The Physics Police

The Physics Police

Wednesday, May 28, 2014

The Universe Is Not Math

Max Tegmark has this crazy theory called the Mathematical Universe Hypothesis. He first published a paper on the topic in 2007. It made very little impact in the physics community, for reasons we shall see later on in this post. Then in 2008 he managed to get a piece published in Discover Magazine. Shortly thereafter he began work on a book finally published in 2013 titled Our Mathematical Universe which he managed to plug on Physics World, Scientific American and Science Friday.

He's even a guest on a this week's episode of Minute Physics in which he asked the leading question Is the Universe Entirely Mathematical?

The answer, of course, is a resounding and obvious NO!

His Mathematical Universe Hypothesis (MUH) states that the External Physical Reality (EPR) is a mathematical structure if it can be described by a Theory of Everything (ToE). He's not only saying that a ToE perfectly describes how the EPR works, he's saying that they are one in the same thing! He makes this unambiguously clear on page 280 of his book.
Whereas most of my physics colleagues would say that our external physical reality is (at least approximately) described by mathematics, I'm arguing that it is mathematics (more specifically, a mathematical structure).
Well, Max, your most of your physics colleagues would be right. One of the first things they teach you in grade school science is that theories are models of the universe, not to be mistaken for the real thing. The MUH might remind some of my readers of a strong version of Platonism.

In other words, the MUH is one giant exercise in equivocation, which can be demonstrated by analogy. Maps correspond to, but aren't the same as the territory they represent. Even a perfect scale-model replica of some territory must be built at some location other than the territory in question, and so is a distinct entity unto its self. Mistaking this replica for the real thing is demonstrably false, and not simply because you can walk right off its edge.

For example, imagine if Max were to claim that, since the design of the Eiffel Tower in Las Vegas is identical to the design of the Eiffel Tower in Paris, they are one in the same tower.
Whereas most of my architecture colleagues would say that the Eiffel Tower in Las Vegas is (at least approximately) described by the Eiffel Tower in Paris, I'm arguing that it is the Eiffel Tower in Paris...
Taking the fancy physics jargon out of the argument exposes it as semantic doggerel.
On the same page 280, in a footnote no less, Max tries to justify this argument from isomorphism.
From the definition of a mathematical structure, it follows that if there's an isomorphism between a mathematical structure and another structure (a one-to-one correspondence between the two that respects the relations), then they're one and the same. If our external physical reality is isomorphic to a mathematical structure, it therefore fits the definition of being a mathematical structure.
Did you notice the GIANT CIRCULAR ARGUMENT?!

Isomorphism is a tool that can only be applied to two mathematical structures. Max expects us to believe that we can use this tool on the ToE and EPR. But this begs the question of whether the EPR is a mathematical structure in the first place!

I find it astounding that buried in a footnote at the bottom of a single page in a 397 page book is one feeble attempt to use circular reasoning and fancy math words to sell abject nonsense to the reader.

I can't for the life of me understand why anyone takes Mad Max seriously.

2 comments:

  1. Not a physics criticism of the MUH, but a semantic one that is still relevant, math is a language and as such is a representation of ideas and things not those things themselves.

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  2. Exactly, Roy. We don't mistake a cook book for food. Even if the cook book's pages specify the quantum state of every molecule in the food, they still taste like paper.

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