Hello Rick,
Your essay was able to capture very well the theme of this year's essay. And nice to read.
If I may take you up on some aspects...
"One way that has been proposed that would overcome this problem is simply to do away with the map/territory distinction entirely in favor of the ultimate reality of the map itself. This is the case with Max Tegmark and his Mathematical Universe Hypothesis (MUH). In a way the MUH poses an even bigger big question; namely is mathematics itself the ultimate reality?"
If this proposal is favoured, then it should also be permissible to call it a Physical Universe Hypothesis or would it not? That is, mathematics is physics and physics is mathematics and therefore ultimate reality should EQUIVALENTLY be both physical and mathematical? This leads me to the next aspect,
Pythagorean idea that mathematics was the language of nature. Pythagoras, of course, inspired Plato who gave us the idea that the kinds of mathematical truths the Greeks were uncovering were both discovered and timeless. Plato also gave us the idea that these "forms" were the fundamental aspect of existence, and something more real than the world we experienced through our senses.
Geometry is fundamental to reality. I don't know if you are aware of the dialectical struggle that took place between the Pythagoreans, Proclus, Aristotle and Plato on how to define and describe the fundamental unit of geometry, the point. While the Pythagoreans, Proclus and partly Aristotle admitted that the point must be of some but very small dimension to be real, Plato suggested that the point was a zero-dimensional object, yet was still real. In Plato's words, "the point is not a geometrical fiction". You can check Metaphysics and Physics by Aristotle for reference. You can also check the references in my FQXi 2013 Essay.
Why I mention this is because of your recall of Plato's idea that these "forms", the 'point' included are the fundamental aspect of existence, and something more real... Is the 'point' real? Is the 'point', a fundamental aspect of existence? Which is the more likely to be real and a fundamental aspect of existence, that which is of zero dimension or that which is of some very, very small but non-zero dimension?
Then concerning your frequent, reference to Platonic features of 'timeless' and 'reversibility', can you educate me?
Can what is timeless be reversible, since reversible means something that can change, and what can change appears not to be a timeless feature.
I explore again in continuation of my previous 2013 effort in this year's essay, the spell as I would like to call it, cast upon our mathematica and physica, by another Greek, Parmenides, who happened to be teacher to the more famous Zeno. Parmenides, asked, "How can what IS perish?" That is, existing mathematical objects, be it of the Platonic or other variety cannot perish but must be eternally existing. Now, IF, and a big IF, our cosmology s correct and there was a Big bang and there will be a Big Crunch, whereby the Universe will perish, will a Mathematical Universe survive this outcome? If not, then we can agree that Mathematical Universe is actually the ultimate reality, as you quote Tegmark to have said. If Mathematical Universe survives, then it cannot be the ultimate reality that we behold in physics but something else, since reality has perished and still Mathematical Universe remains alive so to speak. For them to be one and the same, they must live and perish together.
My essay this year may be long and winding and not quite as straight to the point as I would have wished, but the meat of it is that what exists is not timeless but can perish.
Indeed, I made a proposal you can criticize for my benefit, that "the non-zero dimensional point does not have an eternal existence, but can appear and disappear spontaneously, or when induced to do so."
Best regards,
Akinbo