Talk:Relativity

From Simulism

Just a random thought: what if light is actually comparable to the 'data channel' of a simulation. A simulation cannot run faster than the hardware on which it runs; if in the simulation the data bus has a throughput of 300Mbps, then for the simulation, this is a kind of constant that overshadows the entire simulation. What if 'light' is similar? -- Ivo 12:32, 27 December 2006 (CET)

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I think this article is a really useful contribution. To me, relativity is at the heart of the issue. As you imply, the computational consequences of integrating a relativistic framework is horrendous. Every observer effectively becomes a 'simulation in themselves'. Managing this complexity whereby all of these simulations are consistent would require a huge processing burden. If this were a restrictive device simply to prevent us from reaching other stars, as you say, why bother? Newtonian Mechanics is a good approximation to Einsteinian Mechanics. If we were going to build a simulation of life on earth (e.g. one of Bostrom's ancestor simulations), there would be no reason to incorporate Einsteinian Mechanics. You just make the speed of light infinite and the stars so far away that we don't have any sensible method of getting there.

Because of the complexities involved in incorporating relativity, I think one of two conclusions would follow:
Either
(i) Our 'reality' is NOT a simulation, and this is the way things really are, OR
(ii) Relativitistic effects are so integral to the simulation that the computational complexities involved in creating it are unavoidable. As relativistic effects mainly manifest themselves at the macro level, in this case, it would mean that the designers of the simulation have given us at least a sporting chance of creating achievable relativistic travel. Our future really does lie in the stars. -- TonyFleet 09:30, 11 February 2007 (CET)

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OR

(iii) relativity is a direct result of the algorithms used in the simulation; and we cannot judge wether this is accepted as a "dirty hack" (i.e. relativity does not exist outside of the simulation) or wanted (because relativity exists outside the simulation, too).

I am not buying your argument that "Every observer effectively becomes a 'simulation in themselves'". If that was true, every our physics would imply that, too. And yes, quantum mechanics have some weird stuff with observers, but I think there is no theory that every observer is in its own universe.

-- Kosta 11:07, 12 February 2007 (CET)

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I think TonyFleet did not mean to explain that every observer is residing in it's own universe. What he means by saying that "Every observer effectively becomes a 'simulation in themselves'", is the fact that each observer has it's own simulation, which is coupled in some way to all other simulated observers, to form a coherent universe. They may have their own simulations, but they do share the very same universe, although they all observe the universe differently.

Your remark that "relativity is a direct result of the algorithms used in the simulation" (if we really are living in a simulation then, hell, of course it is) to me is the same thing that TonyFleet stated earlier: "Relativitistic effects are so integral to the simulation". This does not contribute anything new to the discussion. -- Bart 17:34, 12 February 2007 (CET)

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Exactly! Thanks Bart

Just to pursue this further consider the following thought experiments.

The Twins 'paradox'

(NB in this version there is no paradox)

A stays on Earth while B travels to a distant star at near-light speeds. B travels home to find that 20 years have passed for B, but and A is only 1 year older. In the simulator's time frame, both A and B are in the same place at the same time at the outset, and again at the return.

In a degree 1 simulation, the simulator could feasibly arrange things so that B's timeframe slows down while he is journeying, and this would not be not a problem. This is fine for two observers, but just imagine a universe full of them. Each of these would need their own timeframe, which will be constantly changing as they accelerate, decelerate or pass within gravitational fields. Relativity does away with the notion of absolute time, and its difficult to see how the simulation would square with this, without the notion of every observer being a 'simulation in themselves'.

In a degree 2 simulation there are seemingly insurmountable problems: the two minds-in-vats have an external existence in which time for both of them externally will be flowing at the same rate. If a simulator were to try to slow down B's time to the one-fifth rate, the simulated relativistic time-dilatation would be observable by B (ie clocks would run slower, heartbeats would come to a standstill), but it would still feel like 50 years and not 10. Alternatively, if one actually tried to program around this, by having minds in their own simulation-space, there are real issues with free will. Effectively B would need to have knowledge of A's future actions, before A has acted.

The Barn Paradox

(again there is no paradox, just consequences of relativity)

A is at the door of a barn with doors at both ends The back door is closed. B holds a pole which is exactly the same length as the barn. B now goes off into the distance and zooms back towards the barn at near-light speed, entering through the open front door. When B (with the pole) is in the barn, A closes the front door intantaneously.

Now for the fun:

A says: B rushed in at near-light speed; the length of his pole was contracted, and so when I shut the door, for a fraction of the second the pole was entirely contained within the barn; then he burst through the back door. What I saw was: event 1 - front door closed, followed by event 2- back door smashed.

B says Yeahbutnobut A was at the barn which came towards me a near light speed, and so the barn's length was contracted. This means that my pole was too long for the barn, and it burst through the back before he closed the front door. What I saw was: Event 2 - back door smashed, followed by event 1 - front door closed.

Relativity does away with the idea of the simultaneity of two events; two different observers may not even agree on the order in which discrete events occured. Neither of these observer's points of view is correct or incorrect, they are just versions of reality. I for one cannot see how this could be programmed into a simulation without invoking the 'simulation in themselves' scenario.--TonyFleet 19:15, 12 February 2007 (CET)

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Interesting thoughts. I was pondering something that Peter Jenkins recently told me. He refered to an article (I forgot which), that explained how from a statistic viewpoint, we are probably alone in the universe. The reasoning is that with the current progress in technology, it is only a matter of time before we are capable of reaching the farthest regions of space. If that is true, then this is probably true for any civilization in our universe. And if that is true, then surely some of them must have found a way by now to reach us. So either of these is true: 1) we are alone in the universe, or 2) we are not alone, but all the others have not yet developed the means to travel this far either. The reasoning is not 100% solid. However, it leads to an interesting thought: a vast universe with use at the center of it, is similar to the smaller simulations with a boundary (The Truman Show, Dark City). --Ivo 14:44, 11 February 2007 (CET)

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I agree with Tony Fleet that relativity - and, more generally, the whole nature of spacetime - is "at the heart of the issue". I see Kosta makes the point that relativity might be considered a "dirty hack". I think it's more likely that relativity arises as a "design trade-off" with the goal of maintaining the quality of the simulation when the simulated beings travel at high-speed (approaching the speed of light). The downside of this trade-off is that the distortion of time-dilation is introduced, and this might be considered to be a programming "glitch". I consider this in great detail on my website The Big Brother Universe

I agree with Tony Fleet: "Every observer effectively becomes a simulation in themselves". This is because special relativity is observer-dependent: time-ordering of events is different for different observers. But this isn't a problem if you were a simulator because you would specify a position for your computer's viewport within the simulation. Again, I deal with this question in more detail on my website.

I agree with Bart's comment: "each observer has it's own simulation, which is coupled in some way to all other simulated observers, to form a coherent universe." Basically, the combined effect of these observing positions is to produce the Lorentzian spacetime structure of our universe. --Andrewthomas10 15:34, 14 February 2007 (CET)