That is what I'm saying is not happening. I'm saying that in a particle collider, we measure particles, and those exist all the time, not just when we are looking at them. Like, I have DNA and bones, they exist all the time, not just a simulation showing a 'skin' so it doesn't have to render everything.
Unless you are making a bigger point. That a computer that could be simulating every single particle, must exist outside this universe, and maybe mass and energy in this outside universe is so radically different we can't even grasp the scales of it.
Just like someone inside a minecraft world with blocks, couldn't grasp the amount of energy in our world.
The simplest way I can put it is that at some point of compute, there is a crossover where you need less mass to simulate something than the mass of the actual thing is. This will hold true for particle simulations as well. So no, you would not need more particles than the universe has to simulate the universe perfectly.
So lets say you have Minecraft running.
You can completely build a CPU / Memory, etc... Inside Minecraft with Redstone.
Lets say you do this, build a PC inside Minecraft to the point that it is functional enough to run Minecraft. Minecraft running in Minecraft.
There is huge overhead.
You need an astronomically large real PC that could handle running Minecraft such that the Minecraft version running inside Minecraft is usable. That is the scale problem.
I'd have to dig up the citation. But pretty sure this compute power needed to compute the universe has been worked out.
So.. we are basically just a few meters over the start line in terms of doing perfect particle simulations :)
Look at protein folding. For decades, we could do it incrementally faster as our globally available compute increased. Then Alphafold came along and proved that it could be done much more efficiently. Now there's multiple models / companies that are planning to jostle for supremacy in that space.
Our ways of simulating particles will get more sophisticated and efficient as time goes on. Our hardware will push more calculations per watt and per density (aka per unit of mass).
I guess ultimately you take the pessimistic view and I take the optimistic view, so we'll have to agree to disagree. Good talk though!
That’s not how it works though. You’d have a lot of fixed costs to build a computer that simulates exactly the behavior of one particle. But then simulating a secondary particle will have a much, much, much smaller marginal cost.
Since you brought up clipping, games are actually a perfect example. You can see games as very crude simulations of our own reality, or slices of it. Take for example Red Dead Redemption 2. Run it on a PS5. Now compare the size of your PS5 to the mass of what was the old Wild West territory :)
Plus there’s the whole quantum computing thing, where in a way you’re reaching into “alternate” realities for extra compute.