Tag Archives: Habitable Zone

Harvard astrophysicist backs the Rare Earth hypothesis

What is the Rare Earth hypothesis?

It’s the thesis of a recent book written by two scientists at the University of Washington.

Here’s the blurb:

What determines whether complex life will arise on a planet? How frequent is life in the Universe?

In this exciting new book, distinguished paleontologist Peter D. Ward and noted astronomer Donald Brownlee team up to give us a fascinating synthesis of what’s now known about the rise of life on Earth and how it sheds light on possibilities for organic life forms elsewhere in the Universe.

Life, Ward and Brownlee assert, is paradoxically both very common and almost nowhere. The conditions that foster the beginnings of life in our galaxy are plentiful. But contrary to the usual assumption that if alien life exists, it’s bound to be intelligent, the authors contend that the kind of complex life we find on Earth is unlikely to exist anywhere else; indeed it is probably unique to our planet.

With broad expertise and wonderful descriptive imagery, the authors give us a compelling argument, a splendid introduction to the emerging field of astrobiology, and a lively discussion of the remarkable findings that are being generated by new research. We learn not only about the extraordinary creatures living in conditions once though inimical to life and the latest evidence of early life on Earth, but also about the discoveries of extrasolar planets, the parts Jupiter and the Moon have played in our survival, and even the crucial role of continental drift in our existence.

Insightful, well-written, and at the cutting edge of modern scientific investigation, Rare Earth should interest anyone who wants to know about life elsewhere and gain a fresh perspective on life at home which, if the authors are right, is even more precious than we may ever have imagined.

And here’s a review by Library Journal:

“Renowned paleontologist Ward (Univ. of Washington), who has authored numerous books and articles, and Brownlee, a noted astronomer who has also researched extraterrestrial materials, combine their interests, research, and collaborative thoughts to present a startling new hypothesis: bacterial life forms may be in many galaxies, but complex life forms, like those that have evolved on Earth, are rare in the universe. Ward and Brownlee attribute Earth’s evolutionary achievements to the following critical factors: our optimal distance from the sun, the positive effects of the moon’s gravity on our climate, plate tectonics and continental drift, the right types of metals and elements, ample liquid water, maintainance of the correct amount of internal heat to keep surface temperatures within a habitable range, and a gaseous planet the size of Jupiter to shield Earth from catastrophic meteoric bombardment. Arguing that complex life is a rare event in the universe, this compelling book magnifies the significance — and tragedy — of species extinction. Highly recommended for all public and academic libraries.”

Note that Peter Ward is a militant atheist (he has debated against Stephen C. Meyer), and Donald Brownlee is an agnostic. These are not Christians, nor are they even theists. However, I have the book, I have read the book, and I recommend the book. I usually have this book on my shelf at work for show-and-tell.

Now for the latest news about the hypothesis of the book. (H/T Brian Auten of Apologetics 315)

There are always going to be optimistic predictions by scientists who need to attract research funding, but those are hopes and speculations. The data we have today says Earth is rare. The number of conditions required for complex life of any kind is too high for us to be optimistic about alien life in this galaxy, at least. And as the number of requirements for life roll in, the odds of finding alien life that can contact us get slimmer and slimmer.

From the UK Daily Mail. (H/T Peter S. Williams)

Excerpt:

Dr Howard Smith, a senior astrophysicist at Harvard University, believes there is very little hope of discovering aliens and, even if we did, it would be almost impossible to make contact.

So far astronomers have discovered a total of 500 planets in distant solar systems – known as extrasolar systems – although they believe billions of others exist.

But Dr Smith points out that many of these planets are either too close to their sun or too far away, meaning their surface temperatures are so extreme they could not support life.

Others have unusual orbits which cause vast temperature variations making it impossible for water to exist as a liquid – an essential element for life.

Dr Smith said: ‘We have found that most other planets and solar systems are wildly different from our own.

‘They are very hostile to life as we know it.’

‘The new information we are getting suggests we could effectively be alone in the universe.

‘There are very few solar systems or planets like ours. It means it is highly unlikely there are any planets with intelligent life close enough for us to make contact.’ But his controversial suggestions contradict other leading scientists – who have claimed aliens almost certainly exist.

These arguments are actually quite useful, and I include them in my standard list of scientific arguments for theism. (See below) You have to know this stuff cold. Most people believe in aliens because they watched movies made by artists. As a result, they think that humans are nothing special and that God is not interested in us in particular. Which is very convenient for them, because it means they can do whatever they want and not care what God thinks about what they are doing. If you want to defend against the idea that humans are nothing special, and that we were not placed here for a purpose, and that we are not accountable and obligated to seek and know the Creator/Designer, then you’ll need more than feelings. You’ll need science. You’ll need the best science available.

Related posts

Does God exist? Is there any scientific evidence to prove that God exists?

Since I haven’t talked about science in a while, I thought that now would be a good time to list some of the more common arguments for a Creator and Designer of the universe and/or intelligent life. I like to use arguments drawn from mainstream science that do not assume the Bible or inerrancy or anything specifically religious. The arguments below all show that the reality we live in exhibits effects in nature that are not explained by particles in motion, chance and the operation of natural laws.

First, here’s the list of a few of the better-known arguments:

The average knuckle-dragging atheist will not be familiar with any of these arguments, will have never seen them used in academic debates, and will not even click through to read about them. That’s atheism these days – it’s non-cognitive. Atheism is all about escaping from moral values and moral obligations, which are not even rationally grounded by atheism.

The point of being familiar with these arguments is to show that religion and science are virtually identical. Both are trying to explain the external world. Both are bound by the laws of logic. Both use evidence to verify and falsify claims. For example, the discovery of the origin of the universe falsifies Hinduism, Buddhism and Mormonism, but it leaves Christianity, Islam and Judaism unscathed. All religions make truth claims and those claims can be tested against what science tells us about the world.

What is the significance of scientific progress for Christians?

Some general points to know when presenting these arguments.

1. You need to emphasize that atheism is in full flight away from the progress of science. Each of these arguments has gotten stronger as the evidence grew and grew. For example, scientists had to be forced to turn away from the eternal universe as new discoveries arrived, such as the cosmic microwave background radiation measurements. Scientists had to turn away from the view that the cosmological constants are nothing special, as more and more fine-tuned quantities were discovered.

2. Christians need to pay attention in school and score top grades in mathematics and experimental sciences. Science is God-friendly, and we need to have Christians doing cutting edge research in the best labs at the universities. Think of the work done by Doug Axe at Cambridge University in which he was able to publish research showing that very few sequences of amino acids have biological function, so getting functional sequences at random is virtually impossible. One of Doug’s papers is here. We need more people like him.

3. Each of these arguments needs to be studied in the context of polemics and debates. The best way to present each of these arguments is by presenting them as a struggle against opposing forces. For example, when talking about the big bang, emphasize how atheists kept trying to come up with eternal universe speculations. When talking about the fine-tuning, talk about the unobservable multiverse. When talking about irreducible complexity, talk about the co-option fallacy. Don’t preach – teach the controversy.

4. Don’t make lazy excuses about how scientific evidence doesn’t persuade non-Christians. Science is absolutely the core of any argument for Christianity, along with the case for the resurrection of Jesus. Christianity is about knowledge. Christians who refuse to subject their faith to science are probably just trying to make sure that Christianity isn’t so true that it dictates how they should live. They like the uncertainty of blind faith, because it preserves their autonomy to disregard Christian moral teachings when it suits them.

5. The purpose of linking your Christian faith to scientific arguments is to demonstrate to non-Christians that Christianity is real. It is not a personal preference. It is not something you grew up with. It is not something you inherited from your parents. When you link your Christian faith with scientific facts in the external world, you are declaring to non-Christians that Christianity is testable and binding on everyone who shares the objective reality we live in. You can’t expect people to act Christianly without showing that Christianity is objectively true.

6. Scientific arguments are tremendously useful even for believing Christians, because sometimes it is difficult to act in a Christian way when your emotions are telling you not to. When your feelings make it hard for you to behave Christianly, that is when scientific evidence can come into play in order to rationally justify acts of self-denial and self-sacrifice. For example, scientific evidence for the existence of God is a helpful counterbalance to the problem of apparently gratuitous evil, which often discourages Christians.

My complete index of arguments for and against Christian theism is here.

UPDATE: I notice that in the popular culture, people are not really aware of these arguments, and are still arguing for religious faith based on pragmatism and personal experience, not on evidence. Using reason and evidence is much better, and it’s what the Bible teaches, too.