Recently, I picked up the audio book version of “The Privileged Planet”, which is a book by philosopher / economist Jay Richards and astronomer Guillermo Gonzalez. This book is different from books about the origin of the universe and cosmic fine-tuning. It talks about what it takes to make a habitable planet. And it talks about how the habitable places in the universe are also the best places to make scientific discoveries.
Christian scholar Jay Richards was interviewed by Brian Auten of Apologetics 315.
This is going to be old news to readers of this blog who are familiar with the Michael Strauss, Walter Bradley and Guillermo Gonzalez lectures on habitability and fine-tuning. But, it’s nice to see these ideas show up in one of the most prestigious peer-reviewed science journals in the world (if not the most prestigious).
Scientists have known for several years now that stars, galaxies, and almost everything in the universe is moving away from us (and from everything else) at a faster and faster pace. Now, it turns out that the unknown forces behind the rate of this accelerating expansion—a mathematical value called the cosmological constant—may play a previously unexplored role in creating the right conditions for life.
That’s the conclusion of a group of physicists who studied the effects of massive cosmic explosions, called gamma ray bursts, on planets. They found that when it comes to growing life, it’s better to be far away from your neighbors—and the cosmological constant helps thin out the neighborhood.
“In dense environments, you have many explosions, and you’re too close to them,” says cosmologist and theoretical physicist Raul Jimenez of the University of Barcelona in Spain and an author on the new study. “It’s best to be in the outskirts, or in regions that have not been highly populated by small galaxies—and that’s exactly where the Milky Way is.”
Jimenez and his team had previously shown that gamma ray bursts could cause mass extinctions or make planets inhospitable to life by zapping them with radiation and destroying their ozone layer. The bursts channel the radiation into tight beams so powerful that one of them sweeping through a star system could wipe out planets in another galaxy. For their latest work, published this month in Physical Review Letters, they wanted to apply those findings on a broader scale and determine what type of universe would be most likely to support life.
The research is the latest investigation to touch on the so-called anthropic principle: the idea that in some sense the universe is tuned for the emergence of intelligent life. If the forces of nature were much stronger or weaker than physicists observe, proponents note, crucial building blocks of life—such fundamental particles, atoms, or the long-chain molecules needed for the chemistry of life—might not have formed, resulting in a sterile or even completely chaotic universe.
Basically, the best place for a galaxy that permits complex, embodied life to exist is one where you can pick up enough heavy elements from dying stars nearby, but not be in an area that is so crowded by stars that you will be murdered by intense gamma radiation when they die.
The cosmological constant has to be set just right that we spread out enough to make space between spiral arms for life-permitting solar systems, but no so spread out that we cannot pick up the heavy elements we need for a metal-rich star, a moon, and the bodies of the intelligent agents themselves.
As it turns out, our universe seems to get it just about right. The existing cosmological constant means the rate of expansion is large enough that it minimizes planets’ exposure to gamma ray bursts, but small enough to form lots of hydrogen-burning stars around which life can exist. (A faster expansion rate would make it hard for gas clouds to collapse into stars.)
Jimenez says the expansion of the universe played a bigger role in creating habitable worlds than he expected. “It was surprising to me that you do need the cosmological constant to clear out the region and make it more suburbanlike,” he says.
Remember, this is only one of many characteristics that must obtain in order for a have a location in the universe that can support complex, embodied life of any conceivable kind.
Let’s review the big picture
Time for me to list out some of the things that are required for a galaxy, solar system and planet to support complex embodied life. Not just life as we know it, but life of any conceivable kind given these laws of physics.
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
an oxygen-rich atmosphere
a sweeper planet to deflect comets, etc.
planetary neighbors must have non-eccentric orbits
It’s not easy to make a planet that supports life. For those who are interested in reaching out to God, he has left us an abundance of evidence for his existence – and his attention to detail.
Oh, and there’s also a circumstellar habitable zone:
And remember, these requirements for a habitable planet are downstream from the cosmic fine-tuning of constants and quantities that occurs at the Big Bang. No point in talking about the need for plate tectonics if you only have hydrogen in your universe. The habitability requirements are a further problem that comes after the fine-tuning problem.
The best book to read on this topic is “The Privileged Planet“, by Guillermo Gonzalez and Jay W. Richards. The latter is one of my absolute favorite Christian scholars, a real renaissance man. If the book is too much, there is a DVD by the same name that covers everything you need to know at a high level. Just FYI, Gonzalez made the cover of Scientific American in 2001, for his research on habitable zones. This is real evidence you can discuss with anyone, anywhere.
You can also watch the DVD for FREE on YouTube. Not sure how long that will be there. If you like it, buy the DVD, so you can show your friends.
What does science tell us about God?
– the discoveries of Copernicus made humans less significant in the universe
– the discoveries of Darwin should that humans are an accident
– but this all pre-modern science
– what do the latest findings of science say about God?
Evidence #1: the origin of the universe
– the steady state model supports atheism, but was disproved by the latest discoveries
– the oscillating model supports atheism, but was disproved by the latest discoveries
– the big bang model supports theism, and it is supported by multiple recent discoveries
– the quantum gravity model supports atheism, but it pure theory and has never been tested or confirmed by experiment and observation
Evidence #2: the fine-tuning of physical constants for life
– there are over 100 examples of constants that must be selected within a narrow range in order for the universe to support the minimal requirements for life
– example: mass density
– example: strong nuclear force (what he studies)
– example: carbon formation
Evidence #3: the fine-tuning of our planet for habitability
– the type of galaxy and our location in it
– our solar system and our star
– our planet
– our moon
It’s a good lecture explaining a couple of basic arguments for a cosmic Creator and Designer. If you add the origin of life and the Cambrian explosion (Stephen C. Meyer’s arguments), then you will be solid on the basic scientific arguments for a Creator and Designer of the universe.