I don't understand why when scientists go out there to find aliens, they always serach for the basic stuff that we on planet earth need. Water oxygen and the works. Why do they not accept that aliens are different from earthlings and that they do not need water and oxygen to survive? Why always link their basic needs with our earthing needs.

Perhaps they have formed with another materials or molecular structures, or their DNA made with non-earthly physical matter such as electro- energy type. This is why they can hide themselves in our world, or they just appear for one second and disappear the next. They can fly in our air without wings or crafts. They may have a glowing light around their body…….. It doesn’t mean that they are paranormal or supernatural. We can’t use our view to judge or expect them. We only learn from discovery.

This is a new subject--------" The Science of the non-earthly physical world ", No mystery and paranormal.
( probably we humans make mysteries by ourself)

full article click here
http://ufo-spacelife.blogspot.com/2007/10/...-about-non.html

but they survive ok in our atmosphere otherwise theyd die from breathing our air as for water well ufos have been known to steell large amounts of water , an entire swimingpool in brazil was drained after a ufo hoverd above it and in australia a ufo drained a water tank on a farm leaveing the tank cracked at the bottom so its a wonder sporkling why so many anserws yet we have to find them somehow , even scientisits can get there facts wrong i think so best we find out our selfs

Because life that requires water and or oxygen are the only types of life we know of and it's logical to think that where else they exist in the universe there might be life.

If aliens dont need o2 or h20, then why to they have a nose and a mouth?? what purpouse would those features surve? thease are things we need to consider when asking our selves "are they real" these things matter....abductees claim to be in a ship with ET's...well that means they are breathing the same o2...wich could mean that the ship the abductee is in has never left earth and ET breaths are same 02 concentration or the abductee has left earth but yet the room they are in is producing 02 levels that they all can breathe....start with the small things and work your way up...thats how it should be done. The same with the question do they want to be seen or not? that is a damn good question , yet some think its not important..

Those are not real scientists, they're fools, such as Seth Sostchak, the guy who runs SETI. No one, regardless of how well qualified on earth, knows how and where to find alien life. They have no concept of what alien life is, IF it exists. They're looking for microbial evidence, nothing like us.

Possibly they are not really there to look for alien evidence, as they are using techniques of finding alien civilizations based on radio signals. A lot of research funded by the government is designed to be flawed... the project is funded to find answers, however once the answer is found the funding is stopped, so most projects linger on to milk funding.

the other responses have been spot on..

but also consider the fact that most bodies in this universe (bodies as in those that occupy space/time) are formed from Carbon. Most of everything we see around us is formed from the molecules of carbon left over after the big bang.

Without having anything as a guide, determining ANYTHING about an alien species is useless. Hence, we use ourselves and other life on earth as a base. Otherwise it would be the same as asking you:

"Draw a creature that doesn't look anything like you would find on earth"

and expecting it to be an exact representation of what you would find beyond our planet.

Secondly, evolution is not a physical property. 'Evolution' much like Gravity, simply 'exists'. Therefore we must assume that the laws that govern what happens on our planet are constant throughout the universe. Of course the 'environment' will be different, but how life reacts to environments will be the same.

With the complexity and specificity of the workings of us carbon-based organisms, I can't even conceive of another form of life. If they weren't dependent on water and oxygen, they would have no DNA. So what would be their basic building block? It's foolish not to start with life as we know it.

If it's an "earthling" thing, I should very much like to know the inner workings of these non-carbon-based aliens.

How do you know any of that? Seth Shostak is not a fool, he's one of those people who are actually out there trying to solve the question about life in the universe, instead of those nut cases who write about how NASA is covering up civilizations on Mars.

Three elements crucial to life on Earth are Hydrogen, Oxygen and Carbon, the first, third and fourth most common elements in the universe. In certain conditions all that can come together to form life, as it did on Earth. If life could be formed with other elements, it would have a very minute chance of forming. We work with what we know, and chances are it will pay off sooner or later. Searching for anything else would be a waste of time.

I have to agree with these statments above however, even here on earth there has been life forms dicovered that seems to thrive in elements that scientists would never have thought to look before.So there is the possibility that life forms could evolve in a differant way than the life has evolved here on earth.

The logical coarse of action would be to look for planets that have the exact same elements that earth has.It would be the best chance to find life forms other than our own.Given the amount of stars and galaxies in the universe, there is actually a very high chance that there are billions of earth like planets that hold life on them just like our planet has.So why not look towards a differant society needing the same elements that we humans here on earth need.

Scientists have found bacteria living in nuclear reactors, which certainly aren't a Human-friendly environment - however, they are still carbon based...like any other bacteria

Because things usually adapt to their environments.