Evolution News and Views Fails at Exoplanets Too

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Evolution News and Views noticed my previous post, and wrote a little reply. Unfortunately for them they completely missed the point, that Dembski claimed “Darwinists” were making stuff up, when there was good theoretical and (indirect) observational evidence to be confident that planets abounded in the galaxy.

The 55 Cnc system (excluding the outermost planet), 55 Cnc e is marked by the red cross near the sun. The 55 Cne system has features similar to our solar system.

Instead, they chose to focus on whether the planets we have found are habitable, which was beside the point [1]. Guillermo Gonzalez wrote a response for them, which included this:

The typical exoplanetary system is very different from our Solar System. Jovian planets are being discovered in very tight or highly eccentric orbits. Jovian planets in our Solar System are characterized by large nearly circular orbits. Our Solar System looks ever more like the exception, and it is exceptional in ways that are life friendly.

Distribution of orbital periods of the currently discovered exoplanets. The pink bars are “Super Jupiters” and the yellow bars are Jupiter-like planets in Jupiter period orbits.

Well, that’s sort of true, but deeply misleading. When we first started looking Super Jupiters were the norm. To explain why, and why this is no longer true, I’m going to digress for a moment to explain the main methods used to find exoplanets. The first is the radial velocity method. Here the slight wobbles produced in the position of a star by the gravitational tug of an orbiting planet are detected by Doppler shift.

In the transit method, the slight dimming in the stars light as the planet passes in front of it.

Naturally, the changes are very small, right at the limit of our ability to detect them. This means that bigger planets are easier to find than smaller ones, a big planet tugs more, and can block more light. Planets that are closer to their suns are also easier to find, big close worlds tug more, and can block more light.

Distribution of exoplanets distance from their suns. Red is “Hot Jupiters”, Green is multiplanet systems and blue is Jovian planets at Jovian orbits.

When we first found exoplanets, back in 1995, they were jaw-dropping hot super-Jupiters closer to their suns than Mercury and screaming around their suns in a handful of days! This was a big surprise, no one expected big planets to be that close. There were also lots of weird orbits (although some of these eccentric orbits turn out to be artifacts of the way multiple stars systems orbits sum up).

Finding solar systems like ours is rather difficult even given the limitations of the telescopes we are using (which will have great difficulty finding Earth sized worlds in the first place). For example, if you were looking at the Sun for Jupiter, you would have to watch for 12 years to detect it, and you would need to wait 24 years to confirm your detection. So it is no wonder that our explanet detections up until now have been dominated by massive planets orbiting closer to their suns then Mercury is to ours.

Now with Kepler, HARPS and MOST we are seeing a wider range of solar systems, although still biased away from Earth-like worlds and solar systems like our own you can see from the diagrams above that Super Jupiters no longer predominate, and we have more normal sized planets in more normal sized orbits predominating.

While the typical extasolar system is different from our own, with more Saturn and Neptune sized worlds (quite a few are closer in, but these are orbiting smaller suns, so their relative positions aren’t to far off), the way Dr. Gonzales has written his piece suggests that the typical extrasolar system is hot Jupiters in eccentric orbits. Which they are not.

We are still getting weird ones, like the planet where it rains pebbles, but even with the gross under-sampling of Earth-like worlds in the current surveys; of the 677 official and 1270 still to be confirmed planets, 54 are in the habitable zone, and 4 are Earth-like (although they are “super -Earths”). When you use these (grossly underestimated) figures to estimate the number of terrestrial worlds in their stars habitable zone (around stable, long lived stars) you get between 50 million to 50 billion habitable worlds depending on the assumptions you make.

If you take the low end estimate, and factor in habitable exomoons (shades of Avatar), then you get a figure of roughly 100 million habitable environments per galaxy which can now be used to come up with an estimate of habitable worlds in the visible universe. The number works out to 1018, or 10 million trillion.

I’ll let that number sink in a bit. Now, Dr.Gonzales has written that there is a lot of work going on understanding habitable zones, which there is, but he implies that it is all shrinking the habitable zones (which it isn’t). As well, some old constraints (like having a large Moon to stabilise a worlds orbit (which turn out to be relatively common) see to be less constraining than we thought, the abstracts on habitability from the extreme solar system conference).

Even with very conservative estimates, we still have more than enough worlds in the Habitable zones of stars of our Universe to make Dembski’s original statement false. As well, we have seen how once again the Discovery Institutes members try to distort facts. The DI still fails at exoplanets.

[1] The point in question was whether there was any theory of planetary formation at all which gave confidence that there would be large numbers of planets in the galaxy-universe as opposed to the proportion of planets that were habitable. No astronomer or evolutionary biologist ever suggested that all planet bearing stars had a planet in a habitable zone, but as far back as 1978 rough estimates of habitable planets came in at the 10 million mark for our galaxy.

(PS, NASA’s big announcement was a planet orbiting a binary star, a bit like Tatooine, if Tatooine was a frigid gas giant. It could have a habitable Moon though.)

(PPS, I’m an amateur astronomer, not a professional, but I have been using the STEREO spacecraft images to hunt for exoplanets. Boy, do I suck at it. Other teams have found an exoplanet using this system though. I’m also a member of the Planet Hunters and search the Kepler data for planetary candidates)

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NASA’s big announcement was a planet orbiting a binary star, a bit like Tatooine, if Tatooine was a frigid gas giant. It could have a habitable Moon though

Wow! Imagine what the skies on that would be like.

If intelligent life had evolved there imagine what their cosmological mythology would have been like! On Earth, at least, the only really weird things happening in the sky were some tiny, wandering planets and the occasional eclipse, which could be easily dismissed as the work of a giant snake.

Thanks Ian! I generally follow the exoplanet stuff but clearly I need to add your astroblog to my blogroll… Also, I never get why IDists are so skeptical of extrasolar life. They say they like the anthropic arguments, i.e. the Universe is designed to support life.* If this argument makes any sense at all, it ought to predict that life is common rather than rare.

(* Actually, these arguments, before the ID movement got hold of them, were about how the Universe was set up just-so so that life could slowly, gradually, naturally evolve. If you’re just going to supernaturally create life, there’s no real need for a long, slow evolution of the Universe. You might as well just supernaturally create the sun and Earth and ignore the rest of it.)

I have a close peripheral interest in this stuff also. One of my former students got her PhD studying with David Charbonneau at the Harvard-Smithsonian Center for Astrophysics. She is now an assistant professor at Cal Tech.

Just to indicate how active this field is, she had 35 publications in this area before she completed her PhD.

Another of my former students studied at Princeton, Cambridge, and got her PhD with Marc Kamionkowski at Cal Tech, and she is now at the Perimeter Institute In Waterloo, Ontario.

As to the thermodynamics of solar system formation; highly elliptical orbits are indicators of young systems, and circular orbits are indicators of older systems. The reason for this is because you can write the equations of motion for an orbiting body in terms of a “centrifugal potential” plus the gravitational potential. This gives a potential energy in the radial direction of the form

(1/2) L2/mr2 - GMm/r

where L is the angular momentum of the orbiting body, and r is the radial distance between the centers of the masses M and m.

This potential has a minimum at a fixed distance between the masses; i.e., for a circular orbit.

So thermodynamically, orbiting bodies are losing energy through collisions with orbiting debris, by friction caused by periodic gravitational tidal distortions that are large for highly elliptical orbits, and by the heat radiated as a result of such collisions and tidal forces.

Thus, another thing that makes younger systems more visible with current technology is that they are radiating lots of energy in the infrared as well as the visible. Objects with lose-in, highly elliptical orbits are radiating far more energy than are farther-out objects that are small and in circular orbits.

Older solar systems are going to be much harder to find and observe because they are already settled in close their lowest energy state.

Nick Matzke said: I never get why IDists are so skeptical of extrasolar life. They say they like the anthropic arguments, i.e. the Universe is designed to support life.* If this argument makes any sense at all, it ought to predict that life is common rather than rare.

It’s a weird form of geocentrism. What’s the point of having a magic Designer unless he uniquely cares about Earth? We’re special! If the Designer impersonally does his magic all over the universe, then we mean nothing to him and he might as well be a law of nature.

Also, I never get why IDists are so skeptical of extrasolar life. They say they like the anthropic arguments, i.e. the Universe is designed to support life.* If this argument makes any sense at all, it ought to predict that life is common rather than rare.

As SC implies, this is purely to do with the religious belief that human beings are uniquely made in the image of God. While I have no doubt that Christianity (and most other religions) would have no trouble surviving the discovery of extraterrestrial life, they will continue to fight tooth and claw to deny the possibility until the very last moment.

I mean, they cannot seriously deny that the current, highly skewed sampling of exoplanets is a terrible predictor for the number of Earth-like planets we will eventually find, and yet they do. And it is a bit bizarre that they do, since the argument that life itself could be extremely rare is not outside the realm of scientific plausibility, even if there are billions of Earth-twins out there.

Lemme get this straight: The DI’s Michael Medved is convinced that Bigfoot is somewhere on our own planet, and we just haven’t found him yet (presumably because those “scientists” who try are always “expelled”). And the DI has no problem with that. At least in public.

Duhh… of course they have no problem with Bigfoot, and of course he’s hard to find. He’s a demon, just like the pilots of UFOs!

I never get why IDists are so skeptical of extrasolar life.

Lack of evidence, perhaps?

This latest posting by Gonzales in support of Mr. Dumbski is pure unadulterated rubbish. What Prof. Gonzales is basically saying is that we haven’t found solar systems so far that resemble our own, therefore it is unlikely that they exist. The fact is that an observer on a planet circling a star 30 light years away would not be able to detect the planetary system of the Sun, or any of the planets therein, using the best equipment that we currently have available. I would be willing to wager that, in a few years when the more sensitive instrumentation is developed, we will detect exo-planetary systems that resemble our own and, in addition, earth-like planets and/or moons in the habitable zones.

The question is not whether there is life elsewhere in the universe. Given that most stars, at least the single ones, have planets orbiting around them, just by the law of large numbers the probability that life exists elsewhere is very close to 100%.

The issue as to whether there is intelligent life elsewhere in the universe is a much tougher question. This issue rests on the question as to whether the evolution of intelligence is inevitable, due to a selection advantage, once the first replicators appear. As I have argued previously on this site, an argument can be made that increases in encephalization factors, which is a necessary condition for intelligence, appears to have a selective advantage. The evidence is that the Cretaceous dinosaurs had larger encephalization factors then did their Jurassic forbears and today’s mammals have larger encephalization factors then their forbears of 50 million years ago. I would note, however, that this is a necessary condition and is not necessarily sufficient, based on a sample of 1.

In this regard, there was an interesting debate which took place sometime in the early 1990s between Carl Sagan and Ernst Mayr on the topic of intelligence, with Sagan arguing that intelligent life was widespread in the universe while Mayr arguing that it was rather rare. One can use Google to find links to the debate. As we sit here today, IMHO, the question is open.

Nick Matzke said -

Also, I never get why IDists are so skeptical of extrasolar life

They are NOT “skeptical” of it.

They dogmatically and unreasonably deny that it could ever be possible. That is NOT a skeptical attitude, it is a close-minded, dogmatic attitude.

I take a skeptical view of extraterrestrial life. That most certainly does not mean that I deny the possibility. Such a dogmatic denial would be absurd. It means that I am able to discuss the issue in an objective, evidence-based way.

In a very concrete way, FL is actually “right” immediately above. We currently have no definitive evidence of extraterrestrial life. There is a strong predisposition toward finding it intuitively credible that there are many earth-like planets, and much life, within much of the scientific community. That is not the same thing as definitive evidence.

However, if there were evidence, FL would deny it. He has bothered to make his obsessively concrete authoritarian dogma dependent on yet one more potentially testable question. His dogma is already false because the universe is more than 6000 years old, because life evolves, because there was no global flood, because Noah’s ark can’t be literally true even if a global flood were possible, etc, etc. Now he has added to that list. His dogma now also states that there can never be any discovery of or evidence for extra-terrestrial life. This is not a “skeptical” attitude. In fact, it is a completely evidence-independent attitude.

As to why they deny the possibility, there’s probably some decades old obsessive political or social bugbear behind it. It could be an anti-Mormon thing, as Mormon theology includes life on other planets.

FL said:

I never get why IDists are so skeptical of extrasolar life.

Lack of evidence, perhaps?

So where’s the evidence that God magically poofed the world into existence only 10,000 years ago?

Where’s the evidence that God killed all life outside of Noah’s Ark 4,000 years ago?

It should be no surprise that FL would lift a partial sentence out of context and miss Nick Matzke’s entire point.

Most of the natural philosophers in the seventeenth century accepted the doctrine of the plurality of worlds. For example John Wilkins, 1614-72 published his Discovery of a New World in the Moone in 1638, and A Discourse concerning a New Planet in 1640.

Wilkins was a Puritan clergyman (Calvinist); and he rejected the practice of interpreting the scriptures literally. He believed that there was a maximum diversity of beings. He wrote:

“There may be other Species of Creatures beside those that are already known in the World. ‘Tis not Improbable that God might create some of all Kinds, that so he might more Completely Glorifie himself in the Works of his Power and Wisdom.”

Fundamentalist demands for literal (theirs) interpretation of their bible flies in the face of much of the history of the Christian religion. Many people in the past have used scripture to justify their speculations about life on other worlds.

Furthermore, FL’s assertion of “no evidence” completely ignores what we already know about matter. Just because he refuses to learn any of it doesn’t cancel out the fact that it all points to the possibility of life existing many places in the universe.

FL said:

I never get why IDists are so skeptical of extrasolar life.

Lack of evidence, perhaps?

If they applied this principle consistently and conscientiously then they might be worthy of respect.

FL said:

I never get why IDists are so skeptical of extrasolar life.

Lack of evidence, perhaps?

They’ll get used to it just like they got used to the fact that the earth is a sphere and moves

Chris Lawson said:

FL said:

I never get why IDists are so skeptical of extrasolar life.

Lack of evidence, perhaps?

If they applied this principle consistently and conscientiously then they might be worthy of respect.

Too bad there are two sides to a balance sheet.

Duhh… of course they have no problem with Bigfoot, and of course he’s hard to find. He’s a demon, just like the pilots of UFOs!

Or worse, he’s a Darwinist!

SLC said:

This latest posting by Gonzales in support of Mr. Dumbski is pure unadulterated rubbish. What Prof. Gonzales is basically saying is that we haven’t found solar systems so far that resemble our own, therefore it is unlikely that they exist.

See, the problem is that the fundie version of God is rather retarded (for a god). He can only create and be interested in one tiny planet with life. And really only one species thereon, and actually only members of a certain church (theirs). The rest he just burns up in hell. Fundie Jehovah can only handle a few sentient beings at a time.

In this regard, there was an interesting debate which took place sometime in the early 1990s between Carl Sagan and Ernst Mayr on the topic of intelligence, with Sagan arguing that intelligent life was widespread in the universe while Mayr arguing that it was rather rare.

One of the most compelling arguments from Sagan’s COSMOS is that we don’t know yet whether technological-level intelligence is adaptive in the long term or not. We are the only species that has put into its own hands the power to completely destroy itself, intentionally or accidentally. We have a propensity for wiping out large segments of our fellow humans, and even religions that devoutly wish for the end of the world.

We don’t know how useful for survival intelligence is yet. The experiment hasn’t run long enough.

SLC said -

In this regard, there was an interesting debate which took place sometime in the early 1990s between Carl Sagan and Ernst Mayr on the topic of intelligence, with Sagan arguing that intelligent life was widespread in the universe while Mayr arguing that it was rather rare. One can use Google to find links to the debate. As we sit here today, IMHO, the question is open.

I am a huge admirer of Carl Sagan. He was a humane, patient, articulate, extremely accurate public advocate of science. He had the ability to present science to the general public without either oversimplifying, or intimidating.

Having said that, as an informed amateur who looks at the question of abiogenesis from a mainly biomedical perspective, I sometimes feel that those who come at it from an almost exclusively physical sciences background tend to gloss over some issues.

First let’s talk about “LIFE”.

I don’t have or pretend to have an absolutely perfect definition of “life”. However, for the pursuit of biomedical science on earth, I have an extremely well-understood implied, operational definition. What we call “life” on earth is cellular life. Also, although we debate whether viruses are alive, we clearly include the study of viruses as part of the biomedical sciences. And all currently known viruses are parasitic on cellular life, and either evolved from cells, or are indistinguishable from entities that could have evolved from cells. (And there are stripped down bacteria that can be intracellular pathogens of eukaryotic cells and present a possible model of one way viruses might have evolved, e.g. http://microbewiki.kenyon.edu/index[…]p/Mycoplasma.)

Free-living cellular life on earth virtually always has at least the following features - cellular membrane with more than one lipid layer and protein components, some ability to regulate intracellular ionic concentrations relative to extracellular, cytoskeleton, all the components for DNA replication/transcription/translation (that is, all required enzymes, DNA, mRNA, tRNA, and ribosomes), and a preference for L-amino acids.

Current terrestrial abiogenesis seems to unequivocally have a focus on self-replicating molecules in solution. There also appears to be some activity with regard to origin of membranes and cell compartments, e.g. http://www.ncbi.nlm.nih.gov/pubmed/21630138

Still, terrestrial abiogenesis should be regarded as an active field; a clear model of the origin of a cell with the characteristics all modern cells remains a long term goal.

Lacking such a model raises the intriguing question of what we would define as life. Are the invariant features of modern cells inevitable or necessary for sustainable life? Or could things have happened very differently somewhere else, and how much as to be the same before we recognize “life”.

Now let’s talk about “INTELLIGENCE”

The majority of the biosphere consists of plants or microbes, entities which we do not conceptualize as having “intelligence”.

Within metazoans, we currently tend to recognize only some relatively big-brained mammalian species, and some birds, as “intelligent”. The big-brained mammals are all very recent species and lineages. Birds and their dinosaur ancestors occurred much earlier, but still fairly late in the history of life. Certainly it’s hard to contend that there is any case to be made for intelligence on earth before the most recent 5% or so of life’s history on earth (or before ~ 3.5-3.8 billion years of life had passed, to put it another way).

What is the relationship of “intelligence” to life? Does it invariably emerge where something we would call life is present?

A lot of hard questions, in my opinion.

Just Bob -

See, the problem is that the fundie version of God is rather retarded (for a god). He can only create and be interested in one tiny planet with life. And really only one species thereon, and actually only members of a certain church (theirs). The rest he just burns up in hell. Fundie Jehovah can only handle a few sentient beings at a time.

As I noted on another thread, what makes the creationist God so lame-ass is that he has to take orders from creationists.

1) He got one chance to create Adam and Eve, have them populate the planet, then flood the planet and kill everyone but Noah and his family, and so on, and to inspire bronze-age and iron-age figures to create ambivalent and contradictory narratives. But he only got THAT ONE chance. He is not now permitted to correct, suggest interpretations, change his mind, etc. As FL and the gang repeatedly point out, the Bible is now locked in forever (that’s its big advantage over “changeable” science). God has to butt out. He had his moment, and it’s over.

2) Any actions God takes in the modern world are apparently nothing more than responses to fundamentalist prayers or fundamentalist wishes. He’s restricted to things like causing certain high school football teams to win (even if both teams pray to Him, but I guess one team always prays better), striking Texas and Louisiana with disasters to protest the behavior of liberals in other places, and miraculously healing a very tiny proportion of the sick people who pray to him.

God doesn’t rule them; in their minds they rule God.

I’d better make the clarifying statement - I am not religious.

Mike: that’s interesting, about the age of solar systems and orbits. Does that also indicate why the furthest bodies in our system are still in highly elliptical paths?

Just Bob said:

SLC said:

This latest posting by Gonzales in support of Mr. Dumbski is pure unadulterated rubbish. What Prof. Gonzales is basically saying is that we haven’t found solar systems so far that resemble our own, therefore it is unlikely that they exist.

See, the problem is that the fundie version of God is rather retarded (for a god). He can only create and be interested in one tiny planet with life. And really only one species thereon, and actually only members of a certain church (theirs). The rest he just burns up in hell. Fundie Jehovah can only handle a few sentient beings at a time.

harold said:

Just Bob -

As I noted on another thread, what makes the creationist God so lame-ass is that he has to take orders from creationists.

God doesn’t rule them; in their minds they rule God.

The common thread is that the problem of anti-evolutionists and fundamentalist literalists is their total failure of imagination; everything must be limited to what THEY know and understand. Whether it’s how many Earth-like planets exist in the galaxy or what God supposedly did and how, their understanding of it is the final say. This applies to evolution, too: whatever their misunderstandings become the limits of the whole science to them. They don’t understand the power of selection acting on variation, so it must not be that powerful a force. They think evolution demands literal lizards with fully-formed chicken wings, so no Dawrinist is going to tell them that it doesn’t. Politically they tend to fall along authoritarian lines because it means that there really is only one right way to run a country, their own vision of it (whichever vision that happens to be).

Everybody is afflicted with this on some subjects and to varying degrees generally, but it seems to exist in overabundance in the kind of people that become anti-evolutionists. Gonzalez’s problem with the discovery of planet types is not a simple slip-up that he “should” have caught, I think it’s the result of a deep-seated way of thinking about the world. One of the problems that seems to crop up as a result is a more pronounced difficulty in accepting change. If things are limited to the narrow ways you imagine them to be, change requires that things aren’t so limited and that you can accept these differences. While I’d expect the average person on the street (even the average PTer) to still think Hot Jupiters dominate the planets we’ve discovered, someone working in Gonzalez’s field has less excuse. Perhaps that condition fit neatly with his preconceived ideas about the specialness of Earth, and so he wasn’t allowing himself to keep up with progress in a way that changed his view.

-Wheels

ksplawn said:

Mike: that’s interesting, about the age of solar systems and orbits. Does that also indicate why the furthest bodies in our system are still in highly elliptical paths?

-Wheels

The concentrations of material during the earlier stages of solar system evolution will be higher closer in to the star. Thus, for matter clumping to form planets in these regions, there are far more collisions among debris that remove energy and momentum from clumping matter.

This, in turn, means that the material in the far outer reaches of the system will not have clumped as much. Thus, well after the system has settled down into nearly circular orbits and much of the debris has been swept up by the formation of planets, any object that gets gravitationally perturbed into an orbit that takes it into the inner parts of the solar system will have a highly elliptical orbit. And that object is less likely to encounter smaller objects that will collide with it and extract energy from it.

Therefore such remaining objects in highly elliptical orbits will likely remain in such orbits for much longer, unless they collide with one of the already well-formed planets (e.g., the collision of comet Shoemaker-Levy with Jupiter in 1994).

But once a system has settled into circular orbits, the probabilities for further collisions continues to drop as these perturbed objects get swept up by the inner planets.

While I’d expect the average person on the street (even the average PTer) to still think Hot Jupiters dominate the planets we’ve discovered, someone working in Gonzalez’s field has less excuse. Perhaps that condition fit neatly with his preconceived ideas about the specialness of Earth, and so he wasn’t allowing himself to keep up with progress in a way that changed his view.

Guillermo Gonzalez definitely has no excuse.

I had the impression all along that a lot of people at Iowa State were cringing at some of Gonzalez’s pretenses during his pre-tenure trial period there.

Thanks for your comment, and for the link to those conference abstracts.

Mike: that’s interesting, about the age of solar systems and orbits. Does that also indicate why the furthest bodies in our system are still in highly elliptical paths?

I wonder if tidal friction would be a factor in that?

Henry

I won’t add much to the conversation here other than to say that this comments thread has been an enjoyable primer on exoplanets. Thanks for doing what you do here.

harold said:

Free-living cellular life on earth virtually always has at least the following features… all required enzymes, DNA, mRNA, tRNA, and ribosomes…

Note to fundies: This is what good writing in the sciences looks like. Notice the qualifier virtually. Real scientists are careful to avoid absolutes when they’re not always absolutely true. (For an example of crappy science writing, see some of the grandiose and easily punctured absolutes propounded by one we won’t name here [cue Mr. Mnemonic: atheistoclast]).

Note to harold: Do red blood cells contain DNA after they have expelled their nuclei and become functional oxygen carriers? Even if they don’t, I suspect you’d count them as “alive”. Maybe they’d fall outside that “virtually”.

harold said: Any actions God takes in the modern world are apparently nothing more than responses to fundamentalist prayers or fundamentalist wishes.

Not always - look what happened to Texas after Rick Perry asked all Texans to pray for rain: They not only got no rain - God is letting Texas burn as an answer to their prayers for rain.

As I noted on another thread, what makes the creationist God so lame-ass is that he has to take orders from creationists.

They do like to keep their god on a short leash.

I like to imagine that there are other intelligent beings out there on other planets wondering if they are alone in the universe.

Paul Burnett said:

harold said: Any actions God takes in the modern world are apparently nothing more than responses to fundamentalist prayers or fundamentalist wishes.

Not always - look what happened to Texas after Rick Perry asked all Texans to pray for rain: They not only got no rain - God is letting Texas burn as an answer to their prayers for rain.

No, the fires are divine punishment for having slashed funding for volunteer firefighters.

Note to harold: Do red blood cells contain DNA after they have expelled their nuclei and become functional oxygen carriers? Even if they don’t, I suspect you’d count them as “alive”. Maybe they’d fall outside that “virtually”.

Can they metabolize incoming nutrients to make proteins? That strikes me as a major factor in deciding if something is alive or not. (Perhaps more important than whether the something is a cell or not?)

Henry

I like to imagine that there are other intelligent beings out there on other planets wondering if they are alone in the universe.

That reminds me of this:

“Beam me up, Scotty, there’s no intelligent life down here!”

Paul Burnett said:

harold said: Any actions God takes in the modern world are apparently nothing more than responses to fundamentalist prayers or fundamentalist wishes.

Not always - look what happened to Texas after Rick Perry asked all Texans to pray for rain: They not only got no rain - God is letting Texas burn as an answer to their prayers for rain.

As an Austin ex-pat (and someone who sill owns a house there) I’ve been keeping a keen eye out on the Texas weather.

These day’s it seems like not only has God answered Rick, but disturbingly, He seems to be sending a message of His own.

Look at this graphic from the NDMC last week, and tell me it’s not personal.

Heck, it’s so bad in Texas that even the oysters are dying.

In the bay.

Under the water.

Or, if you’re the type to add insult to injury, how about a view of the Bastrop fires from space.

Note how the dividing line between parched brown and verdant green aligns suspiciously well with the Louisiana border.

I don’t care what pat Robertson says. I think those folks down in Naw’ Orleans have more pull with the Big Guy than he thinks.

Apparently, more pull than Rick has, anyway.

Mercifully, after a record shattering 105 days above 100 degrees (the previous record was 70 or so, and when I first moved there in 1999, we averaged about 25) anyway, after 105 days, a third of a year, the weather has finally started to break a bit.

I’m told that Austin has some cloud cover this weekend, and there is actually a chance of a little dribble of rain that will make it all the way to the ground without giving up and going home.

Personally, I think the likely explanation is that God likes good music as much as anyone and decided to take some mercy on the ACL festival this weekend.

Just Bob -

Note to harold: Do red blood cells contain DNA after they have expelled their nuclei and become functional oxygen carriers? Even if they don’t, I suspect you’d count them as “alive”. Maybe they’d fall outside that “virtually”.

Great question. I’m pretty sure I put the term “free living” cells somewhere in my comment, by the way.

The answers are interesting -

1) All of the bone marrow precursors to RBC’s in humans are nucleated - nuclear extrusion is a last step before circulation. For all of their development until the terminal differentiation, they have the elements of cells I mentioned. Nucleated RBC precursors will circulate in a variety of pathological conditions.

2) Human normal RBC’s are arguably no longer cells - they are somewhat short-lived membrane-bound bags of hemoglobin, for the most part (they do last an average of 120 days in a healthy human). But of course, that’s semantic, and we call them cells.

3) The DO contain initially contain anachronistic cytoplasmic RNA, left over from their days of having a nucleus, gene expression, and protein synthesis. This RNA degrades over time (this takes about a day). You can do an old-timey stain on a blood smear (methylene blue) that by good fortune happens to stain RNA. Even before it was 100% clear what was being stained, it was recognized that “reticulocytes” were young RBC’s. http://en.wikipedia.org/wiki/Reticulocyte This is useful, because someone who has normal bone marrow but is “hemolyzing” (body destroying RBCs too quickly - common part of many conditions) will have more young RBCs as the marrow compensates (average life span of RBC is lower, so greater percentage will be retics). “Retic count” is a rather ancient test, but it’s dirt cheap and easy, and a “high retic count” is extremely strong evidence, in many appropriate contexts, of marrow response to hemolysis or other cause of loss of RBCs.

4) All mammals have enucleated RBCs (I’ve heard that the camel/llama group don’t, although even if this is true, they would have evolved from a common ancestor that did), although they don’t all have the same anatomy as in humans http://en.wikipedia.org/wiki/Red_bl[…]erythrocytes. Birds famously do have nuclei in their RBCs. Presumably so do reptiles, but since there are many domestic birds and few domestic reptiles, examination of bird blood is much more common.

Paul Burnett said:

harold said: Any actions God takes in the modern world are apparently nothing more than responses to fundamentalist prayers or fundamentalist wishes.

Not always - look what happened to Texas after Rick Perry asked all Texans to pray for rain: They not only got no rain - God is letting Texas burn as an answer to their prayers for rain.

I know that you know my comment was satirical, and you know that I know that your comment is satirical.

However, even the broadest sarcasm/satire is dangerous on the internet. Purely for the sake of lurkers, I will discuss this issue.

I recently got a good explanation of why (this had puzzled me for years). Someone explained in a thread that they don’t have the ability to recognize satire or sarcasm from verbal content alone; apparently a fair number of people can “get” sarcasm via voice tone but literally can’t recognize it from purely verbal cues. This does not seem to correlate much with overall academic ability; I’m sure it impacts on some types of high level analysis, but fairly educated people tend to have this problem.

Interesting, since so much writing is satirical in nature, but of course, back in the pre-internet era, there was a great deal of self-selection. Undoubtedly, people who knew that they couldn’t tell whether, say, Mark Twain was joking or being serious, simply didn’t bother to read Mark Twain. But on the internet, everybody has to read and write. A common heuristic seems to be to assume that everything means exactly what it says at face value. (NOTE - this does not seem to be related strongly to the authoritarian/obsessive/combative/inability-to-tolerate-any-criticism creationist personality either. Creationists, in fact, use crude but purely verbal sarcasm and satire all the time.)

The number of habitable planets could be even higher with a factor of two or so, in our galaxy up to ~ 2*1010 perhaps.

It is still abysmal statistics, but by microlensing it has been estimated that for every bound (orbiting) planet there is an unbound that has been ejected. This is supported by modern models of planetary systems, AFAIK. Many of those wanderers would have moons with Europa style gravitationally heated habitable ice covered oceans with lifetimes well enough to establish life.

As for “shrinking the habitable zones”, the shrinking is on the concept.

- Solar habitable zones are made problematic by the found dynamics of planetary systems. Planets migrate, they have elliptical orbits that take them in and out of the zone, we are starting to look at atmospheric effects.

The habitable zone concept is a first order tool to estimate statistics of habitables and to focus on habitable targets. That it would be modified with expected (atmospheres) and unexpected (high eccentricities) effects is an expected development.

That it must be replaced by a tool that consider dynamics was not.

- Galactic habitable zones may be fully fragmented by the tentative discovery that terrestrials doesn’t follow star metallicity characteristics.

I wrote on this under the earlier post:

“It bears here, as it is a popular idea among those who a priori wants to see us as unique, to note that the galactic habitable zone concept could be blown wide open by a reconciliation between Kepler and Harps data. HARPS finds planets are much more frequent than Kepler, maybe 2-3 times as many. The answer seems to lie in that there are two different types of superEarth populations, hard core terrestrials and fluffy gas planets, and different methods have different bias on those.

And AFAIU these terrestrials doesn’t seem to follow the metallicity trend seen in other planet populations. (They likely form in different ways, and metallicity of the protoplanetary disk could affect these differently.) I wish I had ready references, but these last weeks have been crazy with new observations and hypotheses, and a layman has only so much time…

Terrestrials can potentially be as numerous regardless of the star’s metallicity. If that is so, the idea of a GHZ becomes restricted to preclude regions with too much environmental radiation (perhaps the core regions and some other dynamical areas that comes and goes), I think. The other conditions would be satisfied with the SHZ.”

The poster who responded to the earlier post did a terrible job on responding to such specifics, by cutting and pasting unsupported general claims. Gonzales are confusing the concept of habitable zone with habitability of planets, and further habitability with habitation statistics.

As I mentioned in the earlier post, a “habitable zone [is] heuristic in the way [it] take[s] a known working biosphere and extrapolate the necessary conditions in a perturbation analysis, what we can change and still have conditions for life as we know it.”

As for the discussion on planetary habitability, it is really the trend that the new data shows how lenient the conditions can be and what a good case study, what a good representation of a random pick out of the distribution, our own system is.

The foremost find is that all systems are individuals, with large trends in formation and lifetime dynamics which result in scatter. But among those wide parameters our own system places well:

- Our sun has an ordinary star with metallicity that are within the peak of the planetary distribution. (Though as noted, that may not mean anything for number of terrestrials.)

- Our planets have orbits with parameters such as numbers, radius, eccentricities et cetera well within the distributions. It has 8 planets, but the current sample trends of at 6 planets and that with virtual non-detectability of Mars massed, even less Mercury massed planets.

- Our system is only 1 sample, but its pattern of 4 planets up to Earth mass, 2 planets up to Neptune mass, 1 planet up to Saturn mass, and 1 Jupiter mass planet follows exactly the Kepler statistic trend of planet numbers following a 1/r2 trend.

The last correspondence between exoplanet predictions and our own system is very impressive to me!

If we leave habitability to look at possibilities for intelligent life, our planet still doesn’t seem unique:

- It is unclear whether a large rotation axis stabilizing moon is harmful or beneficial. However, the fact that three terrestrials and dwarfs seems to have similar impact moons (Earth/Moon system, Mars/Phobos-Deimos-equatorial very elliptical impact scars, Pluto/Charon system) and 2 out of 3 resulted in tight binaries, implies it is a frequent phenomena.

The remaining factor is if we look for technological intelligence, presumably multicellular land life:

- The amount of water on Earth, having enough for plate tectonics but less than full ocean cover or roughly 0.05 % by mass IIRC, seems to be finetuned. However of our own terrestrials 3 of 4 have less water and in models most terrestrials have much more.

It is then the Jupiter-Saturn migration model that leaves us with the amount of water (drier planetoid formation supplemented with watery asteroids). And planetary migration seems to be the norm.

Leaving habitability, which is observed already (a few verified habitable terrestrials, with Kepler and HARPS having more candidates in the pipeline) and shored up by the posted results as Musgrave notes, we get into questions of abiogenesis and long term habitation statistics.

FL said:

I never get why IDists are so skeptical of extrasolar life.

Lack of evidence, perhaps?

No, it is clearly a religious opinion. Would that they use the same analysis on that topic too!

It is also a clear lack of following the thread to use that argument here.* As described, we have plenty of evidence for the existence of such life.

First, we observe habitable planets, as noted in the post.

Second, as I commented there, we now have data that pushes us to reject that abiogenesis is a process with deterministic difficulties. The late date of the habitable Earth-Moon system and the early date of its inhabitation is evidence for easy abiogenesis.

Taken together these evidences for easy habitability and easy abiogenesis means we can observe many systems which have had life at one time or other. As results of abiogenesis are expected to be less robust than established ecologies, we will also observe many systems that have persistent life concurrent with ours.

———- * Again on the spot someone made up a baseless criticism of the scientific method as applied to tested science. I am amazed with what anti-scientists think they can get away with!

—————————————–

harold said:

Having said that, as an informed amateur who looks at the question of abiogenesis from a mainly biomedical perspective, I sometimes feel that those who come at it from an almost exclusively physical sciences background tend to gloss over some issues.

[…]

Still, terrestrial abiogenesis should be regarded as an active field; a clear model of the origin of a cell with the characteristics all modern cells remains a long term goal.

Lacking such a model raises the intriguing question of what we would define as life.

While it is a fascinating topic, it is glossed over because as we can see from above it is orthogonal to observing statistics of habitability and inhabitation.

The only case where details are interesting is in situ observations of living or recent fossilized individuals on places like Mars or Europe where we can’t observe the biosphere directly. Then we can use “the NASA definition” of metabolizing replicators to identify individuals.

Moreover I would claim that it is uninformative on evolution and abiogenesis both.

For the purpose of evolution, which is the general process of life, the necessary and sufficient case for testability is that life can be defined as a property of heritable populations. As opposed to the NASA definition we see that no individual is certain to be “alive”, it takes a viable population.

[And of course the anthropocentric idea that a conscious individual is “alive” is totally besides the biology of these systems! An individual is a byproduct of life.]

It can be useful in cases to identify CHONSP life (biologies), cellular life (complex biologies), life with LUCAs (non-artificial biologies), et cetera.

For the purpose of abiogenesis, which is the general process of pro- to protobiotic transitions, the necessary and sufficient case is simply that chemical and biological populations are obeying a testable theory. This is because of necessity the transition is fuzzy, so naturally “life” is excluded from consideration.

I would claim that since Wächterhäuser’s FeS world hypotheses 1988, abiogenesis is slightly testable. In fact his hypotheses were likely invalidated 20 years later, as a 2008 paper shows they require enzymes very much as selective as modern evolved ones!

To substite for him (ahem!) I want to take the opportunity to introduce another toy model which imply continuing putative testability on abiogenesis:

DNA-protein cell machinery, RNA biosynthesis before the first membranes, the first enzymes are examples of (not fully exclusive) common evolutionary chicken-and-egg problems. Luckily such problems conveniently bottleneck possible pathways to a smaller set.

Bottom up, chemical network enzymes are a natural outcome in newer scenarios. High-temperature reactions seems to be much faster than orthodox theory predicted from scant data. This temperature dependence gives a self-selection for enthalpic pre-proteinous enzymes. [“Impact of temperature on the time required for the establishment of primordial biochemistry, and for the evolution of enzymes”, Stockbridge et al, PNAS, 2010.]

Now looking top down, we see that pathways meet. The first modern metabolic networks originated with purine metabolism, and specifically with the gene family of the P-loop-containing ATP hydrolase fold. [“The origin of modern metabolic networks inferred from phylogenomic analysis of protein architecture”, Caetano-Anollés et al. PNAS, 2007; “Rapid evolutionary innovation during an Archaean genetic expansion”, David et al, Nature, 2010.]

That is, ATP sits at the intersection between a cooling and/or hydrothermal vent active Earth prometabolism and nucleotide protometabolism. (Which compound seems to later have been exaptated by modern proteinous metabolic genes as coenzyme/energy currency.) Minimum change of traits picks ATP use before RNA evolution

Note that this parsimony is an (informal) test of a phylogenetic pathway.

Torbjörn Larsson, OM said:

The number of habitable planets could be even higher with a factor of two or so, in our galaxy up to ~ 2*1010 perhaps.

It is still abysmal statistics, but by microlensing it has been estimated that for every bound (orbiting) planet there is an unbound that has been ejected. This is supported by modern models of planetary systems, AFAIK. Many of those wanderers would have moons with Europa style gravitationally heated habitable ice covered oceans with lifetimes well enough to establish life.

As for “shrinking the habitable zones”, the shrinking is on the concept.

- Solar habitable zones are made problematic by the found dynamics of planetary systems. Planets migrate, they have elliptical orbits that take them in and out of the zone, we are starting to look at atmospheric effects.

The habitable zone concept is a first order tool to estimate statistics of habitables and to focus on habitable targets. That it would be modified with expected (atmospheres) and unexpected (high eccentricities) effects is an expected development.

That it must be replaced by a tool that consider dynamics was not.

- Galactic habitable zones may be fully fragmented by the tentative discovery that terrestrials doesn’t follow star metallicity characteristics.

I wrote on this under the earlier post:

“It bears here, as it is a popular idea among those who a priori wants to see us as unique, to note that the galactic habitable zone concept could be blown wide open by a reconciliation between Kepler and Harps data. HARPS finds planets are much more frequent than Kepler, maybe 2-3 times as many. The answer seems to lie in that there are two different types of superEarth populations, hard core terrestrials and fluffy gas planets, and different methods have different bias on those.

And AFAIU these terrestrials doesn’t seem to follow the metallicity trend seen in other planet populations. (They likely form in different ways, and metallicity of the protoplanetary disk could affect these differently.) I wish I had ready references, but these last weeks have been crazy with new observations and hypotheses, and a layman has only so much time…

Terrestrials can potentially be as numerous regardless of the star’s metallicity. If that is so, the idea of a GHZ becomes restricted to preclude regions with too much environmental radiation (perhaps the core regions and some other dynamical areas that comes and goes), I think. The other conditions would be satisfied with the SHZ.”

The poster who responded to the earlier post did a terrible job on responding to such specifics, by cutting and pasting unsupported general claims. Gonzales are confusing the concept of habitable zone with habitability of planets, and further habitability with habitation statistics.

As I mentioned in the earlier post, a “habitable zone [is] heuristic in the way [it] take[s] a known working biosphere and extrapolate the necessary conditions in a perturbation analysis, what we can change and still have conditions for life as we know it.”

IMHO, it is likely that many if not most of the “wandering” planets were initially formed around multiple star systems and were ejected because of the non-central forces that would be much stronger in such systems. The non-central forces in the solar system, caused mostly by Jupiter and Saturn, were shown by Laplace to be insufficient to cause instability in that system. However, even a dwarf star has 10 or more times the mass of Jupiter and thus would have a much greater effect on any planets which initially formed in the system.

stevaroni said:

As an Austin ex-pat (and someone who sill owns a house there) I’ve been keeping a keen eye out on the Texas weather.

These day’s it seems like not only has God answered Rick, but disturbingly, He seems to be sending a message of His own.

God clearly hates us. Here in the Dallas/Fort worth metroplex, it has been so hot and dry that parks have cracks in the ground you can step in. If you’ve never experienced 109 degrees, it is beyond functioning levels. Breezes feel like leaks from ovens. Car seats and seatbelt buckles can burn. Walking from your car to a building can leave one drenched in sweat. It’s like living on another planet.

Back on topic, I’m just counting the days until life is found in our own solar system. With all the liquids being found (methane on Titan, water on Enceladus, etc.), it seems only a matter of time. The big question will be how similar it is to life here, and whether it supports independent evolution, panspermia, or something else.

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This page contains a single entry by Ian Musgrave published on September 17, 2011 11:04 AM.

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