Tag Archives: The Privileged Planet

Are solar eclipses common? What has to be in place to observe a solar eclipse?

Christianity and the progress of science
Christianity and the progress of science

If there were a Designer of the universe, what would He have to do to allow creatures living on a planet to observe a solar eclipse?

Consider this article from Discovery Institute.

Excerpt:

A rare convergence of events allows Earthlings to witness not just solar eclipses, but perfect solar eclipses, where the Moon just barely covers the Sun’s bright photosphere. Such eclipses depend on the precise sizes, shapes, and relative distances of the Sun, Moon, and Earth. There’s no law of physics or celestial mechanics that requires the right configuration. In fact, of the more than 65 major moons in our Solar System, ours best matches the Sun as viewed from its planet’s surface, and this is only possible during a fairly narrow window of Earth’s history encompassing the present. The Moon is about 400 times smaller than the Sun. But right now, the Moon is about 400 times closer to the Earth than is the Sun. So, the Moon’s apparent size on the sky matches the Sun’s. Astronomers have noted this odd coincidence for centuries. And, since the Sun appears larger from the Earth than from any other planet with a moon, an Earth-bound observer can discern finer details in the Sun’s chromosphere and corona than from any other planet. This makes our solar eclipses more valuable scientifically.

The recent pictures of solar eclipses sent back from the Opportunity rover on Mars nicely illustrate how much better our solar eclipses are. The two small potato-shaped Martian moons, Deimos and Phobos, appear much too small to cover the Sun’s disk, and they zip across it in less than a minute.

Not only do you need things to be finely-tuned to see the eclipse, but you also need observers to be there.

More:

It’s intriguing that the best place to view total solar eclipses in our Solar System is the one time and place where there are observers to see them. It turns out that the precise configuration of Earth, Moon and Sun are also vital to sustaining life on Earth. A moon large enough to cover the Sun stabilizes the tilt of the rotation axis of its host planet, yielding a more stable climate, which is necessary for complex life. The Moon also contributes to Earth’s ocean tides, which increase the vital mixing of nutrients from the land to the oceans. The two moons around Mars are much too small to stabilize its rotation axis.

In addition, it’s only in the so-called Circumstellar Habitable Zone of our Sun–that cozy life friendly ring where water can stay liquid on a planet’s surface–that the Sun appears to be about the same size as the Moon from Earth’s surface. As a result, we enjoy perfect solar eclipses.

Why would the Designer of the Universe want his observers to exist in exactly the right place to observe the solar eclipse? What is the point of seeing a solar eclipse?

Here is the point:

Our ability to observe perfect solar eclipses has figured prominently in several important scientific discoveries, discoveries that would have been difficult if not impossible on the much more common planets that don’t enjoy such eclipses.

First, these observations helped disclose the nature of stars. Scientists since Isaac Newton (1666) had known that sunlight splits into all the colors of the rainbow when passed through a prism. But only in the 19th century did astronomers observe solar eclipses with spectroscopes, which use prisms. The combination of the man-made spectroscope with the natural experiment provided by eclipses gave astronomers the tools they needed not only to discover how the Sun’s spectrum is produced, but the nature of the Sun itself. This knowledge enabled astronomers to interpret the spectra of the distant stars. So, in a sense, perfect eclipses were a key that unlocked the field of astrophysics.

Second, in 1919, perfect solar eclipses allowed two teams of astronomers, one led by Sir Arthur Eddington, to confirm a prediction of Einstein’s General Theory of Relativity–that gravity bends light. They succeeded in measuring the changes in the positions of starlight passing near the Sun’s edge compared to their positions months later. Such a test was most feasible during a perfect solar eclipse. The tests led to the general acceptance of Einstein’s theory, which is the foundation of modern cosmology.

So, you’ve got fine-tuning for the eclipse, fine-tuning for the observers, and with that in place, the observers can collect scientific evidence… including evidence that confirms cosmic fine-tuning as well as general relativity. General relativity is important because if gives us the expanding universe – one of the evidences for the Big Bang cosmology. The Big Bang cosmology states that the entire physical universe came into being out of nothing, about 14 billion years ago. Who could have caused that? If we don’t have eclipses, we are losing out on evidence of cosmic fine-tuning and cosmic creation.

There’s a new Discovery Institute podcast featuring Jay Richards, co-author of the amazing book “The Privileged Planet”.

Details:

On this episode of ID: The Future, CSC Senior Fellow Jay Richards explains how perfect solar eclipses are the tip of an iceberg-size design argument found in a book he co-wrote, The Privileged Planet. The conditions for a habitable planet (right distance from the right size star, a big but not too big moon that is the right distance away to stabilize Earth’s tilt and circulate its oceans) are also conditions that make perfect solar eclipses from the Earth’s surface much more likely. And perfect eclipses aren’t just eerie and beautiful. They’ve helped scientists test and discover things, and are part of a larger pattern: The conditions needed for a habitable place in the cosmos correlate with the conditions well suited for scientific discovery. As Richards notes, this correlation is inexplicable if the cosmos is the product of chance. But if it’s intelligently designed with creatures like us in mind, it’s just what we might expect.

The MP3 file is here.

If you have not seen The Privileged Planet, you can get the same argument as in the book in just over an hour. You can either buy The Privileged Planet DVD, or click here to watch it on YouTube. And it’s narrated by John-Rhys Davies.

Earth-like planet hyped by science-fiction-crazed atheists likely uninhabitable

Apologetics and the progress of science
Apologetics and the progress of science

I found this story on the Facebook page of my good friend William, who supplies so many of the stories I blog about.

This story is from the University of Warwick.

It says:

The most Earth-like planet could have been made uninhabitable by vast quantities of radiation, new research led by the University of Warwick has found.

The atmosphere of the planet, Kepler-438b, is thought to have been stripped away as a result of radiation emitted from a superflaring Red Dwarf star, Kepler-438.

Regularly occurring every few hundred days, the superflares are approximately ten times more powerful than those ever recorded on the Sun and equivalent to the same energy as 100 billion megatons of TNT.

While superflares themselves are unlikely to have a significant impact on Kepler-438b’s atmosphere, a dangerous phenomenon associated with powerful flares, known as a coronal mass ejection (CME), has the potential to strip away any atmosphere and render it uninhabitable.

The planet Kepler-438b, to date the exoplanet with the highest recorded Earth Similarity Index, is both similar in size and temperature to the Earth but is in closer proximity to the Red Dwarf than the Earth is to the Sun.

Lead researcher, Dr David Armstrong of the University of Warwick’s Astrophysics Group, explains:

“Unlike the Earth’s relatively quiet sun, Kepler-438 emits strong flares every few hundred days, each one stronger than the most powerful recorded flare on the Sun. It is likely that these flares are associated with coronal mass ejections, which could have serious damaging effects on the habitability of the planet.

“If the planet, Kepler-438b, has a magnetic field like the Earth, it may be shielded from some of the effects. However, if it does not, or the flares are strong enough, it could have lost its atmosphere, be irradiated by extra dangerous radiation and be a much harsher place for life to exist”.

Discussing the impact of the superflares and radiation on the atmosphere of Kepler-438b, Chloe Pugh, of the University of Warwick’s Centre for Fusion, Space and Astrophysics, says:

“The presence of an atmosphere is essential for the development of life. While flares themselves are unlikely to have a significant impact on an atmosphere as a whole, there is another more dangerous phenomenon associated with powerful flares, known as a coronal mass ejection.

“Coronal mass ejections are where a huge amount of plasma is hurled outwards from the Sun, and there is no reason why they should not occur on other active stars as well. The likelihood of a coronal mass ejection occurring increases with the occurrence of powerful flares, and large coronal mass ejections have the potential to strip away any atmosphere that a close-in planet like Kepler-438b might have, rendering it uninhabitable. With little atmosphere, the planet would also be subject to harsh UV and X-ray radiation from the superflares, along with charged particle radiation, all of which are damaging to life”.

The research, The Host Stars of Kepler’s Habitable Exoplanets: Superflares, Rotation and Activity, is published by the Monthly Notices of the Royal Astronomical Society.

I would send this along to my atheist friends, but they will just wag their fingers at me and tell me that Star Trek and Star Wars have disproved all that experimental science “superstition”.

It’s Friday night, so it might be a good time for everyone to get up to speed with the habitability argument. And look, you can do that for free by watching the 90-minute documentary entitled “The Privileged Planet”. It’s free and it’s awesome!

Have fun!

How tidal effects improve the habitability of a planet

Circumstellar Habitable Zone
Circumstellar Habitable Zone

Science Daily reports on a new factor that affects planetary habitability: tides. Specifically, tides can affect the surface temperature of a planet, which has to be within a certain range in order to support liquid water – a requirement for life of any conceivable kind.

Excerpt:

Tides can render the so-called “habitable zone” around low-mass stars uninhabitable. This is the main result of a recently published study by a team of astronomers led by René Heller of the Astrophysical Institute Potsdam.

[…]Until now, the two main drivers thought to determine a planet’s temperature were the distance to the central star and the composition of the planet’s atmosphere. By studying the tides caused by low-mass stars on their potential earth-like companions, Heller and his colleagues have concluded that tidal effects modify the traditional concept of the habitable zone.

Heller deduced this from three different effects. Firstly, tides can cause the axis of a planet`s rotation to become perpendicular to its orbit in just a few million years. In comparison, Earth’s axis of rotation is inclined by 23.5 degrees — an effect which causes our seasons. Owing to this effect, there would be no seasonal variation on such Earth-like planets in the habitable zone of low-mass stars. These planets would have huge temperature differences between their poles, which would be in perpetual deep freeze, and their hot equators which in the long run would evaporate any atmosphere. This temperature difference would cause extreme winds and storms.

The second effect of these tides would be to heat up the exoplanet, similar to the tidal heating of Io, a moon of Jupiter that shows global vulcanism.

Finally, tides can cause the rotational period of the planet (the planet’s “day”) to synchronize with the orbital period (the planet’s “year”). This situation is identical to the Earth-moon setup: the moon only shows Earth one face, the other side being known as “the dark side of the moon.” As a result one half of the exoplanet receives extreme radiation from the star while the other half freezes in eternal darkness.

The habitable zone around low-mass stars is therefore not very comfortable — it may even be uninhabitable.

Here is my previous post on the factors needed for a habitable planet. Now we just have one more. I actually find this article sort of odd, because my understanding of stars was that only high-mass stars could support life at all. This is because if the mass of the planet was too low, the habitable zone wouldbe very close to the star. Being too close to the star causes tidal locking, which means that the planet doesn’t spin on its axis at all, and the same side faces the star. This is a life killer.

This astrophysicist who teaches at the University of Wisconsin explains it better than me.

Excerpt:

Higher-mass stars tend to be larger and luminous than their lower-mass counterparts. Therefore, their habitable zones are situated further out. In addition, however, their HZs are much broader. As an illustration,

  • a 0.2 solar-mass star’s HZ extends from 0.1 to 0.2 AU
  • a 1.0 solar-mass star’s HZ extends from 1 to 2 AU
  • a 40 solar-mass star’s HZ extends from 350 to 600 AU

On these grounds, it would seem that high-mass starts are the best candidates for finding planets within a habitable zone. However, these stars emit most of their radiation in the far ultraviolet (FUV), which can be highly damaging to life, and also contributes to photodissociation and the loss of water. Furthermore, the lifetimes of these stars is so short (around 10 million years) that there is not enough time for life to begin.

Very low mass stars have the longest lifetimes of all, but their HZs are very close in and very narrow. Therefore, the chances of a planet being formed within the HZ are small. Additionally, even if a planet did form within the HZ, it would become tidally locked, so that the same hemisphere always faced the star. Even though liquid water might exist on such a planet, the climactic conditions would probably be too severe to permit life.

In between the high- and low-mass stars lie those like our own Sun, which make up about 15% percent of the stars in the galaxy. These have reasonably-broad HZs, do not suffer from FUV irradiation, and have lifetimes of the order of 10 billion years. Therefore, they are the best candidates for harbouring planets where life might be able to begin.

This guy is just someone I found through a web search. He has a support-the-unions-sticker on his web page, so he’s a liberal crackpot. But he makes my point, anyway, so that’s good enough for me.

Maybe the new discovery is talking about this now, but I already knew about the tides and habitability, because I watched The Privileged Planet DVD. Actually that whole video is online, and the clip that talks about the habitable zone and water is linked in this blog post I wrote before.

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 discover that tides affect a planet’s habitability

Circumstellar Habitable Zone
Circumstellar Habitable Zone

Science Daily reports on a new factor that affects planetary habitability: tides. Specifically, tides can affect the surface temperature of a planet, which has to be within a certain range in order to support liquid water – a requirement for life of any conceivable kind.

Excerpt:

Tides can render the so-called “habitable zone” around low-mass stars uninhabitable. This is the main result of a recently published study by a team of astronomers led by René Heller of the Astrophysical Institute Potsdam.

[…]Until now, the two main drivers thought to determine a planet’s temperature were the distance to the central star and the composition of the planet’s atmosphere. By studying the tides caused by low-mass stars on their potential earth-like companions, Heller and his colleagues have concluded that tidal effects modify the traditional concept of the habitable zone.

Heller deduced this from three different effects. Firstly, tides can cause the axis of a planet`s rotation to become perpendicular to its orbit in just a few million years. In comparison, Earth’s axis of rotation is inclined by 23.5 degrees — an effect which causes our seasons. Owing to this effect, there would be no seasonal variation on such Earth-like planets in the habitable zone of low-mass stars. These planets would have huge temperature differences between their poles, which would be in perpetual deep freeze, and their hot equators which in the long run would evaporate any atmosphere. This temperature difference would cause extreme winds and storms.

The second effect of these tides would be to heat up the exoplanet, similar to the tidal heating of Io, a moon of Jupiter that shows global vulcanism.

Finally, tides can cause the rotational period of the planet (the planet’s “day”) to synchronize with the orbital period (the planet’s “year”). This situation is identical to the Earth-moon setup: the moon only shows Earth one face, the other side being known as “the dark side of the moon.” As a result one half of the exoplanet receives extreme radiation from the star while the other half freezes in eternal darkness.

The habitable zone around low-mass stars is therefore not very comfortable — it may even be uninhabitable.

Here is my previous post on the factors needed for a habitable planet. Now we just have one more. I actually find this article sort of odd, because my understanding of stars was that only high-mass stars could support life at all. This is because if the mass of the planet was too low, the habitable zone wouldbe very close to the star. Being too close to the star causes tidal locking, which means that the planet doesn’t spin on its axis at all, and the same side faces the star. This is a life killer.

This astrophysicist who teaches at the University of Wisconsin explains it better than me.

Excerpt:

Higher-mass stars tend to be larger and luminous than their lower-mass counterparts. Therefore, their habitable zones are situated further out. In addition, however, their HZs are much broader. As an illustration,

  • a 0.2 solar-mass star’s HZ extends from 0.1 to 0.2 AU
  • a 1.0 solar-mass star’s HZ extends from 1 to 2 AU
  • a 40 solar-mass star’s HZ extends from 350 to 600 AU

On these grounds, it would seem that high-mass starts are the best candidates for finding planets within a habitable zone. However, these stars emit most of their radiation in the far ultraviolet (FUV), which can be highly damaging to life, and also contributes to photodissociation and the loss of water. Furthermore, the lifetimes of these stars is so short (around 10 million years) that there is not enough time for life to begin.

Very low mass stars have the longest lifetimes of all, but their HZs are very close in and very narrow. Therefore, the chances of a planet being formed within the HZ are small. Additionally, even if a planet did form within the HZ, it would become tidally locked, so that the same hemisphere always faced the star. Even though liquid water might exist on such a planet, the climactic conditions would probably be too severe to permit life.

In between the high- and low-mass stars lie those like our own Sun, which make up about 15% percent of the stars in the galaxy. These have reasonably-broad HZs, do not suffer from FUV irradiation, and have lifetimes of the order of 10 billion years. Therefore, they are the best candidates for harbouring planets where life might be able to begin.

This guy is just someone I found through a web search. He has a support-the-unions-sticker on his web page, so he’s a liberal crackpot. But he makes my point, anyway, so that’s good enough for me.

Maybe the new discovery is talking about this now, but I already knew about the tides and habitability, because I watched The Privileged Planet DVD. Actually that whole video is online, and the clip that talks about the habitable zone and water is linked in this blog post I wrote before.