# Tag Info

### following several unknown phenomena detected at the edge of the solar system, is there a 5th force which acts at the edge of the solar system?

I've reviewed your sources, but I don't think they make the claims you say they do. The first relates to interactions between solar wind electrons and cosmic rays. This interaction is complex and ...
• 88.7k
1 vote
Accepted

### What is the goal of predicting gravitational microlensing?

The objective is to calculate the mass of the lensing object. Astrometric gravitational microlensing is an excellent tool to determine the mass of stellar objects. Using precise astrometric ...
• 88.7k

### The preferred way of binning (classifying) data for galaxy snapshots in Python

I think that what you are looking for is just the fourth returned argument of scipy.stats.binned_statistic_2d, called binnumber. It is an array that gives the 2d bin number for each of your stars, so ...
• 2,805

### How can I calculate an orbital elliptic trajectory from the velocity vector?

Thanks to RBarryYoung semi-major axis is now correctly calculated. Major error was finally found. I have applied delta time per Fg gravitational acceleration, but didnt for translation per frame. ...
Sure, these parameters all fall out of orbital energy: $$E=\frac{|\vec{v}|^2}{2}-\frac{\mu}{|\vec{r}|}$$ $$E=-\frac{1}{2}\frac{\mu^2}{|\vec{h}|^2}(1-e^2)$$ $$E=-\frac{\mu}{2a}$$ where $\vec{v}$ is the ...