Very few time-travel stories allow for both a self-consistent single universe and unlimited time-travel. That would almost invariably be an instant victory condition for the time-traveler, and likely boring to read about. That’s why we need restrictions like only six uses per day. Interestingly, there was a movie nearly a quarter century ago that belied it’s understanding of this with its silly premise.
It’s possible some younger readers/listeners haven’t seen this movie, so I’m going to fully endorse Bill & Ted’s Excellent Adventure. It is in my top-five movies to watch when you just want to watch a plain ol’ fun movie. It doesn’t take its subject matter seriously, but it is a damn fun time! And it has the advantage of carrying a very humanistic message.
It is notable in that, like the Harry Potter universe, causality points both ways (present effects having future causes). This makes for a great break-out-of-jail scene once the protagonists realize they are very nearly gods. They never use this power for anything important (it is a goofy comedy, after all) but it’s a fun introduction to the self-consistency principle.
The hard part is actually changing your mind
SFX: Floo Fire
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I believe I went through my entire range of non-cartoony female voices today. I’ve already gone through every single thinking-to-himself voice for Harry, and I had to bring in Brian Jones (Severus) to help me out with Ravenclaw Two. I can only say thank you again to those who volunteer their voices to help. :)
Brian has an amazing radio voice, which I hadn’t heard before due to the inflection he uses when he plays Snape. The richness of it really blew me away. I mean, he has a strong voice IRL, but people sound different when they’re talking casually compared to when they’re intoning. I’ve been told myself a number of times that people are surprised when they hear me on the podcast, and ask if I do post-production on my voice. I don’t, you just fall into a different cadence when you’re performing. As my friend Jon says – it’s natural, it’s just the “Dramatic Chipmunk” version which doesn’t get used in ordinary life. It’s the main reason I actually record a fresh intro every week (as opposed to pasting in a stock intro, like I do with the majority of the outro). Saying those twenty-six words injects me smoothly into narration mode, it’s almost like flipping a switch. Brian just slips into his with a few seconds of preparation. I’m glad to have him on board!
(for more on Bayes’ Theorem, see today’s production notes)
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Rather than production notes, today I’m just providing links to help explain Bayes’ Theorem. Bayes’ Theorem is a way of thinking about beliefs and evidence that allows one to have a more accurate map of reality in their heads. It is what Harry means when he says “Proof, Headmaster? There are only ever probabilities.” It helps us to best know how we know what we know.
The guide I find to be most understandable is Komponisto’s “Bayes’ Theorem Illustrated“. It is simply enough that you can grasp it without even engaging the equations. And as a bonus, it shows you how to grasp the correct answer to the Monty Hall problem.
Another guide is Eliezer’s own “An Intuitive Explanation of Bayes’ Theorem“. I think people are pretty much split on which of the two is better, so if one doesn’t work for you, try the other. They’re both good.
If you’re wondering “What Is Bayesianism, anyway?“, this link will give you the core tenants. It’s much shorter than either of the previous two, and may be the shortest summary possible. And as it notes of LessWrong (and by extension, this podcast) – “that’s basically what this site is for: to help us become good Bayesians.”