Just a reminder that you can see Geraint Lewis and myself talking at Westmead in Sydney next Monday, 5th December. It’s free!
Why are we here? Physics and the Fortunate Universe
Professor Geraint Lewis and Dr Luke Barnes, authors of A Fortunate Universe, offer to take you on a tour of the cosmos, demonstrating that humanity appears to be part of a remarkable set of circumstances involving a special time around a special planet, which orbits a special star, all within a specially constructed universe. It is these sets of conditions that have allowed humans to ponder our place in space and time.
A Sydney Ideas, Westmead forum
Co-presented with School of Physics, Faculty of Science
Date: Monday 5 December, 2016
Time: 5.30 to 7pm
Venue: Conference Room, Westmead Institute
176 Hawkesbury Rd
Westmead NSW
Cost: Free and open to all with online registration requested.
Letters to Nature 
Hi Luke,
I attended the Westmead Talk on Monday and enjoyed the presentation by Geraint and yourself – Thankyou! The presentation, as well as the book (I’m 3/4 through a Kindle version read by Siri-she doesn’t laugh at your Dad jokes) leaves not much in the way of options on the table to explain Fine Tuning. Either a super duper lucky brut fact, a Multiverse or Cosmic IT Guru/Designer. The question/s that I would like to pose is, (warning L plater) given a Multiverse: are all advanced forms of life only ever fated to be found in cookie cutter type universes to our own; and secondly, if similar universes to ours are a necessary ingredient, then isn’t there a hard-upper limit to the number of chemical interactions that can occur within the time slot available for a natural regime of laws and terra forming interactions?
It seems to me that the implication for the revered infinite multiverse is that while we might be able to posit an infinite number of life supporting universes similar to ours, however, all those biophilic universes are profoundly limited in how they can interact over time. This seems to me to put a firm upper probability bound on what is naturally plausible, chemically. The William Payleian hunch is that a naturally occurring 21 jewel automatic wrist watch is way, way, outside the boundaries of natural plausibility in any biophilic region of an infinite multiverse.
Further dubious reasoning is as follows; any universe that forms any structure, does so because fixed laws are operative. But the minimum suite of laws that will generate a minimalist repertoire of chemistry that could spawn any sort of viable biological complexity is super slim. But more importantly, the imposition of fixed laws greatly reduces the possible ways that newly formed chemistry can interact over time. That is, the laws are a massive handbrake on how chemistry can interact within the larger constraints of galaxy and planetary formation. The corollary of this is: given that organisms require catalyzing chemistry (enzymes) to do the heavy lifting of metabolisms, is there enough time for the necessary chemical shuffling to occur to create and localize a minimum package of useful, biologically functional building blocks, functional proteins from a massive possibility space? I ask this question because I once offered up my PC to protein folding at home (website- https://folding.stanford.edu/ ) which boast 106,000 teraflops of computing power, devoted to the same work that nature had to do in looking for needles in a very large haystack. Is a multiverse really going to offer any comfort to biologists that do some honest number crunching?
Apologies for the short novel, Simon
Well that’s a major failure for Siri – doesn’t know a good Dad-joke when she hears one.
We try not to argue that universes that permit life must be similar to our own. We’d prefer more general arguments, such as that a given universe won’t permit interactions or bonds between its fundamental particles. Time isn’t really the issue when you can’t make atoms.
I don’t think one can blame fixed laws. Firstly, the basic stuff of the universe has to obey *some* laws. And secondly, we need stability as well as activity. Think about DNA – we need it to preserve the information that it encodes, but also we need the strand to be able to unravelled so it can be read and divide in cell division.
Whether the multiverse helps biology is a matter for biologists. But it seems that if the age of the Earth and the materials on the Earth are not enough, we just need more planets scattered through the universe. So, that problem just needs more of the same – a big universe will do. But that won’t help with fine-tuning. A big version of our universe is a big fine-tuned universe, and the fine-tuning problem remains.
Enjoy the rest of the book!