
Ask HN: Are we in a top down simulation? - x0054
Let’s assume for a second that the world is simulated. There are, theoretically, 2 ways to do that. The first is the bottom up approach where we design the subatomic structures and make them interact in certain way and let it all evolve as it will. The second, much more difficult to code but much less resource intensive, is the top down approach where we design the rules of reality at a specific snapshot, and the machine running the simulation simply works backwards and forewords in time.<p>Say you wanted to simulate human development. You would setup a world simulation as a snapshot of some 100 million years on earth with the conditions you need, and the simulation would simply compute out in all four dimensions, x, y, z, time, but with less precision with grater distance from the origin. And since we are basically fitting data to the problem at this point, there will be some rounding errors at the edges. Since the precise physics is simulated only when it can be observed in the simulation, not everything that happens in the world actually complies with precise subatomic physics. Sometimes it’s just an approximation of the subatomic physics, or, more accurately, the subatomic physics are an approximation of what would be observed if the world was not simulated.<p>So the inconsistencies between atomic and subatomic worlds could be just a byproduct of a top down simulation. And, if you follow the simulation theory statistical argument, than statistically speaking the less resource intensive top down type of simulations would be far more common. So it’s more likely than not that we are in a top down simulation and quantum physics is just an approximation of our reality, hence the inconsistencies.<p>Thoughts?
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larnmar
While I can see why someone might think that way, the problem is this:
simulating quantum mechanical systems is _much, much_ harder than simulating
classical physics. From a simulator’s point of view, throwing in QM isn’t a
simplification, it changes your simulation from basically linear scaling to a
horrendous exponentially scaling nightmare.

Furthermore, quantum mechanics isn’t really an “optional extra” for our
universe, it’s too important, eg none of the materials or chemicals you see
around you make any sense without quantum mechanics.

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x0054
Think about it this way. You take a crisp photo, blur it a bit, then sharpen
it, then blur it a bit again. The first and the second image will not looks
identical. The first blurred image is the simulation, then we “sharpen” it by
observing it at a subatomic level, then “blur” again by calculating up from
the subatomic observations. The calculations and the “reality” would not
match, but only because the quantum data was generated complexity not
necessarily exactly representing the original.

So, if the base of the reality is designed around something on an atomic
level, when you zoom in past a given level, it would stop making sense if the
program was designed to continually add complexity as it is studied more and
more, perhaps in the effort of discouraging people form thinking that they are
in a simulation :)

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ksaj
> So, if the base of the reality is designed around something on an atomic
> level, when you zoom in past a given level, it would stop making sense if
> the program was designed to continually add complexity as it is studied more
> and more, perhaps in the effort of discouraging people form thinking that
> they are in a simulation :)

I _almost_ can't tell what side you're on.

I think if we are in a simulation, both approaches must be used in tandem.
Rather like how so many ALife concepts are now fully absorbed in AI
frameworks, even though one is clearly bottom-up and the other top-down. The
good stuff is in the middle somewhere.

