Earth-like planets in our galactic neighborhood

Feb 16, 2009 by Jean-Louis Santini
Earth-like planets with life-sustaining conditions are spinning around stars in our galactic neighborhood, US astrophysicists say. They just haven't been found yet.

Earth-like planets with life-sustaining conditions are spinning around stars in our galactic neighborhood, US astrophysicists say. They just haven't been found yet.



Content from AFP expires 1 month after original publication date. For more information about AFP, please visit www.afp.com .

Explore further: Mysteries of space dust revealed

add to favorites email to friend print save as pdf

Related Stories

A guide to the 2014 Neptune opposition season

9 hours ago

Never seen Neptune? Now is a good time to try, as the outermost ice giant world reaches opposition this weekend at 14:00 Universal Time (UT) or 10:00 AM EDT on Friday, August 29th. This means that the distant ...

Spitzer telescope witnesses asteroid smashup

Aug 28, 2014

(Phys.org) —NASA's Spitzer Space Telescope has spotted an eruption of dust around a young star, possibly the result of a smashup between large asteroids. This type of collision can eventually lead to the ...

Light of life

Aug 27, 2014

A fluorescent microscopic view of cells from a type of bone cancer, being studied for a future trip to deep space – aiming to sharpen our understanding of the hazardous radiation prevailing out there.

Recommended for you

Mysteries of space dust revealed

4 hours ago

The first analysis of space dust collected by a special collector onboard NASA's Stardust mission and sent back to Earth for study in 2006 suggests the tiny specks open a door to studying the origins of the ...

Informing NASA's Asteroid Initiative: A citizen forum

Aug 28, 2014

In its history, the Earth has been repeatedly struck by asteroids, large chunks of rock from space that can cause considerable damage in a collision. Can we—or should we—try to protect Earth from potentially ...

Image: Rosetta's comet looms

Aug 28, 2014

Wow! Rosetta is getting ever-closer to its target comet by the day. This navigation camera shot from Aug. 23 shows that the spacecraft is so close to Comet 67P/Churyumov-Gerasimenko that it's difficult to ...

A salty, martian meteorite offers clues to habitability

Aug 28, 2014

Life as we know it requires energy of some sort to survive and thrive. For plants, that source of energy is the Sun. But there are some microbes that can survive using energy from chemical reactions. Some ...

User comments : 31

Adjust slider to filter visible comments by rank

Display comments: newest first

Arkaleus
3.5 / 5 (4) Feb 16, 2009
Science fiction authors have expected this for quite some time, but the universe may actually be more fecund and hospitable than they ever imagined. However, before we get all excited about it, we have to consider that life has been going on around us for quite some time, and there is a very good chance that civilization and intelligence has been going about its business for longer than ours has. We may be the country cousins of the central regions of the galaxy, which may have an established culture. I keep thinking of David Brin's books - his vision of earth meeting up with an already ancient galactic civilization may be spot-on. We really would benefit from a little galactic patronage. The systems of rule that govern today's world are incompetent to lead our species into maturity.
earls
3 / 5 (5) Feb 16, 2009
To assume that we are alone in the galaxy, let alone the Universe is a grandiose mistake and reeks of the ignorant self-importance many had when assuming the Earth was the center of the Universe. In many respects it's no different.

We are but an inevitable natural process of self-organization, there should be absolutely no reason to think we are unique in any way. The failure to seek out, identify, and contact extra-terrestrial beings in our local galactic neighborhood is not a fault of the Universe, but ours.
jonnyboy
1.8 / 5 (4) Feb 16, 2009
Alone in the galaxy?????????????????

We are alone on earth!!!!!!!!!!

We are always alone........so alone
Snowboarder
2.5 / 5 (4) Feb 17, 2009
Last I checked there were over 6.7 billion of us, so while we are vastly more intelligent than any other species on the planet, I think alone might be a bit of an overstatement. Don't worry though, I can guarantee that if there is a civilization out there that has a society which is significantly more advanced technologically than we are, they'll find us before we find them.
JerryPark
3 / 5 (5) Feb 17, 2009
Though there may be millions of life supporting planets, I wonder at the statement that there will be life on planets which are similar to the earth. We have no reason to make such a pronouncement. We have never found life anywhere except on earth. Therefore, we have no basis of expecting life anywhere except on earth.
CreepyD
3 / 5 (3) Feb 17, 2009
It always seems assumed that life needs water too, although I've noticed in documentries they are finally saying 'life as we know it' instead.
Also who's to say ET life would need Oxygen or even a certain temperature. It could be anywhere.
OckhamsRazor
2.3 / 5 (3) Feb 17, 2009
Though there may be millions of life supporting planets, I wonder at the statement that there will be life on planets which are similar to the earth. We have no reason to make such a pronouncement. We have never found life anywhere except on earth. Therefore, we have no basis of expecting life anywhere except on earth.


Are you saying based on that we shouldn't try? That would be profoundly stupid.
earls
3 / 5 (2) Feb 17, 2009
Yes, Jerry, because we've explored so many other planets.
smiffy
5 / 5 (2) Feb 17, 2009
That's right earls. Over nearly 60 years SETI and the like have scanned huge numbers of poential planets and have found zip.
Arkaleus
3 / 5 (2) Feb 17, 2009
I would be willing to wager that SETI is never going to find a RF signature of civilization. We assume far too much in searching for radio patterns similar to our own. We are a barely-emergent sentience with only a fundamental grasp on physics. RF communication would be impossibly slow for any galactic civilization. There may be unimaginably more effective methods of communication that galactic races may use.

Personally, I think we have a better chance of detecting civilization by searching for light sources. Artificial lighting might be detectable with sensitive enough space-based observatories.
smiffy
not rated yet Feb 17, 2009
I think that any incidental artificial light sources would probably be drowned out by the planet's sun. Beamed high frequency EMR probably stands the best chance of making any first communication. A form of Morse code from a powerful laser targetting selected solar systems for instance might be sufficiently robust and penetrating, but I'm not expecting that we will receive one.
By the way, my maths was bad in my previous post. I should have said 50, not 60, years for SETI operation.
earls
1 / 5 (1) Feb 17, 2009
smiffy, a "huge number" being 340 planets? ...The total number of current extra-solar _candidates_.

Of course you could rebuff me with "they scanned large swaths of the sky which surely must have contained millions of planets and heard nil..." Which is all fine and good except it doesn't account for a million variables. Regardless...

As Fermi put it...

"The size and age of the universe incline us to believe that many technologically advanced civilizations must exist. However, this belief seems logically inconsistent with our lack of observational evidence to support it. Either the initial assumption is incorrect and technologically advanced intelligent life is much rarer than we believe, our current observations are incomplete and we simply have not detected them yet, or our search methodologies are flawed and we are not searching for the correct indicators."

I'm easily inclined to believe the latter, but have fun with your half-empty glass.
nkalanaga
2.3 / 5 (3) Feb 17, 2009
Suppose they are out there, and simply aren't sending anything our way? There are many reasons for this, ranging from lack of interest (if all we have is radio we're not advanced enough for them) to paranoia (Hush! something nasty may be looking for us!). If everyone is listening, there wouldn't be anything to hear.

And even Earth's accidental emmisions are getting harder to detect. It's much harder to detect beamed communications than broadcast, as you have to be in the beam. Broadcast TV and radio leaks into space. Signals beamed to a satellite and broadcast to Earth don't, except for directly in line with the beam. Cellphones would be almost impossible to detect, as even from Mars they would simply look like noise.
smiffy
5 / 5 (2) Feb 18, 2009
Regardless of the reasons behind the silence from our galactic neighbours it is becoming more and more evident that the silence is not temporary. It's important to know why someone isn't talking to you - whether it's because they can't, they won't or because they're not there - but the continuing silence means we're unlikely to ever find out. Like the traveller in Walter de la Mare's poem, The Listeners, eventually we will have to haplessly give up. The 60's dream of a galaxy/universe teeming with interstellar civilisation has gone much the same way of many of that decade's dreams. Any further news, whichever way, of extraterrestrial life is bound to be disappointing. The conclusion to be drawn is that we're exceptional, and therefore exceptionally lucky to have what we have. Don't blow it.

I prefer to concentrate on what's in the bottom half of my half-empty glass, rather than the top half.
Modernmystic
1 / 5 (2) Feb 21, 2009
The evidence is mounting that complex, much less intelligent life, is exceedingly rare in the cosmos.

magpies
3.5 / 5 (6) Feb 22, 2009
Sometimes I think I am the only intelligent life on earth let alone the universe.
smiffy
5 / 5 (1) Feb 22, 2009
Sometimes I think I am the only intelligent life on earth let alone the universe
Ironically, that goes for all of us.
neurogalactus
4 / 5 (1) Feb 22, 2009
My 2 cents to the discussion:

For one, SETI is ridiculous in its gigantically optimistic - and foolish at the same time - assumptions that ANY star-faring civilization would use radio waves for long-distance communication. Here, long-distance means lightyears. Should you be unaware of this, let me note that there have already been a few physics papers on possible FTL communications technologies. We're still quite far yet, but the time for initiating relevant research is ripe. I can bet we'll have FTL comms within the next 20-40 years. Without violating Relativity, of course - just as relativity itself doesn't violate Newton's laws, only expands them within non-Newtonian regimes.

Secondly, let me be a bit nasty, and assume a somewhat twisted scenario: What if there are LOTS of Earth-like planets out there, but... 99% are already inhabited by advanced civilizations. :)
(after all, we, Terrans, are a relatively late addition to the Universe's fauna)

barkster
not rated yet Feb 22, 2009
What if there are LOTS of Earth-like planets out there, but... 99% are already inhabited by advanced civilizations.
If the other 99% are more advanced, we can assume they are richer than us. So... We should levy a tax against the other 99% and make them pay for our Earth "stablization" programs (and for keeping the human down)!
Ethelred
not rated yet Feb 23, 2009
(after all, we, Terrans, are a relatively late addition to the Universe's fauna)


Based on what? It took billions of years for life to even manage to stick one cell next to another and get them to specialize. For all we know specialized multicellular life is extremely unusual. Planets couldn't be more than balls of hydrogen and helium until there had been enough novas and especially supernovas. It may be that only solar systems that formed nearly as late as ours could support life at all much less complex life. Then there is the matter of cosmic disasters such as comets. That big Moon of ours may be needed for life to get started as soon as it did. It would explain why we have such a large moon if life needs one to develop before the sun gets to hot.

Sure would be nice to get some actual information. Soon I hope.

Ethelred
neurogalactus
not rated yet Feb 23, 2009
Based on what? It took billions of years for life to even manage to stick one cell next to another and get them to specialize.


Based on the fact that despite life evolution lasts around 5 billion years on an Earth-like planet, the Earth itself (exactly: our Solar system) is definetely not te oldest, so other similar yet much older systems had twice that time to generate life.

For all we know specialized multicellular life is extremely unusual.


Based on what?
Arkaleus
1 / 5 (1) Feb 23, 2009
I'l go out on a limb and state that all advanced races communicate via quantum entanglement. This is probably like telepathy - it occurs instantaneously because there is essentially no space between the two states. If intelligence is universal or at least compatible in all life, communication would likely be in a form that does not propigate - ie telepathy and entanglement.

The problem is we can't detect it yet.

It could also be that the evolutionary path for intelligence is steeper and more exotic than we have yet projected. Sentience may not spend much time in a corporeal state, but might zip right into another dimenion remarkable fast after attaining awareness. This would explain the mostly empty space we see - it is only a temporary garden for transiting species.
Ethelred
1 / 5 (1) Feb 23, 2009
so other similar yet much older systems had twice that time to generate life.


Not possible. Solar systems twice as old don't have the heavy elements needed for life. I pointed that out. Its very possible that only solar systems that started out around the same age of the Universe as ours have enough heavy elements for life. True a billion years here or there could have the galaxy teeming with intelligent life but we could also be the first technological civilization. Not likely perhaps but it would explain the lack of contact. Some species has to be first.

Keep in mind that it took 3.8 billion years for us to evolve and the Earth will not support life for billions of years more. Suns heat up over their lifetimes. The Earth really doesn't all that long (in comparison to how long life has existed)for another intelligent species to arise, if we wipe ourselves out.

Ethelred
Modernmystic
1 / 5 (1) Feb 23, 2009
so other similar yet much older systems had twice that time to generate life.


Not possible. Solar systems twice as old don't have the heavy elements needed for life. I pointed that out. Its very possible that only solar systems that started out around the same age of the Universe as ours have enough heavy elements for life. True a billion years here or there could have the galaxy teeming with intelligent life but we could also be the first technological civilization. Not likely perhaps but it would explain the lack of contact. Some species has to be first.

Keep in mind that it took 3.8 billion years for us to evolve and the Earth will not support life for billions of years more. Suns heat up over their lifetimes. The Earth really doesn't all that long (in comparison to how long life has existed)for another intelligent species to arise, if we wipe ourselves out.

Ethelred



Meaningless post...the solar systems in question don''t have to be anywhere near twice as old to yield technical civilizations. They only need to be a few to a few hundred million years older.

You guys really need to start giving up the proverbial ghost.

If complex life is not rare in the cosmos, then without doubt we should have seen evidence of it by now...we don't see ANY...AYWHERE. No matter how far we look out.

The Fermi Paradox is a bitch....

Couple it with the blatantly obvious and HUGE number of variables that simply must be taken into account by MODERN science (remember the Drake equation was written when our science was more primitive than it is now) in order for just complex life to arise, to say nothing of intelligence and you get a VERY dismal view of our prospects for discovering intelligent life in the cosmos.
Ethelred
not rated yet Feb 24, 2009
They only need to be a few to a few hundred million years older.


I am aware that a few thousand will do quite nicely. But that doesn't remove the meaning of my post as it was in response to a claim of billions. A few hundred million years from now the Earth will be uninhabitable according to present theory. As the Sun ages its temperature increases.

If complex life is not rare in the cosmos,


That's my point. I think it is likely to be very rare. Complex technological life that is. Complex technology as well as life is improbable at best in solar systems that are significantly older than ours. Not only that the time for intelligence to arise is almost always overestimated because people are unaware of the inherently rising temperature of suns. At least in suns similar to ours. Red dwarfs are another story.

, to say nothing of intelligence and you get a VERY dismal view of our prospects for discovering intelligent life in the cosmos.


Now that part of you post is something I suspect might be true. However we simply don't know enough yet to be sure. So far it looks as if space travel is far more difficult than it is in most science fiction. Rockets, chemical, atomic or even anti-matter, just won't do the job. The time it takes to go from one star to another is quite long even at 80% of the speed of light. Which seems to close to the most that can be obtained. For instance the atomic rockets in Heinlein's books couldn't have carried enough reaction mass to reach the velocities he had them doing.

My thinking is that if there are other civilizations they may still be close to their point of origin making communication unlikely unless they happen to be very close. Which is no fun for science fiction fans like me.

Ethelred
neurogalactus
not rated yet Feb 24, 2009
If complex life is not rare in the cosmos, then without doubt we should have seen evidence of it by now


Modernmystic, could you please tell me HOW could we "see" such evidence, and btw WHAT evidence do you have on mind?

If I recall well, these are the only reliable means through which we can confirm the existence of another civilization:

1. They visit us.
2. We visit them.
3. We receive AND decode their radio signal.
4. We detect "collateral" signatures of a likely technological civilization via high-resolution extrasolar imaging & spectroscopy.

Ad.1. Some say they've been visiting us, but don't reveal themselves blah blah etc. Effectively - they haven't. Forget it then.

Ad.2. We're not technologically advanced yet to even launch an expedition to Alpha Centauri.

Ad.3. RF communication is ridiculous - don't expect it to be widely used among civilizations at interstellar distances. It's easy to imagine say 15 technical civilizations within 50LY radius of Sol, out of which NONE uses RF for long-distance communication. It's not only a believable scenario - it's perfectly logical. RF sucks in this context. For that matter I can bet, here and now, we will have FTL communications by the year 2040. If I'm proven correct, it will have turned out that RF were a mere century as the primary means of communication. What is a century against a few thousand years? Against a few million? What is the chance one of those hypothetical 15 civilizations is exactly at that unique era (call it RF-era?)? Poor, IMHO.

Ad.4. Terrestrial Planet Finder, Planet Imager, and Life Finder are technologies of the future. Scheduled for 2025 in the best-case scenario; for 2040 in the worst-case scenario. These are devices designed to detect life signatures, and probably also deduce the existence of a technological society on the basis of chemical composition (which, btw, is VERY untrustworthy, as it assumes that every civilization out there uses combusion, hot-melting etc. that give familiar signatures - which might not be the case at all).

Also, I really advise you guys to read a bit about complexity, emergence, adaptive systems and life itself. The latest research shows that, for one, life as such must be slightly redefined against the old concepts thereof, and, secondly, it is an inevitable product of any chemically active environment. Whereever you have an environment that is chemically rich/diverse, and offers a certain degree of thermodynamical balance (=energy exchange cycles), complex adaptive systems WILL emerge. On top of that, life exhibits the tendency of increasing complexity over time, which means that complex organisms are a natural outcome of evolution, not a product of countless unexplainable "coincidences".

Ethelred, you wrote:
They only need to be a few to a few hundred million years older
, and this is very correct! In fact, it is a much stronger argument than mine (a few billion years). It means that many star systems of almost identical age, where the difference is in the millions, may start evolving life slightly sooner or later than other systems. Besides, we need to count in another factor, namely that due to the specific astronomic and planetary circumstances, life in same-age systems may evolve in different rates, and produce different degree of diversity. On top of that you have random natural disasters that may bring highly-evolved life back to its primordial state.

All in all, currently we have NO ways of telling how many civilizations may have evolved prior to ours, but common sense says that there may be quite a few. Another thing is our complete inability to discover them (unless, of course, you make some ridiculous assumptions in sort of RF comm etc, when you may claim otherwise).

smiffy
not rated yet Feb 24, 2009
Whereever you have an environment that is chemically rich/diverse, and offers a certain degree of thermodynamical balance (=energy exchange cycles), complex adaptive systems WILL emerge.
How do you know this?

I can bet, here and now, we will have FTL communications by the year 2040
.Your bet will not bring about FTL communication. In order to do that you must first overturn and rewrite all of our physics books. I'm looking forward to your papers. I'm also looking forward to your lab experiments because, short of quantum entanglement, there are no observed instances of any FTL phenomena in nature.

Assuming there are many advanced technological civilizations then it would only take one of them to engage in a programme to get in touch with other civilizations using amongst, other other techniqes, RF comms. Perhaps they just happen to be in a part of the sky that SETI haven't scrutinised yet?

Modernmystic
1 / 5 (1) Feb 24, 2009

Modernmystic, could you please tell me HOW could we "see" such evidence, and btw WHAT evidence do you have on mind?


Easily, any type II or type III civilizations engineering on a galactic level could easily be seen from huge distances. We simply don't see them. Dyson spheres etc etc.

Might want to do some reading on the subject.

If I recall well, these are the only reliable means through which we can confirm the existence of another civilization:

1. They visit us.


Of which there is not a single shred of credible evidence.
2. We visit them.


Not likely, since it's hardly proven that they exist to begin with....it's just an assumption.
3. We receive AND decode their radio signal.


Despite decades of listening, we haven't had any of those either.

4. We detect "collateral" signatures of a likely technological civilization via high-resolution extrasolar imaging & spectroscopy.


Almost a non-sequitur. We might be able to infer LIFE from spectroscopy, but any civilization out there is quite likely so FAR (and I do mean FAAARRRR) in advance of us that such means would be trivial. Their signature just by the "mundane" actions of their day to day activities should be apparent for a type II civilization within our galaxy, and should be apparent for a type III civilization outside our own galaxy.

Yet again, we see NOTHING, zero, zilch, nada....

Ad.3. RF communication is ridiculous - don't expect it to be widely used among civilizations at interstellar distances. It's easy to imagine say 15 technical civilizations within 50LY radius of Sol, out of which NONE uses RF for long-distance communication. It's not only a believable scenario - it's perfectly logical. RF sucks in this context. For that matter I can bet, here and now, we will have FTL communications by the year 2040. If I'm proven correct, it will have turned out that RF were a mere century as the primary means of communication. What is a century against a few thousand years? Against a few million? What is the chance one of those hypothetical 15 civilizations is exactly at that unique era (call it RF-era?)? Poor, IMHO.


And yet if there were such civilizations it would be ridiculously easy to put out a powerful enough RF signal for us dummies to hear, in fact some "crack pot" within the civilization would certainly be doing it trying to communicate with the "lesser" forms of life as a hobby. Moreover since it's so easy to do, it would be idiotic for them not to broadcast instructions on how to build FTL communications over an RF signal for millions of years to "speed up" the process once a civilization was capable of receiving them.

In essence, why make us wait until 2040??

Ad.4. Terrestrial Planet Finder, Planet Imager, and Life Finder are technologies of the future. Scheduled for 2025 in the best-case scenario; for 2040 in the worst-case scenario. These are devices designed to detect life signatures, and probably also deduce the existence of a technological society on the basis of chemical composition (which, btw, is VERY untrustworthy, as it assumes that every civilization out there uses combusion, hot-melting etc. that give familiar signatures - which might not be the case at all).


I'm excited for these missions, but not because I think they're going to find technological civilization, they're absolutely not. What they MIGHT find is many worlds on which some kind of life process is happening. This is their ONLY value. Any technological civilization out there would be blatantly obvious to us without the means of these sophisticated instruments....

They'd be engineering their own stars...we'd hardly be worried about detecting their greenhouse gas emissions in their atmosphere...

Also, I really advise you guys to read a bit about complexity, emergence, adaptive systems and life itself. The latest research shows that, for one, life as such must be slightly redefined against the old concepts thereof, and, secondly, it is an inevitable product of any chemically active environment. Whereever you have an environment that is chemically rich/diverse, and offers a certain degree of thermodynamical balance (=energy exchange cycles), complex adaptive systems WILL emerge.


Patently false. DNA, much less a living organism never been reproduced in a lab EVER (at leas not without an extant design to kick start it). Complex adaptive systems do not life make. When someone makes a single cell wholecloth in a very non specific, non tailored experiment I'll be impressed. Until then I'll remain extremely unimpressed with all this kind of work.

As long as we're recommending reading I suggest you read "Rare Earth".

On top of that, life exhibits the tendency of increasing complexity over time, which means that complex organisms are a natural outcome of evolution, not a product of countless unexplainable "coincidences".


Uh no. We didn't have multi-cellular organisms on this planet until VERY recently. In fact if anything it can be shown that single celled live STAGNATES horribly until some process changes that (read Cambrian explosion). In fact we BARELY caught our window. As someone pointed out (might have been you) we're only a few hundred million years away from extinction on this planet due to the sun's evolution. A lot of people think we have billions of years...we don't. We made it by the skin of our teeth.

In fact, it is a much stronger argument than mine (a few billion years). It means that many star systems of almost identical age, where the difference is in the millions, may start evolving life slightly sooner or later than other systems. Besides, we need to count in another factor, namely that due to the specific astronomic and planetary circumstances, life in same-age systems may evolve in different rates, and produce different degree of diversity. On top of that you have random natural disasters that may bring highly-evolved life back to its primordial state.


It's actually a VERY strong argument against your position. You just haven't thought it through...

All in all, currently we have NO ways of telling how many civilizations may have evolved prior to ours, but common sense says that there may be quite a few.


1. Yes we do have the means to detect them.

2. Common sense tells us that since we do have the means to detect highly advanced civilizations and haven't that they DON'T in fact exist.

Ethelred
5 / 5 (1) Feb 24, 2009
Patently false. DNA, much less a living organism never been reproduced in a lab EVER (at leas not without an extant design to kick start it).


Considering how little time and material a lab can work with and that DNA is not likely to have been part of the start of life I don't see that as meaning anything significant.

Complex adaptive systems do not life make.


Complex self-reproducing systems however do make life, even if the complexity is quite low. With or without cells. Demanding cells is a Creationist trick and they aren't needed until the self-reproducing stuff starts to feed on itself.

Uh no. We didn't have multi-cellular organisms on this planet until VERY recently. In fact if anything it can be shown that single celled live STAGNATES horribly until some process changes that (read Cambrian explosion).


There is reason to believe that the Earth was in deep freeze for a long time prior to the Cambrian explosion so it is entirely possible that the Earth is unique in that. I doubt it myself but it is possible. multicellular life did exist long before the Cambrian but it doesn't seem to have had much if any cell specialization. There is also the matter of it taking about two billion years for an oxygen atmosphere to fully develop. I figure that it should take at least that long for simple life to become complex on any planet. On ours it took a bit over 3 billion.

1. Yes we do have the means to detect them.


Only if they are very close. Dyson spheres are thermodynamically impractical and that is not counting the need for a material vastly stronger than diamond. Many possible interplanetary civilizations will NOT have an easily detectable signature.

I think technological life is likely rare but in no way do I see the Earth as inherently unique as I suspect you do. Its that religious tick you have shown in many of your posts about biology.
Modernmystic
1 / 5 (1) Feb 25, 2009
Considering how little time and material a lab can work with and that DNA is not likely to have been part of the start of life I don't see that as meaning anything significant.


Huh?

You might want to read up on abiogenesis. The commonly held thinking is "proteins, and nucleic acids first". You had to have a self replicating molecule like DNA in order to have life. This stuff is really "no brainer" and the basis of all currently accepted scientific thought on the matter.

http://en.wikiped..._of_life

Complex self-reproducing systems however do make life, even if the complexity is quite low. With or without cells. Demanding cells is a Creationist trick and they aren't needed until the self-reproducing stuff starts to feed on itself.


You just contradicted yourself, DNA is a self replicating molecule hence NEEDED in order for cells to arise according to your OWN logic. Check your premises and your own axioms because you have some serious contradictions in your thinking and arguments.

Demanding cells is not a Creationist trick either. Creationists think that there never was single celled life prior to multicellular life and that all organisms were created AS IS by God. You might want to check your definitions.

You're confusing Creationism with intelligent design...which is a common atheistic trick (or intentional deception in most cases).

Way to punch down that strawman though.

There is reason to believe that the Earth was in deep freeze for a long time prior to the Cambrian explosion so it is entirely possible that the Earth is unique in that. I doubt it myself but it is possible.


Well it's the only current way to explain the drop stones. I think that with the current knowledge we have it's the only rational explanation. Which means yet another hurtle/variable needed in order for complex life to develop.

multicellular life did exist long before the Cambrian but it doesn't seem to have had much if any cell specialization. There is also the matter of it taking about two billion years for an oxygen atmosphere to fully develop. I figure that it should take at least that long for simple life to become complex on any planet. On ours it took a bit over 3 billion.


Well it's a matter of debate as to whether or not colonies of single celled organisms constitute a multicellular organism. I tend to reject that notion. Reasonable people may disagree on this point though.

Only if they are very close. Dyson spheres are thermodynamically impractical and that is not counting the need for a material vastly stronger than diamond. Many possible interplanetary civilizations will NOT have an easily detectable signature.


Yes of course your right. They wouldn't be doing anything detectable using 1.22×10^34 J of energy per year. Silly me.

Honestly you really need to get a better grasp of the subject.

I think technological life is likely rare but in no way do I see the Earth as inherently unique as I suspect you do. Its that religious tick you have shown in many of your posts about biology.


As opposed to your atheistic tick? How is that better? We both hold in non falsifiable beliefs.

I don't think Earth like planets are rare. I don't think life is rare. I think that complex life is very rare, and I think that intelligent technological civilizations are EXCEEDINGLY rare....
Ethelred
5 / 5 (1) Feb 26, 2009
Huh?

You might want to read up on abiogenesis.


I have. Many times.

The commonly held thinking is "proteins, and nucleic acids first".


But not DNA for many anymore. RNA is far more likely. It can both code information and carry out the work of enzymes.

You had to have a self replicating molecule like DNA in order to have life.


I think that is impossible. I didn't think even RNA was likely to actually SELF replicate. And recent research has had RNA co-replicate or perhaps self-catalyze is a better term in the lab with the right chemicals. In fact YOU and I posted and argued here

http://www.physor...469.html

Just last month. Plus here are two other articles on RNA and bio-genesis

http://www.physor...714.html

http://www.physor...261.html

What was the matter with this site then. NO COMMENTS at all? Weird. Maybe they weren't allowed then.

That Wiki does cover RNA. You should have read it first. And a link to a RNA World Wiki.

http://en.wikiped...pothesis

I don't fully hold to RNA as the exclusive origin. Proteins could have been involved. THE most important structure in all cells is the Ribosomes which is not RNA nor protein but both.

Cool from that Wiki - Some of my suspicions confirmed. I am NOT full of it. Well not completely anyway.

'Other interesting discoveries demonstrating a role for RNA beyond a simple message or transfer molecule include the importance of small nuclear ribonucleoproteins (SnRNPs) in the processing of pre-mRNA and RNA editing and reverse transcription from RNA in Eukaryotes in the maintenance of telomeres in the telomerase reaction.'

That was at the bottom.

You just contradicted yourself, DNA is a self replicating molecule hence NEEDED in order for cells to arise according to your OWN logic.


False. DNA is NOT self-reproducing. It needs an enzyme polyemerase. Well it does in modern cells anyway. You do need to learn that your ignorance is not my contradiction.

Demanding cells is not a Creationist trick either.


Sure is popular with them. I have debated this before. Just a tad. In other forums.

You might want to check your definitions.


If they are MY definitions then I don't actually have to check them. Which isn't your point but I couldn't resist. However I do have a clue about what we are dealing with and it doesn't require DNA. Or cells. And yes Creationist DO bring them up. As part of a long list of things they claim must exist for life and then use the long list to generate astronomical numbers that are supposed to awe me and others. I guess you just don't have as much experience in knowing what Creationist like to do.

You're confusing Creationism with intelligent design...which is a common atheistic trick (or intentional deception in most cases).


Its not a trick. Its a Sony Rootkit. (signature of someone on Videohelp.com)

Inteligent Design IS creationism. Its just not Young Earth Creationism. That's not a trick, its simply true. Read up on the Dover Trial, I did mention it to you before. See that article I linked to.

Way to punch down that strawman though.


I love the smell of strawmen. That that burning cellulose smell. It smells like .... Like victory.

Not a strawman. Its simply that ID at present is largly a running dog for the Discovery Institute which is a Creationist institution dedicated to getting the Bible into public schools. See the Wedge Document.

http://en.wikiped...strategy

Which means yet another hurtle/variable needed in order for complex life to develop.


It looks like it was a hurdle on this planet anyway. Other planets mileage may vary.

Well it's a matter of debate as to whether or not colonies of single celled organisms constitute a multicellular organism. I tend to reject that notion. Reasonable people may disagree on this point though.


I tried to be reasonable but you forced me. I must mention

Sponges.

They are multicellular. They are not specialized. They cannot survive and reproduce except as a colony. However I suppose you could find reason to disagree. So

Portuguese Man-O-War. Three sets of single celled animals forming a single lifeform. I suspect that some edicarin life may have have had similar tricks. Course that is just spit wadding.

They wouldn't be doing anything detectable using 1.22×10^34 J of energy per year. Silly me.


That is why they are impractical. They looked cool until someone checked the thermodynamics, they have serious heat problem. See David Brin's last (for now anyway) Uplift War book where he has a possibly functional alternative to Dyson Spheres. They still have that need for some sort of Unobtanium stronger than diamond. If buildable they would be detectable as VERY large infrared emitters. Around the size of super giants but not detectable from the ground due to the low temperatures that would be needed to make them thermodynamically viable.


As opposed to your atheistic tick?


Ain't got one. I am Agnostic.

We both hold in non falsifiable beliefs.


I don't go in for beliefs. ID is non-falsifiable though. Not provable either.

I don't think Earth like planets are rare. I don't think life is rare. I think that complex life is very rare, and I think that intelligent technological civilizations are EXCEEDINGLY rare...


Horrors. We agree on something. I may think complex life is even rarer than you. The Moon is important for how the Earth developed and that is almost certainly rare. Based on how it believed to have formed.

Ethelred