For any of these theoretical planets to reach us, they'd have to travel at least tens of parsecs without reasonable access to solar energy. Would something as gigantic as a ram scoop even survive the trek? We have no idea because we haven't yet designed a good enough one.

In conclusion, intelligent life almost certainly exists elsewhere, but we may literally never have the means to interact with it.

It's extremely likely that intelligent alien life has existed, but they've also probably gone extinct. It's much less likely that they currently exist, so I'm going to opt for us being alone because I'm a pessimist.

"Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying."

I think they exist, they have studied us, looked at eachother and shaken their heads then hightailed out of here...

The universe is so enormus and old that civilisations have been and gone sporadicaly through space and time. How many, how often and how long time they exist is certainly up for debate.

the poll is interesting the choices not so much.