2D Celestial collision

[Shadow]

I sure hope it's not...but I'm guessing you know that better than me.

[insane_alien]

should be possible using a FEM (finite element method) Program, of course, there will be resolution issues as computing power and likely your time will be limiting factors.

[iNow]

Pulling this thread back on topic, you might want to google Computational Fluid Dynamics (CFD) for this. and its going to require a fair bit of processing power.

 

One would imagine that the modelling could be improved with clever use of fractals or some sort of Mandelbrot maths. As I understand it, they use fractals when doing modelling of moutains and graphic representations of trees and forests and all manner of things. It drastically reduces the need for computing power since you're not modelling each individual object or atom, just letting the graphic model be self-similar in specific ways.

 

 

(Also, can a Mod break the quantum computer tangent into it's own thread? Those posts really have zero to do with the question asked, and are rather silly at that).

[Phi for All]

This thread is closed until I can sort out the off-topic quantum computing bits from the main thread.

 

OK, the posts about quantum computing capability have been split to their own thread right here.

 

This thread is open again. Please keep to the OP.

Edited December 20, 2008 by Phi for All
thread split

[iNow]

Thx, Phi.

[D H]

What I want to do now is learn calculus properly

Numerical solution of ODEs, in other words. This can get very involved, but can also be quite simple (conceptually). For a system modeled as a collection of point masses, the typical approach is to numerically integrate Newton's second law, yielding a "3-DOF" (3 degrees of freedom) simulation (or in your case, a 2-DOF sim). If there are a small number of particles you can afford (computationally) to use a more accurate ODE solution technique. For a lot of particles (or for a project you need to get done in a semester), I'd recommend starting with symplectic Euler integration and moving up to the Verlet (or velocity Verlet) method. Do not use the basic Euler technique. Ever.

 

One exception: You need to understand the basic Euler technique to understand any of the more advanced techniques. Once you have learned it, forget it. It almost always yields very bad results.

[Shadow]

Thanks for the tip DH. Thanks everyone, for that matter.

 

Just a quick question, I'm attempting to learn calculus from here. Could someone have a quick look and tell me if it's any good? So far, I think it's excellent, if only because it assumes the reader knows practically nothing, but I'd still like the opinion of someone who already knows calculus.

 

Cheers,

 

Gabe

[insane_alien]

its from MIT, it will very likely be a good resource. i had a quick glance and it appeared good.

[Shadow]

Yeah, that was my train of though as well. Thanks! )

[Bignose]

Thanks for the tip DH. Thanks everyone, for that matter.

 

Just a quick question, I'm attempting to learn calculus from here. Could someone have a quick look and tell me if it's any good? So far, I think it's excellent, if only because it assumes the reader knows practically nothing, but I'd still like the opinion of someone who already knows calculus.

 

Cheers,

 

Gabe

 

The author of a calculus book can't really get too wrong -- Calculus has been around long enough that the only possible "mistakes" are typos and the like. What this really comes down to is presentation -- whether you are able to grasp what the author is trying to say.

 

A big issue here is that do NOT just read a section and move on thinking you "got it". You have to do the practice problems. That's the only way to know if you "got it" or not. I didn't look, but if that book doesn't have lots of practice problems with solutions, then it isn't worth much. Calculus is one of those things where you just need to 100's and 1000's of problems to really own it. Once you own it, then you can move on. But, if you really want to learn it and own the knowledge when you are done, do many many practice problems from each section.

 

I also hope that you don't take this the wrong way, but if you are just now learning calculus, there is a long way to go. Major stepping stones before this problem can be done in even a simple way include ordinary differential equations, partial differential equations, and computational method for solving ODEs and PDEs. Calculus is normally a 3 semester course. ODEs 1 more semester, PDEs another 1 semester, and computational methods of solving them may be another semester or included in the ODE & PDE courses. At least 5 semesters or 2 1/2 years of info that builds on top of itself. I don't say this to discourage you at all, but to try to give you a perspective of how far you have to go just to learn the math. That doesn't include anything on learning the physics of the situation, that is only to learn the math so that you can understand what the symbols in the physics equations mean.

 

Again, I do hope that you don't take this as discouragement, because that is the last thing I want to do, I just want you to realize the hill you are looking to climb. If this is something that needs to be done in a matter of weeks, I think you had best look elsewhere. Or look to greatly simplify the scope of your project.

[Shadow]

I know it's about presentation, that's what I meant. And this guy gives LOTS of practice problems, which is also another excellent thing about this book. And I am doing all of the exercises, even though I already think I know it all. But I only finished the first chapter, which contained stuff I already knew, so I'm not surprised.

 

I knew it wasn't going to be easy, but your post did help me appreciate what I was trying to achieve. And it didn't discourage me, quite the opposite. You see, the way I think of this is that the harder it is and the longer it will take, the prouder I will be of myself when I'm finished. And also the more useful it will be. It's the way I think of everything, at least math related. I wish I could extend this view to the real-world-plane...

 

And it doesn't have to be done in weeks, I have all the time in the world. It's not an assignment, it's just something I do in my free time. And since it forces me to learn new things, I can't much complain about my hobby )

 

Cheers,

 

Gabe

[iNow]

I knew it wasn't going to be easy, but your post did help me appreciate what I was trying to achieve. And it didn't discourage me, quite the opposite. You see, the way I think of this is that the harder it is and the longer it will take, the prouder I will be of myself when I'm finished.

What a nice outlook, Gabe. Good luck to you, mate.

[Bignose]

I concur with iNow there. Feel free to keep asking questions on the forum -- that's pretty much the whole point of the forums after all!

 

One other point I meant to write before but forgot to was that if there is a concept in that book that just isn't getting across or you just can't get what the author is trying to say, go find another calc book. Your local library probably has at least 5 or 6 other ones on their shelves. There are other ways of looking at a subject that has been taught and written about as much as calculus, so there is never a reason to sit and struggle with one book. For that matter, if you browse a used book seller website, like abebooks.com which lists the inventories from 100's of used book dealers, you can buy many calculus books for only a dollar or two. Sure, they may have been published 20 or 30 years ago, but the content really hasn't changed that much. And, since you are self-teaching it, it wouldn't hurt to get a few other perspectives on the same topic. Different authors are going to emphasize different things because each will have a different idea on what is most important.

[Shadow]

That's a good idea. Although I think I'd go with the online method, since I find math much easier to understand in English as opposed to Czech (don't ask me why). Which gets pretty confusing sometimes, because I'm familiar with the basics in Czech (eg. what we learn in school) but the more advanced stuff I know in English (eg. what I learn from the internet). It's sometimes a pretty big challenge putting those two together. For example, until a topic a couple of days ago forced me to find out, I had no idea what sets were. Then, when I looked at the Czech translation, I found out that I had known all along, and everything fell into place. But thanks for the advice, I'll be sure to ask if I need anything ;-)

 

Cheers,

 

Gabe