Two theories both explain data

I didn’t make such a claim user, but I have been in arguments that lore or less go like that. Which is infuriating

Have you compared this definition of simplicity with all of the other possible definitions of simplicity?
What if there is a definition of simplicity that assigns probabilities more accurately than your definition of simplicity?

Parsimony

There isn't another simplicity in regards to this.

There is another simplicity in regards to necessary and contingent truths. There is another one more akin to simplexity. I assume you already know about those and how they do not relate to this.

>get 100 samples, gotta make a model
>colleague uses parabolic fit, it's ok
>use 100th degree polynomial fit, get 0 deviation
>get fired
>cry on chinese land measuring forum

Occam's Razor is often phrased as "The simplest explanation that fits the facts." Robert Heinlein replied that the simplest explanation is "The lady down the street is a witch; she did it."

One observes that the length of an English sentence is not a good way to measure "complexity". And "fitting" the facts by merely failing to prohibit them is insufficient.

Why, exactly, is the length of an English sentence a poor measure of complexity? Because when you speak a sentence aloud, you are using labels for concepts that the listener shares—the receiver has already stored the complexity in them. Suppose we abbreviated Heinlein's whole sentence as "Tldtsiawsdi!" so that the entire explanation can be conveyed in one word; better yet, we'll give it a short arbitrary label like "Fnord!" Does this reduce the complexity? No, because you have to tell the listener in advance that "Tldtsiawsdi!" stands for "The lady down the street is a witch; she did it." "Witch", itself, is a label for some extraordinary assertions—just because we all know what it means doesn't mean the concept is simple.

An enormous bolt of electricity comes out of the sky and hits something, and the Norse tribesfolk say, "Maybe a really powerful agent was angry and threw a lightning bolt." The human brain is the most complex artifact in the known universe. If anger seems simple, it's because we don't see all the neural circuitry that's implementing the emotion. (Imagine trying to explain why Saturday Night Live is funny, to an alien species with no sense of humor. But don't feel superior; you yourself have no sense of fnord.) The complexity of anger, and indeed the complexity of intelligence, was glossed over by the humans who hypothesized Thor the thunder-agent.

To a human, Maxwell's Equations take much longer to explain than Thor. Humans don't have a built-in vocabulary for calculus the way we have a built-in vocabulary for anger. You've got to explain your language, and the language behind the language, and the very concept of mathematics, before you can start on electricity.

And yet it seems that there should be some sense in which Maxwell's Equations are simpler than a human brain, or Thor the thunder-agent.

There is: It's enormously easier (as it turns out) to write a computer program that simulates Maxwell's Equations, compared to a computer program that simulates an intelligent emotional mind like Thor.

Who the fuck is this cuckold Occam and why should I give a shit about his wh*toid theories?

Not an explanation because witch is impossible.

>The lady down the street is a witch; she did it.
Another way to look at this explanation is that the needless complexity is hiding not in the word "witch" but in the word "it." If you say "a witch did it," you still don't have a prediction of what "it" is. So your full explanation would have to describe, in complete detail, what happened, so you can assign an antecedent to "it." (A witch can do anything, so there is no more efficient way of describing her actions than just describing, in full detail, everything that happened.)

Any theory that does better than just expressly describing everything that happened will be superior to the "witch" theory. In particular, the laws of physics are much simpler than describing the configuration of every particle in the universe, at every moment of time, for all of time, which is what "it" ultimately is.