Musings on the Multiverse

I’m thinking about what is probably the most common layman understanding of the multiverse, the “parallel universes” theme that frequently shows up in science fiction (e.g. Sliders, select episodes of every Star Trek show ever) and fantasy (e.g. The Chronicles of Narnia). In particular, the two aforementioned science fiction programs employ the idea that upon reaching a choice with two possibilites, both are actually selected, and reality bifurcates, as in the figure above. In fiction, a common plot device is the unusual mechanism (whether technological or supernatural) that allows travel from one world-branch to another. Such a mechanism must be unusual, because we don’t experience such reality shifts in daily life.

What would salvation look like in such a reality?¬† For every choice Abraham ever made, there would be one or more additional Abrahams. Actually it’s worse; the number of Abrahams would be roughly the factorial of the number of choices Abraham faced. Assuming for a moment that most choices are binary (i.e. there are only two options), that the average person faces 1000 choices a day, and that the Bible is correct as to Abraham’s age at death, that gives [thanks, Wolfram!] about 10^(10^9) Abrahams. That’s a one followed by one billion zeros. Abraham alone would require many mansions in every degree of every kingdom, and probably a good bunch in outer darkness as well. Note that this only includes bifurcations caused by Abraham’s choices; the full picture would be much more complicated if we considered the choices made by other sentient beings alive during Abraham’s lifetime. That’s a whole lot of multiplying entities needlessly, so I don’t like it.

Instead consider a version in which for a given choice all possibilities exist in a sense, but only one is actually chosen. Perhaps this is not actually different from how you picture reality without all this multiverse nonsense, but bear with me. I had a striking mental image of a branching tree of possibilities, with most branches dark except for the highlighted pathway from the root to the present moment, which moves along the tree as time proceeds. The following image gives the same idea, only it’s not nearly as pretty as what I imagined.

timeline_simple

Here’s the thing: in this scenario God would not have to do any fancy calculations to discover all the potential future states. He could be located outside of this branching structure, able to observe any part or the whole of it, and yet remain completely inside linear time. Thus this view is compatible with Open Theism (the idea that the future is completely undetermined and unknown, even to God), which, as Geoff J. has so stridently argued over at New Cool Thang, is itself compatible with libertarian free will and Mormonism.

Among all the obvious questions to which I hope you will provide answers (Is this blog post self-consistent? Is it even clear? What are your thoughts?), I hope you’ll consider this one: are the old, unfruitful branches of such a structure plucked off, cast into the fire and burned?

My Life is Headed in a Novel Direction

Last fall, as I went on leave from grad school frustrated with my lack of progress and unsure whether I would return, I acquired Neal Stephenson’s then-brand-new novel Anathem. He writes what are probably my favorite fiction books, particularly his latest works (starting with Cryptonomicon). On his website, Stephenson has a lengthy page of acknowledgments for Anathem with the following disclaimer:

If Anathem were nonfiction, the parts of it where philosophy and science are being discussed would be spattered with footnotes in which I would express my indebtedness to the thinkers of Earth who originated the ideas under discussion. Each of these footnotes would be carefully hedged, in roughly the following manner:

“…. Dear reader, please know that this footnote serves only to acknowledge an intellectual debt and to give fair credit to Person X; if you really want to understand Idea Y, please buy and read Book Z.”

Keeping that general framework in mind, here are the Xs and Ys and Zs.

One of the Zs was The Trouble with Physics by Lee Smolin, and I soon had it from the library. It was reading Smolin’s book that reminded me why I enjoyed studying physics so very much, and ultimately led me to return to school in January to finish my PhD program.

The only problem is that the physics that most interests me (and of which Smolin reminded me) isn’t at all related to what I’m researching for my dissertation. That’s fine for now, as I believe that my current research will prove valuable to me (and hopefully to someone else!) in the future. However, recent developments have led me to once again think deeply about the work I’d like to do following graduation.

Two weeks ago I was at Half Price Books in Seattle, and I saw, in a box on the floor, The Road to Reality by Roger Penrose. I picked it up and felt a thrill go through me. This was another of Stephenson’s Zs. Soon I saw yet another on the shelf: The End of Time by Julian Barbour. Besides being referenced for Stephenson’s novel, Smolin’s discussions of the work of these two men had strongly affected me. I skipped buying some fiction books I wanted in order to buy these two books instead. In the ensuing weeks I’ve had the odd sensation of pieces moving into place, setting up for something wonderful.

So from time to time I’ll be sharing some of my thoughts on some physical and metaphysical ideas here on M*, particularly as they relate to the Gospel of Jesus Christ as I understand it. I will welcome your contributions.

In the meantime it should be clear that the novels of Neal Stephenson have had a profound effect on the direction of my life. What works of fiction have changed the course of your life, and how?