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No, We Probably Don't Live in a Computer Simulation, Says Physicist (gizmodo.com)
Science doesn't have all the answers. There are plenty of things it may never prove, like whether there's a God. Or whether we're living in a computer simulation, something proposed by Swedish philosopher Nick Bostrom. From an article on Gizmodo: This kind of thinking made at least one person angry, theoretical physicist and science writer Sabine Hossenfelder from the Frankfurt Institute for Advanced Studies in Germany. Last week, she took to her blog Backreactions to vent. It's not the statement "we're living in a simulation" that upsets Hossenfelder. It's the fact that philosophers are making assertions that, if true, should most certainly manifest themselves in our laws of physics. "I'm not saying it's impossible," Hossenfelder told Gizmodo. "But I want to see some backup for this claim." Backup to prove such a claim would require a lot of work and a lot of math, enough to solve some of the most complex problems in theoretical physics.
The objection in question ignores Bostrom's basic argument. Bostrom's primary argument for being in a simulation boils down to the observation that it is very likely that an advanced civilization would have the ability to run very accurate simulations. Moreover, one of the things they'd be obviously interested in would be their own past ancestors; if that's the case, then over the very long period that such civilizations will exist one will expect many more "copies" of people on ancient Earth than any of the originals, unless one expects civilization to die out well before we get to that technology level. If the laws of physics are simulated badly enough that we can notice, then they aren't doing an effective ancestor simulation, so the objection here doesn't make sense.
There are a lot of issues with Bostrom's argument; for example, one might question whether simulations of that level of detail will ever be able to be made on a large scale. But the argument being made here doesn't grapple with the fundamental issues.
A previous slashdot commenter (I don't remember which, sorry) said it best. It's apparently ignorant and backwards to believe that God created the universe, but quite forward-thinking and intellectual to think a computer programmer did.
Personally the fact that recently we have found the EM drive may actually work says were are in a simulation. We just found a bug in the physics engine. That or we need to rethink many of our basic assumptions of physics.
Oh, and it's simulations all the way down.
Umm no and here's the rebuttal: http://backreaction.blogspot.c...
That is a weak rebuttal. Basically it says "I don't like this theory therefore it must not be true". A simulation would not have to compute the state of every quark in 13.85B-LY^3 with planck-time granularity. It would just need to compute the sensory input to a single brain.
1. Due to limited computational resources, the simulated universe would be granular or "quantum".
2. To limit computation, reality would be held in a fuzzy probabilistic "superposition" state until it is actually observed, similar to how a GPU running OpenGL will skip the generation of hidden polygons.
3. The maximum speed of information transfer would be finite, to limit the propagation of changes through the universe.
All of these are actually true in our universe, ergo, we are very likely a simulation.
And this, sir, is why you really need to consider taking a course in formal logic and maybe learn about logical fallacies.
None of these assertions, even if they were true in some useful way, constitute a statistical or logical argument for the conclusion. This is true at an openly embarrassing level. Suppose one were designing a rock because you wanted to build a rock wall and for some reason didn't want to use actual rocks. Due to the cost of raw materials, rocks would be finite in size. Because you don't want the wall to be boring, rocks would come in many different colors, sizes, and shapes. Because you don't want the fake rock wall to fall down, rocks would be solid, as opposed to liquid, glass, plasma, gaseous.
All real rocks are actually finite in size, come in many different sizes, shapes, and colors, and tend to be solid to the point where "rock solid" is a standard metaphor in human speech. Ergo, all rocks are obviously designed.
Not!
Teleological arguments are pure bullshit, which is what the physicist in question (as well as myself, also a physicist) are happy to point out.
When one actually looks at rocks or Universes, there is an utter lack of either evidence or a plausible, consistent, evidence linked chain of reasoning that increases the probability that the notion/hypothesis "Rocks are designed" or "We are living in a computer simulation" is/are true from their rightful place (so far) of 0.0000.....(0 until you get bored with writing 0's)...001 to something with a tiny smidgen of actual measure.
These are not independent assertions, by the way. If you take the assertion that the Universe is a simulation seriously, then rocks ARE designed objects, even though there is absolutely nothing about rocks to suggest that they actually are designed.
One could then deconstruct the truth of each of your statements individually. For example, there is nothing in quantum theory that limits computational requirements -- quite the opposite. Indeed, quantum theory is built on top of complex, non-discrete numbers in every quantum textbook ever written -- C-numbers. That is, quantum objects are described in general by (at least) TWO real numbers, not just one. If you attempt to represent the quantum state of a very simple -- the simplest -- two level quantum system such as |\psi> = A|-> + B|+>, one discovers that it requires two continuous degrees of freedom and that the states of the system map nicely into points on a 3D spherical hypersurface. If you try to describe the most general quantum state of N such 2 level objects, it requires 2^N or so continuous degrees of freedom. Consequently, we are limited in our solutions or simulational studies of fully correlated quantum systems to a tiny, tiny handful of e.g. "two level atoms" -- perhaps 20 to 30 of them -- because one very quickly runs out of computational resources to perform even very small general computations.
Second, you are building a whole mountain of assumptions into what appears to be a misinterpretation of the Planck length. To quote Wikipedia's page on this topic:
There is currently no proven physical significance of the Planck length...
so you are quoting something for which there is no direct evidence as evidence in a bad teleological argument for something for which there is no evidence at all.
You also don't address the actual numbers associated with the Planck leng
Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.