Monday, March 9, 2020

259: Is Reality Really Real?

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Recently I read an amusing book by a cognitive scientist named Donald Hoffman, titled “The Case Against Reality”.    Hoffman argues that what we think we are perceiving as reality is actually an abstract mathematical model created by our neurons, with very little relationship to reality as it may actually exist.   Note that this is not one of those popular arguments that we’re living inside a computer simulation— Hoffman isn’t claiming that.   This also isn’t an argument about the limits of our perception, such as our inability to fully observe subatomic particles at a scale that would confirm or deny string theory.    He accepts as a starting point that we do actually exist and are perceiving something.    However, that ‘something’ that we seem to be perceiving is radically different from the core concepts of space, time, and general physics that we think we’re observing.

A key metaphor Hoffman points to is the idea of your computer desktop screen, where you see icons representing files and applications.   You can perform various actions on this screen, moving files between folders, starting applications, etc.   Some of them even have real consequences:   you know that if you drag a file into the trash and click the ‘empty trash’ button, the file will cease to exist on your computer.   Yet you are completely isolated from the world of electrical signals, semiconductor physics, and other real aspects of how those computer operations are actually implemented.   The ultra-simple abstract desktop serves your need for practical purposes in most cases.   Hoffman believes that our view of the universe is similar to a user’s view of a computer desktop:  we are seeing a minimal abstract model needed to conduct our lives.

It’s easy to argue, from observing more primitive animals in nature, that evolution does have a tendency to take shortcuts whenever possible.   Hoffman points out a number of funny examples, like a type of beetle that identifies females through their shiny backs, and can be fooled into trying to mate with a small bottle.   If the species could successfully perpetuate itself by using this shininess heuristic to quickly identify females with minimal energy, why would evolution bother trying to teach it to observe the world in more detail?   Hoffman calls this the FBT, or “Fitness Beats Truth” concept.   He even tries to raise it to the status of a theorem, by making various assumptions and then showing that given the choice between providing true perceptions or the minimal required to enable reproductive fitness in a particular area, the sensible minimal-cost evolutionary mechanism would always choose fitness over truth.

So, it this an unassailable proof that we are simply observing some complex computer desktop, rather than actually perceiving something close to reality?   Actually, I see a few issues with Hoffman’s argument.   The first one is that he dismisses far too casually the idea that maybe, once a certain amount of interaction with reality is needed, it’s easier for evolution to build actual reality-perceiving mechanisms than to come up with a new, complex abstraction that applies to the situation.    While a major computer chip manufacturer can do lots of work using abstract design schematics, for example, at some point they may need to debug key manufacturing issues.   When this happens they stop using purely abstract models, and look at their actual chips using powerful electron microscopes.    Isn’t it possible that evolution could reach a similar point, where there is a need for general adaptability, and the best way to implement it is to provide tools for observing reality?  

Another big argument in favor of our perceptions being close to reality is that we are able to derive very complex indirect consequences of what we observe, and show that they apply in practice.   For example, a century ago Einstein came up with the theory of relativity to help explain strange observed facts, such as the speed of light seeming to be the same for moving and nonmoving objects.   He and other scientists derived numerous consequences from the resulting equations, such as surprising time dilation effects.   Eventually these consequences became critical in developing modern technologies such as the Global Positioning System, which we use every day to accurately navigate our cars.   Could evolution have come up with such a self-consistent abstract system, originally in order to enable groups of advanced monkeys to more efficiently traverse the treetops and gather bananas?   I’m a bit skeptical.   I think for evolutionary purposes, our approximate abstract perception that the speed of light is 0 has been perfect for most of history, and our advanced observations beyond that are detecting a real level of reality that evolution wasn’t particularly caring about.

Finally, one other critical flaw is that Hoffman claims that even our core concepts such as space and time are part of this abstract model that evolution has created for us.   But evolution itself is a process that we have observed to occur in space and over time.  So if evolution has created some kind of abstract model for us, that in itself proves that space and time exist in some sense, or else the overall argument is self-contradictory due to the nonexistence of evolution.    I suppose you could rescue it by saying just enough of space and time is real to enable evolution, but that seems a little hokey to me.

So, for now, I’ll happily move on with my life in the belief that reality really does exist.    

And this has been your math mutation for today.


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