If real Intelligent aliens are watching us perhaps they are laughing at us (or doing whatever aliens do instead of laughing) because they are so different from the way we imagine them. In this article we risk giving amusement to the aliens and try and work out/imagine what they may be like.  Note: Extraterrestrial life may not be intelligent.
Do aliens exist?
Nobody has yet proved that intelligent aliens exist. There are serious scientists at Edinburgh University who think there may be thousands of extraterrestrial civilizations in our Milky Way Galaxy alone. Most serious scientists would probably say we don’t know enough to start making an estimate yet.
One may be able to judge that likelihood by considering the evolution of life on our planet. Some things have evolved many times, while others have evolved only once as far as we can tell. Astrobiology has more details.
The Drake equation gives an estimate of how many communicative alien civilizations there are by multiplying together several factors associated with their emergence:
- R(*) - rate of star formation
- f(p) - fraction of stars with planets
- n(e) - number of Earthlike planets or otherwise habitable planets in a planetary system
- f(l) - fraction of planets where life emerges
- f(i) - fraction of planets with life where intelligent life emerges
- f(c) - fraction of planets where intelligent life becomes able to communicate over interstellar distances
- L - effective lifetime of an interstellar-communicative civilization
However, all but the first few factors are almost total unknowns. Only R(*) was known when astronomer Frank Drake first proposed it, and exoplanet discoveries are providing hints about f(p) and n(e).
Are they already here?
Many people believe that at least some UFO's (Unidentified Flying Objects) are alien spacecraft, and some people believe that aliens have made more intimate contact.
It must be noted that the large majority of UFO sightings are sightings of various known phenomena, and we know of a lot of them, including lots of weird ones (Wikipedia:Identification studies of UFOs). Identified ones are sometimes called IFO's. However, there are some "real UFO's" recognized by mainstream science: ball lightning. It is rare, poorly understood, and controversial. But it seems more like some odd natural phenomenon than ET's.
Many people have claimed that UFO occupants have abducted them, complete with doing clumsy medical examinations and sometimes doing medical experiments, inserting implants, and extracting sperm and egg cells. Betty and Barney Hill were the first well-known abductees, though Antonio Villas-Boas preceded them by a few years. He claimed that he was dragged aboard an alien spaceship, examined, and then raped and spermjacked by a crewwoman.
However, many reported abduction experiences closely resemble sleep-paralysis experiences, and many others may simply be ordinary nightmares.
But the most interesting such people are IMO (lpetrich) the UFO contactees. George Adamski, Truman Bethurum, Daniel Fry, Howard Menger, George van Tassel, Elizabeth Klarer, George King, Reinhold O. Schmidt, Claude "Raël" Vorilhon, "Billy" Eduard Albert Meier, etc. They report close encounters of the friendly kind with alien visitors, either physical or telepathic or both. These visitors look human, and they often have Important Messages for humanity, which they want the contactees to communicate. Both sexes of them are often very good-looking and long-lived, and they come from societies with utopian features like absence of disease, war, and poverty. Though these societies' technologies enable great prosperity with little or no work, people in them prefer learning and self-development to material acquisition. They are also often heavily into spirituality, usually very New-Agey.
There are good reasons to conclude that contactees' accounts are pure fantasy. Many contactees have stated things that we now know are demonstrably false, like the habitability of other Solar-System planets. One might expect their ET contacts to set the record straight, but they haven't. There is also the problem of lack of outside corroboration, the problem that Thomas Paine stated about revelation in his book Age of Reason: a revelation is only a revelation to the one who received it. In fact, one can easily make analogies between UFO contactees and religious prophets. This is a problem because of the extraordinary nature of contactees' claims, and as Carl Sagan had noted, extraordinary claims require extraordinary evidence. Contactee accounts also have a "too good to be true" quality. Who wouldn't want to have friends like their contacts, friends that come from some society that is much like Star Trek's United Federation of Planets?
There is a politically conservative UFO skeptic who objects that UFO contactees all fit the movement-conservative stereotype of liberals. From TESTING UFOS:
Believing the stories given by "contactees," all containing no scientific information, but all containing advice to ban weapons, form a socialist world government, stop pollution, ban money (or wealth), and other typical ideas from the liberal and union side of the political aisle. I have never seen one contactee statement advising more freedom, less government, lower taxes, belief in Christ, or any other conservative thought. Does this mean that all space aliens are liberals? Or are the "contactees" the liberals? Most contactee statements claiming scientific "facts" have been disproved by subsequent discoveries.
Like many other conservatives, he lets indignation substitute for evidence. He can find contactee reports that contain at least some of what he is looking for. No taxes (Truman Bethurum, Aboard a Flying Saucer). Jesus Christ as a reincarnated spiritual adept (George Adamski, Inside the Spaceships). But this conservative would likely consider that belief a wrong way to believe in Jesus Christ, and he almost certainly does not believe in reincarnation.
From BEHIND THE UFO SCENES:
Most "contactees" say the aliens have advocated a socialist liberal political philosophy. These people have proven to have been liberal before the "contact" took place. The messages allegedly given to contactees include:
Get rid of nuclear weapons Live harmoniously End all war Form a socialist world government Stop polluting No more work Share the wealth equally with everyone Stop the space program Stop leaving space junk in orbit Free health care for all Do not land on Mars (or Venus) Legalize polygamy Legalize homosexuality Save the environment No more CB radios (they ruin space communication) Don't eat meat Find your "astral selves" and stop wasting time on material things Stop nuclear bomb testing Come with us to a better planet Get rid of money Legalize marijuana Stop highway construction An ice age will end civilization Global warming will destroy your planet No more power plants No more cars We will deal with only a single world government
In other words, "Be good little socialists, or we will come and exterminate you." Hippie aliens! What next?
What does he want? The opposite of all of these? Even when those opposites are contrary to Jesus Christ's teachings? Teachings like "you cannot serve both God and money" (Matthew 6:24, Luke 16:13).
Also, despite claiming to believe in capitalism, he gets indignant at the sight of contactees actually practicing it, by selling UFO-related merchandise.
What are they like?
Our current knowledge of Astrobiology is nonexistent, so all we can do is speculate whether life can exist and, if so, what forms it will take. There are generally two modes of thought: searching for what is most likely, or searching for plausible options. A central focus of thought is what will another intelligent, technological civilization be like. Note that such speculation does not mean that such a civilization is likely, only that given that one develops, it is interesting to contemplate what will its characteristics, and the characteristics of its members, be like.
A leading line of thought of contemporary astrobiology is that extraterrestrial life will be very similar to our own's in many ways, especially as higher and higher levels of organization are considered. This is because the processes that give rise to life are emergent processes like evolution and game theory that will operate regardless of the subtratum, and also because physics greatly limits the variety of viable options. To pursue discussion along these lines, you might want to take a look at our ETI Scenario I page. For further discussion, see below.
Aliens are probably warm blooded
If intelligent aliens exist they are probably Warm blooded. There are 2 reasons.
- The complex Brain Chemistry that an intelligent organism needs is more likely to be possible if the brain is at a constant temperature.
- Warm blooded Animals need more food than cold blooded animals. They spend more time looking for food. Warm blooded animals need to use their brains to find food. They also need their brains to avoid predators while they are exposed looking for food. Simply being warm blooded creates the evolutionary pressure that can lead to intelligence evolving.
Solitary Aliens with an advanced technology
Intelligence could theoretically evolve among aliens that live solitary lives and dislike mixing or cooperating with their kind. Among such aliens less intelligent individuals could not get help from more intelligent or more experienced fellow aliens the way humans get help and advice from experts. Those who cannot find solutions to their problems die or fail to reproduce. Therefore Natural selection could lead to steadily increasing intelligence to an extent we humans cannot imagine.
It is theoretically possible aliens could evolve that are so enormously intelligent that one single individual can develop an advanced technology without any help at all. We cannot begin to imagine what such a godlike alien would be like. Perhaps God exists. Perhaps God is such an alien. Even godlike aliens will see that they can achieve more together than separately.
However, it is difficult for such would-be sentients to pass knowledge and experience down across the generations. That's because each one of them has to learn everything from scratch, unless there is some way of transmitting one's learning to the genetic material in one's reproductive cells, with one's offspring then tapping that information.
Cooperative Aliens with an advanced technology
Cooperative Aliens would not need to be as intelligent as solitary aliens. If aliens progress as humans do and each generation builds on what previous generations developed they must have some capacity to interact and cooperate together. They must also educate their young. There can be selective pressure for steadily increasing intelligence among cooperative aliens if more intelligent individuals become leaders more easily, also if more intelligent individuals are valued members of the community and are attractive sexual partners.
Would aliens want to help us?
That’s an important question and we cannot find out the answer. If we ever encounter superior aliens the future of humanity could depend on whether they want to help us or to harm us.
If aliens are like us they could do either. If aliens are not like us we cannot begin to work out what they will do. Fortunately the earth probably will not be very useful to aliens. Aliens will probably prefer to live in space stations where they can duplicate conditions of their home planet more effectively. If we ever meet aliens how they treat us might depend on whether they evolved from animals like the gentle, cooperative Bonobo or the aggressive, bullying Common Chimpanzee. Again trying to guess how our alien contacts might have evolved to that extent is impossible though bonobo-like aliens are less likely to destroy themselves before they have a chance to meet us.
Could intelligent aliens read and write?
Reading and writing was an important stage in human development. Literacy was easily as important as metal smelting or the invention of the wheel. Once people could read and write what a community knew could be recorded permanently and far less was forgotten. In pre-literate societies what the community knows is limited by what people remember and when old people die what they have not passed on dies with them.
In humans there is a specific part of the brain that deals with reading and writing.
Major lesions in the left parieto-occipital area can make someone unable to read and/or write while leaving their spoken-language abilities intact. In contrast, lesions in auditory associative areas such as Wernicke’s area will prevent someone both from understanding spoken language and from reading. 
It may be a puzzle why this part of the brain evolved as literacy has not existed during most of human evolution. Possibly the parieto-occipital area enabled our pre-literate ancestors to understand gestures or other visual communications before the human larynx and full speech evolved.
If aliens evolved differently they may not have any part of their brains (if they have them) or whatever else they use for thinking corresponding to the parieto-occipital area. In that case developing reading and writing may be very much more difficult or impossible for them. Perhaps small numbers of exceptionally talented alien scribes would be literate and the written language would be much simpler than for example English spelling is. It is also quite possible that aliens would be stuck at the pre-literate level of civilization until they have evolved to be much more intelligent than we are.
Could a flying saucer be an efficient design for an alien spacecraft?
Flying saucers are possible but perhaps unlikely.
Why hasn't SETI found anything?
This issue is sometimes called the Fermi Paradox, after how physicist Enrico Fermi supposedly once asked "Where are they?" It has provoked a large amount of discussion and numerous proposed solutions. The Fermi Paradox , Expanded | Second Nexus lists numerous solutions in the form of a flowchart. 11 of the Weirdest Solutions to the Fermi Paradox also lists some solutions.
Here is a list:
- Few, if any, other civilizations currently exist
- No other civilizations have arisen
- It is the nature of intelligent life to destroy itself
- It is the nature of intelligent life to destroy others
- Life is periodically destroyed by naturally occurring events
- Inflation hypothesis and the youngness argument
- They do exist, but we see no evidence
- Communication is improbable due to problems of scale
- Intelligent civilizations are too far apart in space or time
- It is too expensive to spread physically throughout the galaxy
- Human beings have not been searching long enough
- Humans are not listening properly (wrong radio frequencies, wrong directions, etc.)
- Civilizations broadcast detectable radio signals only for a brief period of time
- They tend to isolate themselves or lose interest in outsiders
- They are too alien
- They are non-technological
- Everyone is listening, no one is transmitting
- They do not wish to communicate with us (we are too primitive, or whatever)
- Earth is deliberately not contacted (the zoo hypothesis)
- Earth is purposely isolated (planetarium hypothesis)
- It is dangerous to communicate
- The Fermi paradox itself is what prevents communication
- They are here undetected
- They are here unacknowledged
- Self-imposed quarantine
- Destruction by some ET's after certain technological advances (whack-a-mole)
- Incredulity at our nature ("they're made out of meat")
- The simulation hypothesis, run with no simulated ET's
- We are unable to interpret the evidence of their presence
- They have moved to the outer parts of our Galaxy to avoid overheating
- Directed panspermia
- In our Solar System, but preferring the outer parts of it
- They have already contacted us, but governments are keeping it secret, Conspiracy theories along those lines abound, see for example Assange File Reveals Extraterrestrial Contact? WikiLeaks UFO?.
References and footnotes
- A Skeptical Look at Aliens
- Galaxy has 'billions of Earths'
- Why haven't we found aliens yet?
- Ministry of Defence releases further UFO files Also the UK government
- Aliens? Yes Please. UFOs? No Thanks
- Dr David Clarke discusses new MOD UFO release 20/Oct/08 This is connected with the British Government.
- UFOs: Russian or Martian?