A dog will change the weather dramatically, which will substantially effect your perceptions.
In this case, it’s about alt-complexity again. Sure, a dog causes a specific weather-pattern change. But could this specific weather-pattern change have been caused only by this specific dog? Perhaps if we edit the universe to erase this dog, but add a cat and a bird five kilometers away, the chaotic weather dynamic would play out the same way? Then, from your perceptions’ perspective, you wouldn’t be able to distinguish between a dog timeline and a cat-and-bird timeline.
In some sense, this is common-sensical. The mapping from reality’s low-level state to your perceptions is non-injective: the low-level state contains more information than you perceive on a moment-to-moment basis. Therefore, for any observation-state, there are several low-level states consistent with it. Scaling up: for any observed lifetime, there are several low-level histories consistent with it.
I think this is correct, but I would expect most low-level differences to be much less salient than a dog, and closer to 10^25 atoms dispersed slightly differently in the atmosphere. You will lose a tiny amount of weight for remembering the dog, but gain much more back for not running into it.
In this case, it’s about alt-complexity again. Sure, a dog causes a specific weather-pattern change. But could this specific weather-pattern change have been caused only by this specific dog? Perhaps if we edit the universe to erase this dog, but add a cat and a bird five kilometers away, the chaotic weather dynamic would play out the same way? Then, from your perceptions’ perspective, you wouldn’t be able to distinguish between a dog timeline and a cat-and-bird timeline.
In some sense, this is common-sensical. The mapping from reality’s low-level state to your perceptions is non-injective: the low-level state contains more information than you perceive on a moment-to-moment basis. Therefore, for any observation-state, there are several low-level states consistent with it. Scaling up: for any observed lifetime, there are several low-level histories consistent with it.
I think this is correct, but I would expect most low-level differences to be much less salient than a dog, and closer to 10^25 atoms dispersed slightly differently in the atmosphere. You will lose a tiny amount of weight for remembering the dog, but gain much more back for not running into it.