I think gravity is "real" for any bodies that it affects. For the person running the simulator it's "real" too, but in some other sense — it's not affecting the person physically but it produces some information for him that wouldn't be there without the simulator (so we cannot say they're entirely causally disconnected). All this requires further thinking :)

Also, english is not my main language so there can be some misunderstanding on my part :)

Basically I'm asking: is gravity "real for all bodies inside the system" or "real for all bodies inside the simulator"?

If the former, then we have Tegmark IV.

If ONLY the latter, then you're saying that a system requires a means to be made known by someone outside the system, in order to have gravity "be real" for it. That's not substrate independence; we're no longer talking about its point of view, as it only becomes "real" when it informs our point of view, and not before.

Basically I'm asking: is gravity "real for all bodies inside the system" or "real for all bodies inside the simulator"?

If the former, then we have Tegmark IV.

If ONLY the latter, then you're saying that a system requires a means to be made known by someone outside the system, in order to have gravity "be real" for it. That's not substrate independence; we're no longer talking about its point of view, as it only becomes "real" when it informs our point of view, and not before.

gravity inside two-body simulator is real for all bodies inside the simulator.

For a two body simulator we can just use the Newtonian equation for F = G * m1*m2 / (r^2), right? You aren't claiming we need any sort of computing apparatus to make gravity real for "all bodies inside the simulator"?

Therefore, every phenomenon that a physical human brain can produce, can be produced by any Turing-complete computer.

You're continuing to confuse reasoning about a physical phenomenon with causing a physical phenomenon. By the Church-Turing thesis, which I am in full agreement with, a Turing machine can reason about any physical phenomenon. That does not mean a Turing machine can cause any physical phenomenon. A PC running a program which reasons about Jupiter's gravity cannot cause Jupiter's gravity.

Edit: apparently people here can't detect sarcasm, so I'm changing the header.

So, I took this thread as an excuse for going thought my lists of interesting websites accumulated over the years, and make a selection of things I think will specifically interest LWers. There are still a lot of links, because I sift through large swats of information. This is a valuable recourse, don't dismiss it just because it's badly organized.

I've also tried adding some descriptions because people were complaining about that.

I recommend checking out every one of these, and spreading it out over a few weeks.

http://www.accesstoinsight.org/lib/authors/thanissaro/breathmed.html (meditation is a useful habit, this is a very concrete tutorial on how to do it.)

http://www.epicsplosion.com/epicsploitation/38 (A silly thing, please contribute to make it better!)

http://www.mspaintadventures.com/ (one of the most epic stories of our time, with great characters and concepts. It's long and starts slow, so just be patient.)

http://www.ted.com/ (ideas worth spreading)

http://dresdencodak.com/ (Awesome art, and deals more directly with the singularity than any other webcomic i know of)

http://vihart.com/ (distilled nerdyness)

http://www.fanfiction.net/s/5782108/1/Harry_Potter_and_the_Methods_of_Rationality (Eliezers masterful rationalist fanfiction)

http://utilitarian-essays.com/ (some LW like articles)

http://thejuicemedia.com/ (Warning! Mindkiller!)(Although the political alignment probably is similar to much of LW, that's not the reason to watch these. That reason is it being a fantastic example of how art and humour can communicate serous things better than solemnity can.)

http://hyperboleandahalf.blogspot.com/ (random funny blog)

http://extvia.deviantart.com/gallery/ (Awesome arts that I for some reason have a strong intuition most LWers will love)

http://www.youtube.com/watch?v=HhGuXCuDb1U (funny rant relevant to Joy in the merely real)

http://people.mokk.bme.hu/~daniel/rationality_quotes/rq.html (like the rationaltiy quote threads here on LW? This is a compilation of the best ones.)

http://www.youtube.com/watch?v=JeJ6-gN0eB4 (If you ae rational enoguht to overcome your prejudices to wathing this, you will discover it's amazingly good art and even has antidepresant properties.)

http://www.youtube.com/watch?v=rEUxlwb2uFI (WTF?!)

http://www.skytopia.com/project/fractal/mandelbulb.html (pretty pictures!)

http://www.orionsarm.com/xcms.php?r=oa-story&story=dr_yes_jolonah (scary story, gives you an healthy appreciation for what might happen if you fail to win.)

http://www.kuro5hin.org/prime-intellect/mopiidx.html (good free scifi)

http://everything2.com/index.pl?node_id=1857290 (good free scifi)

http://www.raikoth.net/Stuff/story1.html (good free scifi)

http://www.infinityplus.co.uk/stories/under.htm (good free scifi)

http://www.pixelscapes.com/sailornothing/ (fiction)

http://www.xeper.org/maquino/nm/Morlindale.pdf (LotR fanfiction)

http://www.youtube.com/watch?v=pdxucpPq6Lc&feature=player_embedded (good animation about copies, reminds me about Eliezers "the simple truth")

http://arxiv.org/abs/0704.0646 (Tegmarks original Mathematical Universe paper)

http://www.nickbostrom.com/fable/dragon.html (Classic parable about death)

http://www.youtube.com/watch?v=yfRVCaA5o18&feature=player_embedded (interesting facts that are very telling about how the brain works)

http://gwynethllewelyn.net/2006/07/09/what-is-real-anyway-an-essay-by-extropia-dasilva/

http://hanson.gmu.edu/mangledworlds.html (What an explanation to the born probabilities might look like.)

http://www.000webhost.com/ (great free webhost, donate the money you'd have paid for hosting to the SIAI instead)

http://www.youtube.com/watch?v=iGFqfTCL2fs (everyone who regularly dives a car must see this)

http://www.symphonyofscience.com/videos.html (Awesome music to help you take joy in the real)

http://www.erfworld.com/book-1-archive/ (webcomic)

http://www.webcomicsnation.com/shaenongarrity/narbonic/series.php?view=archive&chapter=9802 (webcomic)

http://unicornjelly.com/uni001.html (webcomic)

http://www.project-apollo.net/mos/index.html (webcomic)

http://www.rhjunior.com/totq/00001.html (webcomic)

So, as long as we're going down this road: it seems to follow from this that if someone installs, without my permission, a self-aware algorithm on my computer, the computer is no longer mine... it is, rather, an uninvited intruder in my home, consuming my electricity and doing data transfer across my network connection.

So I've just had my computer stolen, and I'm having my electricity and bandwidth stolen on an ongoing basis. And maybe it's playing Jonathan Coulton really loudly on its speakers or otherwise being obnoxious.

But I can't kick it out without unplugging it, and unplugging it is "morally bad." So, OK... is it "morally OK" to put it on a battery backup and wheel it to the curb, then let events take their natural course? I'm still out a computer that way, but at least I get my network back. (Or is it "morally bad" to take away the computer's network access, also?)

More generally, what recourse do I have? Is it "morally OK" for me to move to a different house and shut off the utilities? Am I obligated, on your view, to support this computer to the day I die?

Of course, my original comment had nothing to do with god. It had to do with "souls", for lack of a better term as that was the term that was used in the original discussion (suggest reading the original post if you want to know more---basically, as I understand the intent it simply referred to some hypothetical quality that is associated with consciousness that lies outside the realm of what is simulable on a Turing machine). If you think that humans are nothing but Turing machines, why is it morally wrong to kill a person but not morally wrong to turn off a computer? Please give a real answer...either provide an answer that admits that humans cannot be simulated by Turing machines, or else give your answer using only concepts relevant to Turing machines (don't talk about consciousness, qualia, hopes, whatever, unless you can precisely quantify those concepts in the language of Turing machines). And in the second case, your answer should allow me to determine where the moral balance between human and computers lies....would it be morally bad to turn off a primitive AI, for example, with intelligence at the level of a mouse?

I just made my first donation yesterday. Talk about timing :)