FOSS gamedev and creative worlds

I saw this interesting video with mod which simulates 3 basics elemets of quantum mechanics. Question to modmakers, is it posible to realize it in minetest?
http://www.youtube.com/watch?v=nD-iVXglyTQ

I also saw that video, but one would need to know how those 3 basic quantum mechanics work to decide if it's possible in Minetest.

It should be possible to do it (I looked at what it was earlier this morning, it is not at all real quantum mechanics), and without too much difficulty, the only problem would be for line of sight functions.

Yeap, they are using 3 simplified interpretations for blocks:
1) Observer effect - when some blocks doesn't exists until you're look at them, or changes from one state to another when you looks at them from specific angle
2) Quantum entanglement - when pair or group of blocks are generated or interact in ways such that the quantum state of each member. But Mass Effect-like telecommunication is impossible though)
3) Quantum superposition - when system exists partly in all its particular theoretically possible states (or, configuration of its properties) simultaneously; but when measured or observed, it gives a result corresponding to only one of the possible configurations

Fess wrote:Yeap, they are using 3 simplified interpretations for blocks:
1) Observer effect - when some blocks doesn't exists until you're look at them, or changes from one state to another when you looks at them from specific angle
2) Quantum entanglement - when pair or group of blocks are generated or interact in ways such that the quantum state of each member. But Mass Effect-like telecommunication is impossible though)
3) Quantum superposition - when system exists partly in all its particular theoretically possible states (or, configuration of its properties) simultaneously; but when measured or observed, it gives a result corresponding to only one of the possible configurations

Today is a great day, Fess. You are becoming more active in the Minetest forums.

For adventure maps, a mod like QCraft could make for some interesting puzzles and traps. Perhaps a mod of that nature would go well with mesecons and digilines?

WTF, I understand nothing.

Fess wrote:1) Observer effect - when some blocks doesn't exists until you're look at them, or changes from one state to another when you looks at them from specific angle

Not okay. Now explain me how it is possible to look at anything which does not exist.

Fess wrote:2) Quantum entanglement - when pair or group of blocks are generated or interact in ways such that the quantum state of each member. But Mass Effect-like telecommunication is impossible though)
3) Quantum superposition - when system exists partly in all its particular theoretically possible states (or, configuration of its properties) simultaneously; but when measured or observed, it gives a result corresponding to only one of the possible configurations

This is way over my head. Can someone translate this to English and/or Minetest-speak, please? :D

IIRC, the idea is that there are special blocks, and when no player is looking at them, they go in "quantum state". Then, when the block is looked at, it will take a different form (i.e., it will be replaced by a different node), depending on under what direction it is observed, and it will stay in that state until no-one observes it again.

On generated mapgen already does the observer effect :)

The video did not help me. I already know the double-silt experiment.
What I wanted to know was how concepts of QM should be applied to Minetest.

Then I found this page in the qCraft wiki, which probably clears my confusion. Am I right quessing that this is what you want to do in Minetest?

If yes:

Fess wrote:Question to modmakers, is it posible to realize it in minetest?

Short answer: No.

Long answer:
Observational dependency: No. I fear the most difficult challenge would be to determine when a node is observed (seen). AFAIK there is no function in the Lua API for this and I don’t know wheather Minetest has even an internal function for this. The only related function I found is minetest.line_of_sight which is of course not exactly what we want here. You could probably do this in Lua if you’re insane. :D
@paramat: I guess the topic isn’t about generated maps.
Superposition: Yes. As soon you figured out a node has been observed this task is trivial compared to the others. You’d just use set_node or LuaVoxelManip etc. to change the nodes.
Quantum entanglement: Partly. Yes for short distances, but probably no for long distances; especially for nodes which are in unloaded areas. IIRC you can’t manipulate a node which is unloaded.

Incudom wrote:For adventure maps, a mod like QCraft could make for some interesting puzzles and traps. Perhaps a mod of that nature would go well with mesecons and digilines?

Yea, thats good basis for some quest like map, it will be interesting combination.
Concerning to observation effect, in this mod
https://forum.minetest.net/viewtopic.php?id=5820
there is a possibility

The dagger will glow when you look in the direction of the lava temple.
When you are sure about where it is, just dig !

The lava dagger is in fact just a compass which shows you the location of the lava temple. It is purely 2-dimenisonal; it works on the X/Z plane.

Even if we extend that dagger to 3 dimensions, it wouldn’t help. We would have to know when a node is inside a player’s field of vision, not when a player looks into kinda the direction. The lava dagger does not take the field of vision into account.

Wheather a node is seen or not is probably going to be engine’s business instead of Lua’s business.

There is a way to check FOV,but it will be too laggy. Good ol' raycasting when players are near the block?

Quantum entanglement is part of a problem of game maps that only know of map areas that are loaded in a given moment of time. Actually this problem is far more basic than quantum mechanics. This is a problem for anything concerning nodes that are far from each other in the map and want to interact.

Imagine building an electric power source somewhere and wanting to transport the energy over a long distance. Will the power stop when the part of the map containing the source unloads? Will my windmill on a high tower power my mine down below? Can I controll all my traffic lights from my super large mesecon computer on the edge of the known world? If the mesecon computer is large enough, will it keep all of itself loaded while processing a function?

Things like carts don't seem to work properlly if parts of the map containing some railing are not loaded. So sending some mining products over a long distance to an automatic unloading station would not work (if we had chest-like carts). I guess this also applies to long distance tube systems though I never tried that.

There have been wishes for real river like systems, so would a river stop flowing if the source is not loaded? Would a very high waterfall run dry if the source at the far top is not loaded?

Maybe this could be solved if the map could store information about nodes connected by some interaction logic. Maybe a second table could be added for this to the database. So that old clients could use the normal map table and ignore the extra content, while new clients could query the extra table whether the at the moment loaded nodes are connected by some logic process to some not loaded nodes that in turn might trigger some action or change some state of nodes in the loaded part.