xkcd

MrY

Thank you for your replies ! LaserGuy : By "pushing" do you actually mean "non-interacting"? Yes, you are right, with the local agitation, atoms that meet (and do not react) just cross each other. But for molecules It's different, they are bigger, they can block an atom moving i...

MrY

Hi, Imagine a cube: its surface is a 2D universe, so a closed universe that loop on itself. This universe contains "atoms": little circles with the same radius, but there are different type of atoms (A, B, C, ...). Some atoms have a "movement" vector: this atoms move according to...

MrY

Have you ever thought, tried, or heard of creating a universe with different physical laws? With: - it own set of fundamental particles (or not) - own forces - ... and perhaps: - absolute time - no inertia - no light/matter/vacuum but different concepts... - in 2D - ... I only know the trilogy of Or...

MrY

In the java application, I take two identical blocks and rotate one of them: dichronauts.png The red side of the second block is no longer a rectangle, and CD distance seems to be greater than AB. But it is just a representation, the second block is not deformed, and we still have AB=CD, right? Is t...

MrY

Yes, I agree, but I don't know how to use them.

Is my example with 2 diagrams correct?
It is possible to have x'=f(x,y) and y'=g(x,y) ?

MrY

I don't know exactly what I'm looking for, but yes I search this kind of transformation I guess, but not only.

Did you play with the java application?

MrY

Basically I would like to redo the following application but in 2d: Http://www.gregegan.net/DICHRONAUTS/02/Interactive.html I imagine that the parallelepipeds have coordinates, and according to their position in space their representation is deformed, but not the object itself. I'm wrong?

MrY

I will rephrase my request: It is possible to have: - a first 2d diagram with points p i (x i ;y i ), for example a segment p 1 p 2 - a second 2d diagram representing corresponding p' i which behave like Minkowski space if a rotate or move my segment in the first 2d diagram? So for the exemple if a ...

MrY

I'm very confused; you seem to be contradicting yourself - you want a 2d *space* (not spacetime), which suggests two spatial dimensions, but you also want 1 space dimension and 1 time dimension, forming a 2d spacetime. Which do you want? I want a space "time-like" dimension :D a space dim...

MrY

I have read this: http://www.gregegan.net/DICHRONAUTS/00/DPDM.html The story of this book take place in a universe with 2 dimensions of space and 2 dimensions of time. I want a 2d space (no spacetime) but with 1 space-like dimension (real) and 1 time-like dimension (imaginary), like this: http://www...

MrY

Hi, I have points p i in a 2d space with a real dimension x and an imaginary dimension y: p i (x i ;i*y i ). I want to represent them in an euclidean edit:Minkowski? space so I search: p' i (x' i ;y' i ). For example, p' 1 and p' 2 must have a distance of sqrt(abs((x 1 -x 2 )²-(y 1 -y 2 )²)) in this...

MrY

Woa, I dit not think that planck units was going to be the center of this discussion! This is not the subject of this topic. Planck units are only practical quantities at the quantum scale. The assumptions that I made, I have only read them. I'm just trying to understand the logic behind it. Moreove...

MrY

Hi ! At the first time of the universe (1 planck time), the universe has a size of 1 planck volume. The Planck density is the maximum possible density. So at this first time, the universe is made at most 1 planck mass? What about the mass-energy conservation? I thought there was no mass-energy creat...

MrY

With second example: Alive gives 2 A for minimum 1 B Bob gives 3 B for minimum 2 C Carole gives 4 C for minimum 2 A Dave gives maximum 2 A for 1 C (positive value for offer, negative value for demand) value of fixed quantity of A : 2a in Alice exchange value of fixed quantity of B : 3b in Bob exchan...

MrY

I found a calculus ! But I think its works only when total supply exceeds total demand and when you don't have to put some goods on the side. There are two kinds of quantities : fixed or not. No-fixed when you want a minimum or maximum amount of a certain good. When the global exchange is total (no...

MrY

Exactly! It is a way to quantify the value of each good independently and have one price per good. Without it, I would have to find a price for each pair of goods in both directions (P A->B and P B->A ) with the constraint that the multiplication of a sequence of prices from a good to get to the sam...

MrY

I first divided my problem into two sub-problems: If the total supply is greater than or equal to the total demand, we look for the price. If the total demand exceeds the total supply, we seek to remove the least possible trades for the supply exceeds demand. For the first sub-problem, I noticed tha...

MrY

Another example with maximum: Alive gives 2 A for minimum 1 B Bob gives 3 B for minimum 2 C Carole gives 4 C for minimum 2 A Dave gives maximum 2 A for 1 C Total supply exceeds total demand. With prices: P A->M = 3 * k P B->M = 2 * k P C->M = 2 * k With k > 0 Alice gives 2 A and receives 3 B (She gi...

MrY

An example would be probably useful to understand my problem: Alice wants to give 2 A for minimum 1 B Bob wants to give 3 B for minimum 1 C Carole wants to give 4 C for minimum 1 A Dave wants to give 1 A for minimum 1 C For each good we see that supply exceeds demand. And there, gropingly, I find th...

MrY

Yes I know, you're right, I agree. But precisely I try not to use intermediate! Neither money nor intermediate transactions. All members make their exchange offers, and only then we solve so as to maximize the amount exchanged. So I'm looking how to formalize my problem to solve it. Someone have any...

MrY

Yes, I still agree with you.
But my problem is to find this prices that maximize the number of exchanges or traded quantities!

For the difference with a stock market, in my barter system there is no money.
A person may request A for B, another B for C and another C for A. That is the worry.

MrY

Yes, I also think it's possible, my question is just how to find these prices automatically! I will try to formalize: Let P A->B the price of 1 A according to B. We know that P A->B * P B->A = 1 (and P A->B * P B->C * P C->A = 1 etc. ...) Given that there are as many prices as possible peer goods, t...

MrY

Hi everybody! Here is the problem I want to solve: Members of a community want to exchange identical and divisible goods. Each person can make exchange offers, and with all these offers, we search for the "price" of each goods to maximize the number of exchanges. At first I see only two ki...

MrY

How did you get this? By assuming the formula that a 1:1 mix of P(a,b,c) and P(a',b',c') gives P((a+a')/2, (b+b')/2, (c+c')/2), and the same formula also works for L No, I guess this result by telling myself that a mix of green L(1,0,1) and black (1,1,1) should look like L(1,1/2,1). It is not at al...

MrY

My goal is to express the colors according to others and primary colors (cyan, magenta, yellow and white). I want to write: cyan + yellow = green As I was taught in elementary school. We see that 2 * yellow + 2 * cyan gives the same green. I concluded that only the percentage of pigments, relative t...

MrY

For the P format, if the sum is not equal to 1, we can say that the difference is completed by a white pigment.

For example, for a gradient of cyan which is composed of x percent of white:
P(1-x ,0, 0) = L(1-x, 0, 0)

MrY

Hi everyone, I'm stuck on finding an equation: I defined a first color format by expressing it from subtractive light: L (c, m, y) where c is the percentage of cyan light m is the percentage of magenta light y is the percent of yellow light The green color is a mix of cyan and yellow, is expressed a...

MrY

The only truly dark period would be the 1 hour or so at noon. http://s17.postimg.org/k3emkodzj/eclipse.png The eclipse occurs for every people in Beta at the same time, but not the same time of the day! For people at the nearest point, Alpha is at zenith, like the sun. But for other people, Alpha a...

MrY

I just noticed that the longitude of a place on Beta can infact be expressed at the time when the eclipse is at half its length: http://s17.postimg.org/k3emkodzj/eclipse.png For people at 12h, the sun is at zenith, like Alpha! Well thought for the fact of high meteorites activity on the outer side! ...

MrY

AMAZING It was exactly what i'm searching on this forum! meaning that Beta would experience a four-year winter, a two-year summer, and spring and fall each one year long Winter is coming ;) . The goal to maximize the angular diameter is perfect! I'm ok for excentricity in Beta orbit ! Making Alpha s...

MrY

To avoid misunderstanding, we need names! I suggest calling the giant (more or less huge and gaseous or not) Alpha, and our earth-like moon Beta. For your posts you can propose your own names! I didn't think that Alpha could sent back so much light. This depends mainly on its size in the sky and its...

MrY

I modify my initial question:

What are the implications of living in a earth-like moon orbiting a planet?

So now the planet is not necessarily giant or exclusively made of gas!

MrY

Agree for two kinds of night! I find this amazing video: https://www.youtube.com/watch?v=pN7P1zZKlMM About the tidal heating, is appearing when the moon orbit has an eccentricity (ground elevation of 100m for Io!). I read that eccentricity is created by orbital resonance with other moons. So tidal a...

MrY

So we can differentiate if a list (a b c d) is in fact (((a b) c) d) or (a (b (c d))) Because for addition and multiplication, no problem: (((a b) c) d) = (a (b (c d))) [[[a b] c] d] = [a [b [c d]]] But for exponentiation: {{{a a} a} a} = ‹a 4› is not equals to {a {a {a a}}} = 4 a For example: {{{a ...

MrY

You're right, that isn't tetration, is the slower growing power tower like you said: the ‹› operation is just the simplification of the {} operation that is the repetition of exponentation (with this form: a^(a^(a^a)), not this: (a^a)^a)^a, because it's tretration). But my question was : Why I shoul...

MrY

With this notation, we have commutativity except for the first term of an exponentiation. The multiplication is a simplification of addition by counting the number of addition I have to make: (2 2 2 2 2 2) = [2 6] (2 2 2 2 2 2) = ([2 3] [2 3]) = [[2 3] 2] = [2 [3 2]] = [2 6] The exponentiation is th...

MrY

Why addition is a binary operation ? The first thing we do is counting by incrementation. Also, we describe a number by the sum of this number unit. (5 equals 1+1+ ... five times). Addition is n-ary! We have to use a list. So for write 1+2+3=6, we can write (1 2 3)=6 Now, we create the # operator th...

MrY

Hi everybody ! What are the implications of living in a earth-like moon orbiting a planet ? This question makes me dream. I looked into it myself but I really want to have your expertise! About the day cycle: With tidal locking, the moon has to turn around the planet in 24h. Also, the planet keeps t...

xkcd

Search found 38 matches

Re: Behavior of atoms in a 2D universe with different physics (no kinetic energy)

Behavior of atoms in a 2D universe with different physics (no kinetic energy)

Universe with different laws of physics

Re: Convert points from a 2d space with a real dimension x and an imaginary dimension y

Re: Convert points from a 2d space with a real dimension x and an imaginary dimension y

Re: Convert points from a 2d space with a real dimension x and an imaginary dimension y

Re: Convert points from a 2d space with a real dimension x and an imaginary dimension y

Re: Convert points from a 2d space with a real dimension x and an imaginary dimension y

Re: Convert points from a 2d space with a real dimension x and an imaginary dimension y

Re: Convert points from a 2d space with a real dimension x and an imaginary dimension y

Convert points from a 2d space with a real dimension x and an imaginary dimension y

Re: Planck density and mass-energy conservation

Planck density and mass-energy conservation

Re: Barter system

Re: Barter system

Re: Barter system

Re: Barter system

Re: Barter system

Re: Barter system

Re: Barter system

Re: Barter system

Re: Barter system

Barter system

Re: Colors format conversion

Re: Colors format conversion

Re: Colors format conversion

Colors format conversion

Re: Living in a earth-like moon orbiting a planet

Re: Living in a earth-like moon orbiting a planet

Re: Living in a earth-like moon orbiting a planet

Re: Living in a earth-like moon orbiting a planet

Re: Living in a earth-like moon orbiting a gas giant

Re: Living in a earth-like moon orbiting a gas giant

Re: "Oh no! We forgot how to say... math... stuff!"

Re: "Oh no! We forgot how to say... math... stuff!"

Re: "Oh no! We forgot how to say... math... stuff!"

Re: "Oh no! We forgot how to say... math... stuff!"

Living in a earth-like moon orbiting a planet