Are Aliens Living Among Us? 350
pickens writes "In recent years scientists have begun to view the existence of life outside of our solar system as ever-more likely. If life does emerge readily under terrestrial conditions, then perhaps it formed many times on our home planet. To pursue this tantalizing possibility, scientists have begun searching deserts, lakes and caverns for evidence of earth-bound 'alien' life-forms, organisms that would differ fundamentally from all known living creatures because they arose independently. Microbes have already been found inhabiting extreme environments ranging from scalding volcanic vents to the dry valleys of Antarctica. Other so-called extremophiles can survive in salt-saturated lakes, highly acidic mine tailings contaminated with metals, and the waste pools of nuclear reactors. Although 'alien' microbes might look like ordinary bacteria, their biochemistry could involve exotic amino acids or different elemental building blocks so researchers are devising tests to identify exotic microbes. If shadow life is confined to the microbial realm, it is entirely possible that scientists have overlooked it."
What about us (Score:4, Interesting)
Who won the race? (Score:4, Interesting)
And here is candidate #2: the extraterestrial, which has to make a journey of at least 10^13 miles ( and probably one or two orders of magnitude more to give it a reasonable chance of existing ) through interstellar space, subject to cosmic rays. It has to travel fast enough to get here before the sun goes nova, yet enter the atmoshere at a slow enough speed to avoid burning up. And if it gets here, it has to adjust to a foreign chemistry, and it has to avoid being eaten by all the decendants of #1.
Those are phenomonal odds in favor of #1.
Real aliens aren't from hollywood! (Score:3, Interesting)
of course, more highly evolved beings likely have more style too
Possibility of life..... (Score:3, Interesting)
"In recent years scientists have begun to view the existence of life outside of our solar system as ever-more likely"
Oh yeah, I'm sure we all agree with that statement!
After 50 years of listening and looking we have, let's see, ONE suspicious signal that never repeated. Well if you consider that good reason for belief I'm not so sure why so many of you have trouble believing in God.... Having worked with several groups that are committed (and some should be) to the search of ET I'm less convinced than ever. Twenty years ago I was certain, now, not so much....
About as provable as Intelligent Design? (Score:3, Interesting)
It's a compelling idea, but what metric would be used to determine if a form of life arose independently? Wouldn't this suffer from the same problem as proving "Intelligent Design" - there is no metric for determining whether something is too complex to have arisen naturally, or too different to by related to known lifeforms. From TFA itself, life as we know it has been found everywhere on the globe, in radically different conditions than ours, which to me suggests that the related lifeforms on earth not only come in a huge variety of forms, but also will probably dominate any system they are in, including the hardest-to-reach ones that we can think of.
It raises an interesting question, however: if life can start, then it can have started more than once. In terms of probability, does this also mean that is has probably started more than once? And if life can start and stop, then does this also mean that life has probably started and stopped?
Re:What about us (Score:4, Interesting)
What is normal?
I've read reports that say that Earth could have been populated (seeded) by life that survived on meteors or other objects from space. I like to call it not-so-intelligent-design. Either way, if these theories are accurate, then that really would make us the "aliens" along with all other life on Earth.
Alien? Tough call (Score:2, Interesting)
Although 'alien' microbes might look like ordinary bacteria, their biochemistry could involve exotic amino acids or different elemental building blocks so researchers are devising tests to identify exotic microbes.
And:
On the other hand, an organism that employed the same suite of nucleotides and amino acids as known life-forms but merely used a different genetic code for specifying amino acids would not provide strong evidence for an independent origin, because the differences could probably be explained by evolutionary drift.
I think that people (Hello, ID'ers!) sometimes underestimate or misunderstand the power of allelic drift. Our world has incredibly diverse and interesting life forms. What may seem bizarre and "alien" on the surface is often simply the effect of random chance.
while life itself can be reinvented (Score:5, Interesting)
whales reinvented what fish do. bats reinvented what birds do
you can go down into deeper and deeper levels of reinvention of life processes too. for example, horseshoe crabs don't have iron-based red blood, they have copper-based blue blood [horseshoecrab.org]. go deeper than that: there are bacteria that have completely reinvented photosynthesis from scratch according to an alternative methodology [splammo.net]
of course the basest differences this article talks about is exotic, alternative forms of energy in superhot environments, superacid environments, weird chemical/ metal concentrations, etc. by necessity then, these animals have very exotic and bizarre biochemistry, but tehy are still in our family tree, because of the way they store their genes
so the deepest alternatives to life as we know it is to find some bugger somewhere who stores its genes in ways other than dna/ rna
find that bugger on earth, win the nobel prize
The odds aren't as poor as you think (Score:3, Interesting)
Bacterial infection of lunar landing sites [cambridge.org] is a serious concern. Here, read this. [panspermia.org]
Here's an excerpt:
Re:Possible, but unlikely (Score:3, Interesting)
exactly. It seems that life is very difficult to get started, even though once it does start it's very tenacious and can survive anywhere. In The Blind Watchmaker Dawkins suggests that running water and clay crystals may be some of the things that are required. In other words, you have organic chemicals laying about (actually, falling from the sky due to comet bombardment) and then being eroded by water. As they travel downstream they are constrained and shaped by crystals. 99.9% of the time, you get nothing. But perhaps once every million years, this results in a molecule that can copy itself being deposited into the shallow sea at the mouth of the stream.
But here's the catch: once that happens, the newly created life starts working its way back upstream, devouring all the raw materials and thus ensuring the process cannot be repeated.
So you make one good point: genesis can only occur under specific circumstances that no longer exist. And I would just add to that this additional point: once it does occur, life eats all the stuff that could be used to make more life.
Re:Real aliens aren't from hollywood! (Score:4, Interesting)
I would disagree. Even given the exact same environmental settings, if a woolly rhino on Earth had a longer horn and was statistically more likely to survive predation actually did survive, while on Earth 2, the same woolly rhino happened to get killed by a freak accident, then longer horns may never have become a trait. Woolly rhinos may have died out earlier, or developed a different defense mechanism.
I think that given even a minor change to the luck of the draw, Earth's species would have turned out looking much differently than they do today.
Re:What about us (Score:5, Interesting)
I'm more interested in the possibility that some species of dinosaur became sentient, built a technological civilization, and then erased all traces of themselves from the planet (causing mass extinctions in the process) before moving out into space. It's no more likely than ape-humping pyramid-building aliens, but sentient space dinosaurs would be a lot cooler.
We're not going to be able to say anything useful about our past until we find something with which to compare it. Finding life on just one other planet would give us enormous amounts of data to compare with Earth's biohistory. Wish more resources were being put into doing that.
Yes aliens are among us, (Score:2, Interesting)
1993 Debut
1995 Post
1996 Telegram
1997 Homogenic
2000 Selmasongs
2001 Vespertine
2004 Medúlla
2005 Drawing Restraint 9
2007 Volta
text book example of the scientific method (Score:5, Interesting)
What they are saying here, is that if life is likely then maybe here on Earth it started, was wiped out, started again, wiped out again and then we are the product of the 3rd or 100th try. Each of the others being wiped out by some natural disaster like a comet impact or whatever. So here finally is a way to test the theory that life is "likely" if we can show that it happen not once but many times on Earth then it was not a one in a trillion chance but a certainty.
To prove this they only need to find one microbe that is not decedent from the same common ancestor is we are. The microbe does not even have to be living. A fossil would be as good if it could be shown not to share an common ancestor with us.
The odd thing is that there could be 100's of these right in plain sight and we'd never know it and even if we did find it how can we be sure.
Re:What about us (Score:3, Interesting)
Well, Eric Von Daniken...and about 75,000 other science fiction authors.
Or wait...maybe the aliens were really the ancient Gods of mythology...
Re:What about us (Score:2, Interesting)
I don't want to fight you.
Stop it.
Put on the glasses.
I told you
I didn't want to be involved.
Dirty motherfucker.
Take a look. Put them on.
No!
I'm sorry.
Put the glasses on. Put them on!
Fuck you!
Re:What about us (Score:5, Interesting)
One of the extraordinary things about life is the sort of places it's prepared to put up with living. Anywhere it can get some kind of a grip, whether it's the in toxicating seas of Santraginus V, where the fish never seem to care whatever the heck kind of direction they swim in, the fire storms of Frastra where, they say, life begins at 40,000 degrees, or just burrowing around in the lower intestine of a rat for the sheer unadulterated hell of it, life will always find a way of hanging on in somewhere.
It will even live in New York, though it's hard to know why. In the winter time the temperature falls well below the legal minimum, or rather it would do if anybody had the common sense to set a legal minimum. The last time anybody made a list of the top hundred character attributes of New Yorkers, common sense snuck in at number 79.
In the summer it's too darn hot. It's one thing to be the sort of life form that thrives on heat and finds, as the Frastrans do, that the temperature range between 40,000 and 40,004 is very equable, but it's quite another to be the sort of animal that has to wrap itself up in lots of other animals at one point in your planet's orbit, and then find, half an orbit later, that your skin's bubbling.
Douglas Adams - Mostly Harmless
Re:What about us (Score:5, Interesting)
For more fun, Google "Hitler AND Vegetarian". Seriously, associating an idea with some of its kookier followers says nothing significant about the truth or falsity of the idea itself. For heaven's sake, Pythagoras thought that BEANS were EVIL, and yet we don't bring that up every time we try to analyze a triangle, do we?
Panspermia may be right. It may be wrong (I tend to think, gut instinct, it is wrong). However, the truth of the matter does not depend on how many kool-aid drinking idiots latch onto one side or the other.
Re:Of course aliens live among us (Score:1, Interesting)
The problem isn't with "uninvited". Everyone is uninvited in the eyes of someone.
Our issue is with "illegal". There is a difference.
Sorry you feel that way, but I have to ask, what country you're referring to and by your affiliation with that country, what gives you the right to speak for the rest of the world?
As bad as America is, it seems everyone is still trying to live here. Can the same be said for your country?