Author here. Thanks for educating me on the subtleties. It seems like I was mixing up a Level 3 multiverse with a Level 2. I made a small edit to remove the sentence about constants changing. And I also added a note that I edited the post.
> The many-worlds interpretation of quantum mechanics imagines our universe as one node in an infinitely branching tree of universes where every possible quantum outcome exists in its own universe. And each time a universe branches, it creates a child universe that is slightly different from the parent universe, e.g., universal constants such as gravity and the speed of light might differ.<p>Pretty sure this is flat out wrong; the Many Worlds hypothesis does not include universes in which universal constants differ.
> According to the many-worlds interpretation of quantum mechanics, your universe branched into many universes the moment you decided to use a for-loop. In this universe you wrote a for-loop, but in another universe you wrote a while-loop.<p>Nonsense. If universes branch into many other universes, they do so when an event on the quantum level needs to be resolved. I presume that during any single decision-making operation, there are trillions of probabilistic quantum events took place in your brain, but your decision to use the for loop was <i>almost certainly</i> fully deterministic, because at this point in time you personally almost always pick for-loops.
It's funny that there is such a pro and anti js movement in the hardcore professional programming world. I know it's a bit off topic. But in every js topic here at hackernews you can feel this tension. I have never seen this before. And this place is visited by the best programmers out there . Very interesting