Is there life in the universe, and if so has it visited Earth?

[DaveC426913]

Basically, you would not accept existence of UFOs even in the case you had seen one?

Of course I would accept it.

The question is, is it reasonable for anyone other than my group of friends to believe it on only our say-so.

Extraordinary claims require extraordinary evidence.

 

[qraal]

One problem with the 'UFO' thing is that people who are convinced they're ETI space-vehicles have moved beyond 'they exist' to 'I know what they are'. Two very different knowledge claims. Weird things fly through the sky I've no doubt, but personally I have no idea what they are that isn't as good as any other idea that explains the observational data. There's no test I can do and no hard evidence I can point to that falsifies or supports any theory that explains the data.

And I mean real data. What people report and what they really see can be quite at odds, so when someone claims a 'metallic disk' I reserve judgement on composition and configuration - I don't know, can't know, what was really seen and what was merely perceived.

I'm yet to see a convincing 'mechanical device' UFO photo that isn't later exposed as a fake, so that can be reasonably put in the 'inconclusive evidence basket' as well. Lights in the sky photos can be anything, so they're equally inconclusive. And alien autospy films are all hoaxes, while grainy, out-of-focus shots of 'live ETIs' could be anything.

So what evidence remains? Plausibility arguments about the exist and presence of ETIs aren't proof and too full of unknowns to be useful. Interstellar travel speculations are fun and interesting but they're not proof of anything either. Do we see highly energetic drive systems blasting into our star system? No. Any arriving vehicles must be stealthed which makes it odd that would become visible for eyewitnesses in Earth's atmosphere.

So do I think UFOs exist? Of course. There's a phenomena to be explained.

DO I think they're slam-dunk evidence of ETI activity on planet Earth? Nope. Insufficient evidence to reach such a definite conclusion.

Does the human mind have a big role to play in the phenomena? You bet.

 

[VooDooX]

fp = fraction of stars with planets around them:5%

5%?! you right i would assume almost EVERY star has planets since there all formed the same way or most of them are anyways from what i observe here with 1 star with 8 planets and 1000's of asteroids and maybe millions of objects in the ort cloud and the Kuiper belt honestly do you believe all but 5 % of stars have nothign around them...

Basically, you would not accept existence of UFOs even in the case you had seen one?

i don't know if i would being scientific i would look first at the most obvious option for such a craft.. advanced HUMAN technology designed to look like a flying saucer what better stealth craft could there be! people who see them will be discredited as crackpots and the enemy nation would never know they were being spied on up close and personal and why not dress the pilots in ET jumpsuits all the further to complete the ruse if they need to land and exit there ship for any reason far stranger things have been done in wari think the most reasonable form of ET's we will ever see is ET machines designed to self propogate and explore then return the info to the home planet much like our probes today do only there's would find a planet build more robots and swarm off from there in every direction till they find another planet and repeat

 

[mikelepore]

5%?! you right i would assume almost EVERY star has planets since there all formed the same way or most of them are anyways from what i observe here with 1 star with 8 planets and 1000's of asteroids and maybe millions of objects in the ort cloud and the Kuiper belt honestly do you believe all but 5 % of stars have nothign around them...

Many parts of the galaxy have almost no metal atoms, therefore stars in those regions can have only gas planets, no solid surfaces. (Ward and Brownlee, _Rare Earth_, paperback, 2004, page 29)

 

[BigFairy]

a matter of time

 

[Pattonias]

Many parts of the galaxy have almost no metal atoms, therefore stars in those regions can have only gas planets, no solid surfaces. (Ward and Brownlee, _Rare Earth_, paperback, 2004, page 29)

I thought that most heavy elements are the result of the death/aging of stars. While the heavy elements are rare in comparison to the total mass of the Universe, wouldn't the distribution of heavy elements be fairly uniform, or present wherever there are stars.

 

[DaveC426913]

wouldn't the distribution of heavy elements be fairly uniform, or present wherever there are stars.

Nope.

There are different generations of stars. Ours is a Population I type star. Older stars are Population II and are metal poor. But really old stars were the first stars made, when there were no metals to be had. They are almost entirely H and He. These are Population III stars.

http://en.wikipedia.org/wiki/Metallicity#Population_I_stars

 

[WhoWee]

Nope.

There are different generations of stars. Ours is a Population I type star. Older stars are Population II and are metal poor. But really old stars were the first stars made, when there were no metals to be had. They are almost entirely H and He. These are Population III stars.

http://en.wikipedia.org/wiki/Metallicity#Population_I_stars

I find it amusing that we can be so certain on this point and yet need to smash an object into the Moon to determine the presence of water.

 

[VooDooX]

nothing we know is ever certain which is why the universe is so weird

 

[DaveC426913]

I find it amusing that we can be so certain on this point

Actually, we don't. If you read the article I linked to, you will see that Pop III stars are thought to exist near the centres of galaxies, generally obscured from view.

 

[VooDooX]

soo if all the stars around the edges have planets its still greater then 5% that's all I am saying

 

[mathman44]

I think intelligent lifeforms will last only for a short period in a biological form. Organisms with a large enough brain to develop a civilization will very soon develop intelligent machines. These machines will then take over control of the planet.

Interesting opinion but I doubt that we will ever make machines as clever as ourselves, and if we somehow do, I would assume that we would also be smart enough to make them controllable.

To address the main questions: I have no idea!

 

[baywax]

Sooooo, anyone seen some strange flying objects of unidentified origin that perform in a way the usual aircraft never do?

 

[DaveC426913]

Interesting opinion but I doubt that we will ever make machines as clever as ourselves,

Why? It just a technical feat.

and if we somehow do, I would assume that we would also be smart enough to make them controllable.

What makes you think we could control them? (OK, I guess your first statement answers that. If you think we won't ever make machines as clever as ourselves, then it's not hard to keep control of them.)

 

[baywax]

What makes you think we could control them? (OK, I guess your first statement answers that. If you think we won't ever make machines as clever as ourselves, then it's not hard to keep control of them.)

People can't control their cars let alone super computers.

Is this all getting at some kind of speculative attempt to prove that alien machines have visited earth? I think the question is "has life visited earth"... other than our own. (Paraphrasing) Life as in biological machines.

 

[DaveC426913]

Is this all getting at some kind of speculative attempt to prove that alien machines have visited earth?

No, it's simply a tangent about the longevity of hypothetical alien races, spawned by Count Iblis in https://www.physicsforums.com/showpost.php?p=2452118&postcount=896".

 

[baywax]

No, it's simply a tangent about the longevity of hypothetical alien races, spawned by Count Iblis in https://www.physicsforums.com/showpost.php?p=2452118&postcount=896".

Thanks for clearing that up DaveC426913. There are a number of things that would either keep an alien population alive or end their species. I was wondering whether or not the drive to harmonize and cooperate was a favorable trait that would lend itself to the longevity of a species. On a cellular level, it has worked well. Multicellular cooperation, specification and harmonization has resulted in the creation of wide spread gene pools of impressive longevity.

For a species to reach a point where they are somehow able to by-pass thousands of light years and visit other solar systems, I would imagine they would have figured out how to keep their own planet and population in fair shape... for some time. It would depend on a lack of planetary/natural disasters for these aliens to enjoy any relative longevity. Unless they had figured out a way to avoid those pit falls of life as well.

 

[baywax]

I would tend to agree. Understanding nature on the level of quantum mechanics and theory of relativity is definitely mold braking point in terms of maturity of knowledge. Economic forces definitely favor globalization, so on the scale of next 100 to 300 years, there is to be more integration between the nations, rather than less. Most likely to the point where nations become irrelevant.

Interstellar travel needs a push from global economy, no nation will be ever rich enough to do it on its own.

And there goes the neighbourhood! Interesting how the EU is shaping up. Big Mother on the rise.

 

[Cryxic]

Is there life in the universe?

I suspect so, but obviously I don't know.

Has it visited Earth?

I would say no, but obviously I don't know the answer here either.

Some of the conversations in this thread remind me of theological debates: a lot of passion for no results. The ultimate resolution to the problem of whether there is life, or intelligent life, in the universe lies in we humans getting our behinds off this planet and looking for it...but we have a bad tendency as a species to settle into easy, convenient answers and avoid doing what's necessary or difficult.

 

[Schrodinger's Dog]

Holy moly I created a Monster?

Zombie thread!

 

[N468989]

we are visitors... simple as that.

 

[Schrodinger's Dog]

we are visitors... simple as that.

Prove it?

 

[N468989]

Prove it?

I can only imagine, life itself most certainly formed on earth, due to our conditions in which we survive, but by what means can we prove that we are not from somewhere else. It's like someone lives in country XYZ, and was born in ABC, does it mean that, where they live now is where they have always been?

You say "Prove A" and i say "Prove !A".

We cannot prove that, since there isn't proof yet or may never be, maybe the absence of proof is proof itself!

We can't find the missing link.

 

[Schrodinger's Dog]

I can only imagine, life itself most certainly formed on earth, due to our conditions in which we survive, but by what means can we prove that we are not from somewhere else. It's like someone lives in country XYZ, and was born in ABC, does it mean that, where they live now is where they have always been?

You say "Prove A" and i say "Prove !A".

We cannot prove that, since there isn't proof yet or may never be, maybe the absence of proof is proof itself!

We can't find the missing link.

Why?

Isn't that just a strong anthropic principle? And thus begging the question endlessly.

 

[N468989]

Why?

Isn't that just a strong anthropic principle? And thus begging the question endlessly.

We can only imagine it's that way, due to our limited understanding of our being. We might be capable of understanding someday, but not today. What we know as valid today, tomorrow can be invalid. Didn't we believe the sun circled the earth?

Proof is there but we haven't been looking hard enough.

Is there life in the universe? Yes, we are part of the universe, so there is life!
Has it visited earth? Without proof, the answer in our living days is no...now its a matter of "to believe or not to believe".

 

[Schrodinger's Dog]

We can only imagine it's that way, due to our limited understanding of our being. We might be capable of understanding someday, but not today. What we know as valid today, tomorrow can be invalid. Didn't we believe the sun circled the earth?

Proof is there but we haven't been looking hard enough.

Is there life in the universe? Yes, we are part of the universe, so there is life!
Has it visited earth? Without proof, the answer in our living days is no...now its a matter of "to believe or not to believe".

How do you induct that?

How do you know we aren't alone?

the Sun and the Earth both circle each other, from each others relative perspective.

Infinity rests on being able to tell where you are, and when.

 

[N468989]

How do you induct that?

How do you know we aren't alone?

To fully understand if we are, or not alone, we must first define what we understand by alone.
Beforehand, we must understand who we are, what is our meaning of existence (if there is such), and what is our purpose.

 

[Schrodinger's Dog]

To fully understand if we are, or not alone, we must first define what we understand by alone.
Beforehand, we must understand who we are, what is our meaning of existence (if there is such), and what is our purpose.

I think therefore I am, you however I'm not so sure about?

Is that it?

Very René Descartes.

 

[VooDooX]

We can't find the missing link.

Or it has been found and is being hidden by the powers that be or the church people in some pretty high places still don't like the idea of evolution

 

[DaveC426913]

To fully understand if we are, or not alone, we must first define what we understand by alone.
Beforehand, we must understand who we are, what is our meaning of existence (if there is such), and what is our purpose.

Why?

 

[Schrodinger's Dog]

Why?

Arm waving dualism FTW!

 

[N468989]

Does it matter? The questions are always Who?What?When?Where?Why?How?

Let's be reasonable, if we had the answer this thread wouldn't even exist, more the less, if you had the answer you wouldn't give a damn so to speak. Give me your opinion instead of refuting/questioning my comments, they only my way of seeing things.

I understand the easy way out, to never answer a question is to ask another question. That's not our point here, so give me your opinion, without the facts.

 

[VooDooX]

Fungi feeding on radiation
http://www.scienceagogo.com/news/20070422222547data_trunc_sys.shtml

"Just as the pigment chlorophyll converts sunlight into chemical energy that allows green plants to live and grow, our research suggests that melanin can use a different portion of the electromagnetic spectrum - ionizing radiation - to benefit the fungi containing it," said co-researcher Ekaterina Dadachova.

Investigating further, the researchers measured the electron spin resonance signal after melanin was exposed to ionizing radiation and found that radiation interacts with melanin to alter its electron structure. This, they believe, is an essential step for capturing radiation and converting it into a different form of energy to make food.

Metal Eating Bacteria
http://www.accessexcellence.org/WN/SU/bactercorrode.php

Bacteria live in clouds/snow
http://www.npr.org/templates/story/story.php?storyId=87761584&ps=rs

Facultative anaerobic Bacteria (able to live with and without oxygen present
http://www.springerlink.com/content/g2t215344n884160/

Bacteria that live on uranium
http://www.sciencedaily.com/releases/2006/10/061019192814.htm
http://www.nanowerk.com/spotlight/spotid=765.php
http://blogs.discovery.com/news_sustainable/2009/09/radioactive_cleanup.html

 

[Ivan Seeking]

I decided to delete the off-topic posts and leave only the references provided. Let's refrain from personal theories about how bacterial or viral life might survive in space and reference only published papers.

thread open.

 

[baywax]

Its always going to be classified as swamp gas..

http://cache.gawker.com/assets/images/io9/2009/10/aaah.jpg



There must be some way to identify if swamp gas is extraterrestrial or not.