Is Reality Digital or Analog?

I stumbled across this question in a Scientific American RSS feed. Does it really ask what it seems to? Unfortunately, that seems to be the case. This is what happens when you let a bunch of physicists loose in a sandbox and ask them to define it.

I have to be careful in framing my criticism of the real question posed here, since I lack any credible qualifications for judging questions of quantum mechanics. What I submit instead is that the “definition” of reality does not fall within the jurisdiction of the laws of quantum mechanics (whatever those turn out to be), any more than the glorious majesty of Half Dome or the Grand Canyon falls within the jurisdiction of the traffic court division of the Superior Court of California, County of Kern.

To my thinking, the question as framed is meaningless. Is the Empire State Building incandescent or fluorescent? How many angels can sit on the head of a pin?

Discussion: “Reality” is not a subset or category of something bigger. When we say “a cat is a carnivorous animal that eats Meow Mix” we define the cat as an example or instance of some higher order category, an animal. The old philosophical fallacy of trying to “define reality” is explained in the necessity of referencing a higher order concept of which “reality” would have to be an instance. There are none. Never mind your hypothetical sets of multiple possible universes and “bubble universes.” If they’re “really” out there, they’re real, therefore part of reality.

At the risk of pandering to the obvious, by definition there is nothing more all-encompassing than reality.

The question in question was originally posed by the Foundation Questions Institute for its third essay contest. You can read the scientific approaches to the “question” here:

I found Jarmo Makela’s prizewinning essay interesting and literarily clever and entertaining right up until page 4:

Partition function

I’m not saying the physicists featured in the Sciam topic really meant to “define reality.” They are bright folks. The philosophical question “is reality digital?” sounds ever so much more satisfyingly grandiose than our poor old dirt mechanic version: “is a quantum state digital, or analog, or can it be both?” Hey Vern, the latter kinda resembles the old photon wave vs. particle controversy, don’t it?

To a quantum physicist, or even to the occasional lay person, fundamental insights can be gained by examining properties of the building blocks of matter. So are those building blocks granular or amorphous? Well, to begin with, through which end of the telescope are we looking? Why must we always assume the nature of matter is to be revealed in the small picture?

As long as we’re asking stoopid questions, is nature revealed in the particle or in The Cloud? Assuming we ever do figure out the fundamental nature of matter, who’ll get first credit? The particle physicists, or the astronomers? My prediction: both.

A question “are subatomic particles essentially digital or analog?” is a far cry from trying to defining reality itself in terms of one or more of its literally infinite attributes.

I’m saying that the best we can do in answering questions about the nature of reality is to examine specific examples, take our measurements, analyze them, and report on our findings. You can approximate any analog process with digital slices – that’s part of our Isaac Newton legacy – and I believe that, on a quantum level, you can even show all analog processes are actually macro averages of discrete yes-no-maybe events. But reality isn’t just a process, it’s a head-scratcher. If you’ll pardon us for saying so, reality’s ever so much more.

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