Do you understand Solomonoff's Universal Prior?
Not the mathematical proof.
But the idea that if you don't yet have data bound to observation, then you decide the probability of a prior by looking at its complexity.
Complexity, defined as looking up the smallest compressed bitstring program for each possible turing machines (and that is the reason why it's intractable unless you have infinite computational ressources yes ?), that can be said to generate this prior as the output of being run on that machine.
The longest the bitstring, the less likely the prior (and this has to do with the idea you can make ...
I've often had half-finished LW post ideas and crossed them off for a number of reasons, mostly they were too rough or undeveloped and I didn't feel expert enough. Other people might worry their post would be judged harshly, or feel overwhelmed, or worried about topicality, or they just want some community input before adding it.
So: this is a special sort of open thread. Please post your unfinished ideas and sketches for LW posts here as comments, if you would like constructive critique, assistance and checking from people with more expertise, etc. Just pile them in without worrying too much. Ideas can be as short as a single sentence or as long as a finished post. Both subject and presentation are on topic in replies. Bad ideas should be mined for whatever good can be found in them. Good ideas should be poked with challenges to make them stronger. No being nasty!