It does feel a bit harder to focus lately ever since I got back home. I used to be more productive in terms of spending time on my "creative" hobbies at night - such as writing or reading ML papers but lately I've just been aimlessly browsing reddit/playing hearthstone. While it's fun to relax once in a while, I think blogging and learning something new can also be relaxing, I just need to overcome the inertia of being lazy and start doing it.
That being said, this is a difficult blog post to write. It sometimes feels almost inconsequential to write thoughts like this down in some concrete fashion because, after all, what impact could it really have? Nonetheless, what spurned me to do this was that I want this blog to be a record of my thoughts especially since I might not be able to always trust my memory to hold it all. So I want to record that, for at least the later half of 2022, I've had the hobby of watching these existential/philosophical videos about science and the mysteries of existence. You know, questions like:
1.) "Why is there something rather than nothing?"
2.) "What came before the Big Bang?"
3.) "Is the universe discrete or continuous?"
4.) "Is the universe computing something? Does it have a goal?"
I've found the Closer to Truth youtube channel (https://www.youtube.com/watch?v=YkB-phz_2cA), is a great resource for this. It's fun to watch random episodes and night to help get me thinking. Speaking of which, another book I read on this topic was "Our Mathematical Universe" by Max Tegmark, who basically postulates that math is the underlying reality of everything and that we all are just mathematical objects (ie. defined by our relationship with other objects) and that also all mathematical objects (*in some sense - maybe they have to be computable) exist.
That being said, this feels more like a guilty pleasure and I don't want to come across as one of those pseudo intellectuals who think they are more smart or enlightened than others because they read/watch popular science videos on these subjects. I fully acknowledge that in order to consider such things seriously you need to dive into the math which likely requires several years of study. As an aside, I like the PBS Spacetime youtube channel too, in the sense that it's not afraid of showing the true nature of how complicated the math can really get.
I'm not sure how deeply I want to go into questions in this particular blog. Maybe I can just express my current thoughts about one of them: "Is the universe computing something? Does it have a goal?"
From a selfish POV, I would like to know the answer to this question because I'd like to help the universe in achieving it. I want validation in the sense that knowing my existence did mean something or matter to the final result and that everything won't just be erased in the heat death of the universe. I want to know that whatever answer the universe was trying to compute, it couldn't have got there without me. Maybe that sounds naive - like I'm searching desperately for something to make myself seem very special but, I think this is actually a pragmatic point of view. At some very high level, I think that I want to feel like I've done something "significant" or "helpful" to others and then just be able to die and move on. You want to know that you've fulfilled your duty and then can disappear without any sense of guilt.
My personal feelings aside, what do I think the "point" of the universe might be? To put it another way, "If existence is the answer, then what is the question?".
In my mind, probably the only obvious answer could be that the universe is trying to understand itself. Maybe the universe (ie. the set of laws that constitute it - fundamental forces, quantum fields, etc.) is the only possible system that can create observers capable of comprehending itself. That is, if a universe was too complicated and all consciousness beings just "popped" into existence (like how we might run our Sims games), it seems highly unlikely they'd ever figure out how they were created or how they came into existence. On the other hand, if the universe was too simple, it wouldn't be able to produce beings that could reason about how it works. The "uniqueness" of this hypothesis is quite nice, it means we don't have to worry about all these other messy possible universes but it also seems far fetched that these laws/constants are the only ones that can work.
That being said, extrapolating this theory a bit further we could just say that the goal of the universe is to produce beings which can "understand" the universe in general. I think this way of thinking is nice in that it gives us a clear goal about performing science to better understand the natural world. It's like a somewhat fun game that might even have a clear answer one day.
Of course, this doesn't answer the question "why play this game? why care about even finding a system that can understand/describe itself?" which is a question that takes an even further step back. I think this is where Max Tegmark comes in and says that the underlying nature of reality is just "math" and that all mathematical objects exist - we're just a particular type of mathematical pattern that's sophisticated enough to reason about the pattern itself. In general I think that the only valid answer to this question (ie. "why does anything at all exist?") has to be of the form "because everything's that possible does exist?"
However, this answer isn't entirely satisfying since clearly our universe seems to have some constraints. Max gets into this when he talks about "computability" since it seems like, in our universe, we can't have quantities which can go to infinity (ie. the speed of light is finite) and clearly there's something we don't know about black hole singularities. Also, no singularity has ever been observed in nature. So, even though we only have a sample size of 1, it does seem like the universe is very carefully crafted to not have any energy quantities suddenly "blow up" to infinity. If we were all just mathematical objects, why would this even matter? It seems like something else is trying to constrain the system itself, or there's some fundamental bounds on what the laws of the universe can do (ie. speed of light has to be finite so "information" can't travel infinitely far and seems to make the universe somewhat "self-consistent") that might reduce the solution space of possible physical laws.
I could ramble on about this for a while, but I hope you get the point. It's nice to think about these questions once in a while and to step far outside my day to day life. But it seems unlikely that we can ever get any concrete answers about why this specific reality exists (through traditional science) so maybe it's just an exercise in humility? Some folks things that such questions are better answered by religion. That being said, I think we (as humans) have gotten much better at explaining the world around us so maybe there is hope for us to understand fully in the far future.
The last thing I want to touch on is the concept of time. It seems from what I've read, I do feel a bit more convinced that time isn't really something that flows or moves forward, it's just part of the geometry of the universe like space is. This becomes more clear when you think about how space/time can switch roles within a black hole or about special relativity and how the "speed of light" is like the conversion rate between space and time. Maybe it's only macro organisms such as ourselves that perceive time in the way we do (ie. that the future is "unwritten" or "yet" to happen) and that the past has already happened. I think I feel similar to the Tralfamadorians in "Slaughterhouse 5" who think that there's no real concept of "time" just slices that you can visit at different places and maybe everything is just experienced all at once.
Maybe this is just being poetic, I'm not sure. This view (I think it's called the "block universe") does seem at odds with quantum mechanics and the idea of an evolving wave function (ie. the notion that everything in the universe is just completed determined as QM has some fundamental notion of randomness). I think I prefer the randomness view better - it would be kind of depressing if everything that ever would exist had already existed but even that might not be true in QM since this "process" could have been going on for an infinite amount of time. Does that mean that "I've" existed in infinitely many situations in the past? Again, this might not be true since things get weird when you consider infinities. I like to go back to the proof that a random walk in 2D will visit the origin infinitely many times, but this is not true for 3D. That is to say, even if there's an "infinite" amount of time in the past, maybe it's not possible that everything will happen infinitely many times - but again, I think the whole concept of "infinities" might just be something that exist within mathematics but can't be realized in the physical world.
Anyway, some family members say this is all too complicated and pointless to think about - they hope that upon death they might get all the answers and the veil will be lifted (via some religious beliefs). I also hope that is true but maybe shouldn't put all my eggs in one basket. There's also the question of, "even if the universe/existence did have a point, would it change how I live my life?" but maybe we can discuss that another time. Either way, I'd prefer to tackle more concrete questions during my lifetime (ie. artificial intelligence and understanding the brain) but this is fun to speculate about once in a while...
