reply to post by Heike
Nice post.
Let's look at one real and one fictional representation of an advanced sentient group visiting another planet.
We visited Mars. How did we do it?
1. We used the smallest possible probes which would be able to contain all the instruments needed to do surveying and sampling;
2. We did not use a stealthy system;
3. We did not visit in person.
The Starship Enterprise visited other planets and except for nearly crashing out of orbit NEVER had craft flying around in the atmosphere.
Any visiting alien species would:
1. Use the smallest, most economically feasible craft necessary to visit other star systems. Let me ask you, why are ALL fantasy depictions of aliens
completely devoid of economic considerations? Because ANY large-scale visitations in giant ships, would break the budget of any Class II
civilization.
2. Use Non-stealth probes. Why use stealth? It's not necessary, it's not testable, it's not viable. So all this talk of SECRECY is only out there
because the ALIEN phenomenon seems stealthy, hiding behind atmospheric phenomenon, lights in the sky and mistaken identifications.
3. Any alien civilizations which might want to visit other planets would FIRST have to assure they would not be destroyed by planetary collisions, or
gamma-ray bursts. This means they MUST have a complete duplication of their main planetary capabilities. Otherwise any group going out to explore
might find their planet has had an extinction event when they return.
4. Cross-contamination by micro-organisms is a REAL, valid and compelling consideration. H.G. Wells was right.
These are only the top four requirements for a carbon-based, sentient, technology-based civilization who might attempt space-faring.
To summarize:
1. No large visits, economics;
2. No stealth;
3. Long dwell time before space-exploration can commence;
4. No visits in person by biological-entities due to contamination risk.
A couple minor concerns.
1. Just as on Earth, the concept of 'PRIME REAL ESTATE' exists. If Mars is not a thriving alien colony, then they are NOT here in our Solar
System.
2. Robust Quarantine - The Galaxy is a vast expanse of mostly empty space. High radiation, Hard vacuum. Vast distances. Intense cold. Micrometeorite
risks.
3. The Fermi paradox. It only would take a million years to colonize an expanse the size of our Galaxy. They're not on every planet yet, and Billions
of years have passed.
4. Time Synchronicity.
The last one, Time Sync is one of the biggest barriers to any theory of Alien Visitation. Our technological civilization has existed for only a few
thousand years. To sync up a visit with our technological phase, taking into account travel time to even the closest systems, would be nearly
impossible.
For all practical purposes, these above factors make the possibility of visits to Earth NOW, by non-human, non-terrestrial entities an extremely small
possibility. So small that any list of explanations would have it so far down at the bottom of choices so as to be negligible.
So, any discussion of Aliens being -here- in person, would have to solve and explain all these exceptional circumstances to be a viable,
top-of-the-list explanation for any observations of what we call the ET-hypothesis.
en.wikipedia.org...
This does not mean that advanced sentient carbon-based live does not exist in the Galaxy or in the Universe.
It simply limits the chances they're coming here. (or even getting off their own planet)
Just some thoughts.
[edit on 11/30/2008 by Badge01]