Wintery Knight

…integrating Christian faith and knowledge in the public square

Paul Davies: the hard problem of the origin of life is not “complexity” – it’s information

Check out this column on the origin of life from the radically leftist UK Guardian, written by agnostic cosmologist Paul Davies. (The same Paul Davies who is occasionally quoted by William Lane Craig)

Excerpt:

The origin of life is one of the great outstanding mysteries of science. How did a non-living mixture of molecules transform themselves into a living organism? What sort of mechanism might be responsible?

[...]Most research into life’s murky origin has been carried out by chemists. They’ve tried a variety of approaches in their attempts to recreate the first steps on the road to life, but little progress has been made. Perhaps that is no surprise, given life’s stupendous complexity. Even the simplest bacterium is incomparably more complicated than any chemical brew ever studied.

But a more fundamental obstacle stands in the way of attempts to cook up life in the chemistry lab. The language of chemistry simply does not mesh with that of biology. Chemistry is about substances and how they react, whereas biology appeals to concepts such as information and organisation. Informational narratives permeate biology. DNA is described as a genetic “database”, containing “instructions” on how to build an organism. The genetic “code” has to be “transcribed” and “translated” before it can act. And so on. If we cast the problem of life’s origin in computer jargon, attempts at chemical synthesis focus exclusively on the hardware – the chemical substrate of life – but ignore the software – the informational aspect. To explain how life began we need to understand how its unique management of information came about.

[...]Sara Walker, a Nasa astrobiologist working at Arizona State University, and I have proposed that the significant property of biological information is not its complexity, great though that may be, but the way it is organised hierarchically. In all physical systems there is a flow of information from the bottom upwards, in the sense that the components of a system serve to determine how the system as a whole behaves. Thus if a meteorologist wants to predict the weather, he may start with local information, such as temperature and air pressure, taken at various locations, and calculate how the weather system as a whole will move and change. In living organisms, this pattern of bottom-up information flow mingles with the inverse – top-down information flow – so that what happens at the local level can depend on the global environment, as well as vice versa.

[...]The way life manages information involves a logical structure that differs fundamentally from mere complex chemistry. Therefore chemistry alone will not explain life’s origin, any more than a study of silicon, copper and plastic will explain how a computer can execute a program. Our work suggests that the answer will come from taking information seriously as a physical agency, with its own dynamics and causal relationships existing alongside those of the matter that embodies it – and that life’s origin can ultimately be explained by importing the language and concepts of biology into physics and chemistry, rather than the other way round.

The point of me posting this is simple. The thing to be explained in the origin of life is not a cake, where you can jumble ingredients together and get something. The thing to be explained is information. The origin of life is a programming problem, not a cooking problem. Where did the software come from – the first basic program that allowed for the basic functions of life, like self-replication.

Dr. Davies is hoping for a naturalistic solution to the problem, because he is a naturalist. But at least he is clear about specifying the thing that needs to be explained. A lot more clear than the journalists who explain intelligent design as the belief that some things are too complex to have evolved. But that’s wrong. The real question is: where did the information come from?

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New paper finds that mass of asteroid belts affect habitability of planets

Science Daily reports. (H/T Evolution News via ECM)

Excerpt:

They suggest that the size and location of an asteroid belt, shaped by the evolution of the Sun’s protoplanetary disk and by the gravitational influence of a nearby giant Jupiter-like planet, may determine whether complex life will evolve on an Earth-like planet.

This might sound surprising because asteroids are considered a nuisance due to their potential to impact Earth and trigger mass extinctions. But an emerging view proposes that asteroid collisions with planets may provide a boost to the birth and evolution of complex life.

Asteroids may have delivered water and organic compounds to the early Earth. According to the theory of punctuated equilibrium, occasional asteroid impacts might accelerate the rate of biological evolution by disrupting a planet’s environment to the point where species must try new adaptation strategies.

The astronomers based their conclusion on an analysis of theoretical models and archival observations of extrasolar Jupiter-sized planets and debris disks around young stars. “Our study shows that only a tiny fraction of planetary systems observed to date seem to have giant planets in the right location to produce an asteroid belt of the appropriate size, offering the potential for life on a nearby rocky planet,” said Martin, the study’s lead author. “Our study suggests that our solar system may be rather special.”

There’s a long list of factors that have to be present for a planet to support life – and more keep appearing every day. Here’s another recent one from the journal Nature.

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What conditions support the minimum requirements for complex life?

You need to have a certain amount of elemental diversity to support the minimal requirements of living systems. For example, you need carbon, hence “carbon-based life”.

The Circumstellar Habitable Zone (CHZ)

Human bodies are made of carbon, and many other heavy elements. You need many different heavy elements in order to make up your physical body. Our star, the Sun, is also made of heavy elements. You also need heavy elements in order to crate a metal-rich star like our Sun. A heavy metal-rich star is required in order to support complex carbon-based life in any solar system. The metal-rich star is required because you need to make sure that it can burn stably for a LONG period of time. A metal-rich star also allows you to have a habitable planet far enough from that metal-rich star so that the planet can support liquid water on the planet’s surface. The zone where a planet can have liquid water at the surface is called the circumstellar habitable zone (CHZ). A solar system is therefore a lot like a campfire – you can’t get too close or you get set on fire, and you can’t get too far or you freeze to death. With planets, you need to keep away so your water doesn’t evaporate from the surface, but not so far away that your water freezes. Liquid water on the surface is needed in order to act as a universal solvent in the chemistry of life.

Circumstellar Habitable Zone

Circumstellar Habitable Zone

Here, watch a clip from The Privileged Planet: (Clip 4 of 12, full playlist here)

A metal-rich star like the Sun is very massive, which allows planets to stay in orbit much further away. Notice that the smaller the star, the closer you have to go to the star. If you go too close to the star then your planet is “tidally locked” – your planet no longer spins on it’s axis – and that’s very bad for life)

The Galactic Habitable Zone (GHZ)

So, where do you get the heavy elements you need for your heavy metal-rich star?

You have to get the heavy elements for your star from supernova explosions – explosions that occur when certain stars die. That’s where heavy elements come from. But you can’t be TOO CLOSE to the dying stars, because you will get hit by nasty radiation and explosions. So to get the heavy elements, your solar system needs to be in the galactic habitable zone (GHZ) – the zone where you can pickup the heavy elements you need but not get hit by radiation and explosions. The GHZ lies between the spiral arms of a spiral galaxy. You can be too close to the center of the galaxy, it’s too dense there and you will get hit with massive radiation that will break down your life chemistry. And you can’t be to far from the center, because you won’t get enough heavy elements from the lower number of dying stars in the spiral arms.

Galactic Habitable Zone

Galactic Habitable Zone

Here, watch a clip from The Privileged Planet: (Clip 10 of 12, full playlist here)

The GHZ is based on a discovery made by astronomer Guillermo Gonzalez, which made the front cover of Scientific American in 2001. That’s right, the cover of Scientific American. That’s when this was discovered.

By the way, you can watch a lecture with Guillermo Gonzalez explaining his ideas further. The lecture was delivered at UC Davis in 2007. That link has a link to the playlist of the lecture, a bio of the speaker, and a summary of all the topics he discussed in the lecture. An excellent place to learn the requirements for a suitable habitat for life. The GHZ and CHZ are ONLY TWO of the requirements for a habitat for life – there are a lot more requirements! Once you list them all out, the odds of getting even one place that is suitable are quite low. If you like this sort of evidence, I recommend the DVD of “The Privileged Planet”, which you can get on Amazon. Or just watch it for free on YouTube.

Positive arguments for Christian theism

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New study on tidal heating strengthens stellar habitability argument

Circumstellar Habitable Zone

Circumstellar Habitable Zone

Note: If you need a refresher on the habitability argument, click here.

Here’s an article entitled “Tidal heating shrinks the ‘goldilocks zone’: Overlooked factor suggests fewer habitable planets than thought”. It appeared in Nature, the most prestigious peer-reviewed science journal.

The gist of it is that tidal forces can alter orbits so that planets don’t spend all of their orbit in the habitable zone. If planets go outside the habitable zone, it damages their supply of liquid water, and any life chemistry going on in there is disrupted.

Excerpt:

A previously little-considered heating effect could shrink estimates of the habitable zone of the Milky Way’s most numerous class of stars — ‘M’ or red dwarfs — by up to one half, says Rory Barnes, an astrobiologist at the University of Washington in Seattle. That factor — gravitational heating via tides — suggests a menagerie of previously undreamt-of planets, on which tidal heating is a major source of internal heat. Barnes presented the work yesterday at a meeting of the American Astronomical Society’s Division on Dynamical Astronomy in Timberline Lodge, Oregon.

The habitable zone is the orbital region close enough to a star for a planet to have liquid water, but not so close that all of the water evaporates. For our Sun, the zone extends roughly from the inner edge of the orbit of Mars to the outer edge of that of Venus. For smaller, cooler stars, such as M-class dwarfs, the zone can be considerably closer to the star than Mercury is to the Sun. And because close-in planets are easier to spot than more distant ones, such stars have been a major target for planet hunters seeking Earth-like worlds.

There’s just one problem with finding habitable planets around such stars, says Barnes. Because tidal forces vary dramatically with the distance between a planet and its star, closer orbits also result in massively larger tidal forces.

Since planets do not have perfectly circular orbits, these tidal forces cause the planet to flex and unflex each time it moves closer to or further from its star; kneading its interior to produce massive quantities of frictional heat. Substantial heat can be produced, he added, with even slight deviations from a perfectly circular orbit. And, Barnes notes, other factors — such as the rate of the planet’s rotation and its axial tilt — can also influence heat production.

A similar tidal process makes Jupiter’s moon Io the most volcanic body in the Solar System. “I’m just scaling that Io–Jupiter system up by a factor of 1,000 in mass,” Barnes said at the meeting. “It’s the same process, on steroids.”

So, stars that are smaller and cooler will have a habitable zone that is closer to the star, exposing them to more tidal forces. More tidal forces makes their orbits less likely to stay circular – within the habitable zone around the star. These variations cause an increase in heat production on the planet. Too much heat means that the planet is unable to support liquid water on the surface, making it inhospitable for life. Therefore, solar systems with less massive stars can be ruled out as possible sites for life, because of these tidal forces.

Filed under: News, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

What conditions support the minimum requirements for complex life?

You need to have a certain amount of elemental diversity to support the minimal requirements of living systems. For example, you need carbon, hence “carbon-based life”.

The Circumstellar Habitable Zone (CHZ)

Human bodies are made of carbon, and many other heavy elements. You need many different heavy elements in order to make up your physical body. Our star, the Sun, is also made of heavy elements. You also need heavy elements in order to crate a metal-rich star like our Sun. A heavy metal-rich star is required in order to support complex carbon-based life in any solar system. The metal-rich star is required because you need to make sure that it can burn stably for a LONG period of time. A metal-rich star also allows you to have a habitable planet far enough from that metal-rich star so that the planet can support liquid water on the planet’s surface. The zone where a planet can have liquid water at the surface is called the circumstellar habitable zone (CHZ). A solar system is therefore a lot like a campfire – you can’t get too close or you get set on fire, and you can’t get too far or you freeze to death. With planets, you need to keep away so your water doesn’t evaporate from the surface, but not so far away that your water freezes. Liquid water on the surface is needed in order to act as a universal solvent in the chemistry of life.

Circumstellar Habitable Zone

Circumstellar Habitable Zone

Here, watch a clip from The Privileged Planet: (Clip 4 of 12, full playlist here)

A metal-rich star like the Sun is very massive, which allows planets to stay in orbit much further away. Notice that the smaller the star, the closer you have to go to the star. If you go too close to the star then your planet is “tidally locked” – your planet no longer spins on it’s axis – and that’s very bad for life)

The Galactic Habitable Zone (GHZ)

So, where do you get the heavy elements you need for your heavy metal-rich star?

You have to get the heavy elements for your star from supernova explosions – explosions that occur when certain stars die. That’s where heavy elements come from. But you can’t be TOO CLOSE to the dying stars, because you will get hit by nasty radiation and explosions. So to get the heavy elements, your solar system needs to be in the galactic habitable zone (GHZ) – the zone where you can pickup the heavy elements you need but not get hit by radiation and explosions. The GHZ lies between the spiral arms of a spiral galaxy. You can be too close to the center of the galaxy, it’s too dense there and you will get hit with massive radiation that will break down your life chemistry. And you can’t be to far from the center, because you won’t get enough heavy elements from the lower number of dying stars in the spiral arms.

Galactic Habitable Zone

Galactic Habitable Zone

Here, watch a clip from The Privileged Planet: (Clip 10 of 12, full playlist here)

The GHZ is based on a discovery made by astronomer Guillermo Gonzalez, which made the front cover of Scientific American in 2001. That’s right, the cover of Scientific American. That’s when this was discovered.

By the way, you can watch a lecture with Guillermo Gonzalez explaining his ideas further. The lecture was delivered at UC Davis in 2007. That link has a link to the playlist of the lecture, a bio of the speaker, and a summary of all the topics he discussed in the lecture. An excellent place to learn the requirements for a suitable habitat for life. The GHZ and CHZ are ONLY TWO of the requirements for a habitat for life – there are a lot more requirements! Once you list them all out, the odds of getting even one place that is suitable are quite low. If you like this sort of evidence, I recommend the DVD of “The Privileged Planet”, which you can get on Amazon. Or just watch it for free on YouTube.

Related posts

Filed under: Polemics, , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

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