"Simple" 4D Kerr Geodesics simulator, source code and docs

m4r35n357
Messages
657
Reaction score
148
Looks like my main pet GR project is about to enter something akin to maintenance mode, since it now does all I currently need it to.

It's nothing earth-shattering at first glance, but is very concise (e.g. ~100 lines of Python for the simulator script) and should be easier to understand than most simulation sources that I have seen ;) I can't really give any visuals here, but I think the way it is implemented is seriously neat, and not published anywhere as far as I know.

It works for particle and light orbits (spherical and "spherical shell", including polar), and even has an initial conditions generator script. To run it you will need a Linux box (tested on Debian Wheezy & Ubuntu Trusty) or virtual machine (VirtualBox works), and also need to be used to executing shell scripts. The README in the project lists dependencies and some example commands to get you started.

Here is the project (this one is BSD licenced), and here is a little paper/technical note that I knocked up to try to explain what's going on under the covers. Hope someone out there finds it useful . . .
 
  • Like
Likes wabbit
UPDATED - NEW LINKS

  • I've now added the cosmological constant to my simulator (dev branch recommended).
  • The primary language of the simulator is now Vala, but I have included a Python port of the RK4 version.
  • Equations are taken from this paper.
 
Thread 'Can this experiment break Lorentz symmetry?'

Thread 'Can this experiment break Lorentz symmetry?'

1. The Big Idea: According to Einstein’s relativity, all motion is relative. You can’t tell if you’re moving at a constant velocity without looking outside. But what if there is a universal “rest frame” (like the old idea of the “ether”)? This experiment tries to find out by looking for tiny, directional differences in how objects move inside a sealed box. 2. How It Works: The Two-Stage Process Imagine a perfectly isolated spacecraft (our lab) moving through space at some unknown speed V...
View full post »

Thread '1-Way Speed of Light'

Does the speed of light change in a gravitational field depending on whether the direction of travel is parallel to the field, or perpendicular to the field? And is it the same in both directions at each orientation? This question could be answered experimentally to some degree of accuracy. Experiment design: Place two identical clocks A and B on the circumference of a wheel at opposite ends of the diameter of length L. The wheel is positioned upright, i.e., perpendicular to the ground...
View full post »

Thread 'How can a black hole absorb matter?'

According to the General Theory of Relativity, time does not pass on a black hole, which means that processes they don't work either. As the object becomes heavier, the speed of matter falling on it for an observer on Earth will first increase, and then slow down, due to the effect of time dilation. And then it will stop altogether. As a result, we will not get a black hole, since the critical mass will not be reached. Although the object will continue to attract matter, it will not be a...
View full post »

Similar threads

I Explore Black Hole Orbits with My Kerr Orbit Simulator on YouTube
Replies
44
Views
8K
Requesting suggestions for languages, libraries, and architectures for parallel (and sometimes non parallel) numerical and scientific computations
Replies
8
Views
4K

Hot Threads

Recent Insights

Back
Top