Tag Archives: Rare Earth

Eric Metaxas: does science make the case for or against God?

This is from famous writer Eric Metaxas, writing in the Wall Street Journal, of all places. He talks about whether recent discoveries have made the world look more created/designed, or more eternal/undesigned.

In the beginning, there was the naturalism, and the naturalism said that habitable planets are common:

In 1966 Time magazine ran a cover story asking: Is God Dead? Many have accepted the cultural narrative that he’s obsolete—that as science progresses, there is less need for a “God” to explain the universe.

[…]The same year Time featured the now-famous headline, the astronomer Carl Sagan announced that there were two important criteria for a planet to support life: The right kind of star, and a planet the right distance from that star. Given the roughly octillion—1 followed by 24 zeros—planets in the universe, there should have been about septillion—1 followed by 21 zeros—planets capable of supporting life.

Then the science happened:

As our knowledge of the universe increased, it became clear that there were far more factors necessary for life than Sagan supposed. His two parameters grew to 10 and then 20 and then 50, and so the number of potentially life-supporting planets decreased accordingly. The number dropped to a few thousand planets and kept on plummeting.

Even SETI proponents acknowledged the problem. Peter Schenkel wrote in a 2006 piece for Skeptical Inquirer magazine: “In light of new findings and insights, it seems appropriate to put excessive euphoria to rest . . . . We should quietly admit that the early estimates . . . may no longer be tenable.”

As factors continued to be discovered, the number of possible planets hit zero, and kept going. In other words, the odds turned against any planet in the universe supporting life, including this one. Probability said that even we shouldn’t be here.

Today there are more than 200 known parameters necessary for a planet to support life—every single one of which must be perfectly met, or the whole thing falls apart. Without a massive planet like Jupiter nearby, whose gravity will draw away asteroids, a thousand times as many would hit Earth’s surface. The odds against life in the universe are simply astonishing.

And again, naturalism confounded by a stream of discoveries of cosmic fine-tuning:

The fine-tuning necessary for life to exist on a planet is nothing compared with the fine-tuning required for the universe to exist at all. For example, astrophysicists now know that the values of the four fundamental forces—gravity, the electromagnetic force, and the “strong” and “weak” nuclear forces—were determined less than one millionth of a second after the big bang. Alter any one value and the universe could not exist. For instance, if the ratio between the nuclear strong force and the electromagnetic force had been off by the tiniest fraction of the tiniest fraction—by even one part in 100,000,000,000,000,000—then no stars could have ever formed at all. Feel free to gulp.

Multiply that single parameter by all the other necessary conditions, and the odds against the universe existing are so heart-stoppingly astronomical that the notion that it all “just happened” defies common sense. It would be like tossing a coin and having it come up heads 10 quintillion times in a row. Really?

Fred Hoyle, the astronomer who coined the term “big bang,” said that his atheism was “greatly shaken” at these developments. He later wrote that “a common-sense interpretation of the facts suggests that a super-intellect has monkeyed with the physics, as well as with chemistry and biology . . . . The numbers one calculates from the facts seem to me so overwhelming as to put this conclusion almost beyond question.”

Theoretical physicist Paul Davies has said that “the appearance of design is overwhelming” and Oxford professor Dr. John Lennox has said “the more we get to know about our universe, the more the hypothesis that there is a Creator . . . gains in credibility as the best explanation of why we are here.”

The greatest miracle of all time, without any close seconds, is the universe. It is the miracle of all miracles, one that ineluctably points with the combined brightness of every star to something—or Someone—beyond itself.

My pastor reads the Wall Street Journal. I am pretty sure this is going to be in his Sunday sermon. It’s the #1 editorial on the Wall Street Journal right now, so he can’t miss it.

You know, as these scientific arguments become more and more mainstream, it really makes me wonder if there is anything more to atheism than some sort of traumatic childhood experience of wounded narcissism. The child experiences some desire for something, and expects God to meet that need. The need is not met. The child, now enraged that it is 1) not God and 2) not in control of God, rejects God. Or maybe it’s just the desire to not be punished for acting immorally. Or to appear “smart” to a crowd of peers. Whatever it is that causes people to believe in atheism, it sure isn’t science. If we are going strictly on the science, then the answer is God. But if the question of God’s existence is about feelings, then the answer is no God. It really is that simple.

What makes a planet suitable for supporting complex life?

The Circumstellar Habitable Zone (CHZ)

What do you need in order to have a planet that supports complex life? First, you need liquid water at the surface of the planet. But there is only a narrow range of temperatures that can support liquid water. It turns out that the size of the star that your planet orbits around has a lot to do with whether you get liquid water or not. A heavy, metal-rich star allows you to have a habitable planet far enough from the star so  the planet can support liquid water on the planet’s surface while still being able to spin on its axis. The zone where a planet can have liquid water at the surface is called the circumstellar habitable zone (CHZ). A metal-rich star like our Sun is very massive, which moves the habitable zone out further away from the star. If our star were smaller, we would have to orbit much closer to the star in order to have liquid water at the surface. Unfortunately, if you go too close to the star, then your planet becomes tidally locked, like the moon is tidally locked to Earth. Tidally locked planets are inhospitable to life.

Circumstellar Habitable Zone
Circumstellar Habitable Zone

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

But there’s more.

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 types of 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 from the dying stars, 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. Not only do you have to be in between the arms of the spiral galaxy, but you also cannot be too close to the center of the galaxy. The center of the galaxy is too dense and you will get hit with massive radiation that will break down your life chemistry. But you also can’t be too far from the center, because you won’t get enough heavy elements because there are fewer dying stars the further out you go. You need to be in between the spiral arms, a medium distance from the center of the galaxy.

Like this:

Galactic Habitable Zone
Galactic Habitable Zone and Solar 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. I actually stole the image above of the GHZ and CHZ (aka solar habitable zone) from his Scientific American article (linked above).

These are just a few of the things you need in order to get a planet that supports life.

Here are a few of the more well-known ones:

  • a solar system with a single massive Sun than can serve as a long-lived, stable source of energy
  • a terrestrial planet (non-gaseous)
  • the planet must be the right distance from the sun in order to preserve liquid water at the surface – if it’s too close, the water is burnt off in a runaway greenhouse effect, if it’s too far, the water is permanently frozen in a runaway glaciation
  • the solar system must be placed at the right place in the galaxy – not too near dangerous radiation, but close enough to other stars to be able to absorb heavy elements after neighboring stars die
  • a moon of sufficient mass to stabilize the tilt of the planet’s rotation
  • plate tectonics
  • an oxygen-rich atmosphere
  • a sweeper planet to deflect comets, etc.
  • planetary neighbors must have non-eccentric orbits

By the way, you can watch a lecture with Guillermo Gonzalez explaining his ideas further. This 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.

Scientists troubled by lack of simple explanation for our life-permitting moon

This entire article from Evolution News is a must-read. It talks about a recent paper by a naturalist named Robin Canup which appeared in Nature, the most prestigious peer-reviewed science journal.

So, there’s too much to quote here. I’ll grab a few snippets to give you the gist of it, then you click through and read the whole thing. 

The moon is important for the existence of a life permitting planet:

Canup knows our moon is important for life:

The Moon is more than just a familiar sight in our skies. It dictates conditions on Earth. The Moon is large enough to stabilize our planet’s rotation, holding Earth’s polar axis steady to within a few degrees. Without it, the current Earth’s tilt would vary chaotically by tens of degrees. Such large variationsmight not preclude life, but would lead to a vastly different climate.

The moon requires an improbable sequence of events:

Canup states that “No current impact model stands out as more compelling than the rest.” All are equally improbable, in other words. Indeed, they are:

It remains troubling that all of the current impact models invoke a process after the impact to effectively erase a primary outcome of the event — either by changing the disk’s composition through mixing for the canonical impact, or by changing Earth’s spin rate for the high-angular-momentum narratives.

Sequences of events do occur in nature, and yet we strive to avoid such complexity in our models. We seek the simplest possible solution, as a matter of scientific aesthetics and because simple solutions are often more probable. As the number of steps increases, the likelihood of a particular sequence decreases. Current impact models are more complex and seem less probable than the original giant-impact concept.

This is a good challenge to naturalism, but it lends support to one part of the habitability argument.

Previously, I blogged about a few of the minimum requirements that a planet must satisfy in order to support complex life.

Here they are:

  • a solar system with a single massive Sun than can serve as a long-lived, stable source of energy
  • a terrestrial planet (non-gaseous)
  • the planet must be the right distance from the sun in order to preserve liquid water at the surface – if it’s too close, the water is burnt off in a runaway greenhouse effect, if it’s too far, the water is permanently frozen in a runaway glaciation
  • the solar system must be placed at the right place in the galaxy – not too near dangerous radiation, but close enough to other stars to be able to absorb heavy elements after neighboring stars die
  • a moon of sufficient mass to stabilize the tilt of the planet’s rotation
  • plate tectonics
  • an oxygen-rich atmosphere
  • a sweeper planet to deflect comets, etc.
  • planetary neighbors must have non-eccentric orbits

This is a good argument, so if you want to learn more about it, get the “The Privileged Planet” DVD, or the book of the same name.

How Earth-like are the 8.8 billion Earth-like planets from a recent estimate?

Previously, I blogged about a few of the minimum requirements that a planet must satisfy in order to support complex life.

Here they are:

  • a solar system with a single massive Sun than can serve as a long-lived, stable source of energy
  • a terrestrial planet (non-gaseous)
  • the planet must be the right distance from the sun in order to preserve liquid water at the surface – if it’s too close, the water is burnt off in a runaway greenhouse effect, if it’s too far, the water is permanently frozen in a runaway glaciation
  • the solar system must be placed at the right place in the galaxy – not too near dangerous radiation, but close enough to other stars to be able to absorb heavy elements after neighboring stars die
  • a moon of sufficient mass to stabilize the tilt of the planet’s rotation
  • plate tectonics
  • an oxygen-rich atmosphere
  • a sweeper planet to deflect comets, etc.
  • planetary neighbors must have non-eccentric orbits

Now what happens if we disregard all of that, and just classify an Earth-like planet as one which only has to potentially support liquid water at the surface? Well, you get a very high estimate of Earth-like planets.

Science journalist Denyse O’Leary responds to a recent estimate based on this questionable criterion, which placed the number of Earth-like planets at 8.8 billion.

Excerpt: (links removed)

A current official definition of habitable planets is “in the zone around the star where liquid water could exist,” but the ones discovered so far are unsuitable in many other ways.

Then a new cosmology term hit the media, “super-Earths.” It means “bigger than Earth,” but smaller than gas giant Neptune. Super-Earths could be the most numerous type of planet, in tight orbits around their star — which is actually bad news for life.Nonetheless, some insist, they may be more attractive to life than Earth is. Indeed, the Copernican Principle allows us to assume that some are inhabited already.

In reality, even the rocky exoplanets (known as of early 2013) that are Earth-sized are not Earth-like. For example, the Kepler mission’s first rocky planet find is described as follows: “Although similar in size to Earth, its orbit lasts just 0.84 days, making it likely that the planet is a scorched, waterless world with a sea of lava on its starlit side.” As space program physicist Rob Sheldon puts it, Earth is a rocky planet but so is a solid chunk of iron at 1300 degrees orbiting a few solar radii above the star. In any event, a planet may look Earth-like but have a very different internal structure and atmosphere.”

David Klinghoffer notes that the study is estimating that 8.8 billion number, but the actual number of Earth-like planets we can see is much lower.

He writes:

The study is supposed to be a major step forward because of its unprecedented accuracy:

For the first time, scientists calculated — not estimated — what percent of stars that are just like our sun have planets similar to Earth: 22 percent, with a margin of error of plus or minus 8 percentage points.

Oh! You see, they calculated. They didn’t just estimate.

Because there are probably hundreds of planets missed for every one found, the study did intricate extrapolations to come up with the 22 percent figure — a calculation that outside scientists say is fair.

Oh. They calculated in the sense of “extrapolating” to “come up” with a figure. In other words, they estimated. The figure of “8.8 billion stars with Earth-size planets in the habitable temperature zone” comes down a bit too when you talk about actual planets that have been observed instead of being merely conjectured and “calculated.”

Scientists at a Kepler science conference Monday said they have found 833 new candidate planets with the space telescope, bringing the total of planets they’ve spotted to 3,538, but most aren’t candidates for life.

Kepler has identified only 10 planets that are about Earth’s size circling sun-like stars and are in the habitable zone, including one called Kepler 69-c.

Ah hah. So from the initial, trumpets-blaring figure of 8.8 billion we’re down more realistically to 10. Not 10 billion, just 10. Meanwhile the silence from space continues absolutely unabated.

That’s the way it tends to go with stories like this, the blaring headline and the inevitable letdown.

One part of the AP press release makes the point that the estimate does not include all the minimum requirements for life. For example, you need an atmosphere, as I stated above. Do the estimated 8.8 billion Earth-like planets have an Earth-like atmosphere? How about an oxygen-rich atmosphere, do the 8.8 billion Earth-like planets have that?

NO:

The next step, scientists say, is to look for atmospheres on these planets with powerful space telescopes that have yet to be launched. That would yield further clues to whether any of these planets do, in fact, harbor life.

You know, after the whole global warming hoax, you would think that these headline writers would have learned their lesson about sensationalizing wild-assed guesses in order to scare up more research money. But a lot of true-believing naturalists are just going to read the headline and not the rest of the article, and they will never know that they’ve been had. Again. I love experimental science, but I don’t love the politicization of science. 

What makes a planet suitable for supporting complex life?

The Circumstellar Habitable Zone (CHZ)

What do you need in order to have a planet that supports complex life? First, you need liquid water at the surface of the planet. But there is only a narrow range of temperatures that can support liquid water. It turns out that the size of the star that your planet orbits around has a lot to do with whether you get liquid water or not. A heavy, metal-rich star allows you to have a habitable planet far enough from the star so  the planet can support liquid water on the planet’s surface while still being able to spin on its axis. The zone where a planet can have liquid water at the surface is called the circumstellar habitable zone (CHZ). A metal-rich star like our Sun is very massive, which moves the habitable zone out further away from the star. If our star were smaller, we would have to orbit much closer to the star in order to have liquid water at the surface. Unfortunately, if you go too close to the star, then your planet becomes tidally locked, like the moon is tidally locked to Earth. Tidally locked planets are inhospitable to life.

Circumstellar Habitable Zone
Circumstellar Habitable Zone

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

But there’s more.

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 types of 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 from the dying stars, 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. Not only do you have to be in between the arms of the spiral galaxy, but you also cannot be too close to the center of the galaxy. The center of the galaxy is too dense and you will get hit with massive radiation that will break down your life chemistry. But you also can’t be too far from the center, because you won’t get enough heavy elements because there are fewer dying stars the further out you go. You need to be in between the spiral arms, a medium distance from the center of the galaxy.

Like this:

Galactic Habitable Zone
Galactic Habitable Zone and Solar 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. I actually stole the image above of the GHZ and CHZ (aka solar habitable zone) from his Scientific American article (linked above).

These are just a few of the things you need in order to get a planet that supports life.

Here are a few of the more well-known ones:

  • a solar system with a single massive Sun than can serve as a long-lived, stable source of energy
  • a terrestrial planet (non-gaseous)
  • the planet must be the right distance from the sun in order to preserve liquid water at the surface – if it’s too close, the water is burnt off in a runaway greenhouse effect, if it’s too far, the water is permanently frozen in a runaway glaciation
  • the solar system must be placed at the right place in the galaxy – not too near dangerous radiation, but close enough to other stars to be able to absorb heavy elements after neighboring stars die
  • a moon of sufficient mass to stabilize the tilt of the planet’s rotation
  • plate tectonics
  • an oxygen-rich atmosphere
  • a sweeper planet to deflect comets, etc.
  • planetary neighbors must have non-eccentric orbits

By the way, you can watch a lecture with Guillermo Gonzalez explaining his ideas further. This 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.