Cool Orbital Mechanics Sim

So I actually haven't had a chance to play with this yet, I will this weekend, but this was pointed out to me by a friend (job says fiend). It does a full Newtonian simulation of whatever you want(demo only dos premade systems).

http://universesandbox.com/

Some points I saw:

You can make tea cups orbit soccer balls, gravity does work at all scales.
Accuracy matters, how small you step through time is very important to things not breaking
Computationally intense, it starts crashing computers (single threaded) at 1k-2k objects
Silly Complex systems is unstable (Firefly verse takes a few months to fail spectacularly)

*This is not a "PA should have XXXX realism or awesome" thread, just showing people a relevant cool toy

I do love Universe Sandbox

While we are checking out cool things, have a look at
http://www.kerbalspaceprogram.com

It totally teaches you all about orbital physics, prograde burns, retrograde burns, hohmann transfer orbits. I now know why the Apollo astronauts had to make their return burn from behind the moon!

Plus it has funny little muppets...

And there's SpaceEngine if you want to see just how big and varied the Universe is.

It's definitely one of the best educational games of the last 10 years, even if it might not have been intended that way.

Why do I try to be productive?

It is fun to see the different physics in each of them
US -full Newtonian simulation, cuz it's a simulation (N body problem)
KSP - sim game so it only looks at the biggest influence (2 Body problem)
SpaceEngine - Exploration program, I'm not sure it has physics in it (as in it has a function that says where object is at a given time), but I have only looked at part of their site

And it's all fine, cuz that's all each one needs.

I'm waiting to play Kerbal, I think right this second it's a bit too close to some classes I took. But I am excited

You are going 10 years ahead. I do not think it is feasible with current PCs and fun gameplay. Here you simulate particles classically and probably relativistically where some of them have radi of interaction (besides mass, velocity, volume, etc.). Game needs more than particle. It needs rigid body that can be destroyed, deformed etc (for example tank that does not interact like ball or point but like rigid body with particular shape where each surface is subject to collission detection and proper phisical simulation). Add at least tens of thousands of these rigid bodies instead of points (particles) and add precise classical mechanics (including relativistic one) and you are set for 64CPU/GPU machine with 64GB of RAM. I don't think that everybody is ready for this. Additionally for the game to be fun, people would like to see day/night shift and other planets at close up like currently with PA or spore. It would be impossible with such engine. Realistic solar system need realistic conditions (for example smaller/bigger planets, greater distances etc.) and more CPU power. Do you know how difficult it would be to create on a computer a solar system based on realistic models which component's have closed orbits? I think if you had such realistic engine in the game 99.999% consumer PCs wouldn't be able to fit simulation in RAM and simulate it in real time and I don't think it would be fun. It could come out that your beautiful planet you created in the editor with nice asteroid belt/orbit crashes into the sun after 3 revolutions but its moon for example crashes first into your planet or gets slingshot into the space. It would be difficult to generate awesome to play solar systems that hold up for hours in the game (and don't get autodestroyed too quckly). It looks great as simulation. It is beautiful but, it may be terrible for a game. You do not want moon to crash into the planet and kill everybody by itself after 20 minutes of the gameplay. You don't want your moonbase to be slingshot into infinity by itself after 9 hours of gameplay. How do you know it is not going to be slingshot into the space or that planetary system is not going to crash after for example 2 or 7 hours of playing the game? You simulate it for such long or make a simplified simulator based on unrealistic model and unrealistic constraints. Simplified model That's what Über ent. people did. It requires less resources and planetary systems in it hold up for good with no pissy surprises.

YEAH KSP is great!
But its in early alpha and its a small dev group, its going forward slowly. but its already quite cool to play it. Love the rocket building part especially. the "flying" part is probably better simulated in Orbiter.

That's awesome!!!

I'm confused. That simulator already exist... I don't think anyone ever suggested all the units should have a full gravity simulation. You can avoid most of the bad stuff you suggest by picking intelligent numbers instead of random ones. I thought Uber confirmed in an interview they were doing more complex simulation of orbits...

And most importantly, I was specifically NOT making suggestions about the game, so I don't understand why the long rant on why simulation is bad

That's n super excellent idea for Planetary Annihilation 2!!!

You are trying to talk about Planetary Annihilation using a technology which generates planets with a different technique using a completely different art style, which in many ways may be less powerful than PA's technology (SpaceEngine uses heightmaps, while PA is meant to be using a fully 3d solution), before the first Planetary Annihilation has had any DLC, before, it's been publicly released, and before even Alpha stage... ok.

I think that he's talking about Planetary Anihilation 2 being played in an entire universe instead of a puny little solar system.
Planetary engines aren't awesome enough. Let's go for galactic engines!

Universe Sandbox is amazing, if orbital mechanics in PA are anything like it the game will be awesome.

You might wanna check this out. It covers both Newtonian and Keplerian laws with a numerical solver.

iTraject: