Who has seen an Alien?

This is a reasonable point but not strictly the case. There are many, many infectious agents which can jump species, including viruses, bacteria, and prion. Mad Cow is a prion disease.

So, if even one of these can occur it nullifies the thesis that 'it's not a problem'.

As I mentioned with prions, the alien doesn't even have to be DNA-based. Any microorganism could take up residence in a biological host and do damage, even if it just multiplied inside the host and didn't cause any toxic or biochemical harm. It could even draw energy from stores. So any team that goes space-faring WILL have an exobiologist, because, alien or not, those that don't will not survive.

On the comment about 'sterilization', it might be prudent to look up what that means. Does anyone think that sterilization is 100%? It's not. Even if there is one surviving cyst or infectious agent, it has the potential to multiply. One virus is all that is needed to reinfect. We don't even know how to sterilize against prions without incinerating the sample.

Hope this helps. Believe me, I don't post an opinion without having a pretty good idea of the basis, but I do appreciate the input, since it allows me to explain further.

Oh, one final thing. Remember Chaos Theory? Well it's true. Just when you think all the bases are covered, you get fooled.

IMO, no space-faring civ will survive very long if they visit ANY planet with a bio-sphere except in Virtual mode. They do not NEED to go there in person, as it were and to do so is fool-hardy.

I seriously doubt that many 'aliens' would survive on a planet with such a high concentration of Oxygen and water, since O2 is a strong oxidizer and water is a Universal solvent.

Edit to add: Someone mentioned the idea that an advanced species might be free of native micro-organisms. Though it may be that viruses are the origin of DNA-based species, also consider that immune and advanced and intelligent and disease-free aliens could pick up an infectious agent that could not be sterilized by normal procedures and transport it here. Yep, Chaos Theory finds a way.

IN FACT, they could pick up the organism here and transporting it could cause it to mutate. (Note that micro-organisms found on the Space Station do mutate and become more virulent). Thus these mutated Earth organisms could be super-infective to us.

Let me add some thoughts about this thread.

1. I think it's a very good thread, and I read all the posts with great interest.

2. I'm posting as a Member who is passionate about other Members, their input and opinion and I'm passionate about the subject. I do not classify myself, but if I did, it would be as a scientist, not as a skeptic. I could write an entire post about my non-skeptical approach and I give every alternate viewpoint some credence, but perhaps, not as high as some would like. I don't discount anything.

3. It hurts my feelings when someone reads a long thoughtful post of mine and all they can say is that it is an attack on the PERSON. It might be a challenge to a belief, but I think I can safely say I've never attacked anyone on this site EVER, and I even try to use neutral terms and non-specific assertions.

4. ISTM that there is little reason for anyone to feel attacked or feel hostility on a thread like this because it's nearly impossible to do so. It's anonymous, well-moderated and even those with a skepical approach are fans of the whole phenomenon.

I'm taking some heat for posting my -contention- about various things, but note I did say 'contention' which means opinion.

If ANYONE can find a post of mine here, or ANYWHERE on the site where I openly attack another Member, use profanity or personal insults of a vulgar nature, I'll remove it (or have a Mod remove it), and further I'll consider strongly resigning from the site.

To get back on topic:
I think it's very possible that some people on Earth have seen something they consider 'alien' and I'd love to hear about it.

IN FACT, the one report on ATS of an encounter with Greys that was robustly reported with diagrams and evidence, received at least three, maybe four applauses from me and I even ended up befriending that Member off site.

To me, I think we may be doing ourselves a disservice by linking Aliens and UFOs. There's probably a better than even chance that any 'non-human' entities we are encountering come from 'elsewhere'. Heck it could even be a 'manifestation' of one's own psychic constructs (in addition to the usual 'inter-dimensional' types, or the future 'us' types that some postulate). Remember lots of children have imaginary friends. Maybe they're really seeing something.

So I'd like to call (*as a Member*) for everyone to:
1. Have courage. Post your experiences in detail. After all you encountered an alien being WHY for gawd's sake (lol) are you afraid to post on an internet board anonymously? I mean seriously. (sure I know that for PTSD people it's hard to discuss the war, but here we're talking about PTSD from aliens not from fellow board members). I'd think that after confrontation with a real alien, all other experiences on Earth would pale by comparison in the 'fear' department. I'm not being flippant, but correct me if I'm in error and I'll be informed.

2. Don't be so quick to claim you're being attacked. I don't really see anyone attacking on this thread.

3. Realize that Mods are Members too and that passion is important. I'm not trying to convince anyone of ANYTHING. I'm trying to be as scientific and thoughtful as I can be.

4. Realize also that your courage is important. What if, by posting your experience, you save someone who is having something similar?

5. Yes, people are experiencing HIGH STRANGENESS. Though some people might be dreaming or be fantasy prone, I don't think ANYONE will say that there is not an element of high strangeness going on. It's just important to be cautious to what we ascribe that, because to just quickly say 'it's aliens from another planet' closes off other lines of inquiry.

Hope this both explains my empathetic position and advances the topic.