Physicists Devise Test For Whether the Universe Is a Simulation 529
olsmeister writes "Ever wonder if the universe is really a simulation? Well, physicists do too. Recently, a group of physicists have devised a way that could conceivably figure out one way or the other whether that is the case. There is a paper describing their work on arXiv. Some other physicists propose that the universe is actually a giant hologram with all the action actually occurring on a two-dimensional boundary region."
Half a test. (Score:5, Insightful)
If I read that right, they mean that their analysis can only conclude either that the universe is a simulation, or that it is either not a simulation or a simulation too accurate to tell via their method. It can't actually prove that the universe is *not* a simulation.
Looks like no need for elaborate and expensive equipment though - just a way to measure the energy of cosmic rays - so why not give it a try?
Quantum Mechanics cannot be simulated ... (Score:5, Insightful)
... efficiently on a classic Turing machine. This has been established since Feynman originally proposed it [wavewatching.net]. So I simply don't understand the premise of this research. Not that this is hasn't come up before with SUSY string theorists [wavewatching.net].
It simply flies into the face of what these days is known about computational complexity [stanford.edu].
Apparently some physicists are completely ignoring this branch of theoretical computer science.
Now if the question was that the universe might be a quantum computing simulation that'll make more sense, as these can also efficiently simulate field theories [wavewatching.net].
But my understanding is that this is not what they are investigating here.
Philosophy vs. Physics (Score:5, Insightful)
I think we really are skirting the boundary between physics and philosophy. I suppose the fact that actual experiments are being proposed pushes the holographic universe idea and the simulation idea towards being actual physics. However, I still have categorizing the holographic universe hypothesis as real physics. By real physics, I mean experimental physics, where we base our ideas about the physical world on what we actually observe.
Re:I hate those types of physicists (Score:5, Insightful)
They never pass the joint around :(
Ha, like any other physicists are any more sane!
Current popular thinking among physicists is that the universe itself does not know the exact location and momentum of fundamental matter.
The Copenhagen interpretation [wikipedia.org] of quantum mechanics tells us that the universe has a true random component. No, not pseudo-random. True random.
The many-words interpretation [wikipedia.org] of quantum mechanics tells us there are obscene numbers of universes that exist, because the universe creates perfect copies of itself every time a quantum decision is made, except for the quantum decision itself being different in each copy. And those universes split, and those do, and those do...
Various tests tell us photons are waves. No, particles. No, both! And electrons too! And more!
Go read up on quantum entanglement [wikipedia.org] if you have not yet believed in enough impossible things before breakfast yet.
Chuckle at the simulation argument all you want, but it's just as sane and likely as these other crazy, wild things. No, scratch that. The simulation argument is far more sane.
Physicists aren't smoking dope...they're all tripping on LSD!
Re:Speed of light (Score:4, Insightful)
Not necessarily a bug, it could be just a way the memory is used, with data and instructions not being properly separated, then maybe you could access instructions by overwriting memory, and normal buffer overflow, but it doesn't have to be a bug, just lack of security features.
Re:Deception (Score:5, Insightful)
What if the "simulation" is simply programmed to deceive this test? Then what do you do?
If no test is possible, then it is not physics but only philosophy.
Scientists perform experiments that are constrained by the laws of nature.
Philosophers perform experiments that are constrained by the laws of logic.
Re:What if they are right? (Score:3, Insightful)
I find that having a good understanding of computers and technology really helps when trying to understanding the universe. There's a lot of comparisons to be made and metaphors to facilitate understanding.
For instance, say the universe was was a car...
Re:Deception (Score:5, Insightful)
There's a difference between "programmed to deceive this test" and "programmed to deceive all tests". This is a test for a particular type of simulation, and will verify or falsify whether we're in that type, but other types, which may or may not have occurred to us, may or may not have other tests that can be performed. So failure to detect a simulation here will not only not prove we're not in a simulation, but will not prove that the hypothesis is unscientific.
On the other hand, success at proving we're in a simulation would certainly be a fascinating result! :)
Re:God and Science (Score:5, Insightful)
Just like when Copernicus said the earth was not the centre of the universe, and all those scientists attacked him?? No, that was Christians.
Well how about evolution? It explains all we see in the natural world elegantly using a simple principle which is supported mathematically. Nope, Christians want to stop people discussing that. The big bang? The existence of other planets? The size of the universe? Fossils? Radio-isotopic dating? No, no, no - Christians HATE these things.
Christianity, and its brother Islam, are jokes. The teach ridiculous things, and demand acceptance without allowing questioning. I'm happy for you to believe that crap if you like, but know that it's bullshit and that you are wasting your time.
Also, and most importantly, stop trying to discourage science. Stop trying to stop people learning things. Christians and Muslims might be happy living in smelly caves, or you may accept the benefits of science at the same time as attacking it, but science is important for all humanity. More important that some bundle of lies, the false idol, cobbled together and continually altered declaring itself as god's word.
Re:Economics not physics (Score:5, Insightful)
Or it just slows down the tick rate, and we have literally no idea. I can't think of any reason a simulation would need to run in real time.
Plank Pixels (Score:4, Insightful)
Their hypothesis rests on the idea that if the universe's fundamental characteristics have a smallest unit, then it's possible the universe is a phenomenon whose behavior is arbitrarily created by something that's not in the universe. I don't see why that makes it possible. We've believed for about a century that the universe is composed of quanta, fundamental characteristics with smallest units. There is an entire Planck scale [wikipedia.org], the smallest possible lengths (in space or time) and other sizes of space and what's in it. I don't see why it's necessary that "the real universe" is continuous rather than granular, and our granular universe isn't the real one. Or even how granularity even implies anything "outside" the universe exists.
Our universe is made of Plank pixels ("planxels"). That doesn't imply anything about anything except our universe and its granularity.
Re:I hate those types of physicists (Score:5, Insightful)
I can't tell if you're joking or not. If not, how about you go and learn a little about some of these topics. With the exception of many-worlds, physicists believe them because a lot of theoretical and experimental work has been done to support these ideas.
Re:There is no boundary (Score:4, Insightful)
Yes, physics is a practice refined from "natural philosophy [wikipedia.org]: thinking in an organized way about nature.
But what metaphysical assumptions is modern physics replete with? Other than necessary falsifiability and universal consistency?
Also, Vikings weren't the first people to arrive in America. Not even from across the Atlantic.
Can't be cobol (Score:2, Insightful)
After all it's after year 2000, and we're still alive. It can't be based on Cobol.
Re:God and Science (Score:4, Insightful)
Nice attempt at false equivalency.
Scientists "assume" that the big bang was a real event because big piles of evidence indicate that it was.
Religionists "assume" that their god created the world because big piles of tradition claim s/he did.
Not much in common between the two, unless you're an idiot who thinks "where you there?" is a good argument against something you don't want to believe.
Re:Deception (Score:4, Insightful)
As you may have noticed, many scientists have initials signifying "Philosophy Doctor" after their names. Technically, scientific investigation is a philosophical investigation technique which derives from the ideas set forth by empiricist philosophers, and is a branch of epistemology.
Science and philosophy haven't been the same discipline for a long, long time. It's a historical artifact, nothing more.