On the other hand, there are a lot of things that make physics tractable to compute, such as the +++- metric tensor and other factors forbidding causality violations. A universe with closed timelike curves becomes very expensive to compute because you usually have to use implicit solvers that are slow and might not even converge, corresponding to various time travel paradoxes.
Couldn't the universe where the simulation runs be so entirely different to ours that computing all that stuff is just easy.
Granted, this scenario doesn't provide us with anything we can take action on, but the idea that we're in a simulation at all doesn't, either.
You don't have to assume anything is true if you don't want to, but if you want to consider whether we're living in a simulation, it's probably worth considering.
>And what would be the point of this simulation that has been running for billions of years?
First, it's billions of years in our time. Second, what's the point of Conway's Game of Life?
Which, for me, is a dead end. It's the same as assuming there's a God, except the moral implications are worse.
> First, it's billions of years in our time.
So, if billions of years of our time fly by like your average simulation run in "their" universe, the simulation can't be very meaningful to them. And it makes the distance between our and "their" physics even larger.
> what's the point of Conway's Game of Life?
None, and that's why nobody runs one with 10^120 cells for billions of years. And if somebody did, the result would be incomprehensible. The gap between us and our creators must then be incomprehensible for us. All this is so outlandish, that the word "likely" shouldn't be anywhere near this discussion.
There is zero evidence for or against the simulation hypothesis, so why would some random person on HN be able to have the answer to this question even if we are in a simulation or even if we simply assume that we are?
The odds of all that happening without it being prevented are all but zero.
We have a better chance that one of the simulators grows attached and—against protocol—decides to uplift us from the simulation into a form where we can directly communicate with them.
Sure, but look at the state of frontend web development :)
When you make a simple simulation of rigid bodies with classical physics you often get numerically unstable results - bodies jerking against each other, slowly passing through, etc. One common way to solve this is to introduce a "frozen" state. When objects are close enough to be at rest with balanced forces - you mark them as frozen and don't compute them every frame to save computing power. You only unfreeze them when some other unfrozen object interacts with them.
Additionally hierarchical space indexing algorithms are often used to avoid n^2 comparisons calculating what interacts and what doesn't. And these algorithms often use heuristics and hashing functions with collisions to subdivide the problem, which might result in objects becoming unfrozen without actually touching each other.
The result from inside this simulation would be weird, nonlinear, nonlocal and look a little like wave function collapse (if particle A whose coordinates hashed through this weird function are the same as those of particle B happens to unfreeze - the particle B unfreezes as well despite not interacting in any way). And this would be probably considered "hard to compute" compared to the simple equations the system developer wanted to simulate.
Example that might be more relatable for scientists - it's much easier and cheaper computationally to make a numerical simulation for 3-body problem than to make an analytic simulation of it. But describing this numerical simulation behavior in terms of physical equations requires much more complex model than the equations that you wanted to compute in the first place. You have to include implementation details like floating point accuracy, overflows, etc. And if you go far enough you have to add the possibility of space ray hitting a memory cell in the computer that runs your simulation.
I'm not saying this is the reason QM is weird - I don't understand QM well enough to form valid hypotheses ;), but I'm saying we might be mistaking the intention of The Developer with the compromises (s)he made to get there. If you take any imperfect implementation of a simple model and treat it as perfect - the model becomes much more complex.
How do you know it's all computed? To make a convincing simulation, you just need to simulate in detail the bits that are actually being observed.
Everything else that happens could just be approximated at larger and larger granularity the further it is away from an observer.
There isn’t actually an observed/unobserved distinction in physics. Unless you mean the simulation is specifically targeting humans, which is a vastly more complicated proposal.
It's also the most likely proposal (with current understanding of universe).
Axis of Evil (Cosmology) calls into question the Copernicus views of the universe. Essentially saying our solar system is somehow back at the center of the universe.
https://www.youtube.com/watch?v=hjVCjdX5XRw
If WE are the subject of the simulation, it's likely everything our instruments observe are like the sky on the Truman show - not there, just phantoms of what we would expect to be there with what the simulation wants us to know about physics.
There's a max speed the speed of light, what if this is the max processing ability of the computer we're running on. What if we're not on a computer at all but some sort of wetware computer system that grows as it needs to, and never runs out of resources?
What if the speed of light in the parent sim is 500x bigger for them, or ours is like a centimeter in comparison.
A dream is a simulation, we could all be dream creatures to some huge extra-dimensional being. Not everything pre-supposes human technology.
I've seen literal "glitches" in reality, so it's pretty easy for me to believe that reality isn't something completely set in stone. For others it challenges everything they believe in, for that I say open your mind.
Donald Hoffman believes that what we see is like what someone in a VR headset sees, outside the VR headset who knows what that world is like, but in this one -- everything except math (which he believes is universal and extra-universal), is made to fit this universe. Physics, science, all of it is unique only inside the headset. There could be many headsets with different settings running parallel (parallel worlds/universes), maybe the speed of light is faster in one than the other, maybe gravity works different, etc... So many things in our understanding are really like "settings" like size of a planck's constant, pie, speed of light, etc. Almost reads like a config file.
I mean if you buy into a "God" being, if computing is a thing which we have it so why wouldn't God? Wouldn't it even make more sense for him to just code up a simulation? I mean it's gotta be a lot less demanding than building a whole universe from nothing.
Just as a thought experiment, I'd propose that our universe and the human experience is incredibly simple. Humans were only given a limited number of senses so that the simulation can be run in this "low fidelity". Compared to the thousands of senses a level or two up. We also are simulated in a simple linear time model, only able to experience a single time at once, greatly reducing the complexity and fidelity needed. Same for the number of dimensions we are able to sense.
2. That the same arguments also apply to our simulator operators. They also inhabit a simulated universe. And so on. Where does it stop, and why?
In a universe where time itself could be fluid, where it could be easy to reverse events, rewrite events, etc - making quantum computers work even way better than we ever could because we're limited by causality.
I mean the people beyond this universe could have 50 senses, like a sense of how far up or down they are, or how much water they can breathe in before they need oxygen if o2 is even a thing, or a sense of time so they can go back/forward through time. If they have 50 senses, our 5 sounds like "nothing" to simulate.
It's all a matter of perspective, I'm sure an ant feels like they keep pretty busy and nothing could possibly simulate their colonies, but I'm sure that would be pretty easy.