Luke A. Barnes

A Fortunate Universe: Life in a Finely Tuned Cosmos by Geraint F. Lewis and Luke A. Barnes is a book about the cosmos for those looking for a bit more than a Discovery Channel series on the universe. Lewis is a Welsh astrophysicist, who is best known for his work on dark energy, gravitational lensing, and galactic cannibalism. Barnes is a postdoctoral researcher at the Sydney Institute for Astronomy, University of Sydney. He works on cosmology, galaxy formation, and the fine-tuning of the universe for life.

The universe has gotten a lot more complicated over the years, but much more accessible. Science shows on television, the internet, and since the 1980s, science books that were not just filled with equations. Einstein used thought experiments as well as Schrödinger. Feynman used diagrams to represent extremely complex mathematical equations. Stephen Hawkings had a best-selling book on science (with only one equation). I remember reading a non-mathematical Quantum Mechanics book back in the mid-1980s that opened up a whole new world to me. The popularization of quantum mechanics and cosmology allowed people with an interest in science to follow along and grasp the post-Newtonian universe.

Lewis and Barnes discuss the universe with all the familiar forces and particles. They, however, look at how our universe is "tuned." They examine what small changes in forces and particles achieve. What would happen to the universe if the strong nuclear force and gravity were at different values? Could stars form? What would their lifecycles be like? Radiation is a serious problem for living beings, but would a universe without radiation support life? The earth would just be a cold dead rock. Radiation keeps the core hot and the magnetic field active. Perhaps the most important aspect of life in the universe is carbon. Carbon is formed inside of stars but by much more than simple fusion.

My background is not in science but I could follow along fairly easily throughout most of the book. There were a few places that I needed to reread or lookup in an external source but, for the most part, the writing was very understandable. The explanations are complete and understandable. Personally, I tend to forget how the weak nuclear force works, but I came away well informed. The writing style is engaging and thought provoking, and although the workings of the universe make rocket science look like child’s play, the writer’s can be entertaining. They also like to drop musical references in their writing.

In addition to what we know about the universe and what changing a variable might accomplish the book discusses what we don’t know and some problems with what we don’t know. The authors tell what happens when theories get stretched too far. In one place the authors discuss the number of 10^120. It’s large number so large in fact that it is nearly impossible. Impossible many times over when discussing the number of protons in the universe. Higgs, dark matter and dark energy, as well as singularities, are part of the discussion and keep the writing current. The authors start and end the book in a discussion format. It provides a good introduction and closes the book well taking in a final discussion of if the universe is so tuned for life could it have been created or designed. A particularly well-chosen closing to what very much seems like a Goldilocks Universe.… (meer)

Rarely am I inclined to give a 5 star rating to a book, but, I believe this one is deserving. Lewis & Barnes provide an engaging introduction to the fine-tuning problem, providing coherent, yet simple explanations of some of the most persuasive examples. The authors are candid and intellectually honest, sharing their own doubts about fine-tuning and previously endorsed examples that ultimately didn't pan out. The ending chapters effectively summarized the data and surveyed several common rejoinders to fine-tuning with responses. The very end provides a surprisingly sophisticated (given the authors' stations as cosmologists) philosophical discussion on the impact of fine tuning in the teleological argument. The footnotes are absolute gems and the bibliography/reco reading is exemplary. My main complaints: the discussion on objective Bayesianism needed an additional 20 pages, the graphics had a hideous font, and Fig. 3 isn't a "Scheckmate".

4.8/5… (meer)

I saw a puddle the other day on my way to work. It was sitting in a pothole, and the hole was exactly the shape of the puddle sitting in it. Honestly, that hole was precisely fine-tuned for that puddle. There is no other explanation. But is this really true? I SAW an unremarkable puddle - using one of my senses. But there are other variables that need to be aligned for that puddle to exist.

Temperature
Barometric pressure
Gravity
Chemical composition
Soil composition
Physical structure
Bounded Harmonics
Yada, Yada, Yada.... Etc.

And that is where the authors were going with this. That "Intelligent Design" could only engineer such an exhaustive list of properties to make it possible

Note: I am not advocating one or the other ... just poking holes in my own analogy.

A more apposite metaphor might be finding a puddle in a pot hole in an otherwise infinite near-flat plane (e.g. z = -exp( -(x^2+y^2) ) ) and when you calculate all other possible universes it turns out they are exactly flat. That makes us feel lucky in a way that physicists are uncomfortable with because, historically, whenever we've appeared to be that special, it turns out we've misunderstood the physics.

This puddle analogy does not address or refute fine-tuning. In the huge majority of possible universes there's no possibility of a depression forming for a puddle to settle in, and thus no possibility for the puddle to comically misconstrue the cause of its existence. Though what I’m tilting at was the appearance of fine tuning. In effect - if you want to assert a reason why something fine-tuned" the universe, you better explain how that thing came into being, and what processes it used for the fine tuning. Otherwise, you are simply making a claim that the universe not only appears fine-tuned, but actually is, and failing to support this.

But the fine-tuning claim is backed up by solid theoretical physics. There have been thousands of papers published on it - it is established science. NOT in the sense that 'God Did It' but in the sense that the very high improbability of this universe is real. It works like this: first all the laws and physical constants of physics have a natural "range" beyond which they produce nonsensical or contradictory results. If with god-like powers you built a machine with dials representing the various individual physical constants of nature (strength of gravity, strength of electromagnetism, strong nuclear force, weak nuclear force, etc., etc.) and a "3D print" button that generated a universe from whatever the settings were at that time, then the odds of getting a universe capable of producing the kind of complex chemistry required for any imaginable kind of life are astronomically low. So low that it beggars belief that the only universe that appears to exist is life-supporting.

It is perfectly valid to assert from this that the universe is staggeringly improbable. You don't have to provide an explanation for HOW the universe came to be in order to show that it is improbable. Imagine if someone were on a flight to the Bahamas and the plane exploded, flinging you screaming into the air and plummeting towards the ground from 18,000 feet. But miraculously when you hit the ground you land in an otherwise uninhabited landscape on a massive pressurised air bag (like they use in move stunts) and are completely unharmed. When you clamber off the air bag you find a comfy armchair, a bowl of crisps and a cold beer and a note that says 'Hi Manuel, please relax, a taxi will arrive for you shortly.' Now, THAT is a highly improbable event. If you filmed the whole thing and showed it to the world it would be unreasonable for anyone to claim it was NOT improbable simply because you couldn't explain how the air bag, chair, beer, personalised note, etc., were there ready for you to land on.

The Letters To Nature blog is really good on all this: https://letterstonature.wordpress.com/

The cosmologist authors also wrote a book, 'A Fortunate Universe: Life in a Finely Tuned Cosmos', which they toured with. It's a fabulous read for the amateur, just the right amount of being over my head to leave me completely thrilled and blown away.

Bottom-line: The probability of a universe with just the right conditions in it for us to exist is 1. If we then wish to establish that there is a reason to think it was explicitly designed that way, we need to look for explicit evidence of that designing. All the arguments that hinge upon 'it is really unlikely' are working their probability backwards. Ultimately my abovementioned airplane crash analogy fails because it is extrapolating a very unlikely circumstance working forward from current conditions - from a position where it hasn't happened yet. This would only be analogous if we were thinking about our universe from a position where it didn't exist yet, or about us from a position where we didn't exist yet. On the other hand, the puddle analogy is about purpose. And all the argument about the specific physical laws which allowed the pothole to exist, is to completely miss the point of the analogy, I'm afraid. That's fine, anyone is welcome to make different analogies, puddle-based or otherwise. The point of the puddle is that 1 is the answer... Of course it will only exist in a shape (the 'shape' being the 'laws of physics') that accommodates it. Again, this has a probability of 1. It can infer nothing about the purpose of the hole from the fact that it exists within it.… (meer)