"Don't know about an air elemental, but I've been with an alien or two." More than that, but they're not really discussing his prolific sex life. He can tell the other doesn't believe him, but he expected that kind of reaction. Given the level of advancement in this world, it seems the proper sort of reaction.

"My people went to the moon centuries ago," he said with a perfectly straight face, made easy because it was true."We travel between planets now - worlds is another term for them. Part of my job was discovering new ones." His fingers stroke the yellow fabric of his uniform shirt, smiling wistfully before looking back at Sam. "And before you say I'm full of shit ask yourself why Id bother making up such a ridiculous story that makes me stand out even more. There's already a stigma against me as a Rifter, I hardly need one as being crazy either." The trouble with being honest.

Not to mention if someone asked him how to sail a water ship or farm something, chances are he'd make himself look the fool anyways since he wouldn't know how to do the things they asked the way they wanted him to in the first place.

It wasn't much in the way of proof, but it was logical in a way. Spock would be proud of the argument - or at least not find it completely illogical.