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Is Kepler-452b an Earth-like planet? Does it support life?

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

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 planet has to be far enough from the star to avoid tidal locking and solar flares
  • 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
  • planet mass must be enough to retain an atmosphere, but not so massive to cause a greenhouse effect

Now what happens if we disregard all of those characteristics, and just classify an Earth-like planet as one which is the same size and receives the same amount of radiation from its star? Well, then you end up labeling a whole bunch of planets as “Earth-like” that really don’t permit life.

Here’s an article from The Conversation which talks about a recent case of science fiction trumping science facts. (H/T JoeCoder)

Excerpt:

NASA’s announcement of the discovery of a new extrasolar planet has been met with a lot of excitement. But the truth is that it is impossible to judge whether it is similar to Earth with the few parameters we have – it might just as well resemble Venus, or something entirely different.

The planet, Kepler-452b, was detected by the Kepler telescope, which looks for small dips in a star’s brightness as planets pass across its surface. It is a method that measures the planet’s size, but not its mass. Conditions on Kepler-452b are therefore entirely estimated from just two data points: the planet’s size and the radiation it receives from its star.

Size and radiation from its star? That’s all?

More:

Kepler-452b was found to be 60% larger than the Earth. It orbits a sun-like star once every 384.84 days. As a result, the planet receives a similar amount of radiation as we do from the sun; just 10% higher. This puts the Kepler-452b in the so-called “habitable zone”; a term that sounds excitingly promising for life, but is actually misleading.

The habitable zone is the region around a star where liquid water could exist on a suitable planet’s surface. The key word is “suitable”. A gas-planet like Neptune in the habitable zone would clearly not host oceans since it has no surface. The habitable zone is best considered as a way of narrowing down candidates for investigation in future missions.

What about plate tectonics – does it have that?

Kepler-452b’s radius puts it on the brink of the divide between a rocky planet and a small Neptune. In the research paper that announced the discovery, the authors put the probability of the planet having a rocky surface about 50%-60%, so it is by no means sure.

Rocky planets like the Earth are made from iron, silicon, magnesium and carbon. While these ingredients are expected to be similar in other planetary systems, their relative quantities may be quite different. Variations would produce alternative planet interiors with a completely different geology.

For example, a planet made mostly out of carbon could have mantles made of diamond, meaning they would not move easily. This would bring plate tectonics to a screeching halt. Similarly, magnesium-rich planets may have thick crusts that are resilient to fractures. Both results would limit volcano activity that is thought to be essential for sustaining a long lasting atmosphere.

What about retaining the right kind of atmosphere, which depends on the mass of the planet. Does it have that?

If Kepler-452b nevertheless has a similar composition to Earth, we run into another problem: gravity. Based on an Earth-like density, Kepler-452b would be five times more massive than our planet.

This would correspond to a stronger gravitational pull, capable of drawing in a thick atmosphere to create a potential runaway greenhouse effect, which means that the planet’s temperature continues to climb. This could be especially problematic as the increasing energy from its ageing sun is likely to be heating up the surface. Any water present on the planet’s surface would then boil away, leaving a super-Venus, rather than a super-Earth.

You might remember that “retain atmosphere” requirement from the lecture by Walter Bradley that I posted with a summary a few days ago.

What about having a Jupiter-sized sweeper planet – does it have that?

Another problem is that Kepler-452b is alone. As far as we know, there are no other planets in the same system. This is an issue because it was most likely our giant gas planets that helped direct water to Earth.

At our position from the sun, the dust grains that came together to form the Earth were too warm to contain ice. Instead, they produced a dry planet that later had its water most likely delivered by icy meteorites. These frozen seas formed in the colder outer solar system and were kicked towards Earth by Jupiter’s huge gravitational tug. No Jupiter analogue for Kepler-452b might mean no water and therefore, no recognisable life.

What about having a magnetic field – does it have that?

All these possibilities mean that even a planet exactly the same size as Earth, orbiting a star identical to our sun on an orbit that takes exactly one year might still be an utterly alien world. Conditions on a planet’s surface are dictated by a myriad of factors – including atmosphere, magnetic fields and planet interactions, which we currently have no way of measuring.

You know, after the whole global warming hoax, you would think that NASA would have learned their lesson about sensationalizing wild-assed guesses in order to scare up more research money from gullible taxpayers who watch too much Star Trek and Star Wars.

The best answer to this is for parents to make sure that their kids are learning the facts about astrobiology from books like “The Privileged Planet” and “Rare Earth”, where the full list of requirements for a life-supporting planet will be found. Pity that we can’t rely on taxpayer-funded public schools to do that for us, because they are too busy pushing Planned Parenthood’s sex education curriculum and global warming fears, instead of real science and engineering.

Polemics

What historical evidence is there to support the post-mortem appearances of Jesus?

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Eric Chabot of Ratio Christi Ohio State University has a great post up about the post-mortem appearances of Jesus.

The post contains:

  • a list of the post-mortem resurrection appearances
  • quotations by skeptical historians about those appearances
  • alternative naturalistic explanations of the appearances
  • responses to those naturalistic explanations

Although there is a lot of research that went into the post, it’s not very long to read. The majority of scholars accept the appearances, because they appear in so many different sources and because some of those sources are very early, especially Paul’s statement of the early Christian creed in 1 Corinthians 15:3-7, which is from about 1-3 years after Jesus was executed by the Romans. Eric’s post lists out some of the skeptical scholars who the appearances, and you can see how they allude to the historical criteria that they are using. (If you want to sort of double-check the details, I blogged about how historians investigate ancient sources before)

Let’s take a look at some of the names you might recognize:

E.P. Sanders:

That Jesus’ followers (and later Paul) had resurrection experiences is, in my judgment, a fact. What the reality was that gave rise to the experiences I do not know. “I do not regard deliberate fraud as a worthwhile explanation. Many of the people in these lists were to spend the rest of their lives proclaiming that they had seen the risen Lord, and several of them would die for their cause. Moreover, a calculated deception should have produced great unanimity. Instead, there seem to have been competitors: ‘I saw him first!’ ‘No! I did.’ Paul’s tradition that 500 people saw Jesus at the same time has led some people to suggest that Jesus’ followers suffered mass hysteria. But mass hysteria does not explain the other traditions.” “Finally we know that after his death his followers experienced what they described as the ‘resurrection’: the appearance of a living but transformed person who had actually died. They believed this, they lived it, and they died for it.”[1]

Bart Ehrman:

It is a historical fact that some of Jesus’ followers came to believe that he had been raised from the dead soon after his execution. We know some of these believers by name; one of them, the apostle Paul, claims quite plainly to have seen Jesus alive after his death. Thus, for the historian, Christianity begins after the death of Jesus, not with the resurrection itself, but with the belief in the resurrection.[2]

Ehrman also says:

We can say with complete certainty that some of his disciples at some later time insisted that . . . he soon appeared to them, convincing them that he had been raised from the dead.[3]

 Ehrman also goes onto say:  

Historians, of course, have no difficulty whatsoever speaking about the belief in Jesus’ resurrection, since this is a matter of public record.[4]

Why, then, did some of the disciples claim to see Jesus alive after his crucifixion? I don’t doubt at all that some disciples claimed this. We don’t have any of their written testimony, but Paul, writing about twenty-five years later, indicates that this is what they claimed, and I don’t think he is making it up. And he knew are least a couple of them, whom he met just three years after the event (Galatians 1:18-19).[5]

Marcus Borg

The historical ground of Easter is very simple: the followers of Jesus, both then and now, continued to experience Jesus as a living reality after his death. In the early Christian community, these experiences included visions or apparitions of Jesus. [8]

The references to Paul are because of the early creed he records in 1 Corinthians 15:3-7, and his conversations with the other eyewitnesses in Galatians. Eric has another post where he goes over that early creed, and it is something that every Christian should know about. It’s really kind of surprising that you never hear a sermon on that early creed in church, where they generally sort of assume that you believe everything in the Bible on faith. But skeptical historians don’t believe in the post-mortem appearances by faith – they believe it (in part) because of 1 Corinthians 15:3-7.

If you want to see a Christian scholar make the case for the resurrection appearances in a debate, then here is a post I wrote with the video, audio and summary of the William Lane Craig vs James Crossley debate on the resurrection.

Polemics

How do atheists try to accommodate the Big Bang in their worldview?

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J. Warner Wallace: God's Crime Scene
J. Warner Wallace: God’s Crime Scene

OK, so J. Warner Wallace has a new book out and it’s about science and God. I know, because I saw pictures of his reading list, that he has read tons and tons of atheists like Carl Sagan, Lawrence Krauss and so on.

He’s writing about some of the things he learned from all this reading on his blog, and I wanted to link to something about Lawrence Krauss trying to accommodate the Big Bang within his worldview of atheism.

Wallace writes:

One of the key pieces of evidence in the universe is simply it’s origin. If our universe began to exist, what could have caused it’s beginning? How did everything (all space, time and matter) come into existence from nothing? One way atheist physicists have navigated this dilemma has simply been to redefine the terms they have been using. What do we mean when we say “everything” or “nothing”? At first these two terms might seem rather self-explanatory, but it’s important for us to take the time to define the words. As I’ve already stated, by “everything” we mean all space, time and matter. That’s right, space is “something”; empty space is part of “everything” not part of “nothing”. For some of us, that’s an interesting concept that might be hard to grasp, but it’s an important distinction that must be understood. When we say “nothing”, we mean the complete absence of everything; the thorough non-existence of anything at all (including all space time and matter). These two terms, when defined in this way, are consistent with the principles of the Standard Cosmological Model, but demonstrate the dilemma. If everything came from nothing, what caused this to occur? What is the non-spatial, atemporal, immaterial, uncaused, first cause of the universe? A cause of this sort sounds a lot like a supernatural Being, and that’s why I think many naturalists have begun to redefine the terms.

Lawrence Krauss, Arizona State University Professor (School of Earth and Space Exploration and Director of the Origins Initiative) wrote a book entitled, “A Universe from Nothing: Why There Is Something Rather than Nothing”. As part of the promotion for the book, Krauss appeared on the Colbert Report where he was interviewed by comedian Stephen Colbert. During the interview, Krauss tried to redefine “nothing” to avoid the need for a supernatural first cause:

“Physics has changed what we mean by nothing… Empty space is a boiling, bubbling brew of virtual particles popping in and out of existence… if you wait long enough, that kind of nothing will always produce particles.” (Colbert Nation, June 21st, 2012)

Now if you’re not careful, you might miss Krauss’ subtle redefinition. In describing the sudden appearance of matter (“particles”), Krauss assumes the prior existence of space (“empty space”) and time (“if you wait long enough”). If you’ve got some empty space and wait long enough, matter appears. For Krauss, the “nothing” from which the universe comes includes two common features of “everything” (space and time), and something more (virtual particles). This leaves us with the real question: “Where did the space, time and virtual particles come from (given all our evidence points to their origination at the beginning of our universe)?” Krauss avoids this inquiry by moving space and time from the category of “something” to the category of “nothing”.

If you’ve got a teenager in your house, you might recognize Krauss’ approach to language. I bet you’ve seen your teenager open the refrigerator door, gaze at all the nutritious fruits and vegetables on the shelves, then lament that there is “nothing to eat.”

I used to say that when I was a teenager, but I grew out of it. I didn’t go on the Comedy Channel and try to convince everyone that what I was saying about the refrigerator was scientific.

Anyway, here is a debate between William Lane Craig and Lawrence Krauss, if you want to see how Krauss defends his “refrigerator has nothing to eat” view of cosmology. I know everybody and even many Christians all think that we have something to hide when it comes to science, but if you would just watch these debates, you would see that there is nothing to fear from science at all. We own it.

Meanwhile, I want to show you that this is not at all rare among atheists.

Look, here is Peter Atkins explaining how he makes the Big Bang reconcile with his atheism – and notice that it’s a completely different view than Krauss:

So, just who is this Peter Atkins, and why is he a good spokesman for atheism?

From his Wikipedia bio.

Peter William Atkins (born August 10, 1940) is an English chemist and a fellow and professor of chemistry at Lincoln College of the University of Oxford. He is a prolific writer of popular chemistry textbooks, including Physical Chemistry, 8th ed. (with Julio de Paula of Haverford College), Inorganic Chemistry, and Molecular Quantum Mechanics, 4th ed. Atkins is also the author of a number of science books for the general public, including Atkins’ Molecules and Galileo’s Finger: The Ten Great Ideas of Science.

[…]Atkins is a well-known atheist and supporter of many of Richard Dawkins’ ideas. He has written and spoken on issues of humanism, atheism, and what he sees as the incompatibility between science and religion. According to Atkins, whereas religion scorns the power of human comprehension, science respects it.

[…]He was the first Senior Member for the Oxford Secular Society and an Honorary Associate of the National Secular Society. He is also a member of the Advisory Board of The Reason Project, a US-based charitable foundation devoted to spreading scientific knowledge and secular values in society. The organisation is led by fellow atheist and author Sam Harris.

Now watch that 6-minute video above. Peter Atkins thinks that nothing exists. He thinks he doesn’t exist. He thinks that you don’t exist. This is how atheism adapts to a world where the Big Bang creation event is fact.

I think Peter Atkins should join Lawrence Krauss on the Comedy Channel and present that view. I would laugh. Wouldn’t you?