Help me identify these fields

[Mark Ian]

http://ctrlv.in/139005

 

 

Hi, Ive been running these particle simulations the last few months, and I dont know what exactly these fields are. If you know, or you know someone that could know... thatd be great! It would be nice to know the mathematical formulas for these things

[derek w]

If you wish to get a response,you should be aware that people are wary of clicking on an external link,that they do not know or trust.

[Mark Ian]

well I thought I also attached the image to the post itself. I just reattached the image to this post so hopefullz that worked. Basicallz I have a reference point and particles which have a direction and velocity. the distance the particle travels is proportional to the distance to the reference point.

50b27bed1b9b4.bmp

[swansont]

I still don't know what I'm looking at. Saying that it's a particle simulation isn't enough.

[Mark Ian]

Surely identification does not require one to fully understand it, though it does require one to have seen it or something similar. But I will explain what I have programmed: On a 2d platform I create n particles and a reference point. Both particles and reference point have x,y coordinates on the plane. The particles move relative to the distance and direction to the reference point (very much similar to coulombs law). The particles are drawn onto a surface each step. This loops indefinitely until I end the program.

[lesolee]

Hi, Ive been running these particle simulations the last few months, and I dont know what exactly these fields are. If you know, or you know someone that could know... thatd be great! It would be nice to know the mathematical formulas for these things

 

... Basicallz I have a reference point and particles which have a direction and velocity. the distance the particle travels is proportional to the distance to the reference point.

 

I don't see how anybody can help you. You just are not saying anything ... yet.

"Running these simulations for months". Why?

What are you trying to achieve?

What is this simulation software?

 

The attached picture was very pretty, but also pretty meaningless without a "key".

 

In general terms a particle will carry on at its initial velocity (speed and direction) unless an external force is applied. So all the tracks should be straight lines. They are curved. A curved track implies a force, in this case possibly a magnetic force. But if you are running a simulation you should already know what you typed in to it, so why are you not saying?

 

Notice that some curve one way and some curve the other. That means the particles have opposite charges. A different radius of curvature means a different mass or a different velocity and you can't tell which from the radius of curvature. If the radius of curvature gets bigger smoothly that suggests the particle is slowing down. The finite and increasing width of the tracks is strange. If this is a sensible program I can only guess that it is showing an uncertainty band around the particle's track.

[doG]

Surely identification does not require one to fully understand it, though it does require one to have seen it or something similar. But I will explain what I have programmed: On a 2d platform I create n particles and a reference point. Both particles and reference point have x,y coordinates on the plane. The particles move relative to the distance and direction to the reference point (very much similar to coulombs law). The particles are drawn onto a surface each step. This loops indefinitely until I end the program.

Basically you've written some algorithm that generates a pretty picture and you want to know if it coincidentally matches the field structure of some known natural phenomena. Good luck!

[Mark Ian]

to lesolee:

 

My reasoning behind not giving full details / only including the image is this: The code needed for the simulation is quite simple. If you are a programmer and have fooled around with particle simulations chances are you have stumbled across this 'pattern'. Posting source code leads to ctrl+c/v which is what I wanted to avoid. The identification of the field is not the main purpose of the thread, contrary to what I claimed in the first post. I'm trying to find people who have coded similar things and would want to talk about it.

 

These simulations are a hobby of mine. I blame my curiosity. I also am into theoretical neuroscience and video game programming. I didn't run this particular simulation for months. What I meant is that I try to figure out why the particles behave the way they do, if I can force the particles in behaving a praticular way, If I can de/stabilize the orbits of the particles, if I can create specific geometirical shapes by manipulating the code... the list really just keeps on going.

 

I use the same program that I use to code my games in game maker studio. The language is comparable to delphi mixed with java phyton and C++, one can import libarays from C++ and export in 5 different file formats so that It can run on windows, mac and various phones. It is compiled in C++ on the windows.

 

if choose(1,2)=1 {
    pt_dist=point_distance(x,y,argument0.x,argument0.y);
    pt_dir=point_direction(x,y,argument1.x,argument1.y);
    x+=lengthdir_x(pt_dist,pt_dir)
    y+=lengthdir_y(pt_dist,pt_dir)
}else{
    pt_dist=point_distance(x,y,argument1.x,argument1.y);
    pt_dir=point_direction(x,y,argument0.x,argument0.y);
    x+=lengthdir_x(pt_dist,pt_dir)
    y+=lengthdir_y(pt_dist,pt_dir)
}

 

I was going to explain what is doing what but Im sure you'll figure this out quickly. its a deviation of coulombs law ( I knew this before I started the thread :.p ).

 

to dog: thanks. Phenomenal deduction skills.

Edited December 13, 2012 by Mark Ian

[lesolee]

I have heard of people writing "physics engines" so that they get realistic simulations of events such as dropping a bag of marbles or realistic games simulations. That is a lot different to simulating "particles". The macroscopic (big) world is very predictable using Newtonian physics. The microscopic world of particle physics is not so easy since the interactions are harder to formulate, although Prof Richard Feynmann said that QED is the most accurately tested and verified theory around.

[Mark Ian]

my experiments are unbound to the macro and microscopic world as they do not directly replicate any natural phenomenon known to me. Nevertheless I think that the fields and spirals and waves and diffractionpatterns that come forth from these simluations reflect something deeply embedded in the logic of the universe. It is fun to go exploring in the jungle, blind folded, with an ak-47.

 

I've tried searching the web quite extensively, but people seem to be more interested in simulating nbodies, fluids and newtonian gravity.