I'm mostly down with the Mathematical Universe and might have independently reached that conclusion. I like to use the example of the Mandelbrot set - did that

I'm mostly down with the Mathematical Universe and might have independently reached that conclusion. I like to use the example of the Mandelbrot set - did that set/image/fractal exist prior to someone writing a program to create a map of it? I would argue that it did. So a mathematical object exists independently from our ever "discovering" it or its definition. That point of view quickly leads to "All things that have a mathematical definition exist in that same sense" which leads to "If there is a mathematical definition of our universe, that is sufficient cause for it to exist". I do object to the talk of computability. Not all mathematically well-defined things are computable. I also don't like the following from the article: >> Are we to take as serious the idea that we live inside an equation? And this equation somehow produces all computations by virtue of its solutions? And that the whole physical universe is just some kind of shared hallucination? A mathematical definition is not limited to "an equation". What does he even mean by "produces all computations"? And then "shared hallucination" also seem nonsensical - we experience things however the definition allows/causes. The only thing I grapple with is why we perceive the passage of time. If there is a mathematical definition of the entire span of the universe and time, that doesn't satisfy me in understanding why "I" am experiencing "now". Some might argue that a "simulation" is "running" but like the Mandelbrot set, the entire thing is defined at once by the definition, and any need to "run" it pushes the whole problem down one level (like where did god exist before he made the universe?) it's turtles all the way down. So while defining the universe over time might involve a definition that looks like a simulation, that still doesn't explain why we experience the simulation at a single point in time.