Aliens

Hey guys, I was watching some interesting shows on TV such as "Ancient Aliens" and "Hanger 1: The UFO Files".
I was curious to see who actually believes in the existence of Aliens in the universe. I do believe there is something out there but that is just my thought.

Is there life abroad...hmm my theory is to master the ones I can see here and now then work about the others, human nature but, I know people who can define the night sky for me but can not even sit and stare at it in enjoyment

it would be arrogant to think that earth is the only planet that has life....and that humans are the most advanced....

we often search for life with a predetermined definition of what qualifies as life...perhaps we need to redefine it...for all we know there could be lifeforms out there that aren't carbon based like on earth....

You can join in the search @ http://setiathome.berkeley.edu/

I personally don't believe the visitation stuff, at least not in recent history. I like to imagine it might have happened in the past though!!!! I think its likely there is other life at least equal to us in the universe.... perhaps all those black holes were created by intelligent life trying to run more and more powerful particle accelerators and tearing the fabric of our reality, curiosity killed the cat
:lol:

adding to what ryujin said - there could be life forms which exist right here on earth in a way that we consider invisible. not simply microscopic - invisible

why not?

if you think its impossible, what makes you the expert? lol

Neil deGrasse Tyson says my thought on the matter perfectly.

https://youtu.be/tykCWO-abUU

Personally, I think the universe is too incredibly vast for there not to be/have been other sentient life. The problem I have with the idea of them visiting us is this:

"If you condense the history of the Earth — about 4.54 billion years — to just one year, humans have been been here for only about 23 minutes of that one year. In real time, humans have been on the Earth about 200,000 years."

That means that we as a species have only existed for 0.0044% of the time the earth has. Now take into consideration that the universe is estimated to be 13.82 billion years , that means that we have only been around for 0.0014% of all time since measurable time began.

Combine the chances of another sentient species achieving interstellar travel in that timeframe with how ridiculously small the earth is in comparison to other objects in our galaxy, not to mention how many galaxies exist, and well... The chances of being found by anything or anyone are just infinitesimally small.

BUT... You never know. Me, I differ to Arthur C. Clarke: "Two possibilities exist: Either we are alone in the Universe or we are not. Both are equally terrifying."

RyuJin wrote: we often search for life with a predetermined definition of what qualifies as life...perhaps we need to redefine it...for all we know there could be lifeforms out there that aren't carbon based like on earth....

Unlikely. Part of the reason life on Earth IS carbon based (and we have good reason to think all life is) lies with the features of carbon. http://www.infoplease.com/cig/biology/organic-chemistry.html

There is SOME evidence, though unsubstantiated, that Silicon could be a substitute for life. http://thelivingcosmos.com/TheNatureofLife/SiliconVsCarbon_12May06.html

This would be true in places like maybe... Saturn's moon Titan? The conditions for life there are slim, but it's mostly due to the fact that it has everything life needs... just at an extremely cold temperature. It's so cold that METHANE is a liquid there.

Then again... life could, in fact, be extremely different than we expect. It's smart to keep our eyes open to all the possibilities, but equally important to understand the patterns that lead to life as we know it.

EDIT:
To talk about the original topic:
When searching for life in our solar system, we are not looking for Martians or aliens that could be advanced or even multicellular. In fact, we're looking for single celled organisms (or even pre-cell organisms!). Most likely, it's RNA-based... and, it will be found where there is liquid water (or maybe possibly Methane, as listed above). This is because we only developed complex biological structure due to the massive build up of oxygen in the atmosphere (which has better bonding qualities than anaerobic energy exchange). Since there is no place else in the solar system with the amount of oxygen we have... You can pretty much guess multicellular/complex life is off the table.

When we are talking about life outside the solar system, we're talking about endless possibilities! Who knows if another gas can produce multicellular evolutionary benefit? We just have no idea...

I'm glad you did the maths Talariq, I was about to bring that up, that the simple chance of coming into contact with aliens, or other aliens having already found us is just, as you said, infitisemally small.

Interestingly enough the exact same process can be used to justify the hypothesis that aliens must also exist. If we assume that life isn't completely unique to Earth but can arise if there are similar-ish conditions elsewhere, then the simple vastness of the universe means the chances of life not existing elsewhere are infitisemally small. It is almost a mathematical certainty that we are not alone, and a hypothesis which will surely be put to test in the next 100 years of space exploration.

Vesha wrote: Neil deGrasse Tyson says my thought on the matter perfectly.

https://www.youtube.com/watch?v=ahYNYW484Vc

Just pointing out as an aside and in response to a few remarks on this:

In biology there are currently seven criteria by which we tell living and non-living things apart. They are both the minimal and the maximal requirement to qualify as a life form. Being based on carbon or being visible are both not among those criteria. So we would not discard a life form just because it is not either of these two.