Tag Archives: Habitability

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

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.

Walter Bradley lectures on the creation and design of the universe

Dr. Walter L. Bradley
Dr. Walter L. Bradley

This lecture is special to me, because I bought a VHS tape of it just after I started working full-time, and watched it a million times. It changed my life. The lecture was delivered at the University of California, Santa Barbara.

About the speaker:

Dr. Bradley received his B.S. in Engineering Science and his Ph.D. in Materials Science from the University of Texas in Austin.

Dr. Bradley taught for eight years at the Colorado School of Mines before assuming a position as Professor of Mechanical Engineering at Texas A&M University (TAMU) in 1976.

During his 24 years at Texas A&M, Dr. Bradley served as Head of the Department of Mechanical Engineering at Texas A&M University and as Director of the Polymer Technology Center, and received five College of Engineering Research Awards. He has received over $4,500,000 in research grants and has published over 140 technical articles and book chapters. He has also co-authored “The Mystery Of Life’s Origin: Reassessing Current Theories. He is a Fellow of the American Society for Materials and of the American Scientific Affiliation and serves as a consultant for many Fortune 500 companies.

He currently serves as Distinguished Professor of Engineering at Baylor University.

The lecture: (63 minutes lecture, 25 minutes audience Q&A)

Summary slide:

This slide summarizes the content of the lecture
This slide summarizes the content of the lecture

Introduction:

  • At the beginning of the 20th century, people believed that the progress of science was pointing away from an intelligent Creator and Designer, and towards naturalism
  • A stream of new discoveries has shifted the support of science towards theism, and away from naturalism
  • Richard Dawkins, an atheist, says that nature only has the appearance of design, but that if you look closer, naturalistic mechanisms can account for the appearance of design
  • When deciding between design and apparent design (“designoid”), it matters whether you think there is an intelligence there to do the designing

Evidence #1: The Big Bang:

  • an eternal “steady state” universe is more compatible with naturalism, but a created universe is more compatible with a Creator
  • In 1929, Hubble used telescopes to observe that the light from distant galaxies was redshifted. The further away galaxies were, the faster they were moving away. Therefore, space is expanding in all directions, suggesting an explosive origin of the universe
  • In 1965, the discovery of the cosmic microwave background radiation matched a prediction of the Big Bang cosmology, and of the creation event
  • In 1992, the COBE space telescope allowed us to test four specific predictions of the Big Bang model, especially the predictions for light element abundances (hydrogen and helium), which matched the predictions of the creation model

Evidence #2: Simple mathematical structure of the physical laws

  • the simple mathematical structure of natural laws allows us to understand these laws, make discoveries, and engineer solutions to problems
  • early scientists saw the mathematical structure of the universe to mean that nature was designed by an intelligent to be understood
  • the fundamental equations of the laws of the universe can be easily written on one side of one sheet of paper
  • Eugene Wigner’s famous paper, “The Unreasonable Effectiveness of Mathematics in the Physical Sciences” makes the point that this simple structure is an unexpected gift that allows is to do science

Evidence #3: fine-tuning of the physical constants and quantities

  • in order for any kind of complex life to survive, we need stars that provide energy within specific ranges for long periods of time
  • in order for any kind of complex life to survive, we need planets with stable orbits that will not suffer from extreme temperature swings as it varies in distance from its star
  • in order for any kind of complex life to survive, we need stable atomic structure
  • in order for any kind of complex life to survive, we need to have chemical diversity and correct relative abundances of each element
  • organic life has minimum requirements: process energy, store information, replicate, and you can’t fulfill those functions if there is only one element, e.g. – hydrogen
  • the energy level from the photons from the sun have to match the energy levels of the different elements in order to drive the chemical bonding needed for life
  • These requirements for life of any imaginable type depend on the values of the constants and quantities. The constants and quantities cannot vary much from what they are, or the universe will lose the characteristics (above) that allow it to support complex life of any imaginable time
  • For example, ratio of strong force to electromagnetic force:
    – if 2% larger, then no stable hydrogen, no long-lived stars, no compounds containing hydrogen, e.g. – water
    – if 5% smaller, no stable stars, heavy hydrogen would be unstable, few elements other than hydrogen

Evidence #4: initial conditions for habitability

  • Universe: expansion rate of the universe must be fast enough to avoid a re-collapse, but slow enough to allow matter to clump together and form stars and planets for complex life to live on
  • Planet: right distance from the star to get the right climate
  • Planet: right mass to retain the right atmosphere

Evidence #5: origin of life and information theory

  • It’s possible to explain every process in an automobile engine using plain old naturalistic mechanisms – no supernatural explanation is necessary to understand the processes
  • But the existence of engine itself: engineering all the parts has to be explained by the work of an intelligence
  • Similarly, we can understand how living systems work, but the existence of the living systems requires an intelligence
  • Even the simplest living system has to perform minimal function: capture energy, store information and replicate
  • Living systems are composed of objects like proteins that are composed of sequences of components complex such that the order of the components gives the overall structure function
  • Developing the components for a simple living cell is very improbable – even given the large number of galaxies, stars and planets in the universe, it is unlikely that complex, embodied life would exist anywhere in the universe

Evidence #6: more initial conditions for habitability

  • Location within the galaxy: you need to be away from the center of the galaxy, because the explosions from dying stars, and excessive radiation will kill life
  • Location within the galaxy: you need to be close enough to the center in order catch the heavy elements you need for life from the explosions of other stars
  • Location within the galaxy: the best location is between two arms of  a spiral galaxy, where you can get the heavy elements you need from dying stars, but without being hit with explosions and harmful radiation
  • Star mass: determines rate at which the sun burns, determines the energy level of photons that are used to drive chemical bonding reactions, determines the length of time the star will be stable
  • Star mass: star mass must be the correct value in order to allow liquid water on the planet’s surface, while still preserving stable orbit

I wish there was more curiosity about science in churches, and young Christians understood how critical science is for grounding the rationality of the Christian worldview. We need to be training up more scientists who think about the big questions, like Dr. Walter Bradley.

Guillermo Gonzalez lectures on the corelation between habitability and discoverability

There are 5 video clips that make up the full lecture, which took place in 2007 at the University of California, Davis.

The playlist for all 5 clips is here.

About the speaker

Guillermo Gonzalez is an Associate Professor of Physics at Grove City College. He received his Ph.D. in Astronomy in 1993 from the University of Washington. He has done post-doctoral work at the University of Texas, Austin and at the University of Washington and has received fellowships, grants and awards from such institutions as NASA, the University of Washington, the Templeton Foundation, Sigma Xi (scientific research society) and the National Science Foundation.

Click here to learn more about the speaker.

The lecture

Here’s part 1 of 5:

And the rest are here:

Topics:

  • What is the Copernican Principle?
  • Is the Earth’s suitability for hosting life rare in the universe?
  • Does the Earth have to be the center of the universe to be special?
  • How similar to the Earth does a planet have to be to support life?
  • What is the definition of life?
  • What are the three minimal requirements for life of any kind?
  • Requirement 1: A molecule that can store information (carbon)
  • Requirement 2: A medium in which chemicals can interact (liquid water)
  • Requirement 3: A diverse set of chemical elements
  • What is the best environment for life to exist?
  • Our place in the solar system: the circumstellar habitable zone
  • Our place in the galaxy: the galactic habitable zones
  • Our time in the universe’s history: the cosmic habitable age
  • Other habitability requirements (e.g. – metal-rich star, massive moon, etc.)
  • The orchestration needed to create a habitable planet
  • How different factors depend on one another through time
  • How tweaking one factor can adversely affect other factors
  • How many possible places are there in the universe where life could emerge?
  • Given these probabilistic resources, should we expect that there is life elsewhere?
  • How to calculate probabilities using the “Product Rule”
  • Can we infer that there is a Designer just because life is rare? Or do we need more?

The corelation between habitability and measurability.

  • Are the habitable places in the universe also the best places to do science?
  • Do the factors that make Earth habitable also make it good for doing science?
  • Some places and times in the history of the universe are more habitable than others
  • Those exact places and times also allow us to make scientific discoveries
  • Observing solar eclipses and structure of our star, the Sun
  • Observing stars and galaxies
  • Observing the cosmic microwave background radiation
  • Observing the acceleration of the universe caused by dark matter and energy
  • Observing the abundances of light elements like helium of hydrogen
  • These observations support the big bang and fine-tuning arguments for God’s existence
  • It is exactly like placing observatories on the tops of mountains
  • There are observers existing in the best places to observe things
  • This is EXACTLY how the universe has been designed for making scientific discoveries

This argument from the “discoverability” of the universe has now been picked up by famous Christian philosopher Robin Collins, so we should expect to hear more about it in the future.

Is the probability of getting a universe that supports complex life 100%?

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

Let’s have a quick review of the famous fine-tuning argument to start.

The argument from cosmic fine-tuning looks at various constants and quantities in our universe that are set at particular values and notes that if any of the values of these constants and quantities were to change, then complex embodied life of any kind could not exist. The argument is fully in line with the standard Big Bang cosmology, and is based on mainstream science.

There are two kinds of finely-tuned initial conditions: 1) constants and 2) quantities. These constants and quantities have to be set within a narrow range in order to permit intelligent life. There are three explanations for this observation: law, chance or design. Law is rejected because the numerical values of constants and quantities are set at the beginning of the universe – when there was no matter, space or time. The values of the constants and quantities were not determined by anything causally prior to the moment the universe began to exist. Chance is not a good explanation, because the probabilities are far, far too small for us to reasonably believe them (e.g. – the chance is 1 in X, where X is much higher than the number of subatomic particles in the visible universe). Since the fine-tuning is not due to law or chance, it must be due to design.

Here’s one example of something that is set correctly to allow complex, embodied life from The New Scientist:

The feebleness of gravity is something we should be grateful for. If it were a tiny bit stronger, none of us would be here to scoff at its puny nature.

The moment of the universe‘s birth created both matter and an expanding space-time in which this matter could exist. While gravity pulled the matter together, the expansion of space drew particles of matter apart – and the further apart they drifted, the weaker their mutual attraction became.

It turns out that the struggle between these two was balanced on a knife-edge. If the expansion of space had overwhelmed the pull of gravity in the newborn universe, stars, galaxies and humans would never have been able to form. If, on the other hand, gravity had been much stronger, stars and galaxies might have formed, but they would have quickly collapsed in on themselves and each other. What’s more, the gravitational distortion of space-time would have folded up the universe in a big crunch. Our cosmic history could have been over by now.

Only the middle ground, where the expansion and the gravitational strength balance to within 1 part in 1015 at 1 second after the big bang, allows life to form.

Changing the value at all means there would be no complex, embodied life of any kind anywhere in this universe.

Here’s a quick video clip to explain what The New Scientist is saying:

Now, this is going to surprise you, but there are some non-theists who try to argue that the finely-tuned constants and quantities that were set up at the beginning of the universe – long before we ever existed – are actually explained by our existence today. 

Atheist Jeffery Lowder summarizes a debate between William Lane Craig and Doug Jesseph, and Jesseph says something like this:

Craig’s argument is like asking the question, “What are your chances of landing in a universe hospitable to life, assuming you were tossed into any old universe whatever.” That is precisely not the point. It’s presupposed in the question that you’re already in a universe which favors life. Confuses conditional probability with unconditional probability.

Unlike me, Lowder is never snarky in his summaries, so this is guaranteed to be accurate.

Here’s what Dr. William Lane Craig says to that idea that our being here explains the fine-tuning:

Now some people have tried to avoid this conclusion by saying that we really shouldn’t be surprised at the enormous improbability of the fine-tuning of the universe because, after all, if the universe were not fine-tuned then we wouldn’t be here to be surprised about it. Given that we are here we should expect the universe to be fine-tuned. But I think the fallacy of this reasoning can be made clear simply by a parallel illustration. Imagine that you were traveling abroad in a third world country and you were arrested on trumped up drug charges, and you were dragged in front of a firing squad of 100 trained marksmen, all with rifles aimed at your heart to be executed. And you hear the command given – “Ready, aim, fire!” And you hear the deafening roar of the guns. And then you observe that you are still alive, that all of the 100 marksmen missed! Now, what would you conclude? Well, I guess I really shouldn’t be surprised that they all missed; after all, if they hadn’t all missed I wouldn’t be here to be surprised about it. Given that I am here, I should expect them all to miss. Of course not. You would immediately suspect that they all missed on purpose. That the whole thing was a set up engineered by some person for some reason. And in exactly the same way, given the incomprehensible improbability of the fine-tuning of the initial conditions for intelligent life, it is rational to believe that this is not the result of chance but of design.

Does it make sense? It’s true that any arrangement of bullet holes in a condemned spy is as unlikely as any other, but the vast majority of possible arrangements of 100 bullet holes result in you being dead. Being marksmen, the shooters definitely know how to hit a target at close range. It doesn’t matter if some hit your head and some hit your heart and some hit your throat – the most common consequence of a hundred bullets fired by expert marksmen at you is “dead you” – regardless of the specific arrangement of bullet holes. If you find yourself not dead, that requires an explanation. The explanation is design.

The importance of having a narrative when confronting the assumption of naturalism

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

How do you present theism as a rational belief to a person who thinks that the progress of science has removed the need for God?

Canadian science writer Denyse O’Leary writes about the history of cosmology at Evolution News.

Excerpt:

What help has materialism been in understanding the universe’s beginnings?

Many in cosmology have never made any secret of their dislike of the Big Bang, the generally accepted start to our universe first suggested by Belgian priest Georges Lemaître (1894-1966).

On the face of it, that is odd. The theory accounts well enough for the evidence. Nothing ever completely accounts for all the evidence, of course, because evidence is always changing a bit. But the Big Bang has enabled accurate prediction.

In which case, its hostile reception might surprise you. British astronomer Fred Hoyle (1915-2001) gave the theory its name in one of his papers — as a joke. Another noted astronomer, Arthur Eddington (1882-1944), exclaimed in 1933, “I feel almost an indignation that anyone should believe in it — except myself.” Why? Because “The beginning seems to present insuperable difficulties unless we agree to look on it as frankly supernatural.”

One team of astrophysicists (1973) opined that it “involves a certain metaphysical aspect which may be either appealing or revolting.” Robert Jastrow (1925-2008), head of NASA’s Goddard Institute for Space Studies, initially remarked, “On both scientific and philosophical grounds, the concept of an eternal Universe seems more acceptable than the concept of a transient Universe that springs into being suddenly, and then fades slowly into darkness.” And Templeton Prize winner (2011) Martin Rees recalls his mentor Dennis Sciama’s dogged commitment to an eternal universe, no-Big Bang model:

For him, as for its inventors, it had a deep philosophical appeal — the universe existed, from everlasting to everlasting, in a uniquely self-consistent state. When conflicting evidence emerged, Sciama therefore sought a loophole (even an unlikely seeming one) rather as a defense lawyer clutches at any argument to rebut the prosecution case.

Evidence forced theorists to abandon their preferred eternal-universe model. From the mid 1940s, Hoyle attempted to disprove the theory he named. Until 1964, when his preferred theory, the Steady State, lost an evidence test.

Here is a quick summary of some of the experimental evidence that emerged in the last few decades that caused naturalists to abandon the eternal universe that they loved so much when they were younger.

The importance of having a narrative

Now I want to make a very, very important point about Christianity and the progress of science. And that point is that it is very important that Christians present the evidence in exactly the way that Denyse presented it in that article – in its historical context, featuring the conflict between naturalists and the experimental evidence.

All Christians should be familiar with the following basic pieces of evidence which fit the war between science and naturalism narrative:

  1. The origin of the universe
  2. The cosmic fine-tuning
  3. The origin of life (biological information)
  4. The sudden origin of the Cambrian phyla
  5. The habitability/observability correlation

When you talk about these evidences as a Christian theist to non-Christians, you have to have cultivated a genuine interest in reconciling your beliefs with science. You have to accept that there are two books that reveal God’s character and attributes. The book of nature, and the book of Scripture. And you need to be flexible about getting these two books to fit together. The book of nature gives us natural theology (see Romans 1). It tells us that God is Creator and Designer. The book of Scripture tells us that God stepped into history as a man to save us by taking the punishment for our headlong rush away from God, which the Bible calls sin. Science is one way that humans can recover some of basic knowledge about God. Knowledge that is only possible because God created and designed the universe (and us) in such a way that we are capable of making discoveries, and that the universe is capable of being explored and understood.

It’s very important to present these five basic evidences to non-Christians in the historical context. And here is the story you must tell: “In the beginning, there was the naturalism, and the naturalism tried to argue from ignorance that God was not Creator and God was not Designer. And then came the science, and now people have to give up their naturalism in order to not be crazy and irrational”. That’s the narrative you use when talking to non-Christians about science.

In the beginning was the naturalism:

  1. In pre-scientific times, atheists maintained that the universe was eternal
  2. In pre-scientific times, atheists maintained that a life-permitting universe was as likely as a life-prohibiting universe
  3. In pre-scientific times, atheists maintained that the cell was a simple blob of jello that could spontaneously emerge in some warm pond
  4. In pre-scientific times, atheists maintained that the sudden origin of the Cambrian phyla would be explained by subsequent fossil discoveries
  5. In pre-scientific times, atheists maintained that there was nothing special about our galaxy, solar system, planet or moon

But then science progressed by doing experiments and making observations:

  1. Scientists discovered redshift and the cosmic microwave background radiation (evidence for a cosmic beginning) and more!
  2. Scientists discovered the fine-tuning of gravity and of the cosmological constant and more!
  3. Scientists discovered protein sequencing and exposed the myth of “junk DNA” and more!
  4. Scientists discovered an even shorter Cambrian explosion period and the absence of precursor fossils and more!
  5. Scientists discovered galactic habitable zones and circumstellar habitable zones and more!

And now rational people – people who want to have true beliefs about reality – need to abandon a false religion (naturalism).

Now naturally, science is in a state of flux and things change. But you have to look at the trend of discoveries, and those trends are clearly going against naturalism, and in favor of Christian theism. No one is arguing for a deductive proof here, we are simply looking at the evidence we have today and proportioning our belief to the concrete evidence we have today. People who are guided by reason should not seek to construct a worldview by leveraging speculations about future discoveries and mere possibilities. We should instead believe what is more probable than not. That’s what a rational seeker of truth ought to do. Proportion belief to probabilities based on current, concrete knowledge.

Atheism, as a worldview, is not rooted in an honest assessment about what science tells us about reality. Atheism is rooted in a religion: naturalism. And the troubling thing we learn from looking at the history of science is that this religion of naturalism is insulated from correction from the progress of science. Nothing that science reveals about nature seems to be able to put a dent in the religion of naturalism, at least for most atheists.

It falls to us Christian theists, then, to hold them accountable for their abuse and misrepresentation of science. And that means telling the story of the progress of science accurately, and accurately calling out the religion of naturalism for what it is – a religion rooted in blind faith and ignorance that has been repeatedly and convincingly falsified by the progress of science in the modern era.

Positive arguments for Christian theism