Odds of Finding Alien Life: An Exploration

[BoomBoom]

My point was there is an immense number of worlds, and turning any of those into a livable planet seems more efficient than traveling halfway across the galaxy. Even if we had the means to get there, I'm having trouble imagining a time where the expense to do it would be anywhere near trivial.

I find it hard to believe that terraforming an entire planet (that would also include travel to said planet) would be a trivial expense either ...in both cost and time.

If we had the capability to travel to other solar systems, a lush green "garden of eden" type planet that already existed would definitely be colonized before I can see us going through the costs and time that it would take to terraform a dead rocky world...even if it was much further away.

If that alien world had a different atmosphere that we couldn't live in, it probably wouldn't be as appealing. So I get your point about how an alien civilization might not have an interest if they can't live here.

It certainly is no guarantee that if advanced alien civilizations existed they would have been here. If they breathed a different substance and were scanning for habitibal planets, we'd be totally over-looked.

All that said, I still have doubts that these types of travel distances are or will ever be even possible...so the point may be moot.

 

[DaveC426913]

If we had the capability to travel to other solar systems, a lush green "garden of eden" type planet that already existed would definitely be colonized before I can see us going through the costs and time that it would take to terraform a dead rocky world...even if it was much further away.

Except that this garden of Eden planet is already colonized (else it would not be lush and green).

So, we wouldn't be colonizing it because

a] I like to believe we would have learned enough not to crowd-out and destroy a thriving ecosystem by polluting it with our own biomass, and

b] it would be totally alien life, so we could not metabolize it. That would make it useless to us. But it's not merely useless, it's worse than useless, because

c] while the rocky planet is passive, its resources merely waiting to be taken, a biologically active planet will actively compete with us for its resources (locking up useful chemicals, overgrowing areas and equipment, infecting, mutating etc.).

No, scientists and engineers are control freaks, and they like a nice, clean, sterile workstation to build on. No build-it-form-scratch effort is too costly when you compare it to unknowns in the form of impurities and contaminations.

(Imagine a lab scientist setting up an experiment to breed flies and deciding it would be better to use dirty containers rather than sterile containers since that way he doesn't have to by as much fly food and the flies will have a head-start on breeding. )

 

[BoomBoom]

Except that this garden of Eden planet is already colonized (else it would not be lush and green).

So, we wouldn't be colonizing it because
a] I like to believe we would have learned enough not to crowd-out and destroy a thriving ecosystem by polluting it with our own biomass
and
b] it would be totally alien life, so we could not metabolize it. That means that it is actually a MUCH WORSE choice than the barren rocky planet. The rocky planet is passive, its resources merely waiting to be taken. But a biologically active planet will actively compete with us for its resources (locking up useful chemicals, overgrowing areas and equipment, infecting, mutating etc.).

a] You obviously have more faith in humanity to do the "right thing" than I do.

b] This kind of depends on the nature of alien life. Since we have yet to find any, it's hard to say how similar or different it would be. But you make a good point...I'm sure there may be some bad diseases out there that we would have no defense against.

c] It just seems to me that terraforming a planet would be a far more extensive endeavor than some make it out to be.

 

[D H]

I like to believe we would have learned enough not to crowd-out and destroy a thriving ecosystem by polluting it with our own biomass

This is a good argument against the Fermi paradox. Since scifi beat scientists to it, I'll call it the "Prime Directive" argument. You can see a nascent form of this directive with respect to opinions on how the discovery of life on Mars (if it that discovery happens) would/should impact terraforming of Mars. The spectrum of opinions:

1. We shouldn't terraform Mars no matter what, even if it's sterile.
2. If Mars has life, we shouldn't terraform Mars, doubly so if the life is non-terrestrial in nature. Variants:
   • If Mars has life, we should leave Mars alone. Period.
   • If Mars has life, we should study it but only with unmanned probes that are completely and thoroughly sterilized multiple times during the fabrication process and a few more times on the way to Mars.
   • If Mars has life, that life is obviously in trouble. We should aeroform Mars rather than terraform it (make Mars more suitable for Mars life).
   • If Mars has life, limited human missions to Mars are acceptable if we take extreme cautions to ensure that we don't introduce any terrestrial life to Mars.
3. If Mars has life, we can still terraform Mars, but we should make little enclaves for those obviously dwindling remnants of Mars life. But only if doing so doesn't cost too much and doesn't interfere with the terraforming project.
4. If Mars has life, we should commit xenocide.

Some reading material:

"Ethics of terraformation"
http://library.thinkquest.org/C003763/index.php?page=terraform02
A summary article. Use this to get a flavor of the debate. From the article, "The vast majority of Mars scientists and planetary biologists belong to the 'Green' camp in that they believe that Mars should be made 'green'. They have several impressive arguments in their arsenal. ... The 'Red' camp, in the minority, is adamantly opposed to the terraformation of Mars. 'Reds' believe that humans have no right to essentially destroy the current face of Mars just for our own concerns, and that we should preserve it in its current state so that we might conduct scientific experiments and learn more about the planet."

David Grinspoon, "Is Mars Ours? The logistics and ethics of colonizing the red planet", Slate, 2004.
http://www.slate.com/id/2093579/
Dr. Grinspoon is the Curator of Astrobiology at the Denver Museum of Nature & Science and has served on multiple NASA and ESA interplanetary science teams. From the article, "But before we go there and set up greenhouses, dance clubs, and falafel stands, let's make sure that, in some subtle form that could be harmed by the human hubbub, life does not already exist there."

Dave Brody, "Terraforming: Human Destiny or Hubris?", adAstra Online
http://www.space.com/adastra/adastra_terraforming_brody-1.html
Summarizes the debate between Chris McKay, astrogeophysicist at NASA Ames and Bob Zubrin, President of the Mars Society. Zubrin ranks as a high 3 on my scale. McKay, 2c.

"Ethics of terraforming", redcolony.com
http://www.redcolony.com/art.php?id=0107290
This article does a semi-decent job of presenting both sides given that redcolony.com is a rabidly pro-terraforming site.

 

[LURCH]

DH, thank you for actually bringing up some of the arguments against the Fermi Paradox. Although this thread is getting fairly long, I think it might be worth our while to discuss some of these example arguments and explore their merits. Although (as has already been mentioned) each of these arguments is "valid" in the philosophical sense, none of them present a very convincing refutation of the Fermi Paradox, in my opinion.

Going down the list:

• Colonization is sporadic. A colony set up by a space-faring species will be on its own. Some colonies will die, some will stay contended in their new home. This is the percolation argument. http://www.geoffreylandis.com/percolation.htp

• 
  
  Particularly the part about some colonies stating contended and remaining where they are. Although this may be theoretically possible, e coloniz it has never been observed in any living species
  
  

  [*]Space colonization is essentially impossible. Space travel even amongst the planets is presently an extremely expensive proposition. Even if a species does manage to expand beyond the bounds of its home planet, expanding beyond the bounds of its home star system may well be forever out of reach. http://www.antipope.org/charlie/blog-static/2007/06/the_high_frontier_redux.html

  
  The theory behind this cannot be definitively disproved (at the moment). However, given that both manned spaceflight and extrasolar spaceflight are already realities, I believe the human race is not far (in cosmic terms) from manned extrasolar spaceflight.
  
  

  [*]Intelligent species don't last long enough to take the first step. They self-destruct.

  
  This one seems fairly likely, but does it actually constitute an argument against the Fermi Paradox? To me it sounds more like an argument for it; we are alone in the universe because other technological civilizations have destroyed themselves.
  
  

  [*]Intelligent species are so incredibly rare that we are for all practical purposes all alone. Stephen Webb, If the Universe Is Teeming with Aliens... Where Is Everybody? Fifty Solutions to Fermi's Paradox and the Problem of Extraterrestrial Life, Springer (2002). Webb provides 50 solutions to the Fermi paradox in this book. This is solution #50, and is his preferred solution.

Now that I re-read it, I see that the claim that we are alone in the universe is a solution to the paradox. It points to a solution of "zero" (other civilizations in the galaxy)
for the Drake Equation.

Another proposed solution is to invoke the famous "Prime Directive," stating that other advanced civilizations exist, they are here in our neighbourhood, but they refrain from making contact. Again, this is not impossible, but no real-world examples can be found. Whenever one civilization has encountered another on this planet, contact is immediately made (often to the detriment of the less technologically advanced civilization).

(BTW; I was not making reffering to that in my earlier post, I was just saying that if other civilizations had colonized Earth before thet rise of man, we would probably not have "risen")

(Took way to long composing my response, but there it is anyway).

 

[DaveC426913]

[*]If Mars has life, we shouldn't terraform Mars, doubly so if the life is non-terrestrial in nature. Variants:

• If Mars has life, we should leave Mars alone. Period.
• If Mars has life, we should study it but only with unmanned probes that are completely and thoroughly sterilized multiple times during the fabrication process and a few more times on the way to Mars.
• If Mars has life, that life is obviously in trouble. We should aeroform Mars rather than terraform it (make Mars more suitable for Mars life).
• If Mars has life, limited human missions to Mars are acceptable if we take extreme cautions to ensure that we don't introduce any terrestrial life to Mars.

2c had never occurred to me.

 

[D H]

DH, thank you for actually bringing up some of the arguments against the Fermi Paradox.

You're welcome.

This one seems fairly likely, but does it actually constitute an argument against the Fermi Paradox?

My bad. The only real argument against the Fermi paradox is along the lines of "They're heeere". What I erroneously called "arguments against" are better called "solutions of".If we stick to discussions of solutions of the Fermi paradox in this thread, the thread might have a chance to continue on. If this thread continues with the overly speculative posts and high school histrionics that have plagued this thread so far, it will be locked. So, please everyone, keep the discussion dispassionate and civil.

 

[BoomBoom]

If this thread continues with the overly speculative posts and high school histrionics that have plagued this thread so far, it will be locked.

With all due respect, the very topic of this thread, "Alien life", requires speculation.

...indeed the Fermi paradox itself is speculative.

 

[D H]

With all due respect, the very topic of this thread, "Alien life", requires speculation.

We have rules against overly speculative posts at this site. That discussions on alien life do take place in serious scientific literature is the sole reason the site's moderators have allowed this thread to have lived as long as it has.

A review of some pertenant rules is in order.

Overly Speculative Posts:
There are many open questions in physics, and we welcome discussion on those subjects provided the discussion remains intellectually sound. It is against our Posting Guidelines to discuss, in most of the PF forums, new or non-mainstream theories or ideas that have not been published in professional peer-reviewed journals or are not part of current professional mainstream scientific discussion. Posts deleted under this rule will be accompanied by a private message from a Staff member, and, if appropriate, an invitation to resubmit the post in accordance with our Independent Research Guidelines. Poorly formulated personal theories, unfounded challenges of mainstream science, and overt crackpottery will not be tolerated anywhere on the site. Linking to obviously "crank" or "crackpot" sites is prohibited.

Guidelines on Langauge and Attitude:
Foul or hostile language will not be tolerated on Physics Forums. This includes profanity, obscenity, or obvious indecent language; direct personal attacks or insults; snide remarks or phrases that appear to be an attempt to "put down" another member; and other indirect attacks on a member's character or motives.

Please treat all members with respect, even if you do not agree with them. If you feel that you have been attacked, and the moderators or mentors have not yet gotten around to doing something about it, please report it using the "Report" button. If you choose to post a response, address only the substantive content, constructively, and ignore any personal remarks.

It is better to walk away from a possible confontation and come back later with constructive arguments.

I find this to be an interesting topic. I would hate to see the thread closed just because too many posts are overly speculative or full of histrionic attacks.

 

[Remnant]

Although intergalactic travel seems unlikely without speeds above c, interstellar travel is quite likely. This is a part of the Fermi paradox; if other intelligent life exists in this galaxy, why aren't they here? Given no lightspeed, and advances no quicker than our current pace, we will be all over this galaxy in less than 100,000 yrs.

If another civilization exists within this galaxy, it would have to be less than 1,000,000 yrs old, or they would have collonized Earth before we arose. This is a very narrow window, and makes it unlikely that such a civilization currently exists.

I'm studying anthropology, and humanoids have been on Earth dating back to 6-7 million yrs ago. So they would of had to come before then. But i completely believe in a united religion and science, and i still think that "ufo's" and aliens are real. Besides that, it gives people hope and helps them look towards the "bigger picture", so even if they aren't real, they are in our hearts.

 

[DaveC426913]

If another civilization exists within this galaxy, it would have to be less than 1,000,000 yrs old, or they would have collonized Earth before we arose.

There is absolutely no rational logic that could possibly lead to that conclusion. Unless you're having trouble with the line between science-fantasy and reality. Or you're actually one of them, and know what they like in a planet...

 

[DaveC426913]

But i completely believe in a united religion and science...

This is impossible. Religion is based on faith as opposed to knowledge; science is based on replacing faith with knowledge.

While it is possible for one person to hold the two tenets at the same time, they are, by definition, in conflict with each other. That's OK too - No one said humans have to be consistent.

But they will never be unified.


But that's another discussion.

Er... Another forum I mean...

 

[Vanadium 50]

DaveC, I disagree with your description of both science and religion, but as you say, it belongs elsewhere. However, the "unification" idea that the truth or falsehood of a proposition depends on how it makes people feel is certainly unscientific.

 

[LURCH]

I'm studying anthropology, and humanoids have been on Earth dating back to 6-7 million yrs ago. So they would of had to come before then.

The point I was trying to make was that humanity would never have achieved civilization at all in that case. Palientologists are generally agreed that the human race would not have risen to the top of the food chain if something hadden't wiped out the dinosaurs. By that same line of reasoning, if some civilized and technologically advanced species had colonized Earth before we started making spears and wearing animal skins, we would still be living in the forest in small troops.

 

[LURCH]

There is absolutely no rational logic that could possibly lead to that conclusion. Unless you're having trouble with the line between science-fantasy and reality. Or you're actually one of them, and know what they like in a planet...

Tell that to Fermi; it's his paradox!

 

[Zdenka]

I don't believe you guys didn't think outside the box: What if Alien 'civilizations' (if we could call them that) are so far more advanced than us, say 3 billion years ahead.. wouldn't we just be animals to them? Or even worse, they'll see us as bacterias and would NOT want to contact such a primitive organism. And they would NOT be limited by the huge traveling distances through space since they can gather enough energy to open portals to other dimensions.

And who says Aliens that advanced aren't here already? Just like Humans using satellites to spy on Chimpanzees undetected, the Aliens could be around us, or even in some hidden dimension in front of us, spying on us. We can't see them of course, because their technology inhibits our detection... they're simply invisible.

For all intents and purposes, I think it'd be impossible for us to imagine how an Alien that's 3 billion years more advanced, would think.. It'd be like a dog trying to imagine what it's like to be living the life of a human being.. going to work, buying shares, space traveling and doing other 'human tasks'. These Aliens (I call them type V civilizations) are so far ahead of us, we simply cannot fathom their minds.

And their agenda could be totally different from ours (the Aliens, I mean)

 

[Mr. Paradox]

Or emagine us as the aliens. That we are the advances species traveling to a distant planet and the aliens we meet there are as advanced as we were in the 1800's and they are the ones who emagine us

 

[Djrob99]

Will we really? Technologically, I certainly agree with you. Socially however, as I pointed out, do you really think we would fund such expeditions that we have no chance of hearing back from in our lifetimes? Are we going to spend trillions of dollars simply to send people out in space to never return?

The only way this seems possible is if every single social crisis on Earth is solved and there's literally nothing better to do.

Or possibly just the opposite, ie its the last great hope to save mankind!

 

[Nabeshin]

Or possibly just the opposite, ie its the last great hope to save mankind!

You're being too romantic.

 

[Waveform]

I don't believe you guys didn't think outside the box: What if Alien 'civilizations' (if we could call them that) are so far more advanced than us, say 3 billion years ahead.. wouldn't we just be animals to them? Or even worse, they'll see us as bacterias and would NOT want to contact such a primitive organism. And they would NOT be limited by the huge traveling distances through space since they can gather enough energy to open portals to other dimensions.

And who says Aliens that advanced aren't here already? Just like Humans using satellites to spy on Chimpanzees undetected, the Aliens could be around us, or even in some hidden dimension in front of us, spying on us. We can't see them of course, because their technology inhibits our detection... they're simply invisible.

For all intents and purposes, I think it'd be impossible for us to imagine how an Alien that's 3 billion years more advanced, would think.. It'd be like a dog trying to imagine what it's like to be living the life of a human being.. going to work, buying shares, space traveling and doing other 'human tasks'. These Aliens (I call them type V civilizations) are so far ahead of us, we simply cannot fathom their minds.

And their agenda could be totally different from ours (the Aliens, I mean)

Yes, I think you have quite a valid point here. if we just look around at the hierarchy of species here and apply the basic same rules to at least the level of our understanding, then advanced civilizations (if any exist) could well fall into this categorization.

I think perhaps that if and when we do discover another life form ie. alien, it will not be advanced to a great degree beyond us.
A guppy swimming in the ocean can discover another guppy. Even if the other guppy is larger and much more colorful.
However, the guppy can not discover a soaring eagle, or at least until he achieves that status over millions of years.
I apologize for the philosophical nature here, but it is the best way I can put it.
I can't give an equation for it.

On the lighter side however. I think if we were advanced enough to do close interstellar travel. I think I would put us on par with the 'Ferengay'.

 

[Saturni]

There is too much space for no life to be out there.. As I said in my other post on "Is the Earth at the center of the Universe?"
Space is never ending. But inside space, bubbles form. In which forms different atmospheres in those bubbles. There is roughly trillions of bubbles forming as we speak.
But yes, I think Alien life exists..

Good luck,
-Derek

 

[Limitless777]

There is one almost unknown Fermi paradox solution which I think is the best.
The logic of the solution is as follows: to communicate and to rule across the vastness of space, any advanced interstellar civilization will have to synchronize the proper time of its starship travelers and couriers with the proper time of the star metropolis (the center of the civilization). In other words, to compensate for the time dilation of light-speed couriers and communications, the entire civilization has to become mobile and mobile at the speed of light. It may include mass transit technologies like teleportation. Corresponding time dilation makes the communication with such civilization almost impossible. The estimate is that our civilization can achieve this level of technology by the middle of this century. In fact, modern fiber optics, and satellite radio lines allow for information to travel close to the speed of light (it is OK for non-biological ET, like AI virtual personalities). See also an article in Philica on Fermi paradox: http://philica.com/display_article.php?article_id=184

 

[Limitless777]

If we stick to discussions of solutions of the Fermi paradox in this thread, the thread might have a chance to continue on. If this thread continues with the overly speculative posts and high school histrionics that have plagued this thread so far, it will be locked.

DH, that is exactly what I suggest too. That is to repeat that there exist one scientific solution to the paradox which explains that they may be not intentionally hiding - and still are everywhere (mobile civilization utilizing light speed in the everyday life, see my previous post).

 

[Limitless777]

Another proposed solution is to invoke the famous "Prime Directive," stating that other advanced civilizations exist, they are here in our neighbourhood, but they refrain from making contact. Again, this is not impossible, but no real-world examples can be found. Whenever one civilization has encountered another on this planet, contact is immediately made (often to the detriment of the less technologically advanced civilization)

They may exist and "be everywhere" and not refrain from the contact but the communication still may be impossible. Consider the case of communication with the star traveler moving almost with the speed of light. Small talk can take thousand of years due to the time dilation. And the jetliner passengers would not jump out just to stare at the crawling ant.

 

[JaredJames]

There is one almost unknown Fermi paradox solution which I think is the best.

the entire civilization has to become mobile and mobile at the speed of light. It may include mass transit technologies like teleportation. Corresponding time dilation makes the communication with such civilization almost impossible.

How is this a solution? Given you can't accelerate an object with mass to the speed of light, it doesn't solve anything.

The estimate is that our civilization can achieve this level of technology by the middle of this century.

"Our civilization"? And whose estimate is this? Certainly not one based in reality. We aren't even close to anything of the sort.

First you propose wee need to travel at the speed of light and then you say we can do so mid 21st century. Nonsense.

In fact, modern fiber optics, and satellite radio lines allow for information to travel close to the speed of light

Those two allow information to travel at the speed of light. It is only the encoding / decoding phases that give a 'delay', but the signal itself is at light speed.

 

[mjacobsca]

I think I am a little late to this thread, but I'm surprised no one has discussed the Rare Earth Theory in this thread. Basically, this theory attempts to add in new developments in our understanding of astrobiolgy, astrophysics, planetary formation, and cosmology to the original Drake Equation in order to come up with an improved, more modern, and more realistic formula for the number of advanced civilizations in our galaxy. They add in a bunch of factors not considered in the Drake equation, such as the benefits of having an extremely large moon to stabilize a planet's tilt along its axis, the presence of a large Jupiter to guard the rocky inner planets from excessive bombardment by wayward asteroids and comets as well as the frequency and timing of the impacts that DO occur, beneficial locations within galactic spiral arms (eg galactic habitable zones in addition to the already considered planetary habitable zones), metallicity of planets, types of planetary orbits, and numerous other factors. The Rare Earth Theory takes a pretty realistic approach to evaluating new factors that Drake never did. Depending on your viewpoint on the new factors they introduce, the number of advanced alien civilizations in our galaxy other than us may be as low as 0. They do, however, believe that primitive life is common. It is certainly an interesting theory that deserves some consideration.

http://en.m.wikipedia.org/wiki/Rare_Earth_hypothesis

 

[Limitless777]

How is this a solution? Given you can't accelerate an object with mass to the speed of light, it doesn't solve anything.
"Our civilization"? And whose estimate is this? Certainly not one based in reality. We aren't even close to anything of the sort.
First you propose wee need to travel at the speed of light and then you say we can do so mid 21st century. Nonsense.

First, you may consider this as an estimate of one prominent futurist and a famous inventor, Ray Kurzweil. He has already proved many times that he is pretty good in technological predictions. According to his estimates, our civilization will become mostly non-biological to the year 2045. It means that most of thinking creatures (virtual personalities) to this year will be traveling virtually through the networks similar to Internet - at the speed of light. It is obvious that for those, who is massless there is no need to accelerate.
Second, you are wrong, there exist promising ideas on light speed travel for massive objects too, so your thesis is not "given". I don't want to discuss these ideas here, but you may consider, for example, the fact that the Dirac equation for massive particle (4-spinor) may be transformed into two equations for massless Weyl 2-spinors. It means by the way that from the certain point of view fermion particles like electron, proton, etc. are moving at the speed of light all the time (no need to accelerate). It is well-known in quantum theory "jiggling" effect. Future inventors may find a way to utilize this.

 

[JaredJames]

First, you may consider this as an estimate of one prominent futurist and a famous inventor, Ray Kurzweil. He has already proved many times that he is pretty good in technological predictions. According to his estimates, our civilization will become mostly non-biological to the year 2045. It means that most of thinking creatures (virtual personalities) to this year will be traveling virtually through the networks similar to Internet - at the speed of light. It is obvious that for those, who is massless there is no need to accelerate.

These ideas have already been discussed here only a few weeks back. I believe the thread was locked for non-sense claims such as these. There is no substance to them.

Second, you are wrong, there exist promising ideas on light speed travel for massive objects too, so your thesis is not "given". I don't want to discuss these ideas here, but you may consider, for example, the fact that the Dirac equation for massive particle (4-spinor) may be transformed into two equations for massless Weyl 2-spinors. It means by the way that from the certain point of view fermion particles like electron, proton, etc. are moving at the speed of light all the time (no need to accelerate). It is well-known in quantum theory "jiggling" effect. Future inventors may find a way to utilize this.

As far as I'm aware, the only methods for FTL travel for massive objects involve 'exotic' as of yet, non-existent entities.

Also, I'm not sure how interchangeable micro and macro scale matters are.

 

[berkeman]

Thread closed pending Moderation of necroposts by Limitless777...