Yeah, the observation that the universe seems maybe well-predicted by a program running on some UTM is a subset of the observation that the universe seems amendable to mathematical description and compression. So the former observation isn’t really an explanation for the latter, just a kind of restatement. We’d need an argument for why a prior over random programs running on an UTM should be preferred over a prior over random strings. Why does the universe have structure? The Universal Prior isn’t an answer to that question. It’s just an attempt to write down a sensible prior that takes the observation that the universe is structured and apparently predictable into account.
Yeah, the observation that the universe seems maybe well-predicted by a program running on some UTM is a subset of the observation that the universe seems amendable to mathematical description and compression. So the former observation isn’t really an explanation for the latter, just a kind of restatement. We’d need an argument for why a prior over random programs running on an UTM should be preferred over a prior over random strings. Why does the universe have structure? The Universal Prior isn’t an answer to that question. It’s just an attempt to write down a sensible prior that takes the observation that the universe is structured and apparently predictable into account.