Physicists To Test If Universe Is A Computer Simulation • Hacker News Board

Re: Physicists To Test If Universe Is A Computer Simulation

#161

Post by jonnathanson » Wed, Apr 17, 2013, 1:32 PM UTC

coolgeek wrote: post #154

polymatter wrote: post #136

Earlier quoted context omitted.

(c) We are unintended by-products of whatever is being simulated.

I think you meant incidental, rather than unintended

Or emergent.

Think of the Deist philosophy of the 18th century: that of God as a "clockmaker," who wound up the universe and then left it to tick. Whatever outcomes emerged were not necessarily the results of his actions or intentions; they were the effects of his original cause. It was a quirky and relatively short-lived philosophy, especially in the Western cannon. But it's eerily applicable here.

If this is all a computer simulation, it's possible the creator(s) of the simulation programmed only the fundamental physics and set up the Big Bang, allowing everything else to unfold and develop as it has.

In effect, this wouldn't be very different (to us) from a non-simultated reality. Hell, it's possible that we're in a simulation that people in the "real" universe set up as a scientific study, to model their own universe's birth and evolution.

Re: Physicists To Test If Universe Is A Computer Simulation

#162

Post by crusso » Wed, Apr 17, 2013, 1:36 PM UTC

specialist wrote: post #87

batgaijin wrote: post #78

Earlier quoted context omitted.

Well the most interesting part of the Matrix trilogy was when Neo used his powers in the 'real' world; specifically stopping the drones and being able to see despite losing his eyesight.

Totally. I expected the simulation within a simulation, turtles all the way down, plot twist. My favorite theory was that all the humans were passengers on a generational seed ship traveling to the next star, kept in near stasis to keep them alive and mostly sane during the millennial transit. That would have played nicely with The Architect's explanation that in the perfect simulated world, humans went insane. So Th…

Such a wasted opportunity.

Yeah, but there were a lot of explosions.

Re: Physicists To Test If Universe Is A Computer Simulation

#163

Post by crusso » Wed, Apr 17, 2013, 1:42 PM UTC

kstenerud wrote: post #24

"The alternative - that we're the first civilisation, in the first universe - is virtually (no pun intended) absurd." As opposed to us simply being some other civilization on one of the other billions of habitable planets in that same "first" universe?

We know absolutely nothing beyond this universe. We barely even know much about this universe.

You can't meaningfully speculate about the nature of what (if anything) is dimensionally/physically/extra-universally "outside" of our universe.

We don't even know what that means, much less if it exists or what the number/nature of it would be.

Our universe may be a piece of candy floating on a chocolate river in another universe that flows eternally.

It's all just make believe. Make believe can be fun, but let's not pretend that we're doing anything more substantial than what three year olds do when talking about space robots.

Re: Physicists To Test If Universe Is A Computer Simulation

#164

Post by polshaw » Wed, Apr 17, 2013, 1:43 PM UTC

What I would like to discuss is what purpose would simulating a universe have for the advanced civilisation?

As the civilisation becomes closer to being capable of creating a perfectly simulated universe, they get less benefit from having one. If we assume the universe we are in is at least similar to 'the first', then the existence of entropy / thermodynamic laws would surely create a significant cost to universe simulation. So I can't see it being done without good reason (eg as a toy), and as the master would have to understand all the factors involved in the universe already to create the simulation, so what would they gain?

Is it right to say that it would be impossible to simulate the universe at full speed? (ie. the computer would need to be powerful enough to simulate itself and more (ie. the rest of the universe)). If so, this would not only make it less useful, but put significant (increasing) limits on the local age of the descendent universes; assuming (fairly, i think) that the master universe does not have an infinite existence with infinite time between shocks. Also, how would it be possible to store all the information for a universe within itself?

Or perhaps we are talking about imperfect simulations, which would make it much more feasible? but then the infinite exponential chain would not be possible as each child would become more crude. Or perhaps only a (diminishing) proportion of space(-time) is simulated.. or maybe the speed of light decreases as simulation levels get deeper?

In writing this I think I have come to the conclusion that it is impossible (in so far as anything is given our imperfect knowledge), at least a complete universe simulation or an endless chain, but I would love for someone to show otherwise.

Re: Physicists To Test If Universe Is A Computer Simulation

#165

Post by jonnathanson » Wed, Apr 17, 2013, 1:46 PM UTC

smoyer wrote: post #153

nnq wrote: post #125

Isn't it obvious for most that for an advanced enough simulation, it is impossible to prove that you are in a simulation from inside the simulation? Even if we find proof that our current model of reality is wrong, it would only mean we need to search for another model of reality, we can't just say "but out theory doesn't actually match the reality because the reality is actually a simulation that computes approximat…

I think the experiment as designed could show you that you are inside a simulation, but would make it hard to show you were real. Think about time-lapse photography and simulated photons. As we get better at doing time-lapse photography (more FPS), we might see movement along the predicted course become step-wise (rather than a smooth function). Barring some weird physical phenomena, this could show we were inside a…

Such a result would show that we're in a simulation built with technology and scientific understanding not entirely different from our own -- that whoever modeled us modeled us after themselves.

But the lack of such a finding wouldn't necessarily disprove a simulation. It's possible we're in a very simplified model of the real universe, and that the simulators --whoever or whatever they are -- inhabit a universe of very different physics and phenomena. Broadly and metaphorically speaking, we're trying to probe for the glass walls at the edge of the fish tank. But what if it's not a fish tank?

Re: Physicists To Test If Universe Is A Computer Simulation

#166

Post by pdonis » Wed, Apr 17, 2013, 1:51 PM UTC

Houshalter wrote: post #124

dgreensp wrote: post #90

Earlier quoted context omitted.

I've always felt there's something deeply fallacious -- or hopelessly wrapped up in human psychology -- about taking a representation of a virtual world that we might create and treating it as on par with the actual universe. It's almost like saying "we're probably characters in a novel," since for every universe there are many novels. Or like that old proof that God exists because he has every desirable quality, inc…

There is a similar argument against AI. That a computer can't "feel" or experience any of the sensations we do. If you type 'emotional_state = "happy"', does that mean your computer feels happiness? Even if you have a complex simulation of neurons, if you zoom in, all you will see is little electrons bouncing through various logic gates and ending up in some kind of pattern. But the thing is, the exact same thing is…

Complexity isn't what makes something intelligent or conscious after all.

Why not?

Re: Physicists To Test If Universe Is A Computer Simulation

#167

Post by jonnathanson » Wed, Apr 17, 2013, 1:51 PM UTC

polshaw wrote: post #164

What I would like to discuss is what purpose would simulating a universe have for the advanced civilisation? As the civilisation becomes closer to being capable of creating a perfectly simulated universe, they get less benefit from having one. If we assume the universe we are in is at least similar to 'the first', then the existence of entropy / thermodynamic laws would surely create a significant cost to universe si…

"What I would like to discuss is what purpose would simulating a universe have for the advanced civilisation?"

The Douglas Adams-style answer would be that we're some kid's physics homework. Perhaps, in a sufficiently advanced civilization, building a working computer model of an advanced universe is child's play.

An alternative is that the simulators inhabit a very different universe from our own, and that our simulation is something entirely new. It's not a replica of their universe; it's a completely different creation. They could be studying various scenarios, of which ours is just one.

We need to bear in mind that we're approaching this problem from our own, subjective understanding of our universe. It's not a given that the simulators' universe is anything like ours.

Re: Physicists To Test If Universe Is A Computer Simulation

#168

Post by ep103 » Wed, Apr 17, 2013, 1:51 PM UTC

polshaw wrote: post #164

What I would like to discuss is what purpose would simulating a universe have for the advanced civilisation? As the civilisation becomes closer to being capable of creating a perfectly simulated universe, they get less benefit from having one. If we assume the universe we are in is at least similar to 'the first', then the existence of entropy / thermodynamic laws would surely create a significant cost to universe si…

You started this post asking one question, and ended it asking a different (IMO much more interesting) question.

To the first one though, so long as politics and war exist, there would always be reason to attempt to run simulations, regardless of the degree of advancement of a civilization.

By the By, Iain Banks plays around / has a recurring thread of simulations and high powered computers in his culture series, if you enjoy sci fi.

Re: Physicists To Test If Universe Is A Computer Simulation

#169

Post by x_ferris » Wed, Apr 17, 2013, 1:54 PM UTC

"The question is, 'Can you communicate with those other universes if they are running on the same platform?," she said.

If we share any form of resources then its going to be possible either through a timing or storage channel attack - this is simplified but here's an example of two vms communicating via the hypervisor:

http://www.idontplaydarts.com/2012/08/data-exfiltration-thro...

Re: Physicists To Test If Universe Is A Computer Simulation

#170

Post by moens » Wed, Apr 17, 2013, 2:09 PM UTC

Jayschwa wrote: post #100

KC8ZKF wrote: post #94

Earlier quoted context omitted.

You have to live as if you have free will. You can't say, "I've considered all the possibilites, and have decided that there is no free will", because considerations and decisions are acts of free will themselves. Of course, that doesn't mean you have free will.

I find it interesting how people often cite determinism as incompatible with free will. Our minds don't violate the laws of physics, but they still make decisions. Similarly, a car can still be described as "driving", even if the physics behind it are deterministic.

Its an easy way to excuse bad habits, that's all.