If the universe was &quot;made of mathematics,&quot; then there would necessarily exist a Grand Unified Theory. But, Hawking asserts that Gödel&#x27;s Theorems imply that not only does a Grand Unified Theory not exist, but that the formulation of one is impossible (<a href="http:&#x2F;&#x2F;www.hawking.org.uk&#x2F;godel-and-the-end-of-physics.html" rel="nofollow">http:&#x2F;&#x2F;www.hawking.org.uk&#x2F;godel-and-the-end-of-physics.html</a>).<p>The author stresses that all of reality is mathematical in structure, but this is at odds with the fact that all mathematical systems containing self-reference are necessarily incomplete. Physics is a self-referential system.<p>If the structure of the universe is mathematical, it is probably a very different math than humans are used to. Insert your favorite flavor of metaphysics here!