Cross the universe and then let some war mad species like humans know the secret of ‘faster than light’ drives.
FAT CHANCE MATEY !
If we make the right assumptions about aliens from other worlds then we could formulate the correct questions to confirm an individual’s origin.
Space travel will someday be like riding in our autos. Granny will get in her capsule, to take a ride through the country or attend Sunday services, her foot will miss the brake and slam into the hyperdrive and crash land here on earth. Tell me Scylla what would she know about any of the stuff you outlined? I bet any of her answers to your questions would seem evasive.
predictive
OOOOH My let me see… we hand and eclipse last week everyone was talking about that.
esoteric
That boy got a big head but I never measured it.
Need I go on?
So here we are, calmly discussing sensible tests.
I would try to add one of my own, but I keep thinking of James T. Kirk coming back for two whales (I think he effectively counts as an alien), and having trouble with the locals.
OK, how do people who’ve met ‘aliens’ know that’s true?
Don’t they usually say there’s a spaceship involved?
Or do they claim telepathic mental contact only?
Take me to your leader, that’s what I would ask.
I looked up this Nemesis thing and found that it is only theoretical and probably does not exist http://seds.lpl.arizona.edu/nineplanets/nineplanets/hypo.html#nemesis.
Is there any other information suggesting that it exist? mrblue92 if no evidence exist then can be say that Scylla is not an alien?
Gotta say that regardless of any verbal claims by the purported alien (or alien channeler), only physical evidence would do for me. Doesn’t have to be anything large or complex; either a small tissue sample from the claimed alien or a manufactured object of any size that contains at least one material (a compound or alloy) not familiar on Earth.
I’ve had a longtime interest in claims of ET visitation, and in fact the biggest problem for me with all such tales is what, for lack of a better term, I’d call “the missing beer cans”. It beggars belief that, if ET’s have somehow made it to Earth, and if, as would further seem likely, have been doing so for thousands of years, that no alien-made tool, failed part, container or whatever has ever been left behind and found and recorded by humans.
From the OP: “We’ll assume no serious difficulties in communication.”
You might ask the alien WHY there are no serious difficulties in communication.
The ETI should, when asked, be able to come up with a believable scenario for how it came to be fluent in an earth language.
It should also, when asked, be able to give us instruction in at least one foreign language; and by foreign I do not mean something that is simply non-indo-european. Unless it claims to be illiterate, it should also be able to give us a fair and consistent picture of whatever script system it uses to express ideas.
I think our 9-headed dragon friend here is closest to the mark. To wit:
People have suggested drawing star maps, etc. But a human could do this if he were trying to perpetrate a hoax. Making a decent star map wouldn’t be too difficult. So what must be done is not to ask somethjing static, but something dynamic, and something indicative of faster than light travel (assuming that’s how our alien got here). There are supernovae all the time, so we’d need to be specific: *What is the next supernova brighter than 10th magnitude that will be seen from the Earth? * Only someone traveling FTL could know that. And even then it must be coincidence, so I would ask for, say, the next 30 brighter than 15th mag. Then I would start to believe.
I can answer this: 0, 0 and nope. 
I’m not a big believer in Nemesis.
May I meet him?
Seriously, if someone claims to have physical contact with an alien, then I think the best questions would be along the lines of how this occurred. When and where did you first meet this alien? Where is he now? (If the person is still communicating with him, he obviously hasn’t gone home yet.) How did he learn English/ you learn his language? Why has he chosen to talk to you and not anyone else? I am assuming that fakers/deluded people probably haven’t thought their stories out too well. If they have, then of course you should go for physical evidence. DNA can be obtained with a cotton swab. A photograph should be pretty simple. Surely the alien has at least one piece of techonology that he can bear to part with for a few hours of testing.
If the alien liaison objects to every single test, then you should probably just ask him what evidence he does have, other than his word. If he has none, then it’s probably best to assume he’s not really in contact with an alien.
Damn. I need to get a better agent.
I must have been busy yesterday… Corrections:
Daddymack
I’m assuming you meant “can we say…” We can say Scylla (for example) is almost certainly not an alien, because it’s very improbable that he is, but unless we go collect some DNA, I don’t see that you’d have any proof either way. Even if he claimed he was human (or male or American or heterosexual for that matter), he could be lying. My point is that a verbal proof is difficult (if not impossible).
Scylla
You’re presuming they would know of one in the near future. If FTL travel is possible by bending space in some way, their home could potentially be too far away to observe anything significant. Or, more likely, if they are relatively local (say Proxima Centauri), they may not have observed any significant phenomena in transit.
Others have pointed out that it may not exist… I would also suggest that the alien probably would not have detailed knowledge of every object in the solar system off the top of his antennae–a navigational computer would be likely be utilized.
I like this idea (though songs might be better–I bet the average person knows more songs than he does poems). Unfortunately there’s no guarantee an alien civilization would have either.
Even better than the poetry question… But I am reminded of an old Simpsons episode with the aliens Kang and Kodos:
“To pronounce [my name] correctly, I would have to… rip out your tongue.”
These assume the alien knows how he got here. He could be an accidental tourist. (“I knew I shouldn’t have pressed that red button…”) Or (as suggested previously) he could just be a button-pusher. (“Damned if I know. I tell the thing where I want to go and it does.”)
These are, of course, decent questions, and I think if you put enough of them together you could probably come up a with a fairly good test of whether or not someone is probably an alien or probably a fake. I just don’t think there are any decisive ones (at least that I’ve read here or can think of).
Mrblue:
Ahhh, an ignorant alien. Well, ignorance and evasiveness would tell us something about the alien’s authenticity, wouldn’t it?
He did say “ask me anything.”
Follow up questions might be “If your civilization is so advanced, why did it send such an incompetent emissary?”
or,
“Can you channel or otherwise let us communicate with someone worth talking to?”
Extraordinary claims do require extraordinary proof, so the onus is on the alien.
If the alien is incapable providing any special perspective or knowledge that we otherwise do not have, than his claim to alienness is absolutely worthless, whether it’s true or not, and is in fact by logic almost certainly a fabrication as (one would assume,) any being capable of spanning interstellar distances mentally or physically would be worth talking to. The fact that this guy’s not, would suggest he didn’t do it.
And assuming an incompetent, or bumbling tourist of an alien, you’d assume it would think it best to keep a low profile, having no demonstrable evidence. Even such a fool as that would know that little good would come out of spurious claims.
“Because your civilization is so backward.” Maybe the guy’s just a grunt cataloging astronomical data and collecting specimens.
Agreed, but it may not seem so extraordinary to him.
Wouldn’t the mere confirmation of the existence of extraterrestrial life be special enough to be worth something?
Who says the alien must have the same concept of skepticism as we do?
Because the ability to reason would seem a fundamental requirement of advanced technology.
Oh, I suppose that you could say they just found the spaceship, or whatever, but this is just getting Silly.
Occam’s razor suggests we’re wasting our time.
A waste of time may be correct. If other parameter (aside from asking a question) were added, as in the Turing Test, then a solution may be possible.
I like the DNA request someone suggested. Even if the ancient astronaut theory is included the DNA would be sufficiently different (or absent) to make a decision
Hmm… IMHO you assume too much. Yes, an alien species with that level of technology would probably have a highly developed reasoning, but to assume their methods of doing so must make sense to us seems almost absurd to me. I mean, take a look at how different people use different methods of reasoning based on their individual experiences on the same planet or even within the same cultures. I would not presume that an alien individual will fit any of our pre-defined views.
Does that mean you have some candidates? (If not, aren’t we wasting our time anyway?) 
Yea, on second thought, I have to agree that’s almost certainly true. It would have to be a pretty big (and far-fetched) coincidence for ancient astronauts to return with DNA that didn’t have any differences.
Yet in manners of technology there are typically not many efficient solutions to a problem. For example, the wheel was weel-known by diverse unconnected cultures that had little else in common.
When you start talking about a highly esoteric technology, like something for star travel or communications, your choices will equally be limited by the laws of physics. THe chances are pretty good we’d recognize a star drive if you showed one to us or described it.
Like the Fermat’s last therorem question, we know the answer, we have a pretty good idea of the broad strokes of how the solution must go, a superior technology will fill in the blanks in a manner that we will find testable.
Uh… weren’t we referring to the logic of a alien who doesn’t understand the technology?
scratching head, wondering if I’ve stayed up too late
You’re comparing interstellar travel to… the wheel? Hmm…
We have a pretty good idea of how the solution must go… Really? Wow, I’m impressed. Are you sure you’re not an alien?
Seriously, I think you’re talking apples and oranges. The wheel is a simple machine. Fermat’s theorem is a mathematical proof. An interstellar drive would be a complicated bit of technology; a closer analogy would be a computer. Where we have an abacus, the aliens might have a Cray. Imagine how difficult it would be to explain the workings of a supercomputer to a human from even just 100 years ago, especially if computer technology was not your primary specialty. Simply put, if the alien couldn’t “dumb down” his explanations enough, they might sound like unverifiable science fiction gibberish.
Not if your talking about the OP. It clearly said that It can prove it’s an alien, ask anything. Hence, suggesting that it knows enough about its technology to prove it anyhow.
We have a pretty good idea of how the solution must go… Really? Wow, I’m impressed. Are you sure you’re not an alien?
[/quote]
This thread already has a link saying Fermats theorum has been solved…
Not really, the human race really understands enough about Physics we would not be totally lost…In theory at least. Our theoretical knowledge far excedes are practical knowledge, while we may know how to do something, we don’t have the ability to do so now, but not because of practicality, mostly due to finaces and resources.
Spiritus Mundi - Your questions are very good. The focus of my post was not so much to critique them as to say that IMHO there are two different situations we are facing, and now on reflection I will add a third scenario:
a) A being appears saying “I’m an alien”. This being has some artifacts from the home world and/or a way of communicating with the home world.
b) A being appears saying “I’m an alien”. This is a Robin Crusoe type who is stranded here with nothing and no way of communicating with the home world.
c) A being appears saying “I’m NOT an alien”. I, Arnold Winkelried, claim that the being IS an alien, and I want to prove it.
In case a), astrological observations or discussion of scientific concepts beyond humanity’s current level of comprehension should be easy to come by (as you, Scylla and others have proposed.)
Case b) is the most interesting one I think. Assuming the alien is your average “Joe Blow” kind of alien (tourist that forgot to get back to the Queen Mary starship on time), what do we think it would know that humans wouldn’t? I would relate that to the question “If I were transported to the past, how could I prove that I’m Future Man?” The situations are similar but not identical.
The simplest would be a biological examination, but if the alien refuses (out of fear, religious reasons, others) I would suggest that a description of the general technology level of their civilization should be convincing. e.g. “How do you get around on your planet? How does that method of transportation work? What do you remember from high school physics, mathematics, biology, chemistry? How many planets in your system? Describe them? How do you communicate? What’s your language? Your alphabet?” Even the “average” alien should be able to accumulate enough of a body of evidence to prove that it’s from a different world. If I’m restricted to just ONE question, I think it would be in the field of astronomy, but I don’t know which question would be the right one.
Case c) - I don’t see any solution outside the medical examination.