why life exist only on earth?

[adi chicago]

why life exist only on earth?

[Wise Young]

why life exist only on earth?

Are you sure that life only exists on earth? Wise.

[adi chicago]

Are you sure that life only exists on earth? Wise.
i dont know for sure ,thats why i asked.

[Wise Young]

i dont know for sure ,thats why i asked.

Given the robustness of life here on earth, I suspect that life not only exists but flourishes elsewhere.

Wise.

[adi chicago]

so many planets around and no life [humans,reptiles,bugs,fish or water].
strange.

[SCI-Nurse]

It is illogical to assume that Earth is the only planet in the entire universe that had all the correctly combined factors that supported the development of living organisms.

It is a conceit that human beings on Earth have developed as they want to believe that it is as they are taught in (primarily) Judeo-Christian religious teachings.

Just because we have not been contacted does not mean that there are not other living (even sentient) beings out there in space. We are probably not worth their trouble to visit or contact!

(KLD)

[adi chicago]

Given the robustness of life here on earth, I suspect that life not only exists but flourishes elsewhere.

Wise.
great words dr.wise.

[NorthQuad]

Check this out Adi.

http://www.youtube.com/watch?v=a7Eyv9Qq-qo&NR

[rfbdorf]

The chance that any particular planet is suitable for life is probably fairly small. But given the large number of planets that apparently exist, the chance that life exists elsewhere is very large, maybe a certainty. Given the laws of relativity, exchanging information with, or visiting another solar system with life is very difficult. How long has mankind been capable of transmitting or receiving signals to or from another star? Maybe 50 years, at most, out of the 4 or 5 *10^9 years of existence of our planet. How long will mankind continue to have that capability, or the will to do so? We can only guess, and hope.
- Richard

[Buck503]

Adi, it depends on what you consider "life".

If scientists found living organisms deep down below the surface of
Mars, then that would be considered life on another planet.

The possibility of finding something like that on another planet is
very good. The possibility of finding life as advanced as we are on
another planet is not likely.

[Juke_spin]

Adi, it depends on what you consider "life".

If scientists found living organisms deep down below the surface of
Mars, then that would be considered life on another planet.

The possibility of finding something like that on another planet is
very good. The possibility of finding life as advanced as we are on
another planet is not likely.
The possibility of there being life as or more advanced than we on another planet is likely. "Absence of proof isn't proof of absence.".

[Adrian]

We know that prokaryotic life can survive in space. A camera retrieved from an earlier moon mission by Apollo 12 contained Strptococcus that had survived on the moon for three years:
http://www.guardian.co.uk/life/thisweek/story/0,,1532305,00.html

But scientists have already discovered Earthlings on another heavenly body. A camera in a Surveyor probe sent to the moon was retrieved by the crew of Apollo 12 almost three years later and shipped back to earth again. Within the camera were a colony of Streptococcus mitis, a tiny microbe that had inadvertently stowed away. The Streptococcus survived three years in a vacuum, experiencing extremes of heat and cold, without food or water, bombarded by lethal radiation. When it got back to the home planet it revived, and began to multiply.


If bacteria can surive the conditions in space then there is a possibility that they have travelled on comets, seeding life from one planet to another - either from Earth to other planets or other plkanet to Earth. This theory is calle panspermia and whilst we do not have evidence that convinces me that it has occurred we do have evidence that bacteria could survive the journey. Not only do we have the Strptococcus from the moon but the only surviviors of the challenger space shuttle crash were bacteria.
The fact that Earth bacteria can survive and flourish in extreme conditions on Earth, in volcanic vents and nuclear power plants for example, suggests that conditions do not have to be as "life friendly" as they are in large parts of the Earth for life to exist elsewhere in space. Given the huge range of conditions that life can survive in, I would be extremely surprised if suitable conditions for life did not exist in many places elsewhere in the universe and just as surprised if life does not exist in at least a small proportion of these places.

[Wise Young]

We know that prokaryotic life can survive in space. A camera retrieved from an earlier moon mission by Apollo 12 contained Strptococcus that had survived on the moon for three years:
http://www.guardian.co.uk/life/thisweek/story/0,,1532305,00.html


If bacteria can surive the conditions in space then there is a possibility that they have travelled on comets, seeding life from one planet to another - either from Earth to other planets or other plkanet to Earth. This theory is calle panspermia and whilst we do not have evidence that convinces me that it has occurred we do have evidence that bacteria could survive the journey. Not only do we have the Strptococcus from the moon but the only surviviors of the challenger space shuttle crash were bacteria.
The fact that Earth bacteria can survive and flourish in extreme conditions on Earth, in volcanic vents and nuclear power plants for example, suggests that conditions do not have to be as "life friendly" as they are in large parts of the Earth for life to exist elsewhere in space. Given the huge range of conditions that life can survive in, I would be extremely surprised if suitable conditions for life did not exist in many places elsewhere in the universe and just as surprised if life does not exist in at least a small proportion of these places.

I like KLD's statement. It is a conceit of humans to think that we are the only form of "life" worth considering.

As I have pointed out in another topic regarding the sizes of planets, gravitational force is likely to have a great influence on the manifestions of "organisms". In a small gravitational field planet, like Earth or Mars, life can be our size or bigger. However, in large planets with substantial gravitational fields, organisms may be very different. However, small organisms can form networks that communicate with each other and may be considered a distributed organism.

The concept of a distributed organism is fascinating. For example, scientists think that some forests are huge organisms composed of many hundreds or thousands of trees that come from a single individual and are connected to each other through a massive root system. Likewise, fungi (mushrooms) are interconnected and can be considered a single organism, as suggested by Thomas Volk in a 2002 article entitled "The Humongus Fungus" (Source (http://botit.botany.wisc.edu/toms_fungi/apr2002.html)), describing a single colony of Armillaria or Honey Mushroom. Genetic analyses revealed that genetically identical members of one single colony may occupy 16 hectare area and is at least 1500 years old, making this among the largest and oldest "organisms" on earth.

Gravitional fields may also influence the time-scale of organisms. We are used to seeing life that moves and reacts within seconds or minutes. But, it is entirely conceivable that organisms on other planets react to stimuli over a time scale of months, years, or even centuries. We may not be able to perceive life that has a very short or very long time scale. It is also entirely possible that life on other plants evolved using a different genetic and non-carbon-based components. We may simply not be able to recognize life on other planets.

Wise.

[JimD]

"Sometimes I think we're alone. Sometimes I think we're not. In either case, the thought is staggering."
- Buckminster Fuller

[rdf]

Considering the age of the Universe, and the extreme environments we find life here on Earth, there's no doubt there are and have been lifeforms in other solar systems in our galaxy. And countless other galaxies.

Hell, whole intelligent civilizations could have flourished for billions of years, and died out, long before the Earth was even created.

If an intelligent species were to survive long enough without either blowing up its own planet, getting wiped out by an asteroid or comet, or somehow or other coming to an end, then they'd develop the technologly to harness the power of their planet. If they survived longer, they would sooner or later harness the power of a star, and if longer still, they'd be able to harness the power of galaxies.

With the harnessing of such power, wormholes could be created, defeating the laws of physics which puts a cosmic speed limit at 186,000 miles/second...and allowing for travel from one end of a galaxy to the other in seconds.

Yeah, I believe there's life out there, intelligent life, and maybe some have survived long enough to create wormholes and travel about the universe. Or they've found other loopholes around the laws of physics. Or maybe we on Earth don't understand physics as much as we think we do. And maybe ETs just haven't seen us yet, or we're not important enough, or we've been explored and are being explored right now.

Or the ETs could explore using nano-robots who can replicate and study the universe without sending themselves.

The possiblitiles are endless. As JimD posted, if there is ET life, that'd be amazing. If there isn't ET life, if we're alone in this endless universe, well, that would be equally amazing. So no matter how you look at it, we live in an amazing universe.

The three types of civilzations I mentioned; able harness power of the planet, harness power of the star, and harnessing the power of the galaxy I believe are how modern-day theoretical physicists type-class civilizations.

We on Earth today don't rate on that scale as we get out power mainly from dead plants and animals. If we learn to harness the power of our planet's processes, we'll rate at the bottom of the three.

[Wise Young]

Considering the age of the Universe, and the extreme environments we find life here on Earth, there's no doubt there are and have been lifeforms in other solar systems in our galaxy. And countless other galaxies.

Hell, whole intelligent civilizations could have flourished for billions of years, and died out, long before the Earth was even created.

If an intelligent species were to survive long enough without either blowing up its own planet, getting wiped out by an asteroid or comet, or somehow or other coming to an end, then they'd develop the technologly to harness the power of their planet. If they survived longer, they would sooner or later harness the power of a star, and if longer still, they'd be able to harness the power of galaxies.

With the harnessing of such power, wormholes could be created, defeating the laws of physics which puts a cosmic speed limit at 186,000 miles/second...and allowing for travel from one end of a galaxy to the other in seconds.

Yeah, I believe there's life out there, intelligent life, and maybe some have survived long enough to create wormholes and travel about the universe. Or they've found other loopholes around the laws of physics. Or maybe we on Earth don't understand physics as much as we think we do. And maybe ETs just haven't seen us yet, or we're not important enough, or we've been explored and are being explored right now.

Or the ETs could explore using nano-robots who can replicate and study the universe without sending themselves.

The possiblitiles are endless. As JimD posted, if there is ET life, that'd be amazing. If there isn't ET life, if we're alone in this endless universe, well, that would be equally amazing. So no matter how you look at it, we live in an amazing universe.

The three types of civilzations I mentioned; able harness power of the planet, harness power of the star, and harnessing the power of the galaxy I believe are how modern-day theoretical physicists type-class civilizations.

We on Earth today don't rate on that scale as we get out power mainly from dead plants and animals. If we learn to harness the power of our planet's processes, we'll rate at the bottom of the three.

rdf,

We humans ain't that shabby... :).

We have harnessed the power of the sun and our planet on a scale that we need. Energy trapped in carbon deposits are a form of solar energy, collected over many years without any effort on our part. We do use some of the intrinsic energy of our planet, including volcanic heat, waves, wind, and magnetic energy. In the past century, we have discovered and harnessed nuclear power, including nuclear fusion which is of course the basis of our solar energy.

Admittedly, we have not yet conquered the lightspeed barrier. However, slower than light-speed travel is not so bad. Time is only relative. Greater-than-lightspeed travel is only necessary for distant galaxies. Within a few years of travel from earth, there is a great deal to explore and learn in the coming century. Also, I am not sure that humans are ready yet to meet other life forms. If we were to meet with any of the life-forms that you postulated, it will be our demise.

In the meantime, we have a lot yet to accomplish on this earth. We must learn how to live on this planet without destroying it. It would be nice if we learned how to cure spinal cord injury and other incurable conditions. It would be great if we learned how to live with each other without all the murder and mayhem. In all our history, we have yet to achieve "peace on earth and good will to all men." Maybe we can achieve these goals in our lifetime. Merry and Happy to you.

Wise.

[rdf]

rdf,

We humans ain't that shabby... :).

We have harnessed the power of the sun and our planet on a scale that we need. Energy trapped in carbon deposits are a form of solar energy, collected over many years without any effort on our part. We do use some of the intrinsic energy of our planet, including volcanic heat, waves, wind, and magnetic energy. In the past century, we have discovered and harnessed nuclear power, including nuclear fusion which is of course the basis of our solar energy.

Admittedly, we have not yet conquered the lightspeed barrier. However, slower than light-speed travel is not so bad. Time is only relative. Greater-than-lightspeed travel is only necessary for distant galaxies. Within a few years of travel from earth, there is a great deal to explore and learn in the coming century. Also, I am not sure that humans are ready yet to meet other life forms. If we were to meet with any of the life-forms that you postulated, it will be our demise.

In the meantime, we have a lot yet to accomplish on this earth. We must learn how to live on this planet without destroying it. It would be nice if we learned how to cure spinal cord injury and other incurable conditions. It would be great if we learned how to live with each other without all the murder and mayhem. In all our history, we have yet to achieve "peace on earth and good will to all men." Maybe we can achieve these goals in our lifetime. Merry and Happy to you.

Wise.
You're very right, Wise. I wasn't demeaning humans on Earth or belittling our accomplishments, just theorizing. It's interesting that you mention achieving peace on earth, as this is an absolute prerequisite to not only survival, but any extra-solar explanatory agenda.

Theorizing, it brings to mind the Drake equation, which I learned in a high-school astronomy and has been tossed around for years:

---------
The Drake Equation (http://www.airynothing.com/smackerels/DrakeEquation.html), as far as mathematical equations go, is quite simple. It consists of a string of unknowns multiplied by each other - that's it, no integration, no differentiation, nothing more difficult that multiplication. This means that the equation is accessible to pretty much everyone. Here it is: N = R* fp ne f l fi fc L Where:
R* is rate of formation of suitable stars (stars like the Sun) in the Milky Way galaxy
fp is the fraction of those stars that have planets
ne is the number of planets capable of sustaining life around each of those stars having planets
fl is the fraction of planets capable of sustaining life that actually evolve life
fi is the fraction of those planets where live has evolved that evolve intelligent life
fc is the fraction of planets with intelligent life that develop the capability to communicate
L is the fraction of the planet's life during which the intelligent life can communicate
MORE (http://www.airynothing.com/smackerels/DrakeEquation.html)-----

The only problem with his equation is we don't know most of the values. Hell, we only know one or two. But even using conservative numbers for the values, the outcome is still millions of planets with intelligent life.

I believe the Europeans have recently launched a new telescope that will be able to detect smaller planets than we can now detect. It should be able to see planets maybe 3 times as big as Earth. Now, we only find Jupiter sized and bigger planets. Instead of finding them by measuring the "wobble," or "doppler shift," caused by gravitation of an orbiting planet on a star, it'll measure the "blink" of light when a planet orbits its star. NASA might be involved with this telescope, too.

But I know NASA has an even better telescope planned to launch in the next 5 or ten years that'll be able to detect Earth sized planets. Imagine that! In a few years, we'll be discovering planets our size in our galaxy...and if a planet is our size or even twice as big, it can't be made of gas, it'll be rocky.

And with our ability to decipher all realms of the visible, infrared, x-ray, ultra-violet, radio, etc., light spectrums and each planet's chemical makeup via spectroscopy, we should be able to tell if plant-life exists on these planets by studying the light and radiation they give off. I may be jumping the gun a bit, but I believe this is possible with this new telescope and our ability to decipher the chemicals on the planet via the planet's light and radiation.

(Imagine if we found a planet giving off high levels of methane and carbon dioxide :))

I'm shooting from the hip here, but that's how I understand how we may be able to see if life exists on these earth-sized or two-times earth-sized planets that we'll certainly discover in the near future.

I should have gone into Astronomy, instead of Aerospace Engineer work. But I'm tired of doing what I'm doing and looking for a change. I'd love to work in Astronomy, or for SETI. Think I'll check out their website, see if they need any help...but I think they've lost most or much of their funding in the last decade.

[rdf]

Here's the space telescope soon to be launched I mentioned above.


----

COROT to scout for rocky planets around other stars (http://space.newscientist.com/article/dn10870-corot-to-scout-for-rocky-planets-around-other-stars.html)


Rocky planets not much bigger than Earth could be detected by a space telescope called COROT set to launch on 27 December. The mission is expected to provide a better understanding of planets smaller than Saturn, of which only a small number of examples are known so far.


The vast majority of the more than 200 extrasolar planets found to date have been detected from the ground by watching for the slight gravitational tug they exert on their parent stars, called the radial velocity technique.


Most of these planets are similar in mass to Jupiter or even heavier, because these 'gas giants' are the easiest to detect. But the new telescope, called COnvection ROtation and planetary Transits (COROT), will be able to detect much smaller planets.


The satellite will use its 27-centimetre telescope to search for dips of light due to planets passing in front of their parent stars in events called transits. It will monitor different patches of the sky that each span the width of about six Full Moons, staring at each for 150 days at a time. Watch an animation of the COROT mission (http://smsc.cnes.fr/IcCOROT/Corot.avi).


The mission is capable of detecting tiny drops in light of only 300 parts per million, which is good enough to detect planets as small as two or three times the size of Earth, says COROT team member Marc Ollivier of the Université Paris-Sud in Orsay, France.

More (http://space.newscientist.com/article/dn10870-corot-to-scout-for-rocky-planets-around-other-stars.html)

----------------------

Here's the NASA Kepler space telescope I also mentioned, to be launched in 2008.

---

Overview of the Kepler Mission
(http://kepler.nasa.gov/about/)
Kepler
... NASA's first mission capable of finding Earth-size and smaller planets around other stars.
Importance of Planet Detection

The centuries-old quest for other worlds like our Earth has been rejuvenated by the intense excitement and popular interest surrounding the discovery of giant planets like Jupiter orbiting stars beyond our solar system.

With the exception of the pulsar planets, all of the extrasolar planets detected so far are gas giants, approximately 150 as of 2005. The challenge now is to find terrestrial planets (habitable planets like Earth), which are 30 to 600 times less massive than Jupiter.


The Kepler Mission, a NASA Discovery mission (http://discovery.nasa.gov/), is specifically designed to survey our region of the Milky Way galaxy to detect and characterize hundreds of Earth-size and smaller planets in or near the habitable zone. The habitable zone encompasses the distances from a star where liquid water can exist on a planet's surface.

More (http://kepler.nasa.gov/about/)

[Tufelhunden]

If Einstein's statement that the universe is absolutely infinite is to be a lemma in an argument, then we can conclude that at some point and location in the universe there are disabled individuals having this exact same conversation at the same time.

[Wise Young]

rdf, Thank you. The Drake Equation (formulated in 1961) is a simple probability equation. The website http://www.activemind.com/Mysterious/Topics/SETI/drake_equation.html allows you to make the calculation based on various assumptions. Even with relatively generous assumptions such as 100 billion stars, 50% of stars have planets, each of those stars have at least one planet able to support life, 20% of those actually evolved life, 20% of those evolved intelligent life, 20% of those communicated, and those communicating civilizations survived 10,000 years, the number of communicating civilizations is smaller than one would think, about 1000. The number could be easily smaller than 1000, due the generosity of some of the assumptions.

Regarding SETI and detection of life, I am concerned that we are only looking for carbon-based lives. The more we learn about life, the more varied it seems to be. Wikipedia has a section of an article devoted to silicon-based life (http://en.wikipedia.org/wiki/Silicon#Silicon-based_life). It pointed out that while silica has a similar valency to carbon and can form complex crystals, that some bacteria in fact have silicon dioxide based skeletons, and that spines of the sea urchin are made of silicon dioxide, it suggests that another solvent besides water would be necessary to allow life to form. In particular, the chemistry of silicon-oxygen interactions would not allow diverse and stable silicon compounds.

The requirement that civilizations must survive for a period of time to increase the chances of detection and live confrontation between them is a particularly interesting one. As a Wikipedia article on SETI (http://en.wikipedia.org/wiki/SETI) suggested:
The third assumption behind SETI is that intelligent life is not inherently self-destructive, but that it finds a sustainable way of living on its planet. The duration of human beings in relation to earth time has been likened to the thickness of a piece of cigarette paper placed on the topmost railing of the Eiffel Tower. Earth-time is the Eiffel tower, human history is the paper. SETI assumes that two pieces of paper, placed on two separate towers, may exist at exactly the same height, that is, that two or more intelligent civilizations may exist simultaneously, and within a relatively short distance from each other that their radio signals may arrive without extensive degradation. However, the periods of time during which life-bearing planets are formed do in fact vary enormously. If a human civilization capable of sending electromagnetic signals continues for hundreds of thousands of years, the paper becomes a little thicker and the likelihood that we will exist simultaneously with another transmitting/receiving civilization is increased. If however, our civilization destroys itself through nuclear war or as a result of the release of greenhouse gases or other erosions of our life support system, and if other civilizations have the same proclivities, then the probability of two competent civilizations coinciding in time and making contact with each other becomes vanishingly small.

I am not sure that I would like being a scientist working on SETI. While the concept is fascinating, the likelihood that I will encounter extraterrestrial intelligent life in my lifetime is likely to be very low. To spend one's whole life on SETI research without a reasonable probability of finding it would probably be very discouraging. On the other hand, I believe that there is much that we can do in science that will have an impact on our world in our lifetime The 20th Century was really the century of physics where the boundaries of our world both in the subatomic and super-macroscopic sense expanded markedly. It was a century during which all our major theories concerning energy, matter, and the expanding universe became well-substantiated.

The 21st century is really the time for biology. After dispelling lingering doubts about evolution and how long humans have been on earth, and the development of molecular tools, we have begun to explore the nature and complexity of life on earth for the first time. In the past decade, we have decisively overturned the dogma that the adult central nervous system cannot regenerate or produce new neurons. We are now well on the way to discovering how to manipulate gene expression and stem cells so that this knowledge can be applied to repairing the central nervous system and restoring function. I tell my students that there has been no other time in human history like now, that whatever I teach them today will probably be untrue within a decade when they become practicing doctors, biologists, or neuroscientists.

Finally, regarding peace on earth, I saw a movie yesterday that stimulated a great deal of thought: "The Curse of the Golden Flower" (Source (http://indiefilm.meetup.com/166/calendar/5318299/)). On the surface, the movie was an depressing story of an emperor who battled his family for power. However, upon further thought, it is a very interesting exposition of the difference between the Eastern and Western cultures. As with several other movies made by Zhang Yimou (like Hero (http://www.heromovie.org/)), it carried a powerful message. That message is the same as the famous Borg phrase from Star Trek (Source (http://en.wikipedia.org/wiki/Resistance_is_futile)): "Resistance is futile." Unlike American movies that usually celebrate the victory of the individual over the system, Chinese movies often celebrate the victory of the system over the individual. "The Curse of the Gold Flower" suggests that sacrifice, bravery, lust, love, filial piety, and everything else that the individual feels and does are not only unimportant but irrelevant if that individual bucks the system. The system will crush the individual. Peace and order take precedence over the individual. Is this an acceptable price for peace?

Wise.

[rdf]

Thanks Wise, interesting ideas you write about.

As to the Drake Equation's solution being <1000, that is for our galaxy, I believe. When I said millions, I was referring to the Universe, not our galaxy alone. There are billions if not hundreds of billions of galaxies, so even if the Drake Equation's solution was one (1), well, you get the picture when considering all galaxies.

But distance causes problems, for sure, unless some have figured out how to fold space/time into a wormhole.

Or as I postured, there might be more to physics than we can now fathom, right before our very eyes, that we're not aware of at this point in our evolution...physics that would allow for space travel.

Maybe folks a thousand years from now will laugh at how sillily present-day humans viewed the universe's laws of physics(I'm sure there is still much we don't know or understand where physics are concerned)...and say, why didn't they just think of this, or that, or discover this, or that? Much like some may laugh today at sailors centuries ago worried about sailing off the edge of the ocean if they went too far west...

I could work for SETI, knowing full well the odds of finding any intelligent life or communication from an ET civilization would be worse than winning the lottery.

Probably much worse, but as they say, hope springs eternal :)

Happy New Year to Everbody, be safe.

[Mike C]

What has always been a big dilemma is the Fermi Paradox. That simple question of "Where are they?" continues to baffle.

From Wikipedia:

The Fermi paradox is a conflict between an argument of scale (http://en.wikipedia.org/wiki/Scale_%28spatial%29) and probability (http://en.wikipedia.org/wiki/Probability), and a lack of evidence (http://en.wikipedia.org/wiki/Evidence). A more complete definition (http://en.wikipedia.org/wiki/Definition) could be stated thus:

http://upload.wikimedia.org/wikipedia/commons/thumb/6/6b/Cquote1.png/20px-Cquote1.png (http://en.wikipedia.org/wiki/Image:Cquote1.png)
The size and age of the universe suggest that many technologically advanced extraterrestrial civilizations ought to exist. However, this belief seems logically inconsistent with the lack of observational evidence to support it. Either the initial assumption is incorrect and technologically advanced intelligent life is much rarer than believed, current observations are incomplete and human beings have not detected other civilizations yet, or search methodologies are flawed and incorrect indicators are being sought.
http://upload.wikimedia.org/wikipedia/commons/thumb/3/33/Cquote2.png/20px-Cquote2.png (http://en.wikipedia.org/wiki/Image:Cquote2.png)
The first aspect of the paradox, "the argument by scale", is a function of the raw numbers involved: there are an estimated 250 billion (2.5 x 1011 (http://en.wikipedia.org/wiki/1_E9)) stars in the Milky Way (http://en.wikipedia.org/wiki/Milky_Way) and 70 sextillion (7 x 1022 (http://en.wikipedia.org/wiki/1_E21)) in the visible universe.[2] (http://en.wikipedia.org/wiki/Fermi_paradox#_note-1) Even if intelligent life occurs on only a minuscule percentage of planets around these stars, there should still be a great number of civilizations extant in the Milky Way galaxy (http://en.wikipedia.org/wiki/Galaxy) alone. This argument also assumes the mediocrity principle (http://en.wikipedia.org/wiki/Mediocrity_principle), which states that Earth (http://en.wikipedia.org/wiki/Earth) is not special, but merely a typical planet (http://en.wikipedia.org/wiki/Planet), subject to the same laws, effects, and likely outcomes as any other world. Some estimates using the Drake equation (http://en.wikipedia.org/wiki/Drake_equation) (see below (http://en.wikipedia.org/wiki/Fermi_paradox#Drake_Equation)) support this argument, although the assumptions behind those calculations have themselves been challenged.
The second cornerstone of the Fermi paradox is a rejoinder to the argument by scale: given intelligent life's ability to overcome scarcity (http://en.wikipedia.org/wiki/Scarcity), and its tendency to colonize new habitats (http://en.wikipedia.org/wiki/Habitat_%28ecology%29), it seems likely that any advanced civilization would seek out new resources and colonize first their star system, and then surrounding star systems. As there is no evidence on Earth or anywhere else of attempted alien colonization (http://en.wikipedia.org/wiki/Colonization) after 13 billion years of the universe's history, either intelligent life is rare or assumptions about the general behavior of intelligent species are flawed.
Several writers have tried to estimate how fast an alien civilization (http://en.wikipedia.org/wiki/Alien_civilization) might spread through the galaxy. There have been estimates of anywhere from 5 million to 50 million years to colonize the entire galaxy; a relatively small amount of time on a geological scale (http://en.wikipedia.org/wiki/Geological_time), let alone a cosmological one (http://en.wikipedia.org/wiki/Timeline_of_the_Big_Bang).[3] (http://en.wikipedia.org/wiki/Fermi_paradox#_note-2) Even if colonization is impractical or undesirable to an alien civilization, large scale exploration of the galaxy is still possible; the means of exploration and theoretical probes involved are discussed extensively below (http://en.wikipedia.org/wiki/Fermi_paradox#Alien_constructs).



An extensive and interesting description about the Fermi Paradox is located here. (http://en.wikipedia.org/wiki/Fermi_paradox)

[Adrian]

http://www.guardian.co.uk/science/story/0,,1989475,00.html
Life on Earth may have announced its arrival billions of years ago
with a whistle and a thump, according to planetary scientists.
Experiments by an international team of researchers back a controversial theory that life flourished on Earth after primitive organisms arrived aboard a meteorite, itself gouged from Mars by a giant impact.



They gathered colonies of micro-organisms including cyanobacteria, which live in rocky fissures, lichen, which smother their surfaces, and spores of the hardy bacterium Bacillus subtilis, and sandwiched them between slices of gabbro, a coarse-grained rock similar to that known to make up Martian meteorites. The researchers then used high explosives to fire a steel plate at the sandwiched organisms and after each shot transferred the microbes to a dish to see if any had survived. The shocks were equivalent to those suffered by Martian meteorites that have been found on Earth, with pressures of up to 50 billion pascals.
To their surprise, the scientists found the lichen and bacterial spores survived all but the most cataclysmic impacts up to 45 billion pascals. The cyanobacteria survived shocks of up to 10 billion pascals.

The findings support the theory of "lithopanspermia", which suggests life may be spread from one planet to another aboard lumps of rock that are knocked off the surface. Writing in the journal Icarus, the scientists state: "These results strongly confirm the possibility of a 'direct transfer' scenario of 'lithopanspermia' for the route from Mars to Earth, or from any Mars-like planet to other habitable planets in the same stellar system."


As it says, this supports the possibility of panspermia but I am yet to be convinced that it supports the probability of it. Bio-genesis on a planet devoid of life is, by all accounts, very improbable and it seems just as improbable, and thus equally probable, that it occurred on Earth as it did on Mars. We know that life exists on Earth but we do not yet know for sure whether life has ever existed on Mars. If we can demonstrate the existence of life on Mars and use carbon-dating or another technique to demonstrate that life on Mars predated life on Earth I feel that would support the theory of its transfer to Earth rather than just supporting the possibility of transfer to Earth.

[Rbrauer]

Yes life is rather robust, but complex forms are less likely. (just an opinion)

Here on Earth we are lucky to have the moon. As the moon revolves around our planet so we exist. The moon creates our tides, as well as quakes. The Earth has an iron core, which the moon causes to rotate, creating a magnetic field. For us, that means a magnetic shield protecting us from severe radiation.

Mars would be nice, but with such a small moon, only a small magnetic field is generated. It would be possible to enlarge the size of a moon by carefully adding mass via asteroids. The issue then lies in, how much is enough? With to much mass it can cause catastrophic quakes to occure.

To manage the planet succesfully would be a great thing. Our problem would then continue to be one of an ever expanding population. It's time to move on.

[artsyguy1954]

rdf,

We humans ain't that shabby... :).

In the meantime, we have a lot yet to accomplish on this earth. We must learn how to live on this planet without destroying it. It would be nice if we learned how to cure spinal cord injury and other incurable conditions. It would be great if we learned how to live with each other without all the murder and mayhem. In all our history, we have yet to achieve "peace on earth and good will to all men." Maybe we can achieve these goals in our lifetime. Merry and Happy to you.

Wise.Excellent point.

[artsyguy1954]

The 21st century is really the time for biology. After dispelling lingering doubts about evolution and how long humans have been on earth, and the development of molecular tools, we have begun to explore the nature and complexity of life on earth for the first time. In the past decade, we have decisively overturned the dogma that the adult central nervous system cannot regenerate or produce new neurons. We are now well on the way to discovering how to manipulate gene expression and stem cells so that this knowledge can be applied to repairing the central nervous system and restoring function. I tell my students that there has been no other time in human history like now, that whatever I teach them today will probably be untrue within a decade when they become practicing doctors, biologists, or neuroscientists.

.
There is much to be done on earth yet without venturing out into space.

But it would be intriguing to touch base with a much more advanced civilization (not just technologically but also spiritually) in order to get a few pointers on how to get it right.:mega:

[rdf]

...But it would be intriguing to touch base with a much more advanced civilization (not just technologically but also spiritually) in order to get a few pointers on how to get it right.:mega:
Yeah, I agree...but they'd probably kill us or eat us before they missionaryized us :mega:

[Wise Young]

Yeah, I agree...but they'd probably kill us or eat us before they missionaryized us :mega:

Our first encounter with aliens may be our last. We are amongst the most intolerant, belligerant, and dangerous species on our world. To think that we or they would survive the first encounter is at best wishful thinking.

Wise.

[Lindox]

Our first encounter with aliens may be our last. We are amongst the most intolerant, belligerant, and dangerous species on our world. To think that we or they would survive the first encounter is at best wishful thinking.

Wise.

Why do we attribute human forms to alien lifeforms?
We can't naturally survive on other planets in our very own universe. Much less in other universes.

Why do we just assume there is no lifeform on say Jupiter? Because we can't see it? Or recognize it?

Just because it wasn't evolved from other species?
Why would we assume other lifeforms are anything like the lifeforms on Earth? Even giving them characteristics of humans..which did evolve from other lifeforms?

Is it possible the alien to us lifeforms are a higher purer form of life? Not in need of arms, legs, or even blood and guts? Possibly pure intellegent energy? So pure it can't be seen by the human eye or anything the human being has developed. And the human mind will not dare to imagine.

[adi chicago]

read this please
How to see and READ the AURA: Part 1




There is nothing “paranormal” in the Universe, except our limited understanding of Nature. What we think we “know” on Earth now is just a tiny drop in the Ocean of Knowledge.

In the distant past, people admired things they could not explain and called them “miracles”. Long ago, people were able to see Auras. Advanced spiritual people such as Buddha, Christ and their immediate students were painted with golden haloes around their heads, because some artists could actually see Auras. In Australia remote West Kimberleys you can find prehistoric cave paintings (bottom left), many thousands of years old, depicting people with golden haloes. (photo courtesy G.L.Walsh) Nature gave us ALL we need to see Auras. All is required is the knowledge how to use your senses together with your conscious effort. If you decide not to try, you will NEVER see the Aura. On the other hand, when you SEE something for yourself, no longer will you need to rely on believing someone. You will KNOW. And you can use your knowledge to learn more.

Many great people in the past complained that "we have eyes and we do not see". Further in this document you will discover what they meant.

ANYONE can see auras to some degree. Rather than create an aura of mystery around my newly acquired skill, my approach is to show everyone what their eyes are capable of. When nearly everyone (including children) sees a similar thing, I consider this a part of our Nature and I say that it deserves our attention.

This page summarizes the content of regular lecture-workshops on seeing and Reading Auras held by Dr. Tom J. Chalko. It was written to be BRIEF. For best results you need to refer to it from time to time. If you want to arrange workshop and have a group of people ready, please contact the author. You can also buy Dr Tom J. Chalko workshop notes (an expanded version of this document).

What is the Aura ?
Everything in the Universe seems to be just a vibration. Every atom, every part of an atom, every electron, every elementary “particle”, even our thoughts and consciousness are just vibrations. Hence, we may define the Aura as a electro-photonic vibration response of an object to some external excitation (such as an ambient light for example). This definition is sufficient for the purpose of reading Auras, providing that we can train ourselves to see the Aura vibration.

The most important property of the Aura seems to be the fact that it contains INFORMATION about the object.

Aura around living (conscious) objects (people, plants ...) changes with time, sometimes very quickly. Aura around non-living object (stones, crystals, water...) is essentially fixed, but can be changed by our conscious intent. Above facts have been observed by scientists in Russia, who have been using Kirlian effect to study Auras for the last 50 years.

The Aura around humans is partly composed from EM (electromagnetic) radiation, spanning from microwave, infrared (IR) to UV light. The low frequency microwave and infrared part of the spectrum (body heat) seems to be related to the low levels of the functioning of our body (DNA structure, metabolism, circulation etc.) whereas high frequency (UV part) is more related to our conscious activity such as thinking, creativity, intentions, sense of humor and emotions. Russian scientists, who seem to be about 3 decades ahead of everyone else in Aura research, make experiments suggesting that our DNA can be altered, by influencing its microwave Aura. The high frequency UV part is very important and most interesting but largely unexplored. And this part can be seen with naked eyes.

Why do we need to see auras ?
Colors and intensity of the aura, especially around and above the head have VERY special meanings. Watching someone's aura you can actually see the other person's thoughts before you hear them expressed verbally. If they do not agree with what this person is saying, you effectively see a lie every time. No one can lie in front of you undetected. We cannot fake the Aura. It shows our True Nature and intentions for everyone to see.

Also, aura is our spiritual signature. When you see a person with a bright, clean aura, you can be SURE that such person is good and spiritually advanced, even if he/she is modest and not aware of it. When you see a person with a gray or dark aura, you may be almost SURE, that such person has unclear intentions, regardless how impressive, eloquent, educated, "good looking" or "well dressed" he/she seems to appear.

It is ESPECIALLY important to check the aura of any religious leader, "spiritual teacher", "master" or a "guru". Such a person should have a clearly defined yellow-golden halo around the head. If he/she does not have it, you are MUCH better on your own.

Joining a sect or a religion that is led by incompetent people without good Auras is very dangerous for your consciousness. Where is the danger ? When the time comes to really use the information stored in your consciousness from this lifetime, there may be almost nothing useful there, if you focus your life on following rituals and the flock of other people. In such case it is necessary to re-learn everything from the beginning. Most sect, religion and political leaders have only two things in mind: money and power to control people. And you can SEE it in their Aura for yourself. Imagine changes on Earth if many people can see Auras of their leaders and start choosing them on the basis of their Auras.

By reading Aura it seems possible to diagnose malfunctions in the body (diseases) long before physical symptoms become evident. By consciously controlling your Aura you can actually heal yourself.

However, healing of the physical body is nothing in comparison to what seeing and reading auras can do for our consciousness, spiritual development and our awareness of Nature.

Everyone has an Aura. But most people on Earth have VERY WEAK and dull Auras. This seems to be a direct consequence of their life long materialistic attitude negating and suppressing the development of consciousness, cultivating fear, envy, jealousy and other similar emotions. Such attitude suppresses their True Nature, and their Auras seem to become suppressed too.

When you learn to see Auras, be prepared for a REALLY HARD question: “Can you tell me what my Aura is ?” and the situation when you don't see any Aura or you see something you don't want to talk about. One of the best answers I found is “why don't you learn to see it for yourself ? “. And this is one of the main reasons why I teach people to see auras.

When people realize that their Aura is on display and many people are able to see it, they will watch what they think. And they will try to see and improve their own Aura. In the process they will become better and wiser, being able to recognize intentions of other people. Surely, the entire world will become much better if all people can see and read Auras.

Children and the Aura:
Very young children (up to 5 years of age) see auras naturally. Infants frequently look ABOVE a person in front of them. When they don't like the color of the aura above the head, or if this color is much different from their parent's aura, they cry, no matter how much smiling the person does.

Children have much cleaner and stronger auras than most of adults, who are usually completely enslaved by the materialistic world and suppress their Nature by following superficial examples. When I taught my 12 year old son to see his own Aura, he told me that when he was little he was able to see Auras most of the time. But no one paid any attention, so he thought that it was not important and maybe there was something wrong with his eyesight. This is a typical scenario. In my opinion children should learn to see and read Auras in a primary school, so they never lose this natural ability.