Notes by Philip Dhingra
Physics

Art and dreams may be quantum observational acts that spring the rest of the multiverse into existence

The typical image of the multiverse theory is that of comic-book style alternate universes, where for every hero in our universe there is a similar-looking but opposing villain in another one. In these alternate universes, there are Bizarro versions of everything, like instead of a Pax Americana it's a Pax Germania with statues of Hitler everywhere.

But alternate, hypothetical universes could mean anything. At its simplest form, it could include universes that are an exact copy of our current one except with one atom randomly changed. If such a universe exists, then it's conceivable of a hypothetical universe where a trillion atoms have randomly changed, so that all of a sudden I find a rabbit sitting on top of my laptop. Or in the blink of an eye, I'm thrown into an actual replica of Lord of the Rings.

As they say, "There are no limits, except for your imagination." While this cliche implies there are endless possibilities, what if it means the complete opposite, that multiverses are bounded somehow by imagination. After all, the set of all conceivable universes is an infinitesimally small subset of all possible universes.

This puts a new spin on dreams and art. What if the act of having a dream or creating art is an act of observation from quantum mechanics? By the mere act of observing an imaginary world rendered in artwork, that universe with those characters and shapes and laws of physics exist in some way. Perhaps our understanding of the word "existence" is limiting in that existence is all about acknowledgment.

# physics philosophy

Asking whether or not we're in a simulator is uninteresting because it's ultimately like asking whether or not God exists

It's like asking whether or not we're in a dream or we're in some other being's thoughts. The question starts in earnest as a physics inquiry, but it clearly becomes a metaphysical one, which presumes the existence of something beyond physics.

# physics religion astronomy

If it were true that time was the fourth dimension, we would be 4D centipedes, with each segment representing a 3D slice of who we are at any given moment

If you live for 80 years, your centipede would be 80 years long. But if this were true, collisions with four-dimensional objects should rotate past or future 3D slices of yourself into the present. If you were to trip on a 4D apple, your centipede would twist in four dimensions so that parts of your past or future selves would stumble into the present. Apparently, this doesn't happen. Physicists respond that time is a special dimension, only going in one direction. But is it possible that time is not a dimension as we know it, but something else, like a series of states that derive from preconditions or some other model we have yet to consider?

# physics

If the universe is deterministic, why can't all existence just be the tentative states of a pen-and-paper Turing machine?

Consider a DVD of the movie Fight Club. If someone placed it in a DVD player, they'd see that Ed Norton punches Brad Pitt in the face. If they don't put the DVD in the player, it's still true that Ed punches Brad. If all DVD players in the world broke down, but we retained the DVDs, it would still be true that in Fight Club, Ed punches Brad. The absence of the players doesn't invalidate the truth about that movie.

If all the DVDs were gone, people would still remember that Ed punches Brad. There would be no proof, and one could say that if we were to go back in time, we would find that indeed it is the case. This thought experiment could go further and further, asking questions like, "What if we erased everyone's memory?" Which begs the question, Is the medium of an event's existence necessary for the event's existence? Can existence be solely predicated on information, or do zeroes and ones have to be etched into a disc?

Likewise, it's possible that we are in a similar movie, a movie that isn't playing anywhere. It doesn't exist in the memory of any being, but it's just what happens in this particular, abstract, and grand, sequence.

# philosophy physics

In the future, the killing of a human-looking creature that can pass the Turing Test will be considered murder

In the movie Source Code, Jake Gyllenhaal plays a character who travels to alternative universes where a train is about to explode from a terrorist attack. While his directives are to ignore everything else and find the terrorists, he feels compelled to save the passengers in these alternative universes. The commanders who give him orders believe that these alternative universes are simply simulations with information necessary for the safety of the main world. But Jake is confronted with such strikingly high-resolution experiences in these other worlds that he can't help but feel compassion.

Consider Jake's viewpoint. Since there is effectively no difference between normal human beings and zombies pretending to be normal human beings, he has no way to access the inner experiences of anybody else. He can only verify his consciousness, and so his ethics shouldn't depend on zombie-verification. Yes, we all want to know whether there is someone truly there receiving pain behind that visage, but in the absence of that certainty, you should err on the side of saving the zombies.

# philosophy futurism physics

Maybe waking up is the quantum observation that chooses a logically consistent dream world to stand in for reality

The infinite multiverse theory has implications for dreams. Perhaps dreams are samples of those infinite permutations of alternative universes, and when we wake up, that's just the so-called "observation" that forces a choice of a world that is logically consistent, i.e. the version of Earth where objects obey gravity. In other words, dreams could be tentative realities, and choosing to wake up is when we decide we can inhabit them.

# dreams physics

The day we realize we're not much different than unplayable sentinels in video games is the day we understand our universe

Consider this Theory of Everything: The universe is a giant abstract computer that doesn't actually have to be run. The obvious counter-argument is that you can look all around you and see "stuff" that changes over time. And that even if we're in a simulation, there has to be a recipient of that "stuff" that processes it over time and appreciates/reacts to it.

The biggest barrier to accepting this Theory of Everything is our absolute faith in our senses. Here is a thought experiment to help undo this:

What if we built a naivete machine, one that had absolutely no preconceptions of the world? It would have no concept of time or cause-and-effect, just simply the ability to check variables with values filled in. Initially, it would be useless since it wouldn't have access to our world. So we'd give it a pointer to a memory address where we placed a video feed. The computer could run a loop, check the memory address, and notice some bits. And then after one frame, it would notice different bits there. So the computer would notice that as the loop advances, those bits are different than what was there before. Then it could notice patterns. It could notice that the bits make a lot more sense if composed in x-y coordinates. And maybe it could figure out that it's a series of 8-bit numbers, seemingly repeating every three. Those would be to us RGB, but to it, simply (0-255, 0-255, 0-255). The computer at this point would not necessarily have a sense of time, but maybe it would have a sense of a "tick" since it can execute one line at a time. To the machine, it "knows" that at each tick, there is a different value in that field.

It could have a history of the values of all the previous ticks. But it wouldn't know whether or not ticks in the future have to be calculated in order to be known. It would only know that to get information for future ticks would require ticking forward.

Based on the video feed, it could notice objects, but these wouldn't feel solid to the machine. Instead, the machine would see recurring patterns of clumps of bits. Eventually, it could form rules to predict what will happen on the next tick based on where the clumps were in previous ticks.

At this point, what does the naivete machine believe? It doesn't believe in cause-in-effect. It doesn't believe in materialism. It doesn't believe in time. All it believes is that as each tick advances, there is different patterned data in a memory address. Even the language I use to imagine how the machine thinks is prejudicial.

# philosophy computer_science physics

The Universe is a giant, abstract Turing machine that doesn't need to be run

The universe is one big, abstract Turing machine, one that doesn't need to be run. According to the Church-Turing thesis, there exists some set of computing rules, that when played out, can approximate anything that is computable. Our universe is computable because everything that exists or happens has a logic to it. Even in the indeterministic world of quantum computing, nothing happens without reason. (Here, the word "reason" is used instead of "cause" so as to be agnostic about the nature of causality or time.) You can observe anything in our universe and ask "Why this and not that," and there will be an answer even if you can't know it.

The exception would be observations at the boundaries, whether at the start or end of time. "At some point, something must have come from nothing," so the saying goes, but using a time-independent, causality-independent framework would restate this to say, "Something must have had no reason." There had to be at least one irrational observation in the universe. Even in the case of infinite regress from incessantly asking, "Why this, not that?", one could step back and ask, "Why this infinite chain, and not something else?"

The opposite of reason is arbitrariness or assertion. Being part of an abstract Turing machine is consistent with the requirement for assertion. In an abstract model, the universe is asserted by possibility. It's possible there is a Turing machine with our assertions, simply because the set of all possible Turing machines exists, at least in the abstract.

Actually, one could deduce the universe is abstract without any knowledge of Turing machines, but the Turing machine metaphor helps us navigate our biases. If you picture a pen-and-paper Turing machine, it would have a network of nodes representing different bits and a pointer representing the current state. The current state could be now, and the bits could represent the position and velocity of every particle in the universe. Consciousness would then work similar to the snapshots of each frame of computation in a video game like World of Warcraft.

Consider the mind of a non-playable character, like a soldier who paces aimlessly throughout the court, waiting for someone to ask them for a quest. The soldier could step up to a pond, see themselves and possibly even click on themselves, asking for a quest. All of it would flow from the scripted narratives of the video game. It may appear random, but randomness in computation only works with a "random" seed, which is something external to the system, like the computer's temperature or the exact millisecond that someone started the game. If we use a strict definition of the universe, one that encompasses any so-called multiverses, then there can be nothing outside of it, and therefore no randomness. As a result, this video game would play out the same way each time, with the character going to the pool, and clicking on themselves for a quest at the same frame. Is the universe coded this way? Not necessarily, but according to the Church-Turing thesis, it could be isomorphic to something like this.

As for the clear sense that "I exist" or the problem of qualia, such as the blue-ness of the color blue, we shouldn't dock points from the abstract Turing model because we can't immediately answer those questions. We should try to understand the universe before the Cambrian explosion. Otherwise, we are limiting our understanding of reality by trying to accommodate the puzzles that have sprung up from the rare branch of evolution that is our minds. There is nothing, because there can't be anything, and yet something must be explained, and the only way to to explain explanation without any human assumptions is that it's all just an explanation, a story, an idea, or an abstract machine that doesn't need to be "run" in order for us to know its reality.

# physics computer_science philosophy

What the spacetime continuum is to physics, the chemical-thought continuum might be to psychology

# physics psychology
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