last day (460 days later) » 

6:04 PM
Do you want to invite TNB or just let people discover Higher Order gradually over time?
 
nah, I'll just let people discover
feel free to invite individuals if you want
 
Yeah, otherwise it would get crowded
 
Sounds good to me.
 
I mean, if it comes up in chat, by all means, feel free to post a link
 
Should we have "whatever we feel like" in the description?
 
6:06 PM
we'll see.
if you want to be an owner, feel free to ask
I don't like making the judgement call, so I won't just hand them out unless people ask
 
I think that at this time, I'll remain a regular user (insofar as that's possible for me).
 
You can always retract ownership later if you want to just hand them out to anyone who arrives
 
@El'endiaStarman lol
on that note, do any of you guys watch Wendover Productions?
he's a little-watched youtuber that makes really high quality videos
 
No, I don't watch much of YouTube nowadays
 
@NathanMerrill I've watched his "Why Trains Suck in America" video.
 
6:10 PM
before that video, I didn't realize that trains were good anywhere else
I totally thought that they were good in a couple of niche cities and for cargo transportation
 
I assumed they were good everywhere except the UK
 
6:48 PM
I'll have to check out some more of his videos later.
 
I've been thinking about the name of this room, and it doesn't feel quite right to me. It makes me feel as if this room and its users are somewhat "better/higher" than those on TNB
 
I was worried about that. I'm open to suggestions
 
Can confirm: current name is a poor choice
 
room topic changed to No name: For discussion about programming, math, and science, or whatever we feel like. Not about PPCG or golfing. (no tags)
 
7:09 PM
room topic changed to Nonsquare rectangles on an n X n board.: For discussion about programming, math, and science, or whatever we feel like. Not about PPCG or golfing. (no tags)
 
I like this new name, it is both related to programming and mathematics
 
Would this be a good room for talking about the quantum-particle-in-a-box simulator I've been working on?
 
for sure
 
ooh, what is that?
 
So I'm writing something that simulated a discrete wavefunction.
0
A: Sandbox for Proposed Challenges

PhiNotPiSimulate a vibrating string code-golf Vibrations are an integral part of physics. In this challenge, you will be implementing a simulation of a vibrating string. This is actually rather easy to do as a result of the Huygens–Fresnel principle, which allows us to use a simulation process simila...

^ I wrote a classical version of the program
although I haven't actually written the spec, it's pretty simple. Now I need to figure out how to update it to use Schrodinger's equation instead of the classical wave equation.
 
7:21 PM
@PhiNotPi By wave function, do you mean something like this?
 
yes
for right now I'm attempting the 1D case
 
room topic changed to Nonsquare rectangles on an n X n board.: For discussion about programming, math, and science, and related topics. Not about PPCG (the site itself) or golfing. (no tags)
@PhiNotPi I feel entirely unknowledgeable about the wave function. Like, I know that strings vibrated, but nothing more :P
 
7:44 PM
so here's the problem I'm currently facing, and it has to do with energy conservation
So I have a complex number Y at a particular time step, and know the value of dY/dT at that time step, how to best approximate Y at the next time step.
 
isn't that well defined?
like, as long as you know the length of time between the two time steps
you simply multiply that by dY/dT
 
the problem I'm having is that the complex number typically rotates over the time step.
If Y and dY/dT are at right angles, then Y should be rotating around the origin.
 
so, use polar coordinates?
actually, I think the problem is that you need both dY/dT and dX/dT
 
Y is the complex number, I should clarify, and dY/dT is also a complex number.
 
hmm...I'm pretty lost then. Like, I know what polar coordinates are, but I've never actually plotted them
hmmm, interesting (looking it up)
can you always reduce a complex number to the form x + yi?
 
7:55 PM
yes
 
I mean, so this is fundamentally a 3D graph
 
Perhaps my choice of variable letters in confusing, let W be the complex number.
 
you have T going in one direction
and the two parts of the number the other two axis
 
Does W move along T, or does it rotate around T? (sorry if this is a stupid question)
 
so, you can either make it a 3D graph, or plot the two parts of the number for each time step (and don't plot T at all)
 
8:01 PM
Let me clarify some variable names going forward. T = time, S = space, W(s,t) = complex number wave function value, dW/dT change in wave function value over time.
let x and y be the components of the complex number, neither of which are real space/time
 
how does space change?
or is space literally a spot in space (like a 3D coordinate)?
 
Time and Space are two independent variables.
 
right, I get that
but is "change in space" mean movement?
 
yes
^^ Schrodinger's equation
let me simplify it some...
 
so, what are you trying to plot, exactly?
how the wave function changes over time at a particular spot in space?
 
8:04 PM
yes
 
then, I go back to my original statement: you need 3 axis.
you have 3 things to plot: x, y, and T
 
Yes, but I don't need to actually graph it. just calculate the points.
 
which variables do you need to calculate? w1 from w0?
 
yes
 
then why doesn't w0 + dW/dT*T work?
I guess the word "rotates" throws me off
 
8:07 PM
because it doesn't conserve energy
Let's say we have a simple standing wave. The complex number should rotate perfectly around the origin.
Multiplying by a complex number with an absolute value of 1 is a rotation.
if W0 is a real number, then dW/dT is a pure imaginary number (no real component)
when you add them, you get a complex number with an absolute value greater than what you started with
 
Can't you normalise it if the value is too big?
 
I think you could do norm(W1)*mag(W0).
 
the problem is that sometimes the amplitude is supposed to change
right now I'm reading this thing to see how they handled it: pnas.org/content/83/15/5360.full.pdf
 
8:26 PM
hey, I think I got a good KoTH idea, but I want to play it with somebody to see how it pans out
anybody want to play?
 
what is it?
 
@NathanMerrill Huh, that's surprisingly relevant to the title of this room... ;)
 
> Your goal is to ensure your opponent zones as few squares as possible.
 
oh, it gave me the idea
 
8:30 PM
not to zone as much as possible?
 
right
 
is score = your zone - opponent's zone?
 
nope, just opponent's zone, lower is better
 
Hmm. Curious.
 
that said, they are often closely correlated, but I indicated that to emphasize that strategies other than "Fill an entire half of the square" work
because p1 could do that, and then its an exact tie
 
8:32 PM
Yeah, you deny zones to your opponent by disrupting 2x2 blocks.
 
let's say that p1 played a 2x2, then p2 filled an entire half
 
still a tie
because p1 would be able to fill in the remaining squares
 
all remaining squares?
 
So you can zone rectangles which overlap previously zoned rectangles?
 
8:34 PM
because you have a hard limit on the total number of squares you can fill
no, but there's no configuration of a 2x2 and a 20x10 that block me from filling in the remaining squares
 
Neither player can occupy more than half the board, so the game becomes one of making areas unzonable.
 
only for 1 player. The other player can play until he's filled in the remaining area
P1: 2x2 square in bottom right.
P2: 10x20 square on left
P1: 2x8 square on right
P1: 8x10 square in middle-right
both players end up with 1/2 exactly
 
Hmm, wait, couldn't you zone a 10x20 rectangle, but leave a one-square-wide strip on one side?
 
yep
but rectangles need to be at least 4 squares big
I didn't say anything about a 2x2
 
Oh, so 1x4 is possible?
 
8:41 PM
yep
I'm actually considering raising that.
 
Very interesting. That does make this challenging.
 
to 5, I think
it forces you to have at least 3 squares in a direction
but I'd like to play test it, if anybody wants to play a game with me
 

 Zoning game

Let's play a game of zoning
 
(Though I probably shouldn't play now, being at work and all...)
 
8:54 PM
lol
 

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