Your yearly dose of is-the-universe-a-simulation • Hacker News Board

Re: Your yearly dose of is-the-universe-a-simulation

#41

Post by AnonNo15 » Wed, Mar 22, 2017, 7:46 AM UTC

simonh wrote: post #36

AnonNo15 wrote: post #29

Earlier quoted context omitted.

It doesn't prevent simulating A universe. You can then compute a difference between the simulated past state and real past state based on (partial) information about the past state. Then you go back and iterate again, eventually improving the accuracy of simulation until there is no distinguishable difference between simulated state and real past state. The simulation might end up being not a perfect copy, but it wou…

If you have a way to find discrepancies between a simulation and reality, why do you need the simulation anymore? I don't buy it. Even simulating just the earth and its environs would probably require a computer as big as a galaxy worth of matter. There's just no conceivable payback that could ever be worth the costs.

You have to actually compute the simulated state and compare it to known bits of the past state to get the results.

Yes, simulating Earth to sufficient precision might require resources of the Type III civilization. However, if something can be done, why shouldn't it be done?

The payback is twofold, actually:

First, you can get provide the meaningful afterlife to your ancestors.

Secondly, once you have hardware and software to simulate a virtual universe, you can create a multitude of them, with different properties and qualities. Think of the same logic behind splitting the physical computer into virtual machines.

Re: Your yearly dose of is-the-universe-a-simulation

#42

Post by bambax » Wed, Mar 22, 2017, 7:46 AM UTC

leni536 wrote: post #26

The statement "we live in a simulation" is not falsifiable. For me this question is simply not interesting.

Also, it doesn't explain anything, and esp. nothing about the simulators: are they themselves simulated (and so it's turtles all the way down, again) or are they not? And if not, why not, and who are they? etc.

Re: Your yearly dose of is-the-universe-a-simulation

#43

Post by tbabb » Wed, Mar 22, 2017, 7:46 AM UTC

leni536 wrote: post #26

The statement "we live in a simulation" is not falsifiable. For me this question is simply not interesting.

I think the fact that it is not falsifiable means that we should not believe it, but that doesn't mean it's not interesting.

Re: Your yearly dose of is-the-universe-a-simulation

#44

Post by teraflop » Wed, Mar 22, 2017, 7:46 AM UTC

RyanCavanaugh wrote: post #13

powera wrote: post #2

I'm yet to hear a simulation theory with more explanatory power than the much simpler theory of "God did it". Most of the claims are variants of "but computers, so science", which is not an argument at all.

Let's say that for a given set of physical laws, you get some "computational power" P, which characterizes how hard it is do to computation using those laws. You could imagine a universe with lower P than ours, where light was much slower, or the only workable transistor had a switching time on the order of seconds. Given a universe with computational power P, you can simulate a "universe" of something like P * 10^-1…

I think the Minecraft analogy is illustrative.

In Minecraft, you can use redstone circuits to construct logic gates, and use those gates to build computational devices that are Turing-complete, in theory. But it's not possible to scale such devices up arbitrarily; you can build a simple CPU, but nothing that even approaches being able to run a nested copy of Minecraft. There are hard upper bounds on the amount of data that the simulation can cope with at once. (You can imagine patching Minecraft to allow keeping more chunks loaded at once, but you can't scale it up by very many orders of magnitude before you end up with something that can't run efficiently on any hardware that physically exists.)

Similarly, as Scott Aaronson describes in the article we're discussing, it's likely that there are finite bounds on how much computation can possibly be done before the heat death of our own universe. So it's fair to be skeptical that a tower of "turtles all the way down" could ever possibly exist, at least on a universal scale. If there's no tall hierarchy, then the anthropic argument (which says that we're unlikely to be at the top) breaks down.

You can certainly hypothesize higher levels which have infinitely fast communication, or other kinds of special properties that make deep simulations more feasible. (Greg Egan proposed one such cosmology in his novel Permutation City.) But you don't get to assume that and still use simulations within our own universe as examples, because you're talking about something entirely different.

Re: Your yearly dose of is-the-universe-a-simulation

#45

Post by bambax » Wed, Mar 22, 2017, 7:48 AM UTC

sebleon wrote: post #12

powera wrote: post #2

I'm yet to hear a simulation theory with more explanatory power than the much simpler theory of "God did it". Most of the claims are variants of "but computers, so science", which is not an argument at all.

*disclaimer: no explanatory power, just food for thought 'cogito, ergo sum' We could very well be 'real' consciousnesses being fed artificial sensory data. While we would exist outside the simulation, our perception of objective reality might be fake.

That's the Matrix, exactly. But they have flip phones there.

Re: Your yearly dose of is-the-universe-a-simulation

#46

Post by MrQuincle » Wed, Mar 22, 2017, 7:50 AM UTC

leni536 wrote: post #26

The statement "we live in a simulation" is not falsifiable. For me this question is simply not interesting.

It might help on an existential level.

+ In the space of all possible universes it is unlikely that we live in the most probable one, but it is likely that we live in a probable one.

+ When I feel existentially lost, I'd like to think that if we look deep into math we will see the necessity of our universe's existence.

+ Our universe is a probable sequence hidden like primes within natural numbers. It exists forever, we only need a mathematical microscope.

For me it helps a bit...

Re: Your yearly dose of is-the-universe-a-simulation

#47

Post by tbabb » Wed, Mar 22, 2017, 7:50 AM UTC

Gupie wrote: post #38

snowwrestler wrote: post #6

Here's what I wrote in a comment here last year about the Bostrom simulation argument specifically: The simulation argument, going back to Bostrom, relies on two flaws. 1) It leverages our optimism to corrupt our understanding of statistics and logic. It essentially says that if you think humanity doesn't destroy itself, then our descendants will probably try to simulate us. But of course if you just take a statistic…

Why does it need to be a complete simulation? At the extreme, it could be a simulation in which you alone are the only conscious entity. Nothing outside your immediate proximity is simulated.

And it only needs to be simulated convincingly enough and in enough detail to fool your human mind.

Re: Your yearly dose of is-the-universe-a-simulation

#48

Post by polotics » Wed, Mar 22, 2017, 7:51 AM UTC

Contributing to the debate: How frequently do you fire up sim-city / how frequently do you fix up lunch?

Re: Your yearly dose of is-the-universe-a-simulation

#49

Post by inopinatus » Wed, Mar 22, 2017, 7:54 AM UTC

intjk wrote: post #31

leni536 wrote: post #26

The statement "we live in a simulation" is not falsifiable. For me this question is simply not interesting.

At the end of the article, Scott essentially says the same thing, but emphasizing the other side of the coin: > [...] the question of whether the universe “really” “is” a simulation has barely come up. Why would it, when there are so many more fruitful things to ask?

I always felt that the point of asking this question was not the answer itself, but that theorising how it might be implemented could lead to hacking the sandbox.

IANATP but I've read, for example, that violating Lorentz invariance is an active research area.

Re: Your yearly dose of is-the-universe-a-simulation

#50

Post by evanb » Wed, Mar 22, 2017, 7:56 AM UTC

RyanCavanaugh wrote: post #13

powera wrote: post #2

I'm yet to hear a simulation theory with more explanatory power than the much simpler theory of "God did it". Most of the claims are variants of "but computers, so science", which is not an argument at all.

Let's say that for a given set of physical laws, you get some "computational power" P, which characterizes how hard it is do to computation using those laws. You could imagine a universe with lower P than ours, where light was much slower, or the only workable transistor had a switching time on the order of seconds. Given a universe with computational power P, you can simulate a "universe" of something like P * 10^-1…

Indeed, computational complexity depends on the physical laws of the universe. Suppose your universe admitted a computer where, with finite power, in the first second you could execute one instruction, and then you could run the next instruction in half a second, and the third in a quarter of a second... etc.

What is "reasonable" to compute in a short amount of time in this universe has changed dramatically! For example, I want to prove the Goldbach conjecture. No problem! Just use this crazy computer to check every case, which is possible because this computer executes an infinite number of steps in two seconds.

Unfortunately [word choice?], in our universe such a computer needs an infinite amount of energy and would collapse into a black hole long before you received your answer!