One of the most interesting and provocative ideas to emerge from the intersection of mathematics, philosophy, and physics is the proposal, by MIT cosmologist Max Tegmark, that our universe is a mathematical structure. Everyone knows that mathematics is indispensable for understanding our universe, but the Mathematical Universe Hypothesis (MUH) says something rather more remarkable. Two of the most salient questions in all of philosophy are:

(1) Why is there something rather than nothing?

(2) Why is mathematics so effective in describing reality as we know it?

The profundity of these questions is quickly made manifest upon the slightest reflection. MUH is an ambitious, albeit ingenious, solution to the inherent problems raised in these two questions. It postulates that reality *is* mathematics in a very real and well-defined sense; more specifically, *physical existence equals mathematical existence*. One might describe such a view as a form of radical Platonism or, equally, a mathematical version of modal realism. In fact, these are the very descriptions employed by Tegmark himself. As such, MUH answers (1) because it entails that there really is no such thing as an ontological nullity or universal negation. Something necessarily exists, namely all possible mathematical structures, which Tegmark refers to as the Mathematical Ensemble or Level IV Multiverse. It also answers (2) by making it trivial. Certainly, if reality is mathematics, then science is merely the endeavor of uncovering how our particular mathematical system operates or behaves.

Now, as a mathematician, this suggestion resonates with me and isn’t so hard to imagine being the case. For most people, however, MUH probably sounds outlandish at best, if not incoherent! After all, what could it possibly mean for reality to *be* mathematics? You mean, the chair I’m sitting on is no different than the equations I write down when doing my math homework?

I grant that, at first sight, the idea seems a bit absurd; but the fog begins to lift, I think, upon a reflection of what mathematics really is. It is my hope to explore, and clarify, this most fascinating idea in a series of posts. Included in this investigation will be an incorporation of Douglas Hofstadter’s ideas espoused in his landmark work, *Gödel, Escher, Bach: an Eternal Golden Braid*, which, I believe, specifically fleshes out Tegmark’s notion of a Self-Aware Sub-Structure (SAS). On Tegmark’s (and presumably Hofstadter’s) view, a human would be an example of a SAS. Hofstadter, however, uses the terminology “strange loops” or “tangled hierarchies”.

These posts are primarily for my own benefit, to engage these ideas and to deepen my understanding. But for anyone who might be reading this blog, I hope that what I write is both interesting and enlightening. Of course, if I totally botch something or if clarification is needed or if there are other ideas that would be interesting to fit in, please feel free to contribute and participate in the comments. Happy reading.

Just here to tell you someone is looking forward to more posts from you.

Thanks Ben! That means a lot to me. I should have the next installment out soon! Stay tuned!

I find the idea that existence defines reality very possible—in fact probable—as well as very intriguing. Everything, from how the wind blows to the way the eye sees can be explained via mathematics. I’m looking forward to understanding more about mathematics *as* reality though, and what that means exactly. Thanks for exploring this! 🙂

Tim –

Thank you for the kind words and input. Your comment is a great encouragement! I too look forward to exploring this idea in depth and understanding it better. Feel free to add your thoughts or questions in at any time! It’s also very nice to hear from you!

Ah, and by existence defining reality, I really mean mathematics defining reality.

(Read before you post, Tim! Sheesh.)

PS. It really has been too long! 🙂

Haha, no worries. I gathered what you meant.

If reality is a formal system then I wonder if the formal system I call “rational discourse” would imply it or contradict it perhaps. And if the latter, then we won’t be able to investigate reality as a formal system using rational discourse. I am reminded of the notion of unrestricted comprehension. In naive set theory, unrestricted comprehension leads to Russell’s paradox. If one maintains unrestricted comprehension, there is always a price to pay whether it is needing a third truth value or stratified comprehension. Why I am reminded of unrestricted comprehension I do not know…

Interesting thoughts!