Life On Other Planets

The universe is billions and billions of galaxies with billions of stars. DrakesEquation gives a quantitative framework about thinking of the probability of life existing beyond earth. Planets are now being found around distant stars. The question is does life exist beyond earth in the universe and if so what form.

Alternatives:

We are alone
We are not alone but everything else is bacteria or simple life
We are not alone and the others are as or more intelligent than us

NaSa? and other organizations have telescope and probe based searches to see if signals from distant civilizations have been sent to us. Names for these programs are SeTi and Origins (see http://history.nasa.gov/seti.html and http://origins.jpl.nasa.gov/).

Many think we are already being visited and many reports of UnidentifiedFlyingObjects? are given each month for instance on http://www.nuforc.org/webreports/ndxevent.html.

CropCircles are an interesting phenomena that some say are pure hoax but others interpret as signs from the visitors.

The biggest problem with most UFO evidence is that it relies almost purely on witness testimony. And, good witness testimony is never enough because the "kook factor" has tainted it. Thus, if we are being visited relatively frequently, it may never be demonstrated beyond a reasonable doubt. Visitors could come and go with immunity. Military planes and cops would not change anything because they weren't believed in the past, so why would they be believed in the future? A military crew of about 3 flying near Davis-Monthan AFB claimed they saw a saucer approach their plane to within about 20 feet for a few minutes in broad daylight :(. Witnesses on the ground also noticed it. I am not saying this is evidence, but only that if visitors really came, it would probably be dismissed unless they landed and stayed on the Whitehouse lawn until hundreds of reports arrived. Anything less would just be another file.

The biggest problem with most UFO evidence is that UFO abduction stories are exactly like ancient elf abduction stories in every detail. Think especially of missing time. An additional problem is that these phenomena can be neatly explained as schizophrenic episodes.

{I don't think abduction stories are the best evidence of UFO being something worth looking into.}

''Even missing time isn't that unusual; everyone has periods of time they can't precisely account for simply because nothing memorable happened in that time, or maybe they took a nap and didn't realize it. Also, people who "recover" memories through hypnosis are more likely to create false memories than recover real ones.

LifeOnOtherPlanets and AlienLifeOnThisPlanet are two related, but significantly different questions. If we ignore the AlienLifeOnThisPlanet question (for obvious reasons), the question of LifeOnOtherPlanets will remain interesting.

Galaxies, like stars, have Habitable Zones. For the MilkyWay Galaxy, in the early stages of galaxy formation there were not enough heavy elements to form terrestrial planets except in the most central regions of the Galaxy, where the danger due to nearby supernovae was very high. As heavy elements spread through the Galaxy, terrestrial planets likely formed and the habitable zone emerged and broadened.

Like a SpreadingActivation from center to spiral arms, as the first habitable worlds' suns died off, masses of the initial surviving intelligent species were forced to migrate outwards. Invariably genetic crises forced many of them to try desparate experiments in systems newly evolving life and intelligence on the edge of the expanding zone. Careful not to be too overt or interfering with the natural development of new cultures, they nevertheless undertook to select individuals from these developing populations at random for various procedures...

One of the curiousities about intelligent life (IL) is that it is likely to arise tens or hundreds of millions of years apart. Unless we are the first in our galaxy, other IL would have several millions of years to spread throughout the galaxy. Even at 1/50th the speed of light (within our current technology if we spend big), they should have spread across the entire galaxy by now. Thus either:

They all nuke themselves to extinction before spreading
IL is rare and we are the first
They know about us but "protect" us from their presence. AKA, "zoo theory"

There is a name for this issue, but I don't remember it.

The issues are labelled the Self-destruction Hypothesis, Fermi's Paradox and the Contemplation Hypothesis repectively. But yes they should be here. Many say they are already here and see them; depends what criteria one is willing to accept.

Why, that's a WalMart theft-detection tag!

One theory is that IL is so rare such that maybe something like only 1 in 1000 galaxies has it. Thus, if IL formed earlier, it would not have gotten here by now due to the distance between galaxies.

But if that theory is wrong, and L in DrakesEquation is high then ... Wal-Mart RFID tags are the least to worry about

CategoryFuture