The Block Universe

1500 words, 7 minute read

The Universe is best represented as a multi-dimensional Block (BU). Every possible value of every potential variable is encoded in that Block. What we call the World is a cross section, i.e. a ‘slice’ or a ‘surface’, of that BU. Every cross-section uniquely orders the variables in the Block. There are innumerable (perhaps infinitely many) such surfaces. How many and which of those surfaces constitute a World is what differentiates various BU models.

For example, according to Pierre-Simon Laplace’s (c. 1800) Classical Determinism (CD), there is one and only one World. While other worlds might have been possible, only one world actually is, and it is immutable: every future event is determined by every past event.

At the other end of the spectrum, we have Hugh Everett’s (c. 1960) Many Worlds Interpretation (MWI) of Quantum Mechanics (QM). According to Everett, everything that might happen can happen and everything that can happen does happen. Every possible value of every variable constitutes its own unique, solipsistic, actual world.

Neither of these popular models is remotely satisfying. Neither provides an account of our  experience of being in a world nor of our intuition of contingency in events.

In addition, CD is based on an assumption that runs afoul of contemporary physics, i.e. that we can determine the position and momentum of every particle in the Universe at one moment in time and so calculate the state of the Universe at every moment in time, past or future. The math may work but the physics doesn’t.  

Turns out, location and momentum are not entirely independent, so it is never possible to determine both at once without there being a certain amount of ‘fuzziness’ in the data (and fuzzy is fatal when it comes to determinism – I mean, one flap of a butterfly’s wing can throw all our plans and predictions into a cocked hat: No picnic for you today!)

If we could know location with the precision required for a deterministic calculation, it would come at the expense of any knowledge whatsoever concerning momentum. Fortunately for us, the relationship between location and momentum is not linear. There is a ‘sweet spot’ where we have enough information about location and momentum to enable informal, imprecise, approximations. No picnic…but probably no asteroid collision either.

Hugh Everett salvaged the picnic! We no longer need to rely on knowing position and momentum to predict the future: Whatever can happen does happen! So enjoy the potato salad and, if you’re over 21, the (spiked) lemonade!

MWI may be irrefutable, but it’s not very useful. It’s really just a device to get around the paradoxes of Quantum Mechanics. The Protection of Picnics is just its side hustle. But its inventory of worlds explodes exponentially and there’s no way to prefer one universe over any other: they’re all just happening!

Riddle: Is ‘everything happens’ the same as ‘nothing happens’? If everything occurs, does anything occur? “Nothing changes if nothing changes.” (AA)

Laplace or Everett, either way your experience is the same; you live in just one world, your world, because either that’s all there is (CD) or, what amounts to the same thing, that’s all there is for you (MWI). Your trajectory is unique according to either model. No matter what choices you appear to make, which alternatives you seem to choose, anyEverett-World will still be your world, and therefore phenomenally indistinguishable from Laplace-World.

So CD and MWI describe the same phenomena differently. CD brings us back to Shakespeare: “To be or not to be.” And to Looney Tunes: “That’s all folks!” One and done. It either is or it is not. If it is, it is what is! Welcome to Hell – but don’t worry, it’s all-inclusive.

Many Worlds relieves the boredom of CD… but at a price: chaos! According to MWI, there is a universe in which I ordered both lasagna and fish at your wedding. Super wedding! Well, not really. I only know from fish or pasta – like meat and dairy, I can’t experience both at the same time if I’m keeping kosher; I can’t combine two worlds. In some world, somebody ate lasagna, but not me; I only got to taste the fish. Rats!

Of course, the bifurcation of reality does not stop at wedding menus. Everything you do functions as a node, a bifurcation point…you and every other human being…you and every other living organism, including each of the 30 trillion independent cells that make up your body! 

Turns out, MWI and CD are two paths to the same result! In both models, what happens just happens. There is no contingency. There’s nothing recognizable as agency, and so of course, there’s no free will. Wait! According to CD ‘only one thing happens’; while according to MWI ‘whatever can happen does happen’. How can the two models be synonymous?

Thanks to Bill Clinton, we can resolve this paradox: it all depends on what the meaning of ‘is’ is. MWI applies ‘is’ to all possible pathways; CD applies it to just one. But I propose a different solution: a modification of MWI I call Many Worlds Modified (MWM):

Suppose ‘the world tree’ (Yggdrasil in Norse mythology) is convergent as well as divergent. We know from Botany that roots and branches, once diverged, can converge (reconnect); so why not divergent World-lines?

If we treat the World as a computer simulation, made up entirely of 1’s and 0’s (+’s and  –‘s), it is easier to see how two different number streams could settle on a single shared value. According to MWM, the inventory of ‘worlds’ grows, but linearly, not exponentially…a big improvement I think you’ll agree:

A

+↙        ↘-

x                  x

+↙      ↘-    +↙     ↘- 

x                x               x

+↙      ↘-  +↙    ↘-    +↙    ↘-    

x                 x                 x               x

Assume, as above, that each variable has one, but only one, of two values (+ or -). Regardless of whether the value of Alpha (A) is + or -, Beta (X) may be either + or -. The Beta state is not conditioned by the Alpha state.

Assume also that the basic properties of arithmetic apply. Therefore, (+ –) is equivalent to (–+). Our first iteration leaves us with just two possible worlds; but our second iteration adds a third option (+ - / - +). According to this model, the Universe inflates to create the additional space needed to accommodate novelty.

Now this is a World you can live in! A world remarkably like our own in fact, and all you needed was Grade 3 arithmetic to generate it. According to Norse mythology (above), 3 Norns (Macbeth’s witches) weave the World-line (Fate) from 3 skeins of yarn. How Trinitarian! MWM is consistent with this cosmology: ++, +-/-+, --. The textile, aka the World, Laertes’ shroud, accretes arithmetically over time. No stasis, no kaos, just logos.

But am I late to the party? 75 years ago, renowned physicist Richard Feynman created another theoretical framework designed to bridge CD and MWI. Like Everett, Feynman takes ‘can happen, does happen’ as his starting point. But he treats ‘does happen’ in terms of mathematical probability rather than physical process.  He appropriately called his model Sum Over Histories (SH).

“Does happen” means “has a probability greater than 0.” Simplistically, with Laplace there is never any ‘event’ (novelty) per se, while with Everett there are inconceivably many; with Feynman there is one actual event but that event is really a ‘path integral’ of multiple virtual events. SH includes vestiges of all possible events. Ah, fresh air! 

Feynman integrates many virtual (probabilistic) events into one ‘many splendored’ physical  (actual) event. But that’s only the beginning of Feynman’s genius! He went on to suggest that, while the probabilistic wave function does collapse into the specific actual event that we ‘see’, all the virtual pathways, summing to an ‘event probability’ of 1, pass on intact into the future…but with varying levels of intensity corresponding to their probability.

Even though neither Laplace nor Everett can be debunked mathematically, their models are not very satisfying. Neither remotely resembles the World we experience. Our World is stable but not frozen, dynamic but not chaotic. SH to the rescue!

SH is much richer than my paltry effort (MWM). However, it introduces complexities from Quantum Mechanics that are not strictly necessary, and its calculations require advanced calculus. MWM is like an n-1 dimensional projection of SH: it’s SH for 3^rd graders and for those with a 3^rd grade knowledge of mathematics…like me!